Migraine is a neurological disorder characterized by recurrent, severe headaches and associated symptoms like light and sound sensitivity. A specific subtype, historically known as basilar migraine, is now formally classified as Migraine with Brainstem Aura (MBA). This condition presents with temporary neurological symptoms originating from the brainstem, making accurate information and proper management essential.
Defining Basilar Migraine
The term “basilar migraine” is an older name for what is now known as Migraine with Brainstem Aura (MBA). The original name was based on the mistaken belief that symptoms were caused by a temporary spasm of the basilar artery. Modern research recognizes the aura as a neural phenomenon involving temporary dysfunction in the brainstem region. This clarifies that the condition is not a stroke or a blood flow issue, but a complex electrical disturbance.
MBA is defined by a migraine headache preceded or accompanied by a reversible aura featuring at least two symptoms localized to the brainstem. The aura phase typically develops gradually over five minutes or more. The headache phase, if it occurs, commonly follows the aura symptoms, often presenting as severe, throbbing pain. The entire aura episode is fully reversible, which distinguishes it from more dangerous neurological events.
Key Symptoms of Brainstem Aura
Brainstem aura symptoms are distinct from the visual disturbances of typical migraine aura, reflecting temporary disruption of brainstem function. Diagnosis of MBA requires at least two specific symptoms localized to the brainstem. Importantly, these neurological symptoms must not include motor weakness, which suggests a different condition called hemiplegic migraine.
A hallmark symptom is vertigo, an intense sensation of spinning or whirling, not simply lightheadedness. Patients frequently experience tinnitus (ringing in the ears), sometimes accompanied by temporary hypacusis (impaired hearing). Difficulty with coordination, known as ataxia, is also common, leading to unsteady walking or loss of balance.
Other manifestations include diplopia (double vision) and dysarthria (slurred speech). Patients may also experience bilateral sensory symptoms, such as tingling or numbness affecting both sides of the body. A decreased level of consciousness, manifesting as confusion or reduced alertness, is another possible symptom. Each individual symptom lasts between five and sixty minutes before resolving completely.
Underlying Causes and Common Triggers
MBA, like other migraines, is a complex genetic disorder influenced by environmental factors. The underlying mechanism involves neurological hypersensitivity, where nerve cells in the brainstem become easily excited, leading to temporary aura symptoms. While a single cause is unknown, a genetic predisposition is suspected, and the condition sometimes runs in families.
Various external and internal factors act as common triggers. Emotional and physical stress are frequent precipitants that initiate the aura. Hormonal fluctuations, especially those related to the menstrual cycle in women, also increase the risk of an episode.
Lifestyle factors play a substantial role in managing attack frequency. Inadequate sleep, skipping meals, and specific dietary components can all be triggers. Dietary irritants may include aged cheeses, foods containing nitrites, or excessive consumption or withdrawal of caffeine. Changes in weather or barometric pressure are external environmental factors that can also prompt an attack.
Diagnosis and Management Strategies
Diagnosis of MBA is primarily clinical, relying on a detailed patient history and precise description of aura symptoms. Because symptoms closely resemble those of a stroke or transient ischemic attack, the diagnostic process involves ruling out these more serious cerebrovascular conditions. This differential diagnosis is paramount for patient safety and correct treatment.
To exclude conditions like stroke, a physician may recommend neuroimaging studies, such as an MRI or MRA, to visualize the brain and its blood vessels. These tests eliminate other potential causes of the severe neurological symptoms, rather than confirming the migraine diagnosis itself. An electroencephalogram (EEG) may also be performed to rule out seizure disorders that can present with similar confusion.
Management of MBA is divided into treating acute attacks and implementing preventive measures. For acute treatment, nonsteroidal anti-inflammatory drugs (NSAIDs) and antiemetic medications to control nausea are often used. Traditional migraine-specific drugs like triptans have historically been used with caution due to the initial concern about basilar artery spasm. Newer acute treatments, such as CGRP receptor antagonists, may be an alternative.
Preventative strategies focus on daily medications to stabilize the nervous system and decrease brain excitability. Commonly prescribed options include anti-seizure medications (topiramate and lamotrigine) and calcium channel blockers (verapamil). Beta-blockers are sometimes used, but with greater caution in MBA patients. Lifestyle modifications, including consistent sleep hygiene and avoidance of personal triggers, are a fundamental part of the long-term management plan.