Faciobrachial dystonic seizures precede Lgi1 antibody limbic encephalitis
Article first published online: 17 MAR 2011
Copyright © 2010 American Neurological Association
Annals of Neurology
Volume 69, Issue 5, pages 892–900, May 2011
How to Cite
Irani, S. R., Michell, A. W., Lang, B., Pettingill, P., Waters, P., Johnson, M. R., Schott, J. M., Armstrong, R. J. E., S. Zagami, A., Bleasel, A., Somerville, E. R., Smith, S. M. J. and Vincent, A. (2011), Faciobrachial dystonic seizures precede Lgi1 antibody limbic encephalitis. Ann Neurol., 69: 892–900. doi: 10.1002/ana.22307
- Issue published online: 22 APR 2011
- Article first published online: 17 MAR 2011
- Accepted manuscript online: 28 OCT 2010 07:27AM EST
- Manuscript Accepted: 15 OCT 2010
- Manuscript Revised: 27 SEP 2010
- Manuscript Received: 3 SEP 2010
To describe a distinctive seizure semiology that closely associates with voltage-gated potassium channel (VGKC)-complex/Lgi1 antibodies and commonly precedes the onset of limbic encephalitis (LE).
Twenty-nine patients were identified by the authors (n = 15) or referring clinicians (n = 14). The temporal progression of clinical features and serum sodium, brain magnetic resonance imaging (MRI), positron emission tomography/single photon emission computed tomography, and VGKC-complex antibodies was studied.
Videos and still images showed a distinctive adult-onset, frequent, brief dystonic seizure semiology that predominantly affected the arm and ipsilateral face. We have termed these faciobrachial dystonic seizures (FBDS). All patients tested during their illness had antibodies to VGKC complexes; the specific antigenic target was Lgi1 in 89%. Whereas 3 patients never developed LE, 20 of the remaining 26 (77%) experienced FBDS prior to the development of the amnesia and confusion that characterize LE. During the prodrome of FBDS alone, patients had normal sodium and brain MRIs, but electroencephalography demonstrated ictal epileptiform activity in 7 patients (24%). Following development of LE, the patients often developed other seizure semiologies, including typical mesial temporal lobe seizures. At this stage, investigations commonly showed hyponatremia and MRI hippocampal high T2 signal; functional brain imaging showed evidence of basal ganglia involvement in 5/8. Antiepileptic drugs (AEDs) were generally ineffective and in 41% were associated with cutaneous reactions that were often severe. By contrast, immunotherapies produced a clear, and often dramatic, reduction in FBDS frequency.
Recognition of FBDS should prompt testing for VGKC-complex/Lgi1 antibodies. AEDs often produce adverse effects; treatment with immunotherapies may prevent the development of LE with its potential for cerebral atrophy and cognitive impairment. ANN NEUROL 2010;