Determination of risk factors and triggers in patients with chronic migraine

Introduction and Objective : Chronic migraine is defined as headache occurring on 15 or more days permonth for more than three months, which, on at least 8 days per month, has the features of migraine headache. Approximately %3 of episodic migraine transform chronic migraine. In this study our aim was to determine the triggers and risk factors that play role in transformation of chronic migraine, guiding clues for patients with migraine like headache with underlying idiopatic intracranial hypertension(IIH) without papilledema. Also it was planned to investigate the effects of chronic migraine on the retinal nerve fiber layer (RNFL). Method : Fifty-seven patients with chronic migraine who admitted to Çukurova University, Faculty of Medicine, Department of Neurology, Headache Clinic between July 2018 to July 2020 were included in this prospective study. Patients were evaluated in detail and classified according to the body-mass index (BMI). Hormone profile, Brain magnetic resonance imagination (MRI), brain / cervical MR venography, visual field and Optical coherence tomography (OCT) assays were planned. Migraine disability level was determine using MIDAS questionnaire. Lumbar Puncture (LP) was performed for the cases with high BMI and significant pathological visual field abnormalities for IIH, followed with cerebrospinal fluid (CSF) pressure measurement. Results : Our study involved 57 (98.25% female) patients. Age, BMI and duration of migraine diagnosis tended to increaseas as MIDAS score increase(p=0,004 , p=0,049, p= 0,045 respectively). Patient with habitual snorring had higher BMI(p=0,028). Patients with family history of migraine had earlier migraine onset(p=0,028). % 77 of patients had history of depressive mood symptom. In terms of IIH 9 of 11 patient who underwent LP had CSF pressure above 250 mmH2O, one patient had 230 mm H2O. According to clinical, visual field, CSF pressure findings, these patients were classified as IIH without papilledema. IIH and chronic migraine patients were compared according to clinical findings. BMI and weight gain rate in the last year were found to be higher and duration of chronicity was shorter in IIH than chronic migraine(p=0,038, p<0,001, p=0,004, respectively). The patients with MIDAS grade 4 had thinner RNLF especiallyin right temporal area(p<0,05). The patients with white matter lessions had thinner RNLF in left temporal area. Conclusions: High BMI, depression and sleep disturbance are important triggers for the transition of episodic migraine to chronic migraine. Obesity, weight gaining in a short period of time and rapid progression to chronicity in terms of migraine should be a warning to IIH, even if the patient has a normal opthalmologic finding. In patients with chronic migraine RNLF does not predict pognosis, but it supports data on the pathophysiology of migraine. Key Words: Chronic Migraine, Idiopatic Intracranial Hypertension without papilledama, MIDAS, RNLF,