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Giant somatosensory evoked potentials in a patient with the anterior spinal artery syndrome
Author(s) -
Triggs William J.,
Beric Aleksandar
Publication year - 1993
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880160510
Subject(s) - anterior spinal artery , somatosensory evoked potential , medicine , spinal cord , myelopathy , lumbosacral joint , scalp , anatomy , magnetic resonance imaging , lesion , median nerve , somatosensory system , evoked potential , surgery , anesthesia , radiology , audiology , psychiatry
We studied a previously healthy 25‐year‐old woman with the anterior spinal artery syndrome, a rare thoracocervical myelopathy with multiple potential etiologies. Quantitative and clinical sensory examination showed dissociated loss of pin‐prick and temperature discrimination below the level of the lesion, with normal light touch, vibratory, and position sense. Magnetic resonance imaging was consistent with cervical spinal cord infarction. Median SEPs showed normal Erb's potential with absent spinal N— 13 and normal scalp N— 20 latency. Tibial SEPs showed normal lumbosacral responses and normal scalp P— 30 latency. Both median and tibial nerve stimulation produced cortical responses of unusually large amplitude (median 38 m̈V, tibial 17 m̈V). We hypothesize that large SEP amplitudes in this patient resulted from loss of anterolateral inhibitory influences on the dorsal column–medial lemniscal system. © 1993 John Wiley & Soncs, Inc.