par Desmedt, Jean Edouard 
;Borenstein, Samuel
Référence Annals of neurology, 1, 1, page (55-64)
Publication Publié, 1977
;Borenstein, Samuel Référence Annals of neurology, 1, 1, page (55-64)
Publication Publié, 1977
Article révisé par les pairs
| Résumé : | A new, double‐step test is described that increases the yield of diagnostically useful data in patients with localized ocular or bulbar paresis who may have myasthenia gravis. The first step involves a program of supramaximal stimulation of the ulnar nerve at a rate of 3 per second for four minutes while electrical responses are recorded in four muscles of the hand and forearm to detect decrements and postactivation exhaustion. The second step delivers the same program under ischemia and elicits decrements from the subclinically involved muscles that reacted normally to the first step. Control tests in a large number of normal subjects established the conditions that efficiently challenge the muscles with a reduced safety factor for neuromuscular transmission while avoiding false‐positive results. The test involves the hypoxic failure of neurochemical processes. The ulnar flexor muscle of the wrist in athletic normal men was surprisingly more susceptible to ischemic exercise than the other normal muscles. The diagnostic uses of the double‐step test are documented in patients in whom the orbicular muscle of the eye and the proximal limb muscles reacted normally, and the concept of occult myasthenia gravis is discussed. Copyright © 1977 The American Neurological Association |
