Article

OBJECTIVE: To evaluate whether or not spinal accessory neuropathy exists in
patients with cervical myofascial pain syndrome (MFPS). DESIGN: Prospective
study. SETTING: A neurophysiologic laboratory in a university hospital.
PARTICIPANTS: Patients with cervical MFPS (n=25) and healthy controls (n=20).
INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: We performed nerve
conduction studies (NCSs) in bilateral spinal accessory nerves, and
electromyography and stimulated single-fiber electromyography in the trapezius
muscles of all patients and controls. Parameters including nerve conduction
velocities (NCVs), amplitudes and areas of compound muscle action potentials
(CMAPs), and mean consecutive differences (MCDs) in single-fiber electromyography
were measured, analyzed, and compared with the disease durations of the patients.
RESULTS: Spinal accessory NCSs showed normative NCVs but with prominently reduced
CMAP amplitude in the patients with cervical MFPS, which is recognized as an
axonal neuropathy of the spinal accessory nerves. Electromyography showed
prominent evidence of denervation and reinnervation patterns in 48% of the MFPS
patients. The abnormal MCDs in single-fiber electromyography indicated a synaptic
delay of motor endplates in the motor units, and may signify evolving instability
of neuromuscular transmission in the spinal accessory nerves innervating
trapezius muscles of the patients. CONCLUSIONS: This study demonstrates
electrophysiologic evidence of neuroaxonal degeneration and neuromuscular
transmission disorder in a significant proportion of patients with cervical MFPS.
We suggest that spinal accessory neuropathy may be associated with cervical MFPS.
CI - Copyright (c) 2011 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS