Restless leg syndrome" frequency and "growing pain" frequency in children who have FNF

Introduction: Familial Mediterranean fever (FMF) is an auto-inflammatory disease accompanied by recurrent fever and serositis. A majority of these patients complain about their leg pain induced by exercise, which is regarded among the minor diagnostic criteria of the disease. Restless leg syndrome (RLS) is a disorder characterized by irritating feeling on the legs and the uncontrolled stimulation of moving the legs while resting in order to remove this feeling. Growing pain (GP) is one of the frequently seen pain syndromes of the childhood period. Growing pain is the bilateral and intermittent leg pain, which is seen in young children generally in the evening and at night. There is no study evaluating association of "restless leg syndrome" and "growing pain" in FMF patients. Aim: The aim of this study is to research the "restless leg syndrome" frequency and "growing pain" frequency in children who have FMF and also to evaluate their effects on quality of life and sleeping quality of patients. Patients and Method: Sixty patients with FMF were consecutively included in this cross sectional study. Demographic characteristics of the patients, existence of FMF story in their families, the age at onset of the disease symptoms, follow-up period of the disease, FMF symptoms and findings including leg pain, MEFV mutation, usage period and dosage of colchicine, compliance of the patient to the treatment, severity score of the disease, serum CRP level, hemoglobin, ferritine, serum iron binding capacity and serum iron levels were recorded. Restless leg syndrome and growing pain criteria were evaluated by a form; and questionnaires of quality of life and sleeping habits were applied in accordance with the age groups.70 healthy children who applied to our Healthy Child Outpatient Clinic and had no chronic diseases were included in the study as the control group. In the control group, questionnaires of quality of life and sleeping habits were applied through a form in which restless leg syndrome and growing pain diagnosis criteria were analyzed. Result: There was no significant difference among patients with FMF and healthy children regarding GP and RLS diagnosis criteria (p=0.44, p=0.23, respectively). Total sleeping score was 48.1 ± 8 in patient group and 45.3 ±7 in control group. There was a significant difference between patient and control group in terms of total sleeping scores (p=0.03). There was no significant difference between the sleeping scores of the patients with and without growing pain in both patient group and control group (p=0.18, p=0.29, respectively). Similarly, there was no significant difference between the sleeping scores of the patients with and without RLS in both patient group and control group (p=0.86, p=0.65, respectively). Moreover; there was no significant difference between the sleeping scores of the patients with and without exercise induced leg pain (ELP) complaints in the patient group (p=0.22). There was a high ratio of GP in patients with ELP. Eight of 27 patients who had ELP fulfilled GP criteria, while two of 33 patients without ELP fulfilled GP criteria (p=0.015). Quality of life forms of 22 patients were filled by their parents because they were under age six. 38 patients filled these surveys both on their own and with their parents. Correlation of total scores of these surveys filled by the patients and their parents was found as significantly strong (r=0.89, p<0.01). A significant inverse correlation was found between total sleeping score and total parent score of quality of life in the patient group (r=0.45, p<0.01). Total parent score of quality of life was significantly and inversely correlated with the age of the patient, dosage of colchicine and disease severity score. Conclusion: There was no significant difference between FMF patients and healthy children in terms of fulfilling RLS and growing pain criteria. It was found that the ratio of fulfilling the growing pain criteria in the patients with ELP complaints was significantly higher when compared to the children without ELP. There was no significant relationship between ELP and RLS. To the best of our knowledge, this is the first study in the literature evaluating GP and RLS frequency in FMF patients. Key words: Familial Mediterranean fever, exercise induced leg pain, growing pain, restless leg syndrome