Surgery for medically intractable childhood seizures originating in the opercular-insular cortex has only been undertaken in the last decade. While the need for SEEG interrogation and rates of post-operative seizure-freedom in children are comparable to adults, several important differences distinguish the pediatric experience. Most pediatric surgical candidates are pre-verbal or non-verbal and cannot describe subjective sensory or affective seizure manifestations. There is a higher representation of frontal lobe seizure semiology compared to adults, whereas ictal and inter-ictal electrographic discharges are typically more widespread throughout the cerebral hemisphere. Cortical malformations constitute the primary underlying pathological finding in the majority of pediatric cases. The recent surgical success in medically refractory children provides a compelling rationale to pursue further clinical studies and offer surgical candidacy in selected patients.

Hemifacial seizures and cerebellar ganglioglioma

In 1996 Harvey et al. reported an infant with a cerebellar ganglioglioma and episodes of hemifacial contraction that were shown conclusively to be epileptic seizures of cerebellar origin. Previous reports in the literature of six infants with cerebellar tumours and ‘hemifacial spasm’ suggested they might have a similar syndrome of cerebellar epilepsy. Since the report by Harvey et al., there have been three further cases reported (Arzimanoglou, 1996; A.S. Harvey et al., unpublished data), with further ictal SPECT evidence in two cases to support an epileptic basis to the attacks of ‘hemifacial spasm’. The clinical seizure characteristics, the location and signal characteristics of the lesions on magnetic resonance imaging (MRI), and the histopathological features of the tumours in these ten patients are so strikingly similar as to conceivably constitute an epilepsy syndrome of infancy characterized by seizures of cerebellar origin.

The initial case remains the most well-studied case in the literature, with unequivocal evidence of an epileptic basis and cerebellar origin of seizures (Harvey et al., 1996). Her seizures began on day 1 of life with twitching of the left orbicularis oculi muscle. She was evaluated at the Miami Children's Hospital at age 6 months when attacks of ‘hemifacial spasm’ were occurring multiple times each day. Immediately prior to each episode she became quiet and fixed her gaze straight ahead.