Study design: Comparative clinical and neurophysiological study in three groups of patients with general diagnosis of neck pain.
Objective: To determine symptoms of muscles dysfunction in patients with myofascial pain syndrome, disc-root conflict, and degenerative changes at cervical spine.
Summary and background data: The explanation for cervical pain origin should be based on results from chosen clinical and neurophysiological studies in correlation with neuroimaging findings.
Methods: Three subgroups of patients (N = 60 each) with certain symptoms were examined. Clinical evaluation included examination of pain intensity in VAS scale, muscle strength in Lovett scale, evaluation of reflexes, Spurling test, assessment of active trigger points (TRPs), and superficial sensory perception. Neurophysiological testing included surface electromyography at rest (rEMG) and during maximal contraction (mcEMG) as well as electroneurography (ENG).
Results: The greatest pain intensity with its decentralization phenomenon occurred in patients with disc-root conflict. Significant decrease of muscle strength was detected in trapezius muscle in myofascial pain syndrome subgroup. Weakness of abductor pollicis brevis muscle in patients with disc-root conflict differed them from patients with myofascial pain syndrome (P = 0.05). Patients with disc-root conflict and degenerative spine disease showed differences (P = 0.03) in reflexes evoked from triceps brachii. Positive Spurling symptom was most common (56.7%) in disc-root conflict subgroup. TRPs in trapezius muscle were found in all patients with myofascial pain syndrome. Results of rEMG amplitude measurements differed patients at P = 0.05. Only mcEMG recording from abductor pollicis brevis muscle allows for their clear cut differentiation. ENG studies showed abnormalities in patients with disc-root conflict and degenerative spine disease (P from 0.05 to 0.02). Positive correlation of VAS, TRPs, and rEMG as well as Lovett scores, mcEMG, and ENG results was found.
Conclusion: Only applying several clinical and neurophysiological tests together makes it possible to differentiate patients with different etiological reasons of pain at cervical spine.
Level of evidence: 4.