Migraine with brainstem aura.
Migraine with brainstem aura, previously known as basilar-type migraine, is a rare and severe subtype of migraine characterized by neurological symptoms originating from the brainstem or both hemispheres of the brain, but without motor weakness. This form of migraine can be particularly alarming due to its resemblance to other serious neurological conditions, such as stroke. Understanding the symptoms, diagnosis, and management of migraine with brainstem aura is crucial for effective treatment and for reducing the impact of these often debilitating attacks.
1. Understanding Migraine with Brainstem Aura
Definition and Overview
Migraine with brainstem aura is a type of migraine with aura that involves symptoms attributable to dysfunction in the brainstem or the occipital lobes, without the presence of motor weakness. The aura phase precedes or accompanies the headache and includes symptoms such as vertigo, dysarthria (difficulty speaking), tinnitus, double vision, and ataxia (loss of coordination). The symptoms are often bilateral and can be mistaken for more serious conditions like stroke or transient ischemic attack (TIA).
Terminology
The term “migraine with brainstem aura” was introduced to more accurately describe the origin of the aura symptoms and to replace the older term “basilar-type migraine.” The change reflects a better understanding of the neurological pathways involved in this condition.
2. Symptoms of Migraine with Brainstem Aura
Aura Phase Symptoms
The aura phase in migraine with brainstem aura typically lasts between 5 and 60 minutes and includes a combination of the following symptoms:
- Vertigo: A sensation of spinning or movement, which is one of the most common symptoms of migraine with brainstem aura. Vertigo can be severe and disorienting, often making it difficult for the individual to stand or walk.
- Dysarthria: Difficulty speaking or slurred speech due to lack of muscle coordination in the speech apparatus. This symptom can be particularly frightening and is often mistaken for a stroke.
- Tinnitus: Ringing or buzzing in the ears is a common symptom during the aura phase. Tinnitus can be unilateral (in one ear) or bilateral (in both ears).
- Diplopia (Double Vision): Double vision or blurred vision may occur, caused by impaired coordination of the eye muscles or disturbances in visual processing.
- Ataxia: A lack of coordination or unsteady movements can be a prominent symptom, making it difficult to walk or perform tasks requiring fine motor control.
- Bilateral Visual Symptoms: These can include visual disturbances such as flickering lights, spots, or temporary loss of vision in both visual fields.
- Bilateral Paresthesias: Numbness or tingling sensations may occur on both sides of the body, typically affecting the face, arms, or legs.
- Decreased Consciousness: Some individuals may experience a temporary alteration in consciousness, ranging from confusion to drowsiness or even fainting in severe cases.
- Hearing Loss: Temporary hearing loss, usually affecting both ears, can occur during the aura phase.
Headache Phase Symptoms
After the aura phase, the headache typically begins. The headache phase includes:
- Severe, Throbbing Pain: The headache is usually intense, throbbing, and located at the back of the head or around the temples. However, it can also be bilateral or involve the entire head.
- Nausea and Vomiting: These symptoms often accompany the headache and can be quite severe, exacerbating the overall discomfort.
- Photophobia and Phonophobia: Sensitivity to light and sound is common, and these symptoms often compel the individual to seek a dark, quiet environment.
- Prolonged Duration: The headache can last from several hours to days, significantly impairing the individual’s ability to function.
Postdrome Phase Symptoms
After the headache subsides, the postdrome phase, often referred to as the “migraine hangover,” begins. Symptoms during this phase can include:
- Fatigue: Profound tiredness or exhaustion is common, and individuals may feel drained of energy.
- Cognitive Fog: Difficulty concentrating, memory lapses, and a general sense of mental sluggishness may persist.
- Mood Changes: Some individuals may experience irritability, depression, or, conversely, euphoria after the migraine resolves.
- Residual Weakness: Although motor weakness is not a feature of migraine with brainstem aura, some individuals may feel weak or unsteady as they recover.
3. Mechanisms and Pathophysiology
Cortical Spreading Depression (CSD)
Migraine with brainstem aura is thought to involve cortical spreading depression (CSD), a wave of electrical activity that slowly moves across the cortex of the brain. In this condition, CSD is believed to affect the occipital lobes and the brainstem, leading to the complex array of neurological symptoms seen in this type of migraine.
Brainstem Involvement
The brainstem, which controls many basic functions such as consciousness, breathing, and balance, plays a central role in the symptoms of migraine with brainstem aura. Dysfunction in the brainstem during a migraine attack can lead to the bilateral and non-motor symptoms characteristic of this condition.
Genetic Factors
While the exact cause of migraine with brainstem aura is not fully understood, there is evidence to suggest a genetic predisposition. Mutations in genes associated with familial hemiplegic migraine (FHM), such as CACNA1A, ATP1A2, and SCN1A, may also play a role in migraine with brainstem aura, though the relationship is not as well-established.
4. Diagnosis of Migraine with Brainstem Aura
Clinical Evaluation
Diagnosing migraine with brainstem aura involves a thorough clinical evaluation, including:
- Medical History: A detailed history of the individual’s symptoms, including the onset, duration, and nature of aura and headache, is crucial. A history of migraines or a family history of migraines is also relevant.
- Physical and Neurological Examination: A comprehensive neurological exam is necessary to assess coordination, reflexes, speech, and other neurological functions. This helps rule out other serious conditions such as stroke or multiple sclerosis.
Diagnostic Criteria
The International Classification of Headache Disorders (ICHD) provides specific criteria for diagnosing migraine with brainstem aura:
- Aura Symptoms: The aura must include at least two of the following fully reversible symptoms: dysarthria, vertigo, tinnitus, hypacusis (reduced hearing), diplopia, ataxia, or decreased consciousness.
- Progression of Aura: The aura develops gradually over 5 minutes or more, with each symptom lasting between 5 and 60 minutes.
- Headache: The headache occurs during the aura or follows within 60 minutes.
- Exclusion of Other Causes: Other conditions that could explain the symptoms, such as stroke, TIA, or epilepsy, must be ruled out.
Differential Diagnosis
Given the serious nature of the symptoms, it is essential to differentiate migraine with brainstem aura from other conditions that can cause similar symptoms:
- Stroke or TIA: These conditions must be promptly ruled out, especially given the similarity in symptoms such as dysarthria, vertigo, and altered consciousness. A stroke typically has a more abrupt onset and is associated with more persistent neurological deficits.
- Epilepsy: Seizures can mimic migraine with brainstem aura, particularly in cases where altered consciousness or speech difficulties are present. An electroencephalogram (EEG) may be necessary to differentiate between the two.
- Multiple Sclerosis (MS): MS can cause episodes of vertigo, ataxia, and other brainstem-related symptoms. MRI findings and a detailed clinical history help distinguish MS from migraine with brainstem aura.
- Vertebrobasilar Insufficiency: This condition, involving reduced blood flow to the brainstem, can produce symptoms similar to those of migraine with brainstem aura. Imaging studies are typically required to rule out vascular causes.
Diagnostic Tests
- MRI and MRA: Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) are often used to exclude other neurological conditions, such as stroke, tumors, or vascular malformations. These imaging techniques can help ensure that the symptoms are due to migraine rather than another cause.
- EEG: If there is suspicion of seizures, an EEG may be performed to rule out epilepsy or other seizure disorders.
- Blood Tests: Blood tests are generally not specific for diagnosing migraine with brainstem aura, but they may be used to rule out other conditions that could cause similar symptoms.
5. Management and Treatment of Migraine with Brainstem Aura
Acute Treatment
Managing the acute phase of a migraine with brainstem aura involves addressing both the aura and headache symptoms:
- Avoidance of Triptans and Ergotamines: Triptans and ergotamines, which are commonly used for other types of migraines, are generally avoided in migraine with brainstem aura due to concerns about their vasoconstrictive properties, which could theoretically increase the risk of stroke in this patient population.
- Nonsteroidal Anti-Inflammatory Drugs (NSAIDs): NSAIDs like ibuprofen or naproxen can help alleviate the headache pain associated with migraine with brainstem aura.
- Anti-Nausea Medications: Medications such as metoclopramide or ondansetron can be used to manage nausea and vomiting during a migraine attack.
- Benzodiazepines: In cases of severe vertigo or anxiety, benzodiazepines like diazepam may be used to calm the nervous system, though their use is typically limited due to the risk of sedation and dependence.
Preventive Treatment
For individuals with frequent or severe migraine with brainstem aura, preventive treatment is crucial to reduce the frequency and severity of attacks:
- Beta-Blockers: Medications like propranolol are often used to prevent migraines and may help reduce the frequency of brainstem aura symptoms.
- Calcium Channel Blockers: Verapamil is another option for migraine prevention, particularly in individuals who do not tolerate beta-blockers well.
- Antiepileptic Drugs: Medications such as topiramate or valproate can be effective in reducing the frequency of migraine attacks and are often used as preventive treatment.
- Tricyclic Antidepressants: Amitriptyline or nortriptyline may be prescribed for migraine prevention, especially in individuals with comorbid conditions such as depression or anxiety.
- Lifestyle Modifications: Maintaining a regular sleep schedule, eating balanced meals, staying hydrated, and managing stress can all help reduce the frequency of migraine attacks.
6. Prognosis and Complications
Prognosis
The prognosis for individuals with migraine with brainstem aura varies. Some people experience a reduction in the frequency and severity of attacks over time, while others may continue to have disabling migraines throughout their lives. Early diagnosis and effective management are essential for improving outcomes.
Potential Complications
- Chronic Migraine: Some individuals with migraine with brainstem aura may develop chronic migraines, experiencing headaches 15 or more days per month.
- Increased Stroke Risk: Although the link between migraine with brainstem aura and an increased risk of stroke is not well-defined, the symptoms’ severity warrants careful monitoring and management to minimize any potential risk.
- Emotional and Psychological Impact: The chronic nature and severity of symptoms can lead to anxiety, depression, and social isolation, significantly affecting the individual’s quality of life.
7. Living with Migraine with Brainstem Aura
Patient Education and Support
- Education: Understanding the nature of migraine with brainstem aura, its triggers, and the importance of early intervention can empower patients to manage their condition more effectively.
- Support Groups: Joining a support group for migraine sufferers can provide emotional support, practical advice, and a sense of community for those living with this condition.
- Emergency Plan: Given the stroke-like symptoms of migraine with brainstem aura, it is important for patients to have an emergency plan in place, including when to seek immediate medical attention.
Work and Daily Life Adjustments
- Workplace Accommodations: Patients may need to work with their employer to arrange accommodations, such as flexible hours or the ability to work from home during an attack.
- Daily Living Adjustments: Planning activities around potential triggers, such as avoiding bright lights or loud environments, can help reduce the impact of migraine with brainstem aura on daily life.
Conclusion
Migraine with brainstem aura is a rare and complex neurological condition that requires careful diagnosis and management due to its severe and often frightening symptoms. Understanding the symptoms, diagnostic criteria, and treatment options is essential for those affected by this condition. With appropriate medical care, lifestyle adjustments, and support, individuals with migraine with brainstem aura can manage their symptoms effectively and maintain a good quality of life, despite the challenges posed by this serious form of migraine.
