To describe the properties of trigeminocervical reflex in normal subjects and in patients with primary fibromyalgia syndrome (PFS) having neck pain.
Prospective testing of trigeminocervical reflex.
University hospital electromyography laboratory in Turkey.
Patients with PFS (n=16) and healthy volunteers (n=20).
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.
The C1 and C3 latencies of trigeminocervical reflex.
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).
In patients with PFS having neck pain, trigeminocervical connections were not influenced and some other mechanisms may be responsible for pain in these patients.