Kamran Ezzati - Neuroscience Research Center, Poorsina Hospital, Faculty of medicine, Guilan University of Medical Sciences, Rasht, Iran
Behdad Ravarian - Neuroscience Research Center, Poorsina Hospital, Faculty of medicine, Guilan University of Medical Sciences, Rasht, Iran
Alia Saberi - Neuroscience Research Center, Department of Neurology, Poursina Hospital, Guilan University of Medical Sciences, Rasht, Iran
Amir Salari - Orthopedic Research Center, Department of Orthopedics, Poursina Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
Zoheir Reihanian - Guilan Road Trauma Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
Mohammadparsa Khakpour - Department of Biology, Facility of science, university of Victoria, Victoria, Canada
Shahrokh Yousefzadeh chabok - Guilan Road Trauma Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran

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 severity and duration. Methods: Patients with neck pain radiating to their upper extremity were examined despite normal MRI findings. We evaluated ۱۰ 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 ۱۰ years of clinical experience with myofascial pain syndrome performed all physical examinations Results: A total of ۱۲۶ patients (۶۹ females and ۵۷ males) participated in this study, out of whom, ۱۴ patients (۱۱.۱%) had no muscular involvement, while ۱۱۲ cases (۸۸.۹%) revealed at least one trigger point. The infraspinatus and scalene muscles were the most commonly involved muscles accounting for ۳۸.۹% and ۳۴.۹% of all the involvements, respectively. The severity of pain was significantly associated with the disability of the patients (r=۰.۶۴, P<۰.۰۰۱). However, the correlation between pain and the number of trigger points was not significant (r=-۰.۱۹, P=۰.۳۱). Finally, the least significantly correlated variables were disability and the number of trigger points (r=-۰.۱۷, P=۰.۰۵). Patient’s age was significantly correlated neither with the number of trigger points (r=-۰.۰۴, P=۰.۶۲), nor the pain duration (r=۰.۰۷, P=۰.۳۹). 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. Level of evidence: II

Disability, Myofascial pain syndrome, neck pain, Radiculopathy, Trigger point