Monosynaptic reflexes in the flexor carpi ulnaris muscle in man
Deschuytere, J.; De Keyser, C.; Rosselle, N.; Deschuttere, M.
Electromyography and Clinical Neurophysiology 21(2-3): 213-222
1981
ISSN/ISBN: 0301-150X PMID: 7262002 Document Number: 179259
A study was undertaken to determine whether or not indirect motor responses may be elicited in the flexor carpi ulnaris muscle after the electrical stimulation of the ulnar nerve proximal to the cubital tunnel. Such responses were induced in normal humans, although it was usually necessary to employ special techniques of facilitation. In some normal subjects indirect motor responses could be derived from the flexor carpi ulnaris muscle without any facilitation and in the absence of a direct motor response. Measurements of latencies of monosynaptic reflexes offer the possibility to reveal lesions of the C8 and Thl ventral and dorsal roots, the lower trunks, the medial cords and the proximal segment of the ulnar nerve. Latency measurements of F waves derived either from the hypothenar muscles or from the thenar eminence appear to be useful for the diagnosis of polyneuropathies. H reflexes elicited in the forearm flexors with standardized techniques are likely more reliable than F waves derived from the hypothenar and thenar muscles. They may reveal la fiber involvement in addition to motor fiber involvement. Their elicitation is less inconvenient for the patient.