Fibromyalgia
(FM) is a chronic pain illness. The causes of FM are not fully understood.
Biochemical, metabolic and disturbed immune-regulatory abnormalities were
suggested as possible causes of FM. Objective: The
study aims at the evaluation of serum serotonin in FM and its correlation with
the pain and the possible electrophysiological abnormalities. Methods: Thirty patients suffering from FM (diagnosed according
American College of Rheumatology for classification of FM ) , not under any medical treatment had i)
An evaluation of serum serotonin ii)
quantitative electromyography (qEMG) iii) Sympathetic skin response test (SSR).
Results: Serum Serotonin (SSL) level was
significantly lower in FM patients compared to control group. A SSL 400 ng/L
was found to be a cut off point for existence of the disease. SSR latency as
well tends to be longer in FM patients. The qEMG showed motor unit potential
de-synchronization, temporal dispersion and increased size. Conclusion:
FM is a disease of low serotonin levels. Determination
of SSL is a sensitive and selective test to assist in the diagnosis and follow
up of FM patients. The value of SSR latency and qEMG tests still need to be
verified however, they can be used to follow up the effects of the
pharmacological and non-pharmacological treatments of FM. [Egypt J Neurol
Psychiat Neurosurg. 2015; 52(2): 101-110]
Key Words:
fibromyalgia, quantitative EMG, serum serotonin, sympathetic skin response.
Correspondence to Nihal El Shazly, Assistant
Professor of Clinical Neurophysiology; Cairo University, Egypt. Email:
nihalelshazly@yahoo.com