Clinical clues to a dizzying headache.

Recent years have witnessed an upsurge of interest in migraine as a cause of vestibular symptoms. Starting with 1970s case reports linking migraine to childhood vertigo, neurotologists worldwide have increasingly diagnosed migraine. Various syndromes of vestibular migraine (VM) have been described, diagnostic criteria proposed, epidemiologic data collected, and neurophysiologic models developed. Yet, the concept that migraine causes vestibular symptoms rests on a surprisingly thin research database. Current concepts of VM are based on expert opinion, not empirical data. No general consensus exists about the definition of VM. No studies have analyzed its essential features. Just one well-controlled medication trial has been published. No biomarkers are known. To stimulate more rigorous research, this paper poses three questions about clinical investigations into migraine and vestibular symptoms: What variables should be measured? What patients should be studied? How might clinical trials yield both clinically useful results and greater insights into pathophysiologic processes? Using these questions, the limits of current knowledge are explored. Applicable research methods from epidemiology to genetics are examined. Pilot data demonstrating pharmacologic and genetic dissection techniques are presented. Ambitious, but practical, near-term clinical research goals are enumerated, including rigorous validation of diagnostic criteria and development of empirically derived management guidelines.