Very small; 1 case annually in specialized centers.
Age at onset
1 to 10 years; peak at 5 to 6 years.
Males = females.
Neurological and mental state
Unknown. Chronic viral infection? Abnormal immune response to viral infection? Autoimmune disorder unrelated to infection?
- First stage with simple focal motor or somatosensory seizures or with epilepsia partialis continua (60%), complex focal seizures without automatisms or secondarily generalized tonic-clonic seizures (GTCS). Seizures deteriorate in weeks or months. Hemiparesis is initially post-ictal and later permanent.
- In the second stage (3 months to 10 years from onset), seizures become longer, more frequent, and widespread. Neurological and mental deficits: hemiparesis, hemihypesthesia, hemianopia, intellectual/language impairment.
- In the third stage, seizure severity and progression of deficits burn out.
No specific diagnostic procedure or abnormality. At onset, all functional and structural tests may be normal. It is the progression and the localization that may be consistent with this diagnosis.
CSF: non-specific abnormalities in half of patients. Oligoclonal or monoclonal banding may be found.
Serial CT brain scan and preferably MRI: progressive hemiatrophy, usually starting in the temporo-insular region.
Magnetic resonance spectroscopy: decreased relative N-acetylaspartate signal intensity over the affected hemisphere.
Functional brain imaging – single photon emission computed tomography (SPECT) and positron emission tomography (PET): inter-ictal hypoperfusion and hypometabolism in the affected side, which worsens with progression of the disease and may be abnormal at a stage that MRI is normal. Ictally, there is regional hyperperfusion corresponding to the epileptogenic region.
Normal initially but gradually deteriorates to severe unilateral abnormalities (slow waves, poverty of physiological rhythms). Inter-ictal multifocal spikes, sharp waves in nearly all EEGs.
Multifocal onset. Focal motor seizures may occur without concomitant EEG changes. Conversely, ictal EEG paroxysms may frequently occur without discernible clinical manifestations. Epilepsia partialis continua often lacks clinico-EEG correlations.
Devastating, with intractable seizures and fixed neurological deficits.
Initially focal seizures and later encephalitis.
Seizures are refractory to AEDs. Intravenous immunoglobulin, steroids, and plasma exchange give equivocal results.
*Expert opinion, please check FDA-approved indications and prescribing information
This page was adapted from:
The educational kit on epilepsies
The epileptic syndromes
By C. P. Panayiotopoulos
Originally published by MEDICINAE
Reviewed and revised June 2008 by Steven C. Schachter, MD
21 Cave Street, Oxford OX4 1BA
First published 2006 and reprinted in 2007