Demyelinating lesions in the trigeminal root were produced by chronic implantation of chromic suture in 12 cats. Two types of abnormal repetitive action potential generation were recorded from demyelinated fibers: reflected spikes and afterdischarge. Both types of abnormal impulse generation were increased by hypocalcemia induced by disodium edetate infusion, hypocapnia produced by hyperventilation, and, to a lesser extent, alkalosis secondary to sodium bicarbonate administration. This hyperexcitability of fibers could be inhibited by hypoventilation with elevation of Pa co 2 or by calcium chloride administration. These results may help explain the pathophysiological basis of paroxysmal symptoms in multiple sclerosis and other disorders in which demyelination is a prominent feature.
ASJC Scopus subject areas
- Clinical Neurology