Unknown but may be rare.

Age at onset
Typically in teenage years or early adult life; may start earlier, 5 to 10 years or later.

Males = females.

Neurological and mental state

Autosomal dominant inheritance with high (~80%) penetrance. It is the first non-ion channel idiopathic focal epilepsy to be described. Mutations of the leucine-rich, glioma-inacivated 1 (LGI1/Epitempin gene) on chromosome 10q are responsible for this disorder.

Clinical manifestations
Simple focal seizures that are the most common consist mainly of simple auditory hallucinations such as ringing, humming, clicking, or unspecified noises. These may infrequently progress to complex focal seizures and generalized tonic-clonic seizures (GTCS). Other sensory symptoms such as visual (lights, colors, and simple figures), olfactory, vertiginous, or cephalic are frequent with simple focal seizures while autonomic, mental, and motor symptoms are less common. Families with brief aphasic seizures have been described.

Secondarily GTCS are rare.

GTCS predominantly nocturnal.

Seizure-precipitating factors

Diagnostic procedures
MRI is normal.

Inter-ictal EEG
Often normal; epileptiform abnormalities rarely occur.

Excellent. Patients are neurologically and mentally normal, and the condition does not appear to affect their otherwise normal life, particularly when on medication. Seizures are generally mild, infrequent, and well controlled with anti-epileptic medication.

Differential diagnosis
Symptomatic lateral temporal lobe epilepsy that lacks a similar family history and that is markedly different from hippocampal epilepsy and familial mesial temporal lobe epilepsy.

Management options*
AEDs indicated for focal seizures. Response to carbamazepine is excellent.

*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 21 Cave Street, Oxford OX4 1BA
First published 2006 and reprinted in 2007

Authored By: 
C. P. Panayiotopoulos MD, PhD, FRCP
Authored Date: 
Reviewed By: 
Steven C. Schachter MD
Sunday, June 1, 2008