GM2 GANGLIOSIDOSIS B1 - PRESENTING AS MOT ONEURON DISEASE WITH FASCICULATIONS

We report on a 43-year old patient suffering from an adult version of a GM2-gangliosidosis type B (Tay Sachs). This disease is a very rare m anifestation of a lysosomal storage disease which can vary broadly in its clinical manifestations. While it affects mainly the spinacerebell ar systems and the second motoneurone, the pyramidal tract is involved to a minor extent. Occasionally, there is also evidence of neuropsych ological disturbances. Differential diagnosis demands differentiation from diseases such as motoneurone disease with an atypical progression , as well as from a multisystemic degeneration, both of which can be r elated to similar clinical symptoms. In addition to the main symptoms such as an affection of the cerebellum and the second motoneurone, our patient presented with a peripheral neuropathy. Furthermore, it is ev ident from this case that, despite a very low residual activity of Hex -A, the clinical deficit remains limited.