Bilaterality of cluster headache. An hypothesis.
D000328:Adult; D000368:Aged; D001341:Autonomic Nervous System / Q000503:physiopathology; D003027:Cluster Headache / Q000503:physiopathology*; D006801:Humans; D008297:Male; D014653:Vascular Headaches / Q000503:physiopathology*