Progressive cerebellar and extrapyramidal motor disturbances in galactosaemic twins.

Progressive cerebellar and extrapyramidal motor disturbances are described in two 16-year-old female twins with classical galctosaemia. The neurological disturbances, characterized by hyper- and dysmetric movements and bilateral intention tremor with choreatic, atactic and even ballistic motor storms, appeared at 12 years of age. Computerized tomography demonstrates cerebral atrophy in cerebellar, brain stem and basal ganglia structures. The central conduction times, determined by somatosensible evoked potentials, are grossly prolonged; the peripheral nerve conduction velocities are normal. The neurological sequelae described are considered a distinct entity in the course of galactosaemia.