What is basilar or Hellenic migraine?

Basilar Migraine (Migraine with Brainstem Aura)

Basilar migraine, now termed "migraine with brainstem aura," is a subtype of migraine with aura characterized by neurological symptoms originating from the brainstem or both cerebral hemispheres simultaneously, without motor weakness, typically affecting young people and adolescents. 1, 2

Historical Context and Terminology

• The condition was previously called "basilar migraine," "basilar artery migraine," or "basilar-type migraine," but these terms have been replaced because the pathophysiology is now understood to involve neural dysfunction rather than vascular insufficiency in the basilar artery 1, 2
• The term "Hellenic migraine" appears to be a misnomer or confusion with "hemiplegic migraine," which is a distinct entity involving motor weakness 2
• Modern classification systems recognize this as a specific subtype of migraine with aura, distinct from hemiplegic migraine by the absence of motor deficits 3, 4

Diagnostic Criteria

To diagnose migraine with brainstem aura, patients must have at least 2 attacks with specific brainstem symptoms lasting 5-60 minutes, followed by headache within 60 minutes. 1

Required Brainstem Symptoms (at least 2 must be present):

• Dysarthria (slurred speech) 3, 5
• Vertigo (spinning sensation) 3, 5
• Tinnitus (ringing in ears) 3
• Impaired hearing 3
• Diplopia (double vision) 3, 5
• Bilateral visual symptoms (affecting both visual fields simultaneously) 3, 5
• Ataxia (cerebellar-type incoordination) 3, 5
• Decreased level of consciousness 3, 5
• Bilateral paresthesias (numbness/tingling on both sides) 3, 5

Temporal Characteristics:

• Aura symptoms must spread gradually over at least 5 minutes 1
• Each individual aura symptom lasts 5-60 minutes 1
• Two or more aura symptoms typically occur in succession 1
• Headache follows within 60 minutes of aura onset 1

Associated Headache Features:

• Throbbing occipital headache (back of head) is characteristic 5
• Headache typically has unilateral location, pulsating quality, moderate-to-severe intensity, and aggravation by physical activity 1
• Nausea/vomiting and photophobia/phonophobia commonly accompany the headache 1

Epidemiology

• Primarily affects children, adolescents, and young adults, with onset usually before age 25 2, 3
• Female predominance is observed 3
• Considered an uncommon subtype of migraine with aura 2

Pathophysiology

The condition results from neural circuitry dysfunction in brainstem structures or bilateral hemispheric involvement, not from vascular insufficiency as previously believed. 2

• Modern understanding rejects the original vascular theory that attributed symptoms to basilar artery vasospasm 2, 6
• The mechanism involves cortical spreading depression affecting brainstem or bilateral cortical regions 2

Critical Differential Diagnoses

Neuroimaging with brain MRI without contrast is recommended for all patients with suspected migraine with brainstem aura to exclude serious conditions. 2

High-Risk Conditions to Exclude:

• Posterior fossa pathology (tumors, structural lesions) 2, 3
• Brainstem and cerebellar stroke 7, 2
• Transient ischemic attacks (TIAs) in the vertebrobasilar territory 7, 2
• CADASIL syndrome (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) 3
• MELAS syndrome (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) 3
• Complex partial seizures 3
• Multiple sclerosis 7
• Hemiplegic migraine with cerebellar symptoms 3

Key Differentiating Features:

• Unlike TIA, migraine aura symptoms spread gradually over ≥5 minutes rather than having sudden, simultaneous onset 1
• Complete reversibility of symptoms is mandatory; persistent deficits suggest alternative diagnoses 8
• Recurrent episodes with similar patterns support migraine diagnosis 2

Additional Investigations When Indicated:

• Contrasted or vascular imaging (MRA/CTA) if vascular pathology suspected 2
• EEG if seizure disorder considered 2
• Lumbar puncture with CSF analysis if infection or inflammatory conditions suspected 2

Treatment Approach

Prophylactic Management:

• Sodium valproate is effective for prevention but is absolutely contraindicated in women of childbearing potential 1, 3
• Calcium channel blockers (such as verapamil) are recommended 3
• Lamotrigine has shown effectiveness in preventing aura symptoms in basilar-type migraine 4
• Betahistine chloride specifically for prophylaxis of vertigo symptoms 3
• Lifestyle modifications and trigger avoidance are foundational 2

Acute Management Controversy:

• The use of triptans remains controversial in migraine with brainstem aura due to theoretical concerns about vasoconstriction in the posterior circulation, though no data support this as a vasospastic condition 6
• Standard acute migraine treatments following evidence-based guidelines should be considered, with individual risk-benefit assessment 2

Prognosis

The prognosis is generally favorable, with most patients responding to appropriate prophylactic therapy. 2

Common Pitfalls to Avoid:

• Do not dismiss as "just migraine" without neuroimaging on first presentation, given the broad differential diagnosis of brainstem symptoms 2
• Do not confuse with vestibular migraine, which has different diagnostic criteria requiring vestibular symptoms of moderate-to-severe intensity lasting 5 minutes to 72 hours 7
• Do not use the outdated term "basilar migraine" in documentation, as it implies incorrect vascular pathophysiology 2
• Do not overlook the requirement for bilateral or brainstem symptoms—unilateral symptoms suggest typical migraine with aura instead 1