COLLICULUS HEMORRHAGES

We report the case of a patient with mesencephalic hematoma involving only the quadrigeminal plate. One case of superior and 3 cases of infe rior colliculus hematoma have already been reported. Involvement of th e quadrigeminal plate frequently follows a pontine or an anterior mese ncephalic hemorrhage. The cause of these hematomas may be due to crypt ic malformations of the quadrigeminal plate or primitive small size he morrhages possibly related to the nature of the arterial system. Patie nts with inferior colliculus lesions present a typical symptomatology consisting of trochlear nerve palsy contralateral to the lesion or bil ateral, contralateral hemiparesthesiae and acuphenes. Superior collicu lus lesion causes upgaze palsy visual blurring, dizziness and left upp er lip paresthesiae. The cause of the different signs and symptoms in both types of lesion are discussed.