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- PATIENTS AND METHODS
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Urinary incontinence (UI) is common in the first phase after a stroke and is a strongly negative prognostic factor [1,2]. In a recent systematic review, UI was the only factor identified in at least two level-A studies (Cochrane collaboration criteria) that predicted poor function in the activities of daily living . The reasons for this are still not fully understood. Only a few authors have excluded patients with pre-existing UI [1,2]. Detrusor overactivity seems to be the most frequent mechanism in UI after a stroke, but underactive detrusor and normal urodynamic findings are also described [4–6]. The clinical presentations of stroke-related UI have not been extensively studied. Apart from disruption of the suprapontine inhibitory pathways, and motor, language or other stroke-specific deficits precluding successful toileting, a stroke might also reduce the ability to perceive and understand bladder signals. In a recent study we found that new-onset UI in stroke patients fell into two different clinical categories, i.e. classical urge UI or UI with impaired awareness (IA) of the need to void. IA-UI emerged as a strong and independent risk factor for poor outcome after 3 months, while urge UI did not . Despite the size of the problem, there are few interventional studies of UI after stroke. Currently there is no evidence of any sustained treatment effects , possibly partly because of inadequate clinical classification. As IA-UI has not been described before, we present the clinical and neuroradiological features of patients with this type of UI, and report the urodynamic findings in seven of them.
PATIENTS AND METHODS
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- PATIENTS AND METHODS
- CONFLICT OF INTEREST
From 1 October 2002 to 15 February 2005, we investigated 315 patients with acute cerebral stroke (first or recurrent) who were consecutively admitted from their homes to the Stroke Unit, Ullevaal University Hospital; 65 with new-onset UI were identified. Participants had a confirmed stroke diagnosis according to the WHO criteria , were fully conscious, not delirious, medically stable and able to communicate. All had a thorough clinical and neurological examination, and cerebral CT within 24 h after admission. The neuroradiologists who interpreted the CT were unaware of the patients’ continence status. Inclusion was based upon informed consent. In patients who consented, but were not able to write or had cognitive impairments that could preclude understanding the urodynamic procedures, we also collected informed assent from the next of kin. The Regional Committee for Ethics in Medical Research approved the study.
Because more than a third of the participants had no visible new vascular lesions on CT, the Oxfordshire Community Stroke Project classification system  was also used. For further clinical description, we used the Barthel Index for activities of daily living  without the urinary continence item (18 points = fully independent; <18 points = dependent in at least one activity); the Mini Mental State Examination (MMSE) , the Screening Instrument for Neurocognitive Impairments in Stroke (SINIS) assessing aphasia, visuocognitive impairment and apraxia ; and the short form of the Informant Questionnaire on COgnitive Decline in the Elderly (IQCODE) .This form consists of 16 questions to the next of kin about patients’ changes in mental function during the past 10 years, each question with a score from 1 (much better) to 5 (much worse); a mean score of ≥3.31 indicates mental decline.
The patients were assessed clinically 7–12 days after the stroke, to allow for stabilization and to reduce bias because of early mortality. Drugs that could influence micturition were discontinued when possible. We measured residual urine volume (≤10 min after voiding) by ultrasonography in all patients in whom it was applicable. All were checked for UTI (defined as bacteriuria of >105 colony-forming units/mL and significant pyuria) and, if positive, treated properly before the assessment.
For each patient, the nurses completed a micturition diary and an observation chart for ≥3 days. If patients did not spontaneously report problems or call for help with toileting, they were asked every 4 h about bladder symptoms (filling sensation, urgency, frequency) and whether they had leaked, and checked for it. We used the ICS guidelines for classification of LUTS . The patients’ concern about their new problem was assessed using the following scale: 0, no problem/not bothered; 1, a small nuisance/slightly bothered; and 2, a major problem/greatly bothered. This scale was adopted and slightly modified from a questionnaire that is part of an epidemiological survey in Norway .
Cysto-urethrometry was performed at a mean (range) of 24 (8–50) days after the stroke. With the patient supine a 12 F low-friction catheter was introduced through the urethra to empty the bladder. Thereafter, we inserted an 8 F catheter with a lumen and pressure sensors at the tip and at the proximal urethral sphincter level (CamTech, Norway), and connected it via two separate transducers to the cystometrograph (Ellipse 4, Andromeda, Germany). Bladder and maximum urethral pressure were recorded continuously. Isotonic saline at room temperature was instilled through the CamTech catheter at 25 mL/min. The examining physician (R.S.) was present during the procedure, observing the patient for movements or other events that could alter the pressure measurements, and scoring them as artefacts on the record sheet. The patients were repeatedly asked to cough and contract the pelvic floor during bladder filling. The first desire to void, strong desire to void, detrusor contractions and maximum cystometric capacity were defined and recorded according to the ICS guidelines . Filling was stopped when a bladder contraction with consecutive leakage occurred, or when 450–500 mL of saline had been instilled. After the catheter was removed and the patients had urinated spontaneously in a comfortable position, we measured residual urine volume by inserting a low-friction catheter. A urine sample was analysed the day after and at any time when infection was suspected. The patients were followed up for a year.
The results were analysed statistically (between-group comparisons of categorical variables) using the chi-square test, with P < 0.05 taken to indicate significance.
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Twenty-seven patients developed the classical symptoms and signs of urge UI, whereas 38 had a different pattern; one subgroup of 16 occasionally had a feeling of bladder fullness immediately before micturition occurred, but often they did not recognize anything before they became wet. They were not always aware of leakage episodes even when they were awake. Only two patients felt greatly bothered about their new problem. The other subgroup of 22 denied having leakage or any urinary problem at all, despite the objective evidence. When the nurses indicated it to them, they either explained it away or acknowledged it, but denied it again on the next occasion. The group denying it was older and had a poorer MMSE score (P = 0.01) than the group with partial awareness; there were no other significant differences.
Because the ICS guidelines do not distinctly address awareness, a new UI category was created, IA-UI, defined as UI with reduced ability either to be aware of bladder signals before leakage, or to take notice of eventual leakage, or both. The mean (range) age of the 38 patients with IA-UI (19 women, six haemorrhagic strokes) was 81 (67–91) years. Compared to those with urge UI, they had more total or partial anterior circulation strokes, more visible new CT lesions, less visible new frontal lobe involvement and a poorer Barthel score on admission; they also tended more often to have declined cognitively before the stroke, and to have visible new parietal damage. Further details are listed in Table 1, which also shows the differences in subjective symptoms and behaviour between the patients with classical urge UI and IA-UI.
Table 1. Clinical characteristics, and subjective symptoms and behaviour, in 65 patients with new-onset UI after a stroke
|Variable||Urge UI (27)||IA-UI (38)||P*|
|Age >80 years||12||23||0.20|
|IQCODE ≥3.31 points|| 5||16||0.06|
|≥1 old lesions on CT||12||23||0.20|
|Visible new lesions on cerebral CT||10||24||0.04|
|Visible new frontal lobe lesions|| 7/10|| 7/24||0.05|
|Visible new parietal lobe lesions|| 2/10||12/24||0.11|
|Modified BI <9 on admission||10||29||<0.001|
|MMSE score <24 on admission|| 7||14||0.38|
|Neurocognitive impairment (SINIS <54 points)||19||37||0.001|
|Use of sedative drugs|| 11||19||0.66|
|Dead or living in nursing home at 1 year|| 3||30||<0.001|
|Continent at 1 year||13/26|| 2/27||0.001|
|Subjective symptoms and behaviour|
|Strong urge to urinate||Always present||Absent|| |
|Sensation of bladder filling before leakage||Always present||Often absent|| |
|Micturition frequency||Increased (>8/day)||Normal or increased|| |
|Awareness of leakage||Always present||16 sometimes present; 22 denied leakage|| |
|Acknowledgement of urinary problem||Always present||16 present; 22 absent|| |
|Bother||24 greatly bothered||2 greatly bothered|| |
|3 slightly bothered||14 slightly bothered; 22 not bothered (denied leakage)|| |
Of the 38 patients with IA-UI, 24 (63%) had visible new stroke-related CT lesions (17 right-sided, seven left-sided). New lesions in the basal ganglia and internal capsule/thalamus were as frequent as in the frontal or parietal lobes. Patients with no new lesions showed more old lesions (nine of 14 vs one of 24, P < 0.001) and had more often declined mentally before the stroke than those with new lesions (10 of 14 vs five of 24, P = 0.002). Of the 12 patients with parietal lobe involvement, 10 denied their UI; no particular subtype of IA-UI dominated in the patients with other lesional locations.
Seven patients had a urodynamic assessment, i.e. three with denial who acknowledged their UI after information, and four with partial awareness. The remaining 31 could not be tested because there was no consent (19), they were discharged to a nursing home or other hospital department before test (five), death (three), and considerable immobility (four).
The urodynamic findings are shown in Table 2; two of the three patients who denied their UI had normal cysto-urethrograms, but felt no desire to void. In the third, the urethral pressure was low during the entire procedure, mostly ≈10 cmH2O; it declined repeatedly to zero or below. The first episode occurred at 60 mL of saline with no distinct detrusor contraction, resulting in leakage. During further filling there was a small contraction at 60 mL simultaneously with a negative urethral pressure and subsequent leakage. The patient had no desire to void. All four patients with partial awareness showed terminal detrusor overactivity. As shown in Table 2, the first desire to void was at quite high volumes, except in one patient, and none expressed a strong desire to void.
Table 2. The urodynamic findings in seven patients with IA-UI
|CT lesions||T/P/O (R) I||NNL||P (L) I||NNL||NNL||Fr/T/P (R) I||BG (R), H|
|Degree of awareness||Denial||Denial||Denial||Partial||Partial||Partial||Partial|
|Volume at FDV*, mL||–||–||–||250||275||315||120|
|Volume at first UBC, mL||60||–||–||500†||285||315||120|
|Cystometric capacity, mL||60||FS at 450||FS at 450||FS at 500||285||315||120|
|Urethral pressure, cmH2O||Low‡||Normal||Normal||Normal||Normal||Normal||Normal|
|Residual urine, mL||–||–||150||350||–||–||–|
Four of the 38 patients died before discharge (all due to recurrent strokes), 31 were discharged to nursing homes and three to their homes. After a year, a further seven patients had died, four were living at home, and only two of the surviving 27 had become continent. The two who recovered from IA-UI were those who had felt greatly bothered by it in the acute phase after the stroke. By contrast, 13 of the 27 patients with urge UI had completely recovered and six had improved after a year; 24 were living at home and two in nursing-homes; only one had died (Table 1).
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- PATIENTS AND METHODS
- CONFLICT OF INTEREST
We describe a hitherto unheeded stroke-related type of UI that is distinctly different from classical urge UI in its clinical and prognostic features. IA occurs to various degrees and includes not only levels of attention and perception, but also apprehension of bladder signals. Imaging studies in healthy volunteers show that the frontal lobes and various midbrain structures are important in conscious recognition of afferent bladder signals and the volitional inhibition of the micturition reflex [17,18]. However, correct identification (gnosia) and validation of the signals in a given social situation are likely to depend also on parietal and temporal functions . In previous studies with incontinent stroke patients, parietal lesions are common, as well as frontal and midbrain lesions , supporting our findings. Visible new lesions in the frontal lobes dominated in the patients with urge UI, whereas those with IA-UI tended to have more parietal damage (Table 1). Nearly all patients in the group with visible parietal lesions denied their UI, i.e. had a kind of anosognosia. There are no published reports of the denial of UI, but anosognosia of motor deficits after a stroke is common in patients with right-sided lesions. It occurs in association with frontal, parietal, temporal and subcortical damage, but most frequently if both frontal and parietal structures are involved [21,22]. It is related to extensive lesions and predicts a poor outcome [21,23]. In older patients with stroke and a poor mental capacity before the stroke because of vascular or nonvascular disease, anosognosia can occur even after a minor vascular event. Thus, denial of UI could rather be seen as a marker of severe brain dysfunction than as a risk factor per se. UI with partial awareness and denial of UI might represent steps on a continuum of the severity of brain disease, and probably explain the prognostic impact of stroke-related UI.
A retrospective study described a urodynamic subtype of overactive bladder in old age, the so-called uninhibited overactive bladder , that truly corresponds to the terminal detrusor overactivity  found in the present patients with partial awareness. A minority of such patients had neurological diagnoses. In a study of 73 incontinent geriatric patients (40 with possible dementia), 14 of 34 with confirmed detrusor overactivity had reduced bladder sensation ; these patients had a cortical dysfunction, as evaluated by MMSE and single-photon emission CT, more often than those with normal sensation. Their clinical symptoms were not mentioned, but might have been equal to IA-UI with partial awareness.
The present patients were considerably disabled and only a few urodynamic assessments were possible, but even these showed different patterns of bladder/urethral behaviour. The only common feature was a poor perception of bladder filling; those who denied leakage had the poorest perception. Urodynamic testing is a focused situation; most patients performed better than in normal situations with many competing stimuli. If awareness fails, UI might occur merely by a spinal reflex voiding, as in infants; this could explain the normal cystograms.
As only CT was available, valid information on the extent of lesions could not be provided. We excluded patients with severe aphasia, mainly due to extensive left-sided infarction; many of these were incontinent. This might have biased the results, but it would have been impossible to differentiate between pure communication and other cognitive failure in this group. We did not measure abdominal pressure during cysto-urethrometry, a procedure recommended in the ICS guidelines . It was considered that it would put further strain upon the patients without giving significant additional information. With one of the investigators continuously observing for artefacts, we think that the measurements generally reflect the true intravesical pressure.
The study included all incident cases in a prospective cohort, but there were relatively few patients and more samples would be necessary to confirm the results in similar age groups. Reservations should be made in generalizing the findings, but most stroke victims are elderly, and there will be more older stroke survivors in the future.
Clinical observation with an emphasis on urgency/frequency symptoms, awareness and concern seems useful for the better management of UI after a stroke. Patients with classical urge UI might recover spontaneously or benefit from established treatment measures as much as others with no stroke. Patients with denial or lack of concern will not respond to any measures. Those with preserved insight might be helped by early behavioural and awareness training, such as prompted voiding in the first place, or even by additional medical treatment if uninhibited detrusor activity is present. This could be a topic for further investigations.