Prevalence of Cervical Myofascial Pain Syndrome and its Correlation with the Severity of Pain and Disability in Patients with Chronic Non-specific Neck Pain

Background: Nonspecific chronic neck pain is increasing according to work-related gestures and modern lifestyle. Myofascial pain syndrome is a common problem and may be a primary disease. This study was designed to evaluate the prevalence of cervical myofascial pain syndrome in patients with chronic non-specific neck pain with normal MRI. We also examined the correlation between patients' age as well as pain seventy and duration. Methods: Patients with neck pain radiating to their upper extremity were examined despite normal MRI findings. We evaluated 10 different muscles based on myofascial pain syndrome criteria and also recorded pain intensity and functional ability using visual analogue scale and neck disability index, respectively. A physical therapist with at least 10 years of clinical experience with myofascial pain syndrome performed all physical examinations Results: A total of 126 patients (69 females and 57 males) participated in this study, out of whom, 14 patients (11.1%) had no muscular involvement, while 112 cases (88.9%) revealed at least one trigger point. The infraspinatus and scalene muscles were the most commonly involved muscles accounting for 38.9% and 34.9% of all the involvements, respectively. The severity of pain was significantly associated with the disability of the patients (r=0.64, P<0.001). However, the correlation between pain and the number of trigger points was not significant (r=-0.19, P=0.31). Finally, the least significantly correlated variables were disability and the number of trigger points (r=-0.17, P=0.05). Patient's age was significantly correlated neither with the number of trigger points (r=-0.04, P=0.62), nor the pain duration (r=0.07, P=0.39). Conclusion: Myofascial pain syndrome is a common disorder in patients with nonspecific chronic neck pain, despite normal MRI findings. Although, pain is not correlated with the number of trigger points in these patients, we demonstrated a small correlation between patients' disability and the latter variable.