IMPAIRMENT OF SMOOTH-PURSUIT IN PONTINE LESIONS - FUNCTIONAL TOPOGRAPHY BASED ON MRI AND NEUROPATHOLOGIC FINDINGS

Eye movements were studied in two patients with pontine lesions identi fied by magnetic resonance imaging in one patient and computerized tom ography with neuropathological correlation in another patient. Impairm ent of ipsilateral saccades were explained by unilateral lesion of the paramedian pontine reticular formation. Ipsilateral dorsolateral and lateral pontine nuclei lesions result in unilateral impairment of smoo th put suit. Bilateral damage to the dorsomedian pontine nuclei result in bidirectional horizontal smooth pursuit deficit, predominantly tow ards the more pathologic affected side. In addition, these bilateral l esions may also account for impairment of vertical smooth pursuit. The se findings confirm that pontine nuclei are an important relay for hor izontal and vertical smooth pursuit movements.