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The neurophysiological profile of vitamin B 12 deficiency
Author(s) -
Fine Edward J.,
Soria Emlllo,
Paroski Margaret W.,
Petryk Diane,
Thomasula Linda
Publication year - 1990
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.880130213
Subject(s) - vitamin b , medicine , nerve conduction , sensation , nerve conduction velocity , sural nerve , endocrinology , vitamin , cardiology , surgery , psychology , neuroscience
Abstract Reports of the incidence and severity of physiological abnormalities of vitamin B 12 deficiency sharply differ. To resolve these controversies we performed evoked response and nerve conduction studies in 10 males with vitamin B 12 deficiency. The minimum criteria for this diagnosis were diminished position and vibration sensation and vitamin B 12 levels <220 pg/ml. We found normal BAERs in 9/10 patients. The central interpeak latencies of the median and peroneal SERs were abnormal in 4/10 and 818 patients, respectively. The VERs were abnormal in 7/10 patients. Wefound absent or diminished amplitudes of sural sensory and peroneal motor action potentials in 8/10 patients. Abnormal peroneal F response chronodispersion was present in 7/10 patients. Nerve conduction velocities (NCV) were normal in 9/10 patients. EMG demonstrated abnormalities consistent with denervation in lower extremity muscles in 8/10 patients. These studies present a profile of vitamin B 12 deficiency: essentially normal BAERs, mildly abnormal VERs and median SERs, and markedly abnormal peroneal SERs. NCV studies are consistent with sensory‐motor axonopathy.