A case of Gerstmann-Sträussler-Scheinker syndrome with the P105L prion protein gene mutation presenting with ataxia and extrapyramidal signs without spastic paraparesis.

We describe the clinical features of a patient with Gerstmann-Sträussler-Scheinker syndrome with a mutation in the prion protein gene at codon 105 (GSS105) who presented with ataxia. Neurologic examination showed memory disturbance, dysarthria, extrapyramidal signs (bradykinesia and resting tremor) and ataxic gait without spasticity. Although GSS105 has been referred to as "spastic paraparesis-type GSS", the patient did not show spastic paraparesis or pyramidal signs, even 11 years after the onset of symptoms. Thus, the spectrum of the GSS105 phenotype varies among patients and requires further clinicopathologic elucidation.