Definition and Overview
Migraine with aura is a subtype of migraine characterized by transient focal neurological symptoms that typically precede or accompany the headache phase. It accounts for 25-30% of all migraine and is caused by cortical spreading depression (CSD), a wave of neuronal depolarization followed by suppression that propagates across the cerebral cortex [1].
Types of Aura
Visual Aura
The most common type (90% of auras). Manifestations include scintillating scotoma (flickering zigzag lines), fortification spectra (expanding arc of shimmering lights), and hemianopic visual field defects. Symptoms typically develop over 5-20 minutes and last 5-60 minutes [2].
Sensory Aura
Occurs in 30-40% of aura patients. Typically starts as tingling in the hand, gradually spreading up the arm to the face and tongue (cheiro-oral distribution), following the cortical homunculus. Duration 5-60 minutes.
Speech/Language Aura
Occurs in 10-20%. Dysphasic symptoms include difficulty finding words, paraphasic errors, and rarely complete aphasia. Must be distinguished from stroke.
Rare Auras
Hemiplegic migraine involves motor weakness; retinal migraine causes monocular visual symptoms. Brainstem aura produces vertigo, dysarthria, tinnitus, and decreased consciousness [3].
Pathophysiology
Cortical spreading depression (CSD) is a slowly propagating wave (2-5 mm/min) of neuronal and glial depolarization followed by sustained suppression of neural activity [4]. CSD activates trigeminal afferents, triggering the headache phase. The rate of CSD propagation matches the gradual march of visual and sensory aura symptoms.
Stroke Risk
Migraine with aura doubles the risk of ischemic stroke (relative risk 2.0-2.5). Risk is highest in women under 45 who smoke and use estrogen-containing contraceptives (8-10 fold increased risk) [5]. Combined oral contraceptives are contraindicated in migraine with aura.
Treatment
Acute treatment is similar to migraine without aura. Triptans should be taken at the onset of headache (not during aura). For patients with prolonged or troublesome aura, intranasal ketamine has shown some benefit.
Preventive therapy follows standard migraine prevention guidelines. Lamotrigine may specifically reduce aura frequency. Cardiovascular risk modification (smoking cessation, avoiding estrogen-containing contraceptives) is essential.