Migraine: More Than Just a Headache
Abstract & Commentary
By Dara G. Jamieson, MD, Associate Professor, Clinical Neurology Director, Weill Medical College; Cornell University. Dr. Jamieson is a consultant for Boehringer Ingelheim and Merck, and is on the speaker's bureau for Boehringer Ingelheim, Merck, Ortho-McNeil, and Pfizer.
Synopsis: The neuronal activation that triggers migraine headaches produces more than just head and face pain. Symptoms of disordered visual processing, disequilibrium, and delayed gastric emptying occur in migraine patients as either a headache accompaniment or as a separate symptom.
Sources: Vincent MB, Hadjikhani N. Migraine aura and related phenomena: beyond scotomata and scintillations. Cephalagia 2007;27:1368-1377; Vukovíc V, Plavec D, Galinovíc I, et al. Prevalence of vertigo, dizziness, and migrainous vertigo in patients with migraine. Headache 2007;47:1427-1435; Aurora S, Kori S, Barrodale P, et al. Gastric stasis occurs in spontaneous, visually induced, and interictal migraine. Headache 2007;47:1443-1446.
As questioning of migraine patients reveals, a migraine is much more than just pain. It is a complex constellation of complaints that is often presaged by premonitory symptoms; segueing into an aura; evolving into head, face, and neck pain and its many accompanying symptoms; and finishing with symptoms of fatigue or euphoria. Migraine accompaniments mirror the gamut of neurologic complaints, with some symptoms more easily recognized than others. Migraine patients also are more susceptible to their environments, even in between painful attacks, and often report interictal sensitivity to bright lights, strong scents, and the motion of cars and boats. These three papers reveal myriad of neurological and systemic symptoms that vulnerable migraine patients learn to recognize as part of their disorder.
The most frequent migraine aura is visual, consistent with underlying spreading depression that is initiated in the occipital cortex. While the most common visual auras are bright flashes of light or expanding, zigzagging horseshoes with loss of vision, Vincent and Hadjikhani describe subtler visual symptoms related to colors and complex visual phenomena. More than one-half of their patients with migraine, who responded to an e-mail questionnaire, reported abnormalities discerning faces and colors, language and memory abnormalities, irritability, or sleep disturbances that generally were related to the migraine attack or persisted interictally. While the symptoms were more common in patients with migraine with aura, these symptoms, especially cognitive complaints, also occurred in patients who did not have migraine aura. Visual symptoms included prosopagnosia, dyschromatopsia, and visual agnosia, which were manifested as disturbances of visual naming, stimulus appreciation, or meaning attribution. The authors hypothesize a variable clinical expression threshold that determines how spreading depression, which begins in occipital regions and expands into visual association areas, translates into different visual processing symptoms in migraine patients.
Complaints of dizziness, disequilibrium, and motion intolerance, while noted in the general population, are significantly more common in migraine patients. Episodic vertigo, not associated with headache, frequently occurs in patients who also have migraine headaches. Vukovíc and associates compared the retrospective prevalence of dizziness and vertigo in predominantly female migraine patients (327) and non-headache controls (324). The lifetime prevalence of a sense of vertigo or dizziness was 51.7% in migraine patients, as compared to 31.5% in the controls (p<0.0001). Almost one-fourth of migraine patients had migrainous vertigo, which was defined as episodic vestibular symptoms accompanied by migraine head pain or its accompanying symptoms. Dizziness and vertigo as migraine accompanying symptoms were associated with migraine with aura, more than migraine without aura.
Impaired gastric motility during a migraine attack is associated with the migraine's characteristic nausea and vomiting, and gastric stasis leads to decreased absorption of oral acute migraine medications. Aurora and colleagues showed previously that delayed gastric emptying, present during a migraine attack, also occurs between migraine attacks and during induced migraine attacks triggered by an alternating black and white checkerboard pattern. The authors performed gastric emptying studies on three patients during spontaneous migraine, visually induced migraine, and between migraine attacks. Using two different techniques, time to half emptying was delayed during spontaneous migraine, induced migraine, and between migraine, as compared to normative values. However, the results were variable, as one older patient did not show delay during any testing, and a delay in emptying was found during spontaneous migraine in only one patient. Since the patients were tested at a mean interval of almost 7 hours after the onset of a spontaneous migraine, as opposed to almost immediately after an induced migraine, time from onset of migraine symptoms may affect gastric stasis. Other factors such as age and concomitant medication use may factor into the correlation of gastric stasis with migraine.
Migraine phenomenology reveals a disorder that expands beyond the pain and its usual accompanying symptoms. Patients with migraine may experience a multitude of symptoms that are both associated with and distinct from the headache. The variety of migraine-associated visual phenomena indicates an involvement of cortical spreading depression beyond its initiation in the occipital cortex, migrating into neighboring areas subserving cognitive interpretation of visual symptoms. The clear association between migraine and vertigo and dizziness is not easily explained, with vascular, cerebellar, and hypotensive mechanisms proposed. Studies of gastric dysfunction during and distinct from migraine headaches provides evidence of autonomic dysfunction in a subset of migraine patients; this correlates with the crucial role of the hypothalamus in triggering primary headaches, including migraine. What is clear is that migraine is much more than a disorder of blood vessel diameter. Migraine is a neuronal, as distinct from a vascular, disorder that involves many separate but connected areas of the brain. We need to recognize the many different symptoms experienced by migraine patients to help them with a disorder that extends beyond their headache.