Atypical transient ischemic attacks in thrombocythemia of various myeloproliferative disorders.

Neurological symptoms of transient unsteadiness, dysarthria, dysphasia, dysbasia, transient monoor hemiparesis, hemiparesis, scintillating scotomas, amaurosis fugax, vertigo, dizziness, migraine accompaniments, syncope and seizures were the presenting manifestations of thrombocythemia in various myeloproliferative disorders. Erythromelalgia preceded or followed the neurologic ischemic attacks. The neurologic and ocular attacks usually had a sudden onset, lasted for a few seconds to several minutes and occurred independently or sequentially rather than simultaneously. This clinical syndrome is caused by platelet-mediated ischemic and thrombotic processes in the end-arterial microvasculature and reflects the existence of a platelet dependent and aspirin responsive arterial thrombophilia in thrombocythemia as novel disease entity, which confirms and elucidates Mitchell's hypothesis.