Abstracts

Rationale: Lafora Body Disease (LBD) is a condition characterised by progressive myoclonus epilepsy (PME) and cognitive dysfunction, usually with onset in adolescence. Current treatment options are limited. We describe 3 siblings with LBD, the diagnostic difficulties encountered with the proband and their response to low carbohydrate diets (LCD). The response to a strict ketogenic diet (KD) in the proband is discussed. Methods: The proband was an adolescent, born of consanguineous parents of Pakistani origin, who presented at the age of 12 with recurrent transient loss of consciousness, then deteriorating school performance, absence and myoclonic seizures, unsteady gait and occasional simple and complex visual hallucinations. EEG showed almost continuous spike and slow wave activity over the occipital areas and frequent bursts of generalised paroxysmal activity. Two punch-biopsies of the axillary skin were non-diagnostic: either normal or devoid of apocrine glands. A third biopsy demonstrated Lafora bodies. Genetic testing (University of Lyon, Prof. A. Calender) showed a homozygous nonsense mutation with substitution of a “stop” codon for “lysine” in exon 1 of the EPM2A gene. She had a brother and a sister, aged respectively 11 and 7, both homozygous for the family mutation. The proband was established on clonazepam, sodium valproate and levetiracetam and LCD with good improvement of her seizures and stabilisation of her cognitive status. Her siblings were also commenced on a LCD. At the age of 16 years the proband showed significant deterioration in cognitive function with loss of mobility and difficult seizure control. Various anticonvulsant medications were tried. Gastrostomy feeding was commenced due to inadequate oral intake and unsafe swallow. Ketogenic diet was commenced following gastrostomy. Results: There was marked improvement in level of alertness, awareness and communication with return of appetite and seizure control following introduction of KD. EEG done before and after KD was commenced showed reduced polyspike and wave activity and brief periods of relatively normal electrical activity 2 weeks after KD. The brother who is still cognitively intact had a few episodes of collapse, generalised tonic-clonic seizures and probable absences over 2 years after the diagnosis was made. He has not had any seizures for over a year since he has been on the LCD. The younger sister remains asymptomatic and is tolerating her LCD too. Conclusions: Significant improvement in cognitive function and seizure control with improved EEG record were observed in a patient with LBD on the KD. Seizure control was established with LCD alone in another patient and the third patient remains pre-symptomatic on LCD. The role of KD and LCD should be explored further in LBD.