The newly proposed National Institute on Aging-Alzheimer's Association (NIA-AA) criteria for mild cognitive impairment (MCI) due to Alzheimer's disease (AD) suggest a combination of clinical features and biomarker measures, but their performance in the community is not known.

The Mayo Clinic Study of Aging (MCSA) is a population-based longitudinal study of non-demented subjects in Olmsted County, Minnesota. A sample of 154 MCI subjects from the MCSA was compared to a sample of 58 amnestic MCI subjects from the Alzheimer's Disease Neuroimaging Initiative 1 (ADNI 1) to assess the applicability of the criteria in both settings and to assess their outcomes.

In the MCSA, 14% and in ADNI 1 16% of subjects were biomarker negative. In addition, 14% of the MCSA and 12% of ADNI 1 subjects had evidence for amyloid deposition only, while 43% of MCSA and 55% of ADNI 1 subjects had evidence for amyloid deposition plus neurodegeneration (MRI atrophy, FDG PET hypometabolism or both). However, a considerable number of subjects had biomarkers inconsistent with the proposed AD model, e.g., 29% of MCSA subjects and 17% of the ADNI 1 subjects had evidence for neurodegeneration without amyloid deposition. These subjects may not be on an AD pathway. Neurodegeneration appears to be a key factor in predicting progression relative to amyloid deposition alone.

The NIA-AA criteria apply to most MCI subjects in both the community and clinical trials settings however, a sizeable proportion of subjects had conflicting biomarkers which may be very important and need to be explored. ANN NEUROL 2013. © 2013 American Neurological Association

Anti-NMDA receptor (NMDAR) encephalitis is an autoimmune encephalitis with a characteristic neuropsychiatric syndrome and severe and prolonged clinical courses. In contrast, standard clinical MRI remains normal in the majority of patients. Here, we investigated structural and functional brain changes in a cohort of patients with anti-NMDAR encephalitis.

Twenty-four patients with established diagnosis of anti-NMDAR encephalitis and age- and gender-matched controls underwent neuropsychological testing and multimodal MRI, including T1w/T2w structural imaging, analysis of resting state functional connectivity, analysis of white matter using diffusion tensor imaging, and analysis of grey matter using voxel-based morphometry.

Patients showed significantly reduced functional connectivity of the left and right hippocampus with the anterior default mode network. Connectivity of both hippocampi predicted memory performance in patients. Diffusion tensor imaging revealed extensive white matter changes, which were most prominent in the cingulum and which correlated with disease severity. In contrast, no differences in T1w/T2w structural imaging and grey matter morphology were observed between patients and controls.

Anti-NMDAR encephalitis is associated with characteristic alterations of functional connectivity and widespread changes of white matter integrity despite normal findings in routine clinical MRI. These results may help to explain the clinico-radiological paradox in anti-NMDAR encephalitis and advance the pathophysiological understanding of the disease. Correlation of imaging abnormalities with disease symptoms and severity suggests that these changes play an important role in the symptomatology of anti-NMDAR encephalitis. ANN NEUROL 2013. © 2013 American Neurological Association

Healthy nonepilepsy women and women with generalized and focal epilepsy were investigated during ovulatory (n = 11, 46, and 43, respectively) and anovulatory (n = 9, 42, and 41) cycles. Patients were divided based on seizure pattern into catamenial (C1 = perimenstrual, C2 = periovulatory, C3 = luteal seizure exacerbation), noncatamenial, and seizure free. Cortical excitability was assessed using motor threshold (MT) and paired pulse stimulation at short (2–15 milliseconds) and long (100–300 milliseconds) interstimulus intervals twice, at the (1) late follicular and (2) mid luteal phases of the menstrual cycle.

In controls, cortical excitability was greatest in the follicular study, where intracortical facilitation was increased (p < 0.05). The opposite was seen in women with epilepsy, where intracortical facilitation was greatest and intracortical inhibition was least in the luteal studies (p < 0.05). There were no differences between the ovulatory and anovulatory groups in any of the cohorts. No changes were observed in MT.

Nonhormonal factors are involved in the cyclicity of cortical excitability across the menstrual cycle. Normal menstrual cycle variations in cortical excitability are altered in a similar pattern in ovulatory and anovulatory women with epilepsy regardless of seizure patterns. The underlying neural changes associated with epilepsy may alter responses to sex hormones. This may be an important underlying mechanism for catamenial seizure clustering. ANN NEUROL 2013. © 2013 American Neurological Association

The Three-City–Bordeaux–Alienor study is a population-based cohort of 812 participants with a 3-year follow-up period. All participants were aged 72 years or older. An eye examination was performed on all subjects. An OAG was determined based on optic nerve damage and visual field loss. Incident dementia was actively screened for and confirmed by a neurologist.

A total of 41 participants developed dementia over the 3-year follow-up period. Future incident dementia cases had an increased prevalence of OAG (17.5% vs 4.5% for nondemented participants, p = 0.003). After adjustment for age, gender, education, family history of glaucoma, vascular comorbidities, and apolipoprotein ε4, our results showed that participants with an OAG were 4× more likely to develop dementia during the 3-year follow-up period (odds ratio = 3.9, 95% confidence interval = 1.5–10.4, p = 0.0054). An increased risk of dementia was also associated with 2 markers of optic nerve degeneration (vertical cup:disk ratio and minimal rim:disk ratio). However, no association was found between a high intraocular pressure and/or the use of intraocular pressure-lowering medications and incident dementia.

If the association between OAG and dementia is confirmed, direct and noninvasive quantification of the amount of retinal ganglion cell axonal loss may be a useful biomarker of cerebral axonal loss in the future. It may also offer new breakthroughs in understanding the underlying pathophysiological mechanisms of both diseases. ANN NEUROL 2013. © 2013 American Neurological Association

Inflammatory mediators (IMs) or control solution were applied to the rat dura mater to elicit a presumed state of cephalic pain. Hind paw incision was used in separate groups of animals to model noncephalic postsurgical pain. Drugs were given systemically or microinjected within the rostral ventromedial medulla (RVM), nucleus accumbens (NAc), or rostral anterior cingulate cortex (rACC). Peripheral nerve block was produced at the level of the popliteal fossa, and behavior was assessed using evoked sensory stimuli or conditioned place preference (CPP). Immunohistochemistry and brain microdialysis measurements were performed.

Dural IMs produced long-lasting generalized cutaneous allodynia. RVM lidocaine produced CPP, increased NAc c-Fos, and dopamine release selectively in rats receiving dural IMs; CPP was blocked by intra-NAc α-flupenthixol, a dopaminergic antagonist. Intravenous α-calcitonin gene-related peptide (αCGRP)_(8–37) produced CPP and elicited NAc dopamine release selectively in rats treated with dural IMs. Prior lesion of the rACC or treatment with systemic sumatriptan or αCGRP_(8–37) abolished RVM lidocaine-induced CPP in IM-treated rats. Sumatriptan treatment blocked NAc dopamine release in IM-treated rats receiving RVM lidocaine. Systemic sumatriptan did not alter pain relief-induced CPP in rats with incisional injury.

Cephalic pain was unmasked in rats by assessment of motivated behavior to seek relief. Relief of pain activates the dopaminergic reward pathway to elicit negative reinforcement of behavior. Medications clinically effective for migraine headache selectively elicit relief of ongoing cephalic, but not postsurgical, noncephalic pain. These studies provide a platform for exploring migraine pathophysiology and for the discovery of new headache therapies. ANN NEUROL 2013. © 2013 American Neurological Association

The prediction model cohort included 62 MCI subjects screened with structural magnetic resonance imaging (MRI) and ¹¹C-labeled Pittsburgh compound B positron emission tomography (PET). We identified an anatomical shape variation-based neuroimaging predictor of brain amyloidosis and defined a sMRI-based brain amyloidosis score (sMRI-BAS). Amyloid beta positivity (Aβ⁺) predictive power of sMRI-BAS was validated on an independent cohort of 153 MCI patients with cerebrospinal fluid Aβ_1–42 biomarker data but no amyloid PET scans. We compared the Aβ⁺ predictive power of sMRI-BAS to those of apolipoprotein E (ApoE) genotype and hippocampal volume, the 2 most relevant candidate biomarkers for the prediction of brain amyloidosis.

Anatomical shape variations predictive of brain amyloidosis in MCI embraced a characteristic spatial pattern known for high vulnerability to Alzheimer disease pathology, including the medial temporal lobe, temporal–parietal association cortices, posterior cingulate, precuneus, hippocampus, amygdala, caudate, and fornix/stria terminals. Aβ⁺ prediction performance of sMRI-BAS and ApoE genotype jointly was significantly better than the performance of each predictor separately (area under the curve [AUC] = 0.88 vs AUC = 0.70 and AUC = 0.81, respectively) with >90% sensitivity and specificity at 20% false-positive rate and false-negative rate thresholds. Performance of hippocampal volume as an independent predictor of brain amyloidosis in MCI was only marginally better than random chance (AUC = 0.56).

As 1 of the first attempts to use an imaging technique that does not require amyloid-specific radioligands for identification of individuals with brain amyloidosis, our findings could lead to development of multidisciplinary/multimodality brain amyloidosis biomarkers that are reliable, minimally invasive, and widely available. ANN NEUROL 2013. © 2013 American Neurological Association

JC virus (JCV) seropositivity is a risk factor for progressive multifocal leukoencephalopathy (PML) in patients on natalizumab. Accordingly, the JCV serological antibody test is of paramount importance in determining disease risk.

We tested the accuracy of the JCV serum antibody test by comparing the results of JCV serology to JC viruria and viremia in 67 patients enrolled in a single-center, retrospective cohort study. Bodily fluids (urine and blood) were assessed for JCV DNA by real time quantitative polymerase chain reaction 6 to 47 months earlier (mean 26.1 months) before JCV antibody testing. In 10 individuals, blood and urine samples were obtained on two separate occasions at 6 month intervals.

Forty (59.7%) of the 67 patients were JCV seropositive. Of 27 JCV seronegative patients, 10 (37%) had JC viruria. Urine JCV DNA copy numbers were significantly higher in the seropositive group (mean log copy number: 5.93; range 1.85 - 9.21) than the seronegative group (mean log copy number: 2.41; range 1.85 - 5.43) (p=0.0026). Considering all body fluid test results, 50 (74.6%) of the 67 patients were previously infected with JCV.

The false negative rate of the JCV serology in this study was 37%; therefore, JCV serostatus does not appear to identify all patients infected with JCV. Thus, a negative JCV antibody result should not be conflated with absence of JCV infection. This discordance may be important in understanding JCV biology, risk for PML and PML pathogenesis. ANN NEUROL 2010

Anesthetics have been linked to widespread neuronal cell death in neonatal animals. Epidemiological human studies have associated early childhood anesthesia with long-term neurobehavioral abnormalities, raising substantial concerns that anesthetics may cause similar cell death in young children. However, key aspects of the phenomenon remain unclear, such as why certain neurons die, while immediately adjacent neurons are seemingly unaffected and why the immature brain is exquisitely vulnerable, while the mature brain seems resistant. Elucidating these questions is critical for assessing the phenomenon's applicability to humans and defining the susceptible age, for predicting vulnerable neuronal populations, and for devising mitigating strategies.

This study examined the effects of anesthetic exposure on late- and adult-generated neurons in newborn, juvenile, and adult mice, and characterized vulnerable cells using birthdating and immunohistochemical techniques.

We identify a critical period of cellular developmental during which neurons are susceptible to anesthesia-induced apoptosis. Importantly, we demonstrate that anesthetic neurotoxicity can extend into adulthood in brain regions with ongoing neurogenesis, such as dentate gyrus and olfactory bulb.

Our findings suggest that anesthetic vulnerability reflects the age of the neuron, not age of the organism, and therefore may apply to children as well as adults undergoing anesthesia. This observation predicts that the observed differences in vulnerability among brain regions would be expected to closely follow the regional peaks in neurogenesis. This knowledge may help guide neurocognitive testing of specific neurological domains in humans following exposure to anesthesia, dependent on the individual's age during exposure. ANN NEUROL 2010

Maternal immune activation (MIA) triggered by infections, has been identified as a cause of autism in the offspring. Considering the involvement of perturbations in innate immunity in epilepsy, we examined whether MIA represents a risk factor for epilepsy as well. The role of specific MIA components– interleukin-6 and interleukin-1β was also addressed.

MIA was induced in C57BL/6 mice by polyinosinic–polycytidylic acid (PIC) injected during embryonic days 12-16. Beginning from postnatal day 40, the propensity of the offspring to epilepsy was examined using hippocampal kindling; autism-like behavior was studied using the sociability test. The involvement of interleukin-6 and interleukin-1β in PIC-induced effects was studied by the co-administration of the cytokine antibodies with PIC, and by delivering recombinant cytokines in lieu of PIC.

The offspring of PIC-exposed mice exhibited increased hippocampal excitability, accelerated kindling rate, prolonged increase of seizure susceptibility after kindling, and diminished sociability. Epileptic impairments were abolished by antibodies to interleukin-6 or interleukin-1β. Neither of the recombinant cytokines alone increased the propensity to seizures; however when combined, they produced effects similar to the ones induced by PIC. PIC- induced behavioral deficits were abolished by interleukin-6 antibodies and were mimicked by recombinant interleukin-6; interleukin-1β was not involved.

In addition to confirming previously established critical role of interleukin-6 in the development of autism-like behavior following MIA, the present study shows that concurrent involvement of interleukin-6 and interleukin-1β is required for priming the offspring for epilepsy. These data shed light on mechanisms of comorbidity between autism and epilepsy. ANN NEUROL 2013. © 2013 American Neurological Association

Clinical and neuroimaging parameters predictive of the changing clinical course of multiple sclerosis (MS) from relapsing remitting to secondary progressive have not been clarified yet. We specifically designed a prospective five-year longitudinal study aimed at assessing demographic, clinical and magnetic resonance imaging (MRI) parameters that could predict the changing clinical course of MS.

At study entry and after 5 years, clinical and MRI (i.e., grey matter and white matter lesions, including spinal cord lesions, global and regional cortical thinning) parameters were assessed in a training set of 334 consecutive relapsing remitting MS patients and in an independent validation set of 84 relapsing remitting MS patients.

Sixty-six (19.7%) relapsing remitting MS patients changed their clinical course during the study and entered into the secondary progressive phase. Age (p=0.001,OR=1.2), cortical lesion volume (p<0.001,OR=1.7) and cerebellar cortical volume (p<0.001, OR=0.2) at study entry were found to predict the changing clinical course. The model including only these three variables correctly identified 252/268 (94.0%) patients that maintained the relapsing remitting course and 58/66 (87.8%) patients that became secondary progressive (cross-validated error rate: 7.2%). When applied on the validation set, the model obtained a similar error rate (8.4%).

A prediction model based on age, cortical lesion load and cerebellar cortical volume explainssuitablythe probability of relapsing remitting MS patients to evolve into the progressive phase. Grey matter damage appears to play a pivotal role in determining the changing clinical course of MS. ANN NEUROL 2010

MicroRNA (miRNAs) are single stranded, small non-coding RNAs that regulate gene expression. Because they are stable in serum, they are being developed as biomarkers for cancer and other diseases. In MS, miRNAs have been studied in cell populations but not in the circulation. In MS a major challenge is to develop immune biomarkers to monitor disease. We asked if circulating miRNAs could be identified in MS and whether they linked to disease stage and/or disability.

368 miRNAs were measured in EDTA plasma in 10 RRMS, 9 SPMS and 9 healthy controls (HC) using qPCR and Exiqon Human Panel I assays. 19 miRNAs from this discovery set were validated using qPCR on an independent set of 50 RRMS, 51 SPMS and 32 HCs.

We found that circulating miRNAs are differentially expressed in RRMS and SPMS vs. HC and in RRMS vs. SPMS. We also found miRNAs linked to EDSS. hsa-miR-92a-1* was identified in the largest number of comparisons. It was different in RRMS vs. SPMS, RRMS vs. HC and showed association with EDSS and disease duration. miR-92 has target genes involved in cell cycle regulation and cell signaling. The let-7 family of miRNAs differentiated SPMS vs. HC and RRMS vs. SPMS. Let-7 miRNAs regulate stem cell differentiation, T cell activation, activate TLR-7 and are linked to neurodegeneration. hsa-miR-454 differentiated RRMS vs. SPMS and hsa-miR-145 differentiated RRMS vs. HC and RRMS vs. SPMS; both were associated with EDSS. Interestingly, the same circulating miRNAs (let-7 and miR-92) that were differentially expressed in RRMS vs. SPMS also differentiated ALS vs. RRMS subjects, but were not different between SPMS and ALS, suggesting similar processes may occur in SPMS and ALS.

Our results establish circularting miRNAs as a readily accessible blood biomarker to monitor disease in MS. ANN NEUROL 2010

Chronic stroke patients with severe hand weakness, respond poorly to rehabilitation efforts. Here, we evaluated efficacy of daily brain-machine-interface training to increase the hypothesized beneficial effects of physiotherapy alone in patients with severe paresis in a double blind sham-controlled design proof of concept study.

32 chronic stroke patients with severe hand weakness, were randomly assigned to two matched groups and participated in 17.8 ± 1.4 days of training rewarding desynchronization of ipsilesional oscillatory sensorimotor rhythms (SMR) with contingent online movements of hand and arm orthoses (experimental group, n=16). In the control group (sham group, n=16) movements of the orthoses occurred randomly. Both groups received identical behavioral physiotherapy immediately following BMI training or the control intervention. Upper limb motor function scores, electromyography from arm and hand muscles, placebo-expectancy effects and functional magnetic resonance imaging (MRI) blood oxygenation level dependent activity were assessed before and after intervention.

A significant group x time interaction in upper limb Fugl-Meyer motor (cFMA) scores was found. cFMA scores improved more in the experimental than in the control group, presenting a significant improvement of cFMA scores (3.41±0.563 points difference, p=0.018) reflecting a clinically meaningful change from no activity to some in paretic muscles. cFMA improvements in the experimental group correlated with changes in functional MRI laterality index and with paretic hand electromyography activity. Placebo-expectancy scores were comparable for both groups.

The addition of BMI training to behaviorally oriented physiotherapy can be used to induce functional improvements in motor function in chronic stroke patients without residual finger movements and may open a new door in stroke neurorehabilitation. ANN NEUROL 2010

Hemorrhagic transformation (HT) is a major complication of ischemic stroke that worsens outcomes and increases mortality. Disruption of the blood brain barrier is a central feature to HT pathogenesis, and leukocytes may contribute to this process. We sought to determine whether ischemic strokes that develop HT have differences in RNA expression in blood within 3 hours of stroke onset prior to treatment with thrombolytic therapy.

Stroke patient blood samples were obtained prior to treatment with thrombolysis, and leukocyte RNA assessed by microarray analysis. Strokes that developed HT (n=11) were compared to strokes without HT (n=33) and controls (n=14). Genes were identified (corrected p-value <0.05, fold change ≥|1.2|) and functional analysis performed. RNA prediction of HT in stroke was evaluated using cross-validation, and in a second stroke cohort (n=52).

Ischemic strokes that developed HT had differential expression of 29 genes in circulating leukocytes prior to treatment with thrombolytic therapy. A panel of 6 genes could predict strokes that later developed HT with 80% sensitivity and 70.2% specificity. Key pathways involved in HT of human stroke are described, including amphiregulin, a growth factor that regulates matrix metalloproteinase-9; a shift in transforming growth factor-beta signaling involving SMAD4, INPP5D and IRAK3; and a disruption of coagulation factors V and VIII.

Identified genes correspond to differences in inflammation and coagulation that may predispose to HT in ischemic stroke. Given the adverse impact of HT on stroke outcomes, further evaluation of the identified genes and pathways is warranted to determine their potential as therapeutic targets to reduce HT and as markers of HT risk. ANN NEUROL 2010

Musician's dystonia is a task-specific movement disorder that causes twisting or repetitive abnormal finger postures and movements, which tend to occur only while playing musical instruments. Such a movement disorder will probably lead to termination of the careers of affected professional musicians. Most of the currently available treatments have yet to provide consistent and satisfactory results. We present the long-term follow-up results of ventrooralthalamotomy for 15 patients with musician's dystonia.

Between October 2003 and September 2010, 15 patients with medically intractable task-specific focal hand dystonia that occurred only while playing musical instruments underwent ventrooralthalamotomy. We used Tubiana's musician's dystonia scale to evaluate the patients' pre- and postoperative neurological conditions.

All patients except one (93%) experienced dramatic improvement of dystonic symptoms immediately after ventrooralthalamotomy. The mean follow-up period was 30·8 months (range, 4–108 months). Noneof the patients experienced recurrence or deterioration of symptoms during the follow-up periods.

Ventrooralthalamotomy remarkably improved musician's dystoniaand the effect persisted for a long duration. ANN NEUROL 2010

There is a recognized need to improve selection of patients with carotid artery stenosis for carotid endarterectomy (CEA). We assessed the value of MRI defined carotid plaque hemorrhage (MRIPH) to predict recurrent ipsilateral cerebral ischemic events, and stroke in symptomatic carotid stenosis.

179 symptomatic patients with ≥50% stenosis were prospectively recruited, underwent carotid MRI and were clinically followed up until CEA, death or ischemic event. MRIPH was diagnosed if the plaque signal intensity was >150% that of the adjacent muscle. Event-free survival analysis was done using Kaplan Meier plots and Cox regression models controlling for known vascular risk factors. We also undertook a meta-analysis of reported data on MRIPH and recurrent events.

114 patients (63·7%) showed MRIPH, but suffered 92% (57 out of 62) of all recurrent ipsilateral events and all but one (25 out of 26) future strokes. Patients without MRIPH had an estimated annual absolute stroke risk of only 0·6%. Cox multivariate regression analysis proved MRIPH as a strong predictor of recurrent ischemic events (HR=12·0; 95% CI: 4·8 – 30·1, P<0·001) and stroke alone (HR =35.0, 95% CI: 4·7 - 261·6, P=0·001). Meta-analysis of published data confirmed this association between MRIPH and recurrent cerebral ischemic events in symptomatic carotid artery stenosis (OR: 12·2; 95% CI: 5·5 – 27·1; P<0·00001).

MRIPH independently and strongly predicts recurrent ipsilateral ischemic events, and stroke alone, in symptomatic ≥50% carotid artery stenosis. The very low stroke risk in patients without MRIPH questions current risk benefit assessment for CEA in this subgroup. ANN NEUROL 2010

To identify plasma-based biomarkers for Parkinson's Disease (PD) risk.

In a discovery cohort of 152 PD patients, plasma levels of 96 proteins were measured by multiplex immunoassay; proteins associated with age at PD onset were identified by linear regression. Findings from discovery screening were then assessed in a second cohort of 187 PD patients, using a different technique. Finally, in a third cohort of at-risk, asymptomatic individuals enrolled in the Parkinson's Associated Risk Study (PARS, n=134), plasma levels of the top candidate biomarker were measured, and dopamine transporter (DAT) imaging performed, to evaluate the association of plasma protein levels with dopaminergic system integrity.

One of the best candidate protein biomarkers to emerge from discovery screening was apolipoprotein A1 (ApoA1, p=0.001). Low levels of ApoA1 correlated with earlier PD onset, with a 26% decrease in risk of developing PD associated with each tertile increase in ApoA1 (Cox proportional hazards p<0.001, hazard ratio=0.742). The association between plasma ApoA1 levels and age at PD onset replicated in an independent cohort of PD patients (p<0.001).

Finally, in the PARS cohort of high-risk, asymptomatic subjects, lower plasma levels of ApoA1 were associated with greater putaminal DAT deficit (p=0.037).

Lower ApoA1 levels correlate with dopaminergic system vulnerability in symptomatic PD patients and in asymptomatic individuals with physiological reductions in dopamine transporter density consistent with prodromal PD. Plasma ApoA1 may be a new biomarker for PD risk. ANN NEUROL 2010

To examinechanges in the response properties of meningeal nociceptors that might lead to migraine pain and examine endogenous processes that could play a role in mediating them using a clinically relevant model of migraine triggering, namely infusion of the NO donor nitroglycerin (NTG).

Single unit recordings made in the trigeminal ganglion of rats were used to test changes in the activity and mechanosensitivity of meningeal nociceptors in response to administration of the migraine triggerNTGor anotherNO donor SNAPat doses relevant to the human model of migraine headache.Immunohistochemistry and pharmacological manipulations were used to investigate the possible role of meningeal vascular signaling inmediating the responses of meningeal nociceptors to NO.

Infusion of NTG promoted a delayed and robust increase in the mechanosensitivity of meningeal nociceptors with a time course resembling the development of the delayed migraine headache. A similar sensitization was elicited by dural application of NTG andSNAP. NTG-evoked delayed meningeal nociceptor sensitization was associated with a robust ERK phosphorylation in meningeal arteries. Pharmacological blockade of meningeal ERK phosphorylation inhibited the development of NTG-evoked delayed meningeal nociceptor sensitization

The development of delayed mechanical sensitization evoked by the migraine trigger NTG is potentially of great importance as the first finding of a neurophysiological correlate of migraine headache in meningeal nociceptors. The arterial ERK phosphorylation and its involvement in mediating the NTG-evoked delayed sensitization points to an important, yet unappreciated, role of the meningeal vasculature in the genesis of migraine pain. ANN NEUROL 2010

The importance of the cholinergic system for cognitive function has been well-documented in animal and human studies. The objective of this study was to elucidate the cognitive and functional connectivity changes associated with enhanced acetylcholine (ACh) levels. We hypothesized older adults with mild memory deficits would show behavioral and functional network enhancements with an acetylcholinesterase inhibitor treatment (donepezil) when compared to a placebo control group.

We conducted a 3-month, double-blind, placebo-controlled study on the effects of donepezil in twenty-seven older adults with mild memory deficits. Participants completed a delayed recognition memory task. FMRI scans were collected at baseline prior to treatment and at 3-month follow-up while on a 10mg daily dose of donepezil or placebo.

Donepezil treatment significantly enhanced the response time for face and scene memory probes when compared to the placebo group. A group-by-visit interaction was identified for the functional network connectivity of the left fusiform face area (FFA) with the hippocampus and inferior frontal junction, such that the treatment group showed increased connectivity over time when compared to the placebo group. Additionally, the enhanced functional network connectivity of the FFA and hippocampus significantly predicted memory response time at 3-month follow-up in the treatment group.

These findings suggest that increased cholinergic transmission improves goal-directed neural processing and cognitive ability and may serve to facilitate communication across functionally-connected attention and memory networks. Longitudinal fMRI is a useful method for elucidating the neural changes associated with pharmacological modulation and is a potential tool for monitoring intervention efficacy in clinical trials. ANN NEUROL 2010

To analyze the texture of T2-weighted MRI of postmortem MS brain, and to determine whether and how MRI texture correlates with tissue pathology.

Ten brain samples from 3 subjects with MS were examined. Areas of complete, partial, or no loss of luxol fast blue (myelin) and Bielschowsky (axons) staining were marked on histological images, and matched on corresponding MRI as lesions, diffusely abnormal white matter (DAWM), and normal appearing WM (NAWM). The number of CD45+ cells (inflammation) was also counted. MRI texture was computed using polar Stockwell transform and compared to histology.

Thirty-four lesions, 17 DAWM and 36 NAWM regions were identified. After mixed effects modeling, MRI texture heterogeneity was greater in lesions than in DAWM (p < 0.001) and NAWM (p < 0.001), and was greater in DAWM than in NAWM (p < 0.001); the number of CD45+ cells was greater in both lesions (p < 0.001) and DAWM (p = 0.005) than in NAWM. In MRI, a gradient of texture heterogeneity was detected in lesions, with gradual tapering toward perilesional NAWM. Moreover, besides univariate correlation with histological markers, texture heterogeneity correlated independently with normalized myelin density (p < 0.01) when random effects were considered. Within sample, MRI texture correlated with myelin and axonal density in 7/10 samples (p < 0.01).

Texture analysis performed on routine clinical MR images may be a potential measure of tissue integrity. Tissues with more significant myelin and axonal pathology are associated with greater texture heterogeneity. ANN NEUROL 2010

Seizures have been implicated as a cause of secondary brain injury, but the systemic and cerebral physiologic effects of seizures after acute brain injury are poorly understood.

We analyzed intracortical EEG and multimodality physiological recordings in 48 comatose subarachnoid hemorrhage patients to better characterize the physiological response to seizures after acute brain injury.

Intracortical seizures were seen in 38% of patients and 8% had surface seizures. Intracortical seizures were accompanied by elevated heart rate (P=0.001), blood pressure (P<0.001), and respiratory rate (P<0.001). There were trends for rising cerebral perfusion pressure (P=0.03) and intracranial pressure (P =0.06) seen after seizure onset.Intracortical seizure associated increases in global brain metabolism, partial brain tissue oxygenation, and regional cerebral blood flow (rCBF) did not reach significance, but a trend for a pronounced delayed rCBF rise was seen for surface seizures (P=0.08). Functional outcome was very poor for patients with severe background attenuation without seizures and best for those without severe attenuation or seizures (77% vs. 0% dead or severely disabled, respectively). Outcome was intermediate for those with seizures independent of the background EEG and worse for those with intracortical only seizures when compared to those with intracortical and scalp seizures (50% and 25% death or severe disability, respectively).

We replicated in humans complex physiologic processes associated with seizures after acute brain injury previously described in laboratory experiments and illustrated differences such as the delayed increase in regional cerebral blood flow. These real-world physiologic observations may permit more successful translation of laboratory research to the bedside. ANN NEUROL 2010

Although there is growing awareness of the long term cognitive effects of repetitive mild traumatic brain injury (rmTBI; e.g., sports concussions), whether or not repeated concussions cause long term cognitive deficits remains controversial. Moreover, whether or not cognitive deficits depend on increased amyloid beta deposition and tau phosphorylation, or are worsened by the apolipoprotein E4 allele remains unknown. Here, we use an experimental model of rmTBI to address these clinical controversies.

A weight drop repeated mild TBI (rmTBI) model was used that results in cognitive deficits without loss of consciousness, seizures, or gross or microscopic evidence of brain damage. Cognitive function was assessed using a Morris Water Maze (MWM) paradigm. Immunostaining and ELISA were used to assess amyloid beta deposition and tau hyperphosphorylation. Brain volume and white matter integrity were assessed by MRI.

Mice subjected to rmTBI daily or weekly but not bi-weekly or monthly had persistent cognitive deficits as long as 1 year after injuries. Long term cognitive deficits were associated with increased astrocytosis but not tau phosphorylation or amyloid beta (ELISA) or plaques and tangles (immunohistochemistry), brain volume loss or changes in white matter integrity (MRI). APOE4 was not associated with worse MWM performance after rmTBI.

Within the vulnerable time period between injuries, rmTBI produces long term cognitive deficits independent of increased beta amyloid or tau phosphorylation. In this model, cognitive outcome is not influenced by APOE 4 status. The data have implications for long term mental health of athletes who suffer multiple concussions. ANN NEUROL 2010

We examined the therapeutic potential of Tregs and the mechanisms of neuroprotection in vivo in 2 rodent models of ischemic stroke and in vitro in Treg–neutrophil cocultures using a combined approach including cell-specific depletion, gene knockout mice, and bone marrow chimeras.

Systemic administration of purified Tregs at 2, 6, or even 24 hours after middle cerebral artery occlusion resulted in a marked reduction of brain infarct and prolonged improvement of neurological functions lasting out to 4 weeks. Treg-afforded neuroprotection was accompanied by attenuated blood–brain barrier (BBB) disruption during early stages of ischemia, decreased cerebral inflammation, and reduced infiltration of peripheral inflammatory cells into the lesioned brain. Surprisingly, Tregs exerted early neuroprotection without penetrating into the brain parenchyma or inhibiting the activation of residential microglia. Rather, both in vivo and in vitro studies demonstrated that Tregs suppressed peripheral neutrophil-derived matrix metallopeptidase-9 production, thus preventing proteolytic damage of the BBB. In addition to its potent central neuroprotection, Treg treatment was shown to ameliorate poststroke lymphopenia, suggesting a beneficial effect on immune status.

Our study suggests that Treg adoptive therapy is a novel and potent cell-based therapy targeting poststroke inflammatory dysregulation and neurovascular disruption. ANN NEUROL 2013

In a population-based study with 490 newly diagnosed idiopathic PD cases diagnosed during 1992–2008 at the University of Washington Neurology Clinic or Group Health Cooperative in western Washington State and 644 unrelated, neurologically normal controls, we examined whether PD was associated with self-reported typical frequency of consumption of peppers, tomatoes, tomato juice, and potatoes during adulthood, while adjusting for consumption of other vegetables, age, sex, race/ethnicity, tobacco use, and caffeine.

PD was inversely associated with consumption of all edible Solanaceae combined (relative risk [RR] = 0.81, 95% confidence interval [CI] = 0.65–1.01 per time per day), but not consumption of all other vegetables combined (RR = 1.00, 95% CI = 0.92–1.10). The trend strengthened when we weighted edible Solanaceae by nicotine concentration (p_trend = 0.004). An inverse association was also evident for peppers specifically (p_trend = 0.005). The potentially protective effect of edible Solanaceae largely occurred in men and women who had never used tobacco or who had smoked cigarettes <10 years.

Dietary nicotine or other constituents of tobacco and peppers may reduce PD risk. However, confirmation and extension of these findings are needed to strengthen causal inferences that could suggest possible dietary or pharmaceutical interventions for PD prevention. Ann Neurol 2013

MJD was modeled by transducing the striatum of male adult C57Bl/6 mice with lentiviral vectors encoding mutant ataxin-3 in one hemisphere and wild-type ataxin-3 in the other hemisphere (as internal control). Caffeine (1g/L) was applied through the drinking water. Mice were killed at different time points (from 2 to 12 weeks) to probe for the appearance of different morphological changes using immunohistochemical analysis.

Mutant ataxin-3 caused an evolving neuronal dysfunction (loss of DARPP-32 staining) leading to neurodegeneration (cresyl violet and neuronal nuclei staining) associated with increased number of mutant ataxin-3 inclusions in the basal ganglia. Notably, mutant ataxin-3 triggered early synaptotoxicity (decreased synaptophysin and microtubule-associated protein-2 staining) and reactive gliosis (glial fibrillary acidic protein and CD11b staining), which predated neuronal dysfunction and damage. Caffeine reduced the appearance of all these morphological modifications, which were also abrogated in mice with a global A_2AR inactivation (knockout).

Our findings provide a demonstration that synaptotoxicity and gliosis are precocious events in MJD and that caffeine and A_2AR inactivation decrease MJD-associated striatal pathology, which paves the way to consider A_2ARs as novel therapeutic targets to manage MJD. Ann Neurol 2013

We compared the level of cytokine production by myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) in healthy subjects and MS patients, following in vitro stimulation of Toll-like receptors 7/8. We also evaluated the effect of the main endocannabinoid, anandamide (AEA), in these DC subsets and correlated cytokine levels with defects in the endocannabinoid system.

mDCs obtained from MS patients produce higher levels of interleukin-12 and interleukin-6, whereas pDCs account for lower levels of interferon-α compared to healthy subjects. AEA significantly inhibited cytokine production from healthy mDCs and pDCs, as well as their ability to induce Th-1 and Th-17 lineages. Moreover, we found that in MS only pDCs lack responsiveness to cytokine inhibition induced by AEA. Consistently, this specific cell subset expresses higher levels of the anandamide hydrolase fatty acid amide hydrolase (FAAH).

Our data disclose a distinct immunomodulatory effect of AEA in mDCs and pDCs from MS patients, which may reflect an alteration of the expression of FAAH, thus forming the basis for the rational design of new endocannabinoid-based immunotherapeutic agents targeting a specific cell subset. Ann Neurol 2013

To explore whether loss of hippocampal myelin alters expression of neuronal microRNAs (miRNAs), we compared miRNA profiles from myelinated and demyelinated hippocampi from postmortem MS brains and performed validation studies.

A network-based interaction analysis depicts a correlation between increased neuronal miRNAs and decreased neuronal genes identified in our previous study. The neuronal miRNA miR-124 was increased in demyelinated MS hippocampi and targets mRNAs encoding 26 neuronal proteins that were decreased in demyelinated hippocampus, including the ionotrophic glutamate receptors AMPA2 and AMPA3. Hippocampal demyelination in mice also increased miR-124, reduced expression of AMPA receptors, and decreased memory performance in water maze tests. Remyelination of the mouse hippocampus reversed these changes.

We establish here that myelin alters neuronal gene expression and function by modulating the levels of the neuronal miRNA miR-124. Inhibition of miR-124 in hippocampal neurons may provide a therapeutic approach to improve memory performance in MS patients. Ann Neurol 2013

Subjects who agreed to participate had a brain magnetic resonance imaging and positron emission tomography scan with ¹¹C-labeled Pittsburgh compound B (PiB) following completion of a Gb treatment clinical trial. The youngest subject in this imaging study was 82 years, and the mean age of the subjects was 85.5 years at the time of the scans; 152 (80%) were cognitively normal, and 38 (20%) were diagnosed with mild cognitive impairment (MCI) at the time of the PiB study.

A high proportion of the cognitively normal subjects (51%) and MCI subjects (68%) were PiB-positive. The APOE*4 allele was more prevalent in PiB-positive than in PiB-negative subjects (30% vs 6%). Measures of memory, language, and attentional functions were worse in PiB-positive than in PiB-negative subjects, when both normal and MCI cases were analyzed together; however, no significant associations were observed within either normal or MCI subject groups alone. There was no relationship between Gb treatment and Aβ deposition as determined by PiB.

The data revealed a 55% prevalence of PiB positivity in nondemented subjects age >80 years and 85% PiB positivity in the APOE*4 nondemented elderly subjects. The findings also showed that long-term exposure to Gb did not affect the prevalence of cerebral Aβ deposition. ANN NEUROL 2012

Using task-free functional magnetic resonance imaging, we mapped intrinsic connectivity to the dorsal midbrain tegmentum (dMT), a region that shows focal atrophy in PSP. Two healthy control groups (1 young, 1 older) were used to define and replicate the normal connectivity pattern, and patients with PSP were compared to an independent matched healthy control group on measures of network connectivity.

Healthy young and older subjects showed a convergent pattern of connectivity to the dMT, including brainstem, cerebellar, diencephalic, basal ganglia, and cortical regions involved in skeletomotor, oculomotor, and executive control. Patients with PSP showed significant connectivity disruptions within this network, particularly within corticosubcortical and cortico-brainstem interactions. Patients with more severe functional impairment showed lower mean dMT network connectivity scores.

This study defines a PSP-related intrinsic connectivity network in the healthy brain and demonstrates the sensitivity of network-based imaging methods to PSP-related physiological and clinical changes. Ann Neurol 2013;

We combined in vivo systemic lipopolysaccharide-induced or interleukin (IL)−1β–induced sensitization of neonatal and adult rodent cortical neurons to excitotoxic neurodegeneration with in vitro IL-1β sensitization of human and rodent neurons to excitotoxic neurodegeneration. Within these inflammation-induced sensitization models, we assessed metabotropic glutamate receptors (mGluR) signaling and regulation.

We demonstrate for the first time that group I mGluRs mediate inflammation-induced sensitization to neuronal excitotoxicity in neonatal and adult neurons across species. Inflammation-induced G protein–coupled receptor kinase 2 (GRK2) downregulation and genetic deletion of GRK2 mimicked the sensitizing effect of inflammation on excitotoxic neurodegeneration. Thus, we identify GRK2 as a potential molecular link between inflammation and mGluR-mediated sensitization.

Collectively, our findings indicate that inflammation-induced sensitization is universal across species and ages and that group I mGluRs and GRK2 represent new avenues for neuroprotection in perinatal and adult neurological disorders. Ann Neurol 2013;00:000–000

We included 226 patients: 89 with Alzheimer disease–related cognitive impairment (ADCI) and 137 with subcortical vascular cognitive impairment (SVCI). All subjects underwent amyloid imaging with [¹¹C] Pittsburgh compound B (PiB) positron emission tomography, and MRI to detect CMBs and markers of subcortical SVD, including the volume of white matter hyperintensities (WMH) and the number of lacunes.

Parietal and occipital lobar CMBs counts were higher in PiB⁺ ADCI with moderate WMH than PiB⁺ ADCI with minimal WMH, whereas PiB⁻ patients with SVCI (ie, “pure” SVCI) showed both lobar and deep CMBs. In multivariate analyses of the whole cohort, WMH volume and lacuna counts were positively associated with both lobar and deep CMBs, whereas amyloid burden (PiB) was only associated with lobar CMBs. There was an interaction between lacuna burden and PiB retention on lobar (but not deep) CMBs (p<0.001).

Our findings suggest that although deep CMBs are mainly linked to subcortical SVD, both subcortical SVD and amyloid-related pathologies (eg, CAA) contribute to the pathogenesis of lobar CMBs, at least in subjects with mixed lobar and deep CMBs. Furthermore, subcortical SVD and amyloid-related pathologies interact to increase the risk of lobar CMBs. Ann Neurol 2013;00:000–000

Animals (n=127) with experimental models of thrombosis were imaged with microcomputed tomography 5 minutes (and/or ∼3 weeks) after intravenous injection of glycol chitosan (GC) gold nanoparticles (AuNPs).

Nanoparticles accumulated in the thrombus, allowing computed tomography visualization of both the presence and extent of primary and recurrent thrombi in mouse carotid arteries without a single failure of detection. Nanoparticle thrombus imaging was also effective in monitoring the therapeutic efficacy of thrombolysis (n=118 tissue plasminogen activator [tPA] therapies). Thrombus evolution (either spontaneous or post-tPA) could be mapped at high resolution in both space and time. Due to a long circulating half-life, GC-AuNPs remain available for entrapment into fibrin matrix for an extended period of time (up to 3 weeks), allowing repetition or ongoing monitoring of thrombogenesis and thrombolysis.

This is the first report on a hyperacute direct thrombus imaging technique using thrombus-seeking AuNPs and computed tomography. When translated into stroke practice, the thrombus imaging may allow us to advance to personalized thrombolytic therapy by demonstrating thrombus burden, distribution, and character in a prompt and quantitative manner. Further study into this area is indicated. ANN NEUROL 2013;00:000–000

We reviewed 158 patients who underwent FLE surgery from 1995 to 2010. The primary outcome was seizure freedom at last follow-up (Engel class IA). Analyses employed Cox proportional and multiphase hazard modeling.

The mean age at surgery was 20.4 years, and mean epilepsy duration was 12.0 years. The estimated chance of seizure freedom was 66% (95% confidence interval [CI] = 62–68) at 1 postoperative year, 52% (95% CI = 48–56) at 2 years, and 44% (95% CI = 39–49) at 5 years and beyond. Seventy-five percent of recurrences occurred within 6 postoperative months. Both younger age at surgery (<18 years) and shorter epilepsy duration (<5 years) correlated with better seizure outcomes on univariate analysis, but only epilepsy duration remained statistically significant after multivariate modeling. Independent poor prognostic indicators included left-sided resections and acute postoperative seizures (APOSs; whole model log-rank test p < 0.0001). APOSs were particularly predictive of early epilepsy recurrence, starting within 6 postoperative months (adjusted risk ratio [RR] = 4.42, p < 0.0001), whereas long epilepsy duration correlated with late recurrences (RR = 6.25, p < 0.0001). Worse outcomes were seen with longer epilepsy duration for duration cutoffs of 2, 5, and 10 years independently for adults and children, although statistical significance was only achieved in children (66% seizure free at 5 postoperative years if operated on within 5 years of epilepsy onset vs 31% if later; p = 0.01).

Early resection may improve seizure outcomes of FLE surgery, particularly in children. Ann Neurol 2013;

Cognitive ERPs elicited by sound (P300) and speech (N400) were used to assess information processing in 92 behaviorally unresponsive patients diagnosed as in the state of either UWS (n=53) or MCS (n=39). ERPs were assessed with a clinical standard evaluation method and a computerized method, the t-continuous wavelet transform. The patients' clinical outcome was followed up between 2 and 14 years after discharge from the rehabilitation center.

Within the first year of the disease, many patients showed an intact P300 and several also an N400, indicating considerable residual information processing. At clinical follow-up, about 25% of the patients recovered and regained communicative capabilities. A highly significant relationship between N400, but not P300, presence and subsequent recovery was found.

Results specify cognitive capabilities in disorders of consciousness, and determine their prognostic value. Specifically the N400 ERP is suggested as an important tool to assess information-processing capacities that can predict the likelihood of recovery of patients in UWS or MCS. Ann Neurol 2013;

This was a single-center, prospective case–control study of volunteer MS and non-MS participants. A neurosonologist, blind to the subjects' diagnosis, used high-resolution B-mode imaging with color and spectral Doppler to systematically investigate, capture, and record extracranial and intracranial venous drainage. These neuroimaging results were evaluated and scored by an expert blinded to subjects' information and with no interactions with the participants.

Altogether, 276 subjects were studied: 206 with MS and 70 non-MS. MS patients were older than non-MS subjects (48.3±9.9 vs 44.3±11.8 years, p<0.007), with durations from first symptoms and diagnosis of 13.7±10 and 9.9±7.8 years, and Expanded Disability Status Scale of 2.6±2.0. Overall, 82 subjects (29.7%) fulfilled 1 of 5 NS criteria proposed for CCSVI; 13 (4.7%) fulfilled 2 criteria required for diagnosis, and none fulfilled >2 criteria. The distribution of subjects with 0, 1, or 2 criteria did not differ significantly across all diagnostic groupings, between MS and non-MS subjects, or within MS subgroups. CCSVI was present in 7.14% of non-MS and 3.88% of MS patients (p=0.266). No significant differences emerged between MS and non-MS subjects for extracranial or intracranial venous flow rates.

NS findings described as CCSVI are much less prevalent than initially reported, and do not distinguish MS from other subjects. Our findings do not support the hypothesis that CCSVI is causally associated with MS. ANN NEUROL 2012;

A total of 340 LADIS (Leukoaraiosis and Disability Study) participants, aged 65 to 84 years, underwent brain MRI including DWI at baseline. Neuropsychological and functional assessments were carried out at study entry and repeated annually over a 3-year observational period. Linear mixed models and Cox regression survival analysis adjusted for demographics, WMH volume, lacunes, and brain atrophy were used to evaluate the independent effect of the DWI measures on change in cognitive performance and functional abilities.

The mean global apparent diffusion coefficient (ADC) and the relative peak height and peak position of the ADC histogram in NABT predicted faster rate of decline in a composite score for speed and motor control. Higher mean ADC and lower peak height were also related to deterioration in executive functions and memory (specifically working memory), with peak height also being related to more rapid transition to disability and higher rate of mortality. Mean ADC in WMH had less pronounced effects on cognitive and functional outcomes.

DWI microstructural changes in NABT predict faster decline in psychomotor speed, executive functions, and working memory regardless of conventional MRI findings. Moreover, these changes are related to functional disability and higher mortality. ANN NEUROL 2013

We used a novel ultrasensitive technique on patients from a retrospective multicenter case–control study, and evaluated the anti-Aβ autoantibody concentration in the cerebrospinal fluid (CSF) of 10 CAA-ri, 8 CAA, 14 multiple sclerosis, and 25 control subjects. Levels of soluble Aβ40, Aβ42, tau, P-181 tau, and APOE genotype were also investigated.

During the acute phase of CAA-ri, anti-Aβ autoantibodies were specifically increased and directly correlated with Aβ mobilization, together with augmented tau and P-181 tau. Following clinical and radiological remission, autoantibodies progressively returned to control levels, and both soluble Aβ and axonal degeneration markers decreased in parallel.

Our data support the hypothesis that the pathogenesis of CAA-ri may be mediated by a selective autoimmune reaction against cerebrovascular Aβ, directly related to autoantibody concentration and soluble Aβ. The CSF dosage of anti-Aβ autoantibodies with the technique here described can thus be proposed as a valid alternative tool for the diagnosis of CAA-ri. Moreover, given the similarities between ARIA developing spontaneously and those observed during immunization trials, anti-Aβ autoantibodies can be considered as novel potential biomarkers in future amyloid-modifying therapies for the treatment of AD and CAA. Ann Neurol 2013;73:449–458

Whole exome sequencing of DNA from 3 patients in a 3-generation pedigree was used to identify a new PD-associated mutation in SNCA. Clinical and pathological features of the patients were analyzed. The cytotoxic effects of the mutant and wild-type proteins were assessed by analytical ultracentrifugation, thioflavin T binding, transmission electron microscopy, cell viability assay, and caspase-3 activation.

We identified a novel SNCA G51D (c.152 G>A) mutation that cosegregated with the disease and was absent from controls. G51D was associated with an unusual PD phenotype characterized by early disease onset, moderate response to levodopa, rapid progression leading to loss of autonomy and death within a few years, marked pyramidal signs including bilateral extensor plantar reflexes, occasionally spasticity, and frequently psychiatric symptoms. Pathological lesions predominated in the basal ganglia and the pyramidal tracts and included fine, diffuse cytoplasmic inclusions containing phospho-α-synuclein in superficial layers of the cerebral cortex, including the entorhinal cortex. Functional studies showed that G51D α-synuclein oligomerizes more slowly and its fibrils are more toxic than those of the wild-type protein.

We have identified a novel SNCA G51D mutation that causes a form of PD with unusual clinical, neuropathological, and biochemical features. Ann Neurol 2013;73:459–471

Using the preclinical AD classification, 430 cognitively normal subjects from the Mayo Clinic Study of Aging who underwent brain magnetic resonance (MR), ¹⁸fluorodeoxyglucose (FDG), and Pittsburgh compound B positron emission tomography (PET) were evaluated for FDG PET regional volumetrics, MR regional brain volumetrics, white matter hyperintensity volume, and number of infarcts. We examined cross-sectional associations across AD preclinical stages, those with all biomarkers normal, and the sNAP group.

The sNAP group had a lower proportion (14%) with apolipoprotein E ε4 genotype than the preclinical AD stages 2 + 3. The sNAP group did not show any group differences compared to stages 2 + 3 of the preclinical AD group on measures of FDG PET regional hypometabolism, MR regional brain volume loss, cerebrovascular imaging lesions, vascular risk factors, imaging changes associated with α-synucleinopathy, or physical findings of parkinsonism.

Cognitively normal persons with brain injury biomarker abnormalities, with or without abnormal levels of β-amyloid, were indistinguishable on a variety of imaging markers, clinical features, and risk factors. The initial appearance of brain injury biomarkers that occurs in cognitively normal persons with preclinical AD may not depend on β-amyloidosis. ANN NEUROL 2013;73:472–480

We analyzed nonsynonymous single nucleotide polymorphisms (SNPs) from human LTBP4 in 254 nonambulatory subjects with known DMD mutations. These SNPs, V194I, T787A, T820A, and T1140M, form the VTTT and IAAM LTBP4 haplotypes.

Individuals homozygous for the IAAM LTBP4 haplotype remained ambulatory significantly longer than those heterozygous or homozygous for the VTTT haplotype. Glucocorticoid-treated patients who were IAAM homozygotes lost ambulation at 12.5 ± 3.3 years compared to 10.7 ± 2.1 years for treated VTTT heterozygotes or homozygotes. IAAM fibroblasts exposed to transforming growth factor (TGF) β displayed reduced phospho-SMAD signaling compared to VTTT fibroblasts, consistent with LTBP4' role as a regulator of TGFβ.

LTBP4 haplotype influences age at loss of ambulation, and should be considered in the management of DMD patients. ANN NEUROL 2013;73:481–488

We trained pattern classifiers to predict the presence of white matter damage in 25 TBI patients with microbleed evidence of TAI compared to neurologically healthy age-matched controls. We then applied these classifiers to 35 additional patients with no conventional imaging evidence of TAI. Finally, we used regression analyses to predict indices of neuropsychological outcome for information processing speed, executive function, and associative memory in a group of 70 heterogeneous patients.

The classifiers discriminated between patients with microbleeds and age-matched controls with a high degree of accuracy, and outperformed other methods. When the trained classifiers were applied to patients without microbleeds, patients having likely TAI showed evidence of greater cognitive impairment in information processing speed and executive function. The classifiers were also able to predict the extent of impairments in information processing speed and executive function.

The work provides a proof of principle that multivariate techniques can be used with DTI to provide diagnostic information about clinically significant TAI. ANN NEUROL 2013;73:489–499

The genetic linkage was confirmed and defined by microsatellite and single nucleotide polymorphism haplotyping. The whole linked genomic region was sequenced with targeted high-throughput and Sanger sequencing, and coding transcripts were sequenced on the cDNA level. WDM muscle biopsies were studied by Western blotting and immunofluorescence microscopy. Splicing of TIA1 and its target genes in muscle and myoblast cultures was analyzed by reverse transcriptase polymerase chain reaction. Mutant TIA1 was characterized by cell biological studies on HeLa cells, including quantification of stress granules by high content analysis and fluorescence recovery after photobleaching (FRAP) experiments.

The linked haplotype at 2p13 was narrowed down to <806 kb. Sequencing by multiple methods revealed only 1 segregating coding mutation, c.1362 G>A (p.E384K) in the RNA-binding protein TIA1, a key component of stress granules. Immunofluorescence microscopy of WDM biopsies showed a focal increase of TIA1 in atrophic and vacuolated fibers. In HeLa cells, mutant TIA1 constructs caused a mild increase in stress granule abundance compared to wild type, and showed slower average fluorescence recovery in FRAP.

WDM is caused by mutated TIA1 through a dominant pathomechanism probably involving altered stress granule dynamics. Ann Neurol 2013;73:500–509

The EPITHET and DEFUSE studies obtained diffusion and perfusion magnetic resonance imaging (MRI) in patients 3 to 6 hours from onset of ischemic stroke. EPITHET randomized patients to tissue plasminogen activator (tPA) or placebo, and all DEFUSE patients received tPA. VLCBV was defined as cerebral blood volume<2.5th percentile of brain contralateral to the infarct. Parenchymal hematoma (PH) was defined using European Cooperative Acute Stroke Study criteria. Reperfusion was assessed using subacute perfusion MRI coregistered to baseline imaging.

In DEFUSE, 69 patients were analyzed, including 9 who developed PH. The >2 ml VLCBV threshold defined in EPITHET predicted PH with 100% sensitivity, 72% specificity, 35% positive predictive value, and 100% negative predictive value. Pooling EPITHET and DEFUSE (163 patients, including 23 with PH), regression models using VLCBV (p<0.001) and tPA (p=0.02) predicted PH independent of clinical factors better than models using diffusion or time to maximum>8 seconds lesion volumes. Excluding VLCBV in regions without reperfusion improved specificity from 61 to 78% in the pooled analysis.

VLCBV predicts PH after stroke thrombolysis and appears to be a more powerful predictor than baseline diffusion or hypoperfusion lesion volumes. Reperfusion of regions of VLCBV is strongly associated with post-thrombolysis PH. VLCBV may be clinically useful to identify patients at significant risk of hemorrhage following reperfusion. ANN NEUROL 2013;73:510–519

Control infants (noncooled, n=106) of the National Institute of Child Health and Human Development Neonatal Research Network hypothermia trial had serial esophageal and skin temperatures over 72 hours. Each infant's temperature was ranked to derive an average of the upper and lower quartile, and median of each site. Temperatures were used in logistic regressions to determine adjusted associations with death or IQ<70 at 6 to 7 years. Secondary outcomes were death, IQ<70, and moderate/severe cerebral palsy (CP). IQ and motor function were assessed with Wechsler Scales for Children and Gross Motor Function Classification System. Results are odds ratio (OR; per degree Celsius increment within the quartile or median) and 95% confidence interval (CI).

Primary outcome was available for 89 infants. At 6 to 7 years, death or IQ<70 occurred in 54 infants (37 deaths, 17 survivors with IQ<70) and moderate/severe CP in 15 infants. Death or IQ<70 was associated with the upper quartile average of esophageal (OR=7.3, 95% CI=2.0–26.3) and skin temperature (OR=3.5, 95% CI=1.2–10.4). CP was associated with the upper quartile average of esophageal (OR=12.5, 95% CI=1.02–155) and skin temperature (OR=10.3, 95% CI=1.3–80.2).

Among noncooled infants of a randomized trial, elevated temperatures during the first postnatal days are associated with increased odds of a worse outcome at 6 to 7 years. Ann Neurol 2013;73:520–528

Forty-two nondemented CAA patients, 50 HE subjects, and 43 AD/MCI patients had brain MRI and PiB PET. Multivariate linear regression was used to assess the independent association between PiB retention and white matter disease volume, controlling for age, gender, apolipoprotein E genotype, and vascular risk factors within each group.

CAA patients were younger than HE and AD subjects (68 ± 10 vs 73.3 ± 7 and 74 ± 7.4, p < 0.01) but had higher amounts of WMH (median = 21 vs 3.2 and 10.8 ml, respectively, p < 0.05 for both comparisons). Global PiB retention and WMH showed strong correlation (rho = 0.52, p < 0.001) in the CAA group but not in HE or AD. These associations did not change in the multivariate models. Lobar microbleed count, another marker of CAA severity, also remained as an independent predictor of WMH volume.

Our results indicate that amyloid burden in CAA subjects (with primarily vascular amyloid) but not AD subjects (with primarily parenchymal amyloid) independently correlates with WMH volume. These findings support the idea that vascular amyloid burden directly contributes to chronic cerebral ischemia and highlights the possible utility of amyloid imaging as a marker of CAA severity. Ann Neurol 2013;73:529–536

Genome-wide linkage analysis was carried out in 14 family members followed by genome sequencing in 2 individuals. The index patient underwent a detailed neurological follow-up examination, including electrophysiological studies and magnetic resonance imaging scanning. Biopsies of the skin and olfactory mucosa were obtained, and expression levels of TUBB4 mRNA were determined by quantitative real-time polymerase chain reaction in 3 different cell types. All exons of TUBB4 were screened for mutations in 394 unrelated dystonia patients.

The disease-causing gene was mapped to a 23cM region on chromosome 19p13.3-p13.2 with a maximum multipoint LOD score of 5.338 at markers D9S427 and D9S1034. Genome sequencing revealed a missense variant in the TUBB4 (tubulin beta-4; Arg2Gly) gene as the likely cause of disease. Sequencing of TUBB4 in 394 unrelated dystonia patients revealed another missense variant (Ala271Thr) in a familial case of segmental dystonia with spasmodic dysphonia. mRNA expression studies demonstrated significantly reduced levels of mutant TUBB4 mRNA in different cell types from a heterozygous Arg2Gly mutation carrier compared to controls.

A mutation in TUBB4 causes DYT4 dystonia in this Australian family with so-called whispering dysphonia, and other mutations in TUBB4 may contribute to spasmodic dysphonia. Given that TUBB4 is a neuronally expressed tubulin, our results imply abnormal microtubule function as a novel mechanism in the pathophysiology of dystonia. Ann Neurol 2013;73:537–545