ROLE OF PONTINE NUCLEI DAMAGE IN SMOOTH-PURSUIT IMPAIRMENT OF PROGRESSIVE SUPRANUCLEAR PALSY - A CLINICAL-PATHOLOGICAL STUDY

We performed a quantitative study of the pontine nuclei in the basis p ontis and a semiquantitative study of extrapontine structures involved in smooth pursuit in four patients with severe impairment of horizont al smooth pursuit and histopathologically confirmed diagnosis of progr essive supranuclear palsy (PSP). There were only slight changes in the extrapontine structures involved in smooth pursuit, but there was a s ignificant neuronal loss-massive in three patients and mild in one pat ient-in all nuclei of the basis pontis. Our results suggest that degen erative lesions affecting the pontine nuclei are largely responsible f or the horizontal smooth pursuit impairment in PSP.