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.
Solomon
David
D
Johns Hopkins University, Baltimore, MD, USA. dsolomon@dizzy.med.jhu.edu
Ramat
Stefano
S
Leigh
R John
RJ
Zee
David
D
D001933:Brain Stem / Q000473:pathology / Q000502:physiology; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D006801:Humans; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000502:physiology; D015835:Ocular Motility Disorders / Q000209:etiology / Q000473:pathology; D011689:Purkinje Cells / Q000502:physiology; D012438:Saccades / Q000502:physiology*