Hemangioblastoma and oculomotor pathology.

We examined voluntary eye movements of 20 ophtalmologically screened patients (mean age of 51 years) with operated hemangioblastoma (HAB) in the cerebellum. Constant and pseudo-random saccades and pseudo-random smooth pursuit eye movement (PRPEM) test (with 4 frequency combinations) were evaluated. As controls 38 healthy subjects were examined. In the logistic regression analysis latency and accuracy of constant saccades were the best predictors for operated HAB with correct overall classification rate of 79.3%. Accuracy was worse and latency longer in operated HAB group than in control group. In pseudo-random saccades correct classification between the groups was achieved in 82.8% of all cases with latency and accuracy as predictors. In PRPEM test the best frequency combinations in differentiating operated HAB patients from controls were 0.25 and 0.425 Hz for gain, and 0.3 and 0.7 Hz for phase and gain, the correct overall classification rate being 73.3% in both cases. The characteristic changes in voluntary eye movements after removal of cerebellar hemangioblastoma seem to be insufficient timing of initiating the eye movement.