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the report by Harvey et al., there have been three further cases reported (Arzimanoglou, 1996; A.S. Harvey et al., unpublished data), with further ictal SPECT evidence in two cases to support an epileptic basis to the attacks of ‘hemifacial spasm’.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.

Introduction

Sturge–Weber syndrome (SWS), is a sporadic, congenital, frequently progressive, neurological disorder classically characterized by the association of a congenital facial capillary angioma with leptomeningeal angiomatosis. Epilepsy, mental retardation, and focal neurological deficits are the major neurologic abnormalities (Alexander & Norman, 1960; Alexander, 1972; Gomez & Bebin, 1987). The motor attacks include, in addition to epileptic seizures, transient hemiparesis or hemiplegia, often leaving a definite neurological deficit. Other features of the syndrome include hemiatrophy, homonymous hemianopia, glaucoma, dental abnormalities, and skeletal lesions (Roach & Bodensteiner, 1999).

Vascular abnormalities

Although the cutaneous capillary angioma is the hallmark of the SWS, most children born with facial port-wine stains do not have the syndrome. The SWS facial angioma is classically found on the forehead and upper eyelid. For a patient with any facial port-wine stain, the risk of having the SWS is only about 8%. It increases to 25% when half of the face, including the ophthalmic division of the trigeminal nerve, is involved (Morelli, 1999). Intracranial leptomeningeal angiomatosis is almost always ipsilateral to the cutaneous nevus. Exceptions to the rule are not infrequent and the correlation between the extent and location of the naevus and that of the pial angioma is poor (Alexander, 1972; Gomez & Bebin, 1987; Pascual-Castroviejo et al., 1993). Some children have bilateral nevus with unilateral pial involvement or vice versa. Angiomas may extend beyond the face and involve the neck, trunk or limbs on one or both sides (Uram & Zubillaga, 1982). In a recent series of 20 surgically treated SWS patients, six presented with extensive cutaneous angiomatosis, which was bilateral in three (Arzimanoglou et al., 2000).