The history is the most important tool in differentiating between migraine without aura and epilepsy.59 Migraine and epilepsy have many symptoms in common Table: Common Symptoms of Migraine and Epilepsy but certain features are useful in distinguishing them:
|Consciousness||Usually clear||Usually clouded|
|Aura||Usually visual, present in 20%||Variable|
|Family history||Often positive for migraine||Sometimes positive for epilepsy|
|EEG||Nonspecific abnormalities||Spikes and sharp waves|
In general, attacks of migraine are of more gradual onset and longer duration than epileptic seizures. Nausea and vomiting are more commonly associated with migraine. Prolonged confusion or lethargy after the attack favors epilepsy.
When tonic or clonic movements are absent, differentiating migraine with aura from epilepsy can be difficult. The characteristics of the aura may help (see Table: Prodrome and aura in migraine and epilepsy ).73 For instance, the aura usually lasts longer than 5 minutes in migraine and less than 5 minutes in epilepsy (usually less than 1 minute).4 In addition, the aura symptom profiles differ. Automatism, positive motor features, and alteration of consciousness favor an epileptic aura. A mix of positive and negative features, such as a scintillating scotoma, favors migraine.74
The characteristics of the elementary visual hallucinations often differ as well. Colorless glittering scotomata are typical of migraine, as are black-and-white zigzag patterns (also termed fortification lines) that appear concentrically around the point of fixation, usually unilaterally. The phenomenon of a geometric pattern with expansion from the center to the periphery of the visual field (rarely in the reverse direction) and a simultaneous increase in size over a period of several minutes reflects migrainous cortical impulse propagation. The regular angular patterns in the photopsias that accompany migraine correspond to the cortical structures that generate them.75–77 Photopsias in migraine may evolve into a scotoma or a temporary homonymous hemianopia. Resolution of the visual field defect typically occurs without any positive visual phenomena. Colors may be seen as well, or spots, circles, and beads, with or without colors. When these occur, they are usually part of the scintillating scotoma or teichopsia and not a predominant independent feature of the migrainous visual hallucination.
In contrast, visual auras in epilepsy are predominantly multicolored, with a circular or spherical pattern, as opposed to the predominantly black-and-white zigzag pattern of migraine.78 During a seizure, hallucinations that begin unilaterally may later encompass the whole visual field, and simple hallucinations may develop into complex forms. In contrast to migraine, epileptic visual auras last for only seconds (with the rare exception of persistent visual auras),79 thus limiting the patient’s opportunity to observe and describe the hallucinations. The auras are often associated with head or eye movement and alteration of consciousness.
The sensory auras of migraine and epilepsy also differ. In migraine, the auras are paresthesias (pins and needles) that typically begin in the hand, move up the arm, skip the shoulder, and move into the face and tongue over a period of 10 to 15 minutes. They are often associated with a visual aura.54 The sensory aura in epilepsy is typically briefer and is often described as burning, cramping, stinging, aching, electric, or throbbing.
Correctly diagnosing and separating epilepsy and migraine can be more difficult in children than in adults. Young children often give only a partial description of their symptoms, and features useful in diagnosing epilepsy or migraine in adults may not be present or may be difficult to elicit in children. In children with migraine, hemicranial pain and visual auras occur less often than in adults. The first symptoms of migraine may not even be associated with headaches.80 Children are also less likely to experience or report feelings of déjà vu or have olfactory hallucinations as part of a simple partial seizure or temporal lobe epilepsy.
Reviewed and revised April 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.
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