Posterior Fossa Lesions

Presenting Symptom: slow saccades. 1/3/74: 14 year old girl being studied by Dr. Zee with a history pf several years of progressive difficulty in gait with some sensory changes and weakness of the limbs suggestive of polyneuropathy. There are also mild cerebellar signs. Diagnosis is not made. The interesting eye finding is apparently an absence of the saccadic movements. Or at least the slowness of the saccadic movement. On the other hand, the following movements appear to be intact. Vertical movements are less affected. Noteworthy is the curious two components on gaze from upper left to lower right, such that the patient looks down first with a saccade and then has a slow almost pursuit movement to the right. A video recording was made of this. An attempt was also made to do an EMG but this was unsuccessful because of patient's apprehensiveness. However, Dr. Zee made a recording with Dr. Robinson showing normal pursuit movements and absence of the saccade horizontally. The opticokinetic response was very poor but we could not tell whether this was the slow component or the fast component which was defective. Anatomy: Posterior cranial fossa. Pathology: Lesions of posterior cranial fossa. Disease/ Diagnosis: Posterior Fossa Lesion