Generalized Paroxysmal Fast Activity in EEG: not an uncommon finding in genetic generalized epilepsy

Objective: To study generalized paroxysmal fast activity (GPFA) in patients with genetic generalized epilepsy (GGE) Background: GPFA is an electroencephalographic (EEG) finding in patients with GGE consisting of 10–35 Hz bifrontally predominant generalized fast activity seen almost exclusively in sleep. Historically GPFA is linked to epileptic encephalopathy with tonic-absence seizures, refractory absence epilepsy and mental retardation. However, GPFA can be an atypical finding in patients with GGE and may indicate good response to anti-epileptic medications. GPFA could denote a different electroclinical syndrome and favorable clinical profile in patient with GGE. We report cognitive profile and seizure characteristics in seven patients with GGE and GPFA. Design/Methods: EEGs of all patients were reviewed by epileptologists at our comprehensive epilepsy center. Epilepsy database was searched for “GPFA”, “generalized epilepsy” and “generalized spike and wave discharges (GSWD)”. The seizure type, frequency, neurological work-up, cognitive profile and imaging data were obtained from chart review. Results: All seven patients had normal cognitive function. Awake and sleep states were captured on EEGs of all patients. All patients had GSWD and GPFA. The main seizure-type was generalized tonic-clonic (GTCS) in five patients, absences in one and myoclonic absences in the other. None of the patients had tonic seizures. Age at onset of epilepsy ranged from 5 to 26 years. None of the patients had MRI lesions. The mean seizure frequency at the time of EEG was 4.5/month in four patients while three patients were seizure free on two AEDs. Conclusions: GPFA can be an unnoticed common electrographic finding in patients with genetic generalized epilepsy. While GPFA remains an important diagnostic EEG feature for epileptic encephalopathy (Lenaux-Gestaut syndrome) it is not always associated with absence or tonic seizures. GPFA may have a spectrum of variable phenotypic expression and may be associated with good seizure outcome in patients with GGE. Disclosure: Dr. Sagi has nothing to disclose. Dr. Bhatt has nothing to disclose. Dr. Abou-Khalil has received financial support for research activities with Valeant Pharmaceuticals International, UCB Pharma, Schwarz Biosciences, King Pharma, Ortho-McNeill, and Icagen, Inc. Dr. Sonmezturk has nothing to disclose. Dr. Arain has received personal compensation for activities with UCB, Inc., GlaxoSmithKline, and Pfizer as a consultant.