Trigeminocervical Reflex in Fibromyalgia Patients

Objective: To describe the properties of trigeminocervical reflex in normal Subjects and in patients with primary fibromyalgia syndrome (PFS) having neck pain. Design: Prospective testing of trigeminocervical reflex. Setting: University hospital electromyography laboratory in Turkey. Participants: Patients with PFS (n=16) and healthy volunteers (n=20). Interventions: Trigeminocervical reflex is a brainstem reflex that is evoked by stimulating the sensory branches of the trigeminal nerve and can be recorded from the neck muscles. Electric stimulation of the supraorbital nerve evokes a reflex response (C3) and early reflex response (C1). The mean latencies of C1 and C3 of patients with PFS were compared with normal values. Main Outcome Measure: The Cl and C3 latencies of trigeminocervical reflex. Results: In healthy volunteers, C3 latency +/- standard deviation was 54.17+/-6.00ms ipsilaterally and 51.25+/-9.26ms contralaterally. The difference was not significant (P=.26). The C1 latency was 17.46+/-4.89ms. In patients with PFS, C1 latency was 13.83+/-4.48ms and the C3 latency was 62.70+/-18.22ms. The difference was not significant between the patients (P=.08) and healthy volunteers (P=.17). Conclusion: In patients with PFS having neck pain, trigeminocervical connections were not influenced and some other mechanisms may be responsible for pain in these patients.