Generalised paroxysmal fast activity (GPFA) is not always a sign of malignant epileptic encephalopathy

Generalised paroxysmal fast activity (GPFA) consists of 8-26 (most frequently around 10 Hz), 2-50 seconds (usually below 10 seconds) bursts of generalised rhythmic discharges with frontal predominance, appearing most frequently during NREM sleep. The pattern is traditionally linked to Lennox-Gastaut (LGS) or late LGS (LLGS) syndrome and associated with tonic-axial seizures, pharmaco-resistency and poor prognosis including mental deterioration. We present here four patients with GPFA, who had neither LGS/LLGS syndrome, nor mental deterioration, two of them are seizure-free, two had infrequent seizures on medication.

All the patients had neurological work-up and high resolution MRI studies. They were followed for years including repeated EEGs in awake state and during sleep.

The main seizure-type was generalised tonic-clonic seizure in three patients and absence in one. Onset of epilepsy varied from 7 to 21 years. No MRI lesion was found. All of them had generalised spike-and-wave discharges during the course of their epilepsy but some had also focal clinical or EEG features, were more difficult to treat, as atypical features compared to the classic generalised epilepsies with generalised spike-wave pattern.

Although GPFA should remain an important diagnostic feature of both the classical and late variant of LGS, our cases clearly demonstrate that GPFA could represent a possible electrographic variant in certain generalised epilepsies showing atypical features; better treatability and outcome than in LGS and no mental deterioration.