[A case of Gerstmann-Sträussler-Scheinker disease with severe muscular atrophy and vertical gaze palsy].

Here we report a case of 56-year-old man with Gerstmann-Sträussler-Scheinker disease (GSS). He had gait disturbance, limb and truncal ataxia, dysarthria and dysphagia at the age of 53. When he developed vertical gaze palsy and dystonic posture of the neck, subcortical dementia, progressive supuranuclear palsy was suspected. Thereafter dementia rapidly progessed, and CT scan showed severe atrophy of the brain. Since severe muscular atrophy and fasciculation also appeared, and abnormality in the codon 102 of prion protein gene was found, he was diagnosed to have the classical type of GSS. GSS with vertical gaze palsy has never been reported, and involvement of the lower motor neuron is also very rare. Therefore, the present case is an atypical type of GSS.