Migraine and Complex Regional Pain Syndrome: A Case-Referent Clinical Study.

We studied clinical phenotype differences between migraineurs with CRPS (Mig + CRPS) and those without (Mig - CRPS). Mig + CRPS cases and Mig - CRPS referents aged ≥18 years were enrolled. Diagnosis was made in accordance with International Classification of Headache Disorders-3 beta (ICHD-3 beta) for migraine and Budapest Criteria for CRPS. Migraines both with and without aura were included. A total of 70 Mig + CRPS cases (13% males, mean age 48 years) and 80 Mig - CRPS referents (17% males, mean age 51 years) were included. 33% of Mig + CRPS and 38% of Mig - CRPS exhibited episodic migraine (EM) while 66% of Mig + CRPS and 62% of Mig - CRPS had chronic migraine (CM) (OR = 0.98, CI 0.36, 2.67). Median duration of CRPS was 3 years among EM + CRPS and 6 years among CM + CRPS cohort ( p < 0.02). Mig + CRPS (57%) carried higher psychological and medical comorbidities compared to Mig - CRPS (6%) (OR 16.7, CI 10.2, 23.6). Higher migraine frequency was associated with longer CRPS duration. Migraineurs who developed CRPS had higher prevalence of psychological and medical disorders. Alleviating migraineurs' psychological and medical comorbidities may help lower CRPS occurrence.