A quick look at slow saccades after cardiac surgery: where is the lesion?

Saccadic palsy is a reported complication of cardiac surgery. One case that came to autopsy showed midline pontine gliosis; however, in most cases, no lesions are evident on neuroimaging. Since the saccadic palsy may range from single large slow saccades to a "staircase" of very small saccades that are normal in speed, it seems plausible that more than one mechanism is possible. Here we postulate that, in those patients who make a staircase of small saccades, loss of cerebellar Purkinje cells could cause fastigial nucleus neurons to fire prematurely, thereby decelerating saccades via inhibitory burst neurons.