Hemiplegic Migraine: Clinical Symptoms and Presentation
Hemiplegic migraine is characterized by transient motor weakness (hemiparesis or hemiplegia) during attacks, accompanied by typical migraine aura symptoms including visual disturbances, sensory changes, and speech impairment, with motor symptoms typically lasting less than 72 hours. 1, 2
Core Motor Symptoms
- Reversible motor weakness affecting one side of the body is the defining feature, distinguishing hemiplegic migraine from other migraine subtypes 1, 2
- Motor symptoms usually resolve within 72 hours, though prolonged attacks can occur 1, 2
- In severe cases, motor weakness can progress to complete hemiplegia 1
Associated Aura Symptoms
Visual manifestations occur commonly and include:
- Bright scintillating lights, zigzag lines, or scotomas (blind spots) 3
- Visual disturbances that spread gradually over 5-20 minutes 3
- In rare severe cases, irreversible visual impairment can develop 4
Sensory symptoms affect approximately 31% of patients with aura:
- Unilateral paresthesia and numbness, typically spreading gradually in the face or arm 3
- Sensory changes that predominantly affect one side 3
Speech and language impairment including:
- Aphasic speech disturbance 5
- Speech difficulties that develop gradually alongside other aura symptoms 2
Brainstem and Consciousness Symptoms
- Impaired consciousness or decreased level of consciousness during severe attacks 1, 2
- Brainstem aura symptoms including dysarthria and vertigo 5
- In severe cases, seizures may accompany attacks, particularly in patients with CACNA1A mutations 6
Headache Characteristics
- Headache typically follows the aura phase but can occur simultaneously 3
- Moderate to severe pain intensity 5
- Pulsating quality 5
- Associated with nausea and/or vomiting 5
- Photophobia (light sensitivity) and phonophobia (sound sensitivity) 5, 3
Additional Neurological Features
Cerebellar manifestations may include:
- Episodes of gait or limb ataxia 7
- Progressive cerebellar atrophy in severe cases with repeated attacks 6
Movement disorders can occur as part of the clinical spectrum 7
Critical Warning Signs
Loss of consciousness is a recognized feature of hemiplegic migraine (unlike typical migraine where it should prompt alternative diagnosis), particularly in severe attacks 1, 2
Prolonged attacks lasting beyond typical duration warrant urgent evaluation:
- Persistent vasodilation and hyperperfusion in the affected hemisphere can occur 4
- Risk of permanent neurological deficit with cortical necrosis in rare severe cases 4
- Brain atrophy may develop following repeated severe attacks, particularly in pediatric patients 6
Genetic Subtype Considerations
Patients with identified mutations (CACNA1A, ATP1A2, or SCN1A) may present with:
- More complex and disabling phenotype developing earlier in life 7
- Additional comorbidities including epilepsy beyond the ictal period 7
- Chronic ataxia between attacks 1
- Intellectual disability in some cases 2
Common Pitfall
Do not dismiss persistent neurological symptoms as benign - while aura symptoms typically resolve completely, severe or prolonged hemiplegic migraine attacks can result in permanent deficits and structural brain changes 6, 4. Patients with frequent severe attacks may require aggressive prophylactic treatment to prevent permanent brain damage 6.