Abstracts

Rationale: Lafora disease (LD) is an autosomal recessive, fatal form of progressive myoclonus epilepsy characterized by the presence of intracellular polyglucosan inclusions in the brain, liver and skin. Though reported sparsely from all over the world, there are geographic isolates such as south India where higher frequency has been reported. The aim was to describe the clinical, pathological, electrophysiological and genetic aspects of Lafora disease from south India, emphasizing the specific phenotypic characteristics from this region.Methods: The case records of the histopathological proven cases (n=47) of Lafora disease have been reviewed and the phenotypic characteristics were analyzed. Results: Forty seven cases of LD were seen between 1982 to 2007 at NIMHANS, Bangalore, India. The age ranged from 8 to 20 years with a mean of 13.3 ± 2.2 years. The duration of illness ranged from 2 months to 9 years (3 ± 2.2 y). All patients had myoclonus with GTCS. Cognitive decline was seen in 42 (87.3%). 10% had visual loss. Optic atrophy was seen in 10 (21.2%). Scalp EEG was abnormal in all. However photosensitivity, a hallmark of this disorder from the western countries was seen in only 8.5% of cases. It is interesting to note that EEG and SSEP gave clue in the asymptomatic sibs of the patient’s, years before clinically manifested. Positive family history was noted in 15 (32%). Three families had more than 3 members affected. Axillary skin biopsy confirmed the diagnosis in 44 cases and remaining was positive in liver and brain. Genetic evaluation done in 15 cases, six were EPM2A positive and six were EPM2B. Latter had longer duration of illness compared to the former. Conclusions: Geographic isolate 47 cases of Lafora disease, one of the largest series in the world literature have been reported from south India. This is probably due to high rate of consanguinity in this region. Genotype – phenotypic variation of this disorder will be highlighted.