Hemiplegic Migraine: Symptoms, Types, Causes and Treatment

Hemiplegic migraine (HM) is a rare and complex neurological disorder that stands apart from typical migraine types, largely due to its dramatic and sometimes alarming symptoms. Though infrequent, understanding hemiplegic migraine is essential for patients, families, and clinicians, as its presentation can mimic other serious neurological conditions such as stroke. In this comprehensive article, we’ll explore the key symptoms, the main types of HM, what causes it, and current approaches to treatment—providing an accessible, evidence-based guide for anyone seeking to better understand this unique migraine variant.

Symptoms of Hemiplegic Migraine

Hemiplegic migraine is notorious for its striking, often frightening symptoms that go well beyond the typical visual auras or throbbing pain associated with standard migraines. The hallmark feature is temporary weakness or paralysis (hemiparesis) on one side of the body, but this is just the beginning. Recognizing the full spectrum of symptoms is crucial for early identification and proper care.

Symptom	Description	Typical Duration	Source(s)
Hemiparesis	Weakness/paralysis on one side of the body	Minutes to <72 hours	1 3 4 5 6
Visual Aura	Visual disturbances (flashing lights, blind spots)	Often prolonged (compared to typical migraine)	1 2 3 4
Sensory Aura	Numbness, tingling, or altered sensation	Often prolonged	1 2 3 4
Aphasia	Speech or language difficulties	Variable	1 2 4
Headache	Severe, often follows aura	Can be prolonged (> typical migraine)	1 2 3 4 5
Other Symptoms	Ataxia, impaired consciousness, epilepsy, transient blindness	Variable	3 4 6

Table 1: Key Symptoms

The Core Features of Hemiplegic Migraine

Hemiplegic migraine attacks often begin with aura symptoms, progressing from visual changes (such as seeing zigzags or flashing lights) to sensory disturbances (numbness, tingling), and then to motor weakness or paralysis on one side of the body—often described as hemiparesis. Speech difficulties (aphasia) are also common, and in severe cases, patients may experience confusion, impaired consciousness, or even coma 1 2 3 4 6.

How Symptoms Progress and Differ from Other Migraines

Unlike typical migraine with aura, where symptoms are usually brief and mostly visual, hemiplegic migraine aura symptoms are more prolonged and can include multiple domains (visual, sensory, language, and motor) during a single attack 1 2. Notably, the motor symptoms (weakness or paralysis) are a defining characteristic and can last from minutes to as long as 72 hours, with full recovery expected in most cases 3 4 5 6.

The typical order of symptom development is:

• Visual aura
• Sensory aura
• Aphasia
• Motor weakness (hemiparesis/paralysis)
• Sometimes, brainstem symptoms (e.g., dizziness, double vision, ataxia) 1 2 4

Other Neurological and Systemic Symptoms

In severe or genetically predisposed cases, additional neurological features may be present:

• Permanent cerebellar signs (nystagmus, ataxia)
• Epileptic seizures
• Transient blindness
• Intellectual disability (especially in familial forms with certain mutations) 3 4 6

The headache phase usually follows the aura and can be severe, throbbing, and longer-lasting than in standard migraines, sometimes persisting even after other symptoms have resolved 1 2 3 4 5.

Types of Hemiplegic Migraine

Not all hemiplegic migraines are the same. The disorder is classified into two main types based on family history and genetics, but there are important clinical overlaps.

Type	Defining Feature	Genetic Basis	Source(s)
Familial HM	At least one first/second-degree relative with similar attacks	Mutations in CACNA1A, ATP1A2, SCN1A, PRRT2, SLC1A3 (variable)	1 3 4 5 6 10 11 12 14
Sporadic HM	No family history of HM	Can have mutations in same genes; often idiopathic	2 3 4 5 14

Table 2: Types of Hemiplegic Migraine

Familial Hemiplegic Migraine (FHM)

FHM is diagnosed when at least one first- or second-degree relative also experiences attacks meeting criteria for HM. FHM is inherited in an autosomal dominant pattern, and several genes have now been implicated—including CACNA1A, ATP1A2, SCN1A, PRRT2, and SLC1A3 1 3 4 5 6 10 11 12 14.

Subtypes of FHM

• FHM with cerebellar signs: Some families, especially those with CACNA1A mutations, also experience permanent symptoms like nystagmus or ataxia.
• Pure FHM: Families with only transient symptoms during attacks, with normal neurological function between episodes 6.

Sporadic Hemiplegic Migraine (SHM)

SHM is diagnosed when a patient has all the clinical features of HM, but without any family history. Genetically, some sporadic cases have mutations in the same genes as familial cases, while others have no identifiable mutation—implying that additional genetic or environmental factors are involved 2 3 4 5 14.

Clinical Similarities and Differences

Both types share virtually identical clinical features during attacks, and genetic testing can sometimes reveal the same underlying mutations in both familial and sporadic forms. The distinction is therefore mainly based on family history, not on symptoms 2 14.

Causes of Hemiplegic Migraine

Understanding what causes hemiplegic migraine involves delving into genetics, brain physiology, and the complex interplay between neuronal and vascular changes. While some causes are well established, research continues to uncover new contributing factors.

Cause Type	Key Details	Notable Genes/Factors	Source(s)
Genetic	Mutations disrupt ion transport and neuronal signaling	CACNA1A, ATP1A2, SCN1A, PRRT2, SLC1A3	3 4 5 6 7 9 10 11 12 14
Pathophysiology	Cortical spreading depression, neuronal hyperexcitability	Altered ion channel function	5 7 8 9
Hormonal	Female predominance, estrogen influence	Estrogen modulates susceptibility	7
Other Factors	Not all cases have known mutations; environmental triggers	Unknown genes, triggers	3 4 5 14

Table 3: Causes and Risk Factors

Genetics: The Foundation of Hemiplegic Migraine

Hemiplegic migraine is the only migraine type with well-established genetic mutations. The main genes implicated encode proteins crucial for ion transport in neurons:

• CACNA1A: Encodes a calcium channel; mutations are linked to both FHM and episodic ataxia. Different mutations can lead to pure FHM or FHM with cerebellar signs 6 10.
• ATP1A2: Encodes a sodium-potassium pump; mutations disrupt neuronal ion balance 5 14.
• SCN1A: Encodes a sodium channel; mutations can cause both FHM and epilepsy, highlighting the overlap between these neurological conditions 9 11.
• PRRT2 and SLC1A3: More recently implicated, particularly in childhood-onset and complex cases 5 12.

Pathophysiology: What Happens in the Brain

The prevailing theory is that genetic mutations make the brain more susceptible to cortical spreading depression—a wave of neuronal and glial cell depolarization that moves across the cortex, temporarily disrupting function and causing aura symptoms (including motor weakness) 5 7 8. Neuronal hyperexcitability, due to altered ion channel function, lowers the threshold for these events, leading to the characteristic attacks 3 5 7.

Hormonal and Environmental Influences

Hemiplegic migraine is more common in females, and research suggests that estrogen and other ovarian hormones may increase susceptibility to attacks, possibly explaining the sex difference in prevalence and severity 7. While genetic mutations set the stage, environmental triggers (such as stress, minor head trauma, or certain foods) may still play a role in precipitating attacks, though these are less well defined than in typical migraine 3 4 5.

The Role of Triggers

Common triggers (as reported anecdotally) can include:

• Emotional stress
• Physical exertion
• Head trauma
• Certain foods or substances

However, many attacks occur spontaneously or with no identifiable trigger 3 4 5.

Mimics and Differential Diagnosis

Because hemiplegic migraine can closely resemble stroke, epilepsy, or other neurological conditions, a careful differential diagnosis is essential—especially in first-time or atypical cases 4 8 15.

Treatment of Hemiplegic Migraine

Managing hemiplegic migraine is challenging due to its rarity, the severity of symptoms, and a lack of large clinical trials. As a result, treatment strategies rely on case studies, physician experience, and adapting protocols from more common migraine types.

Treatment	Approach/Drug	Notes/Precautions	Source(s)
Acute	Acetaminophen, NSAIDs	First-line for pain	14 15
Acute	Triptans	Once controversial; now considered safe/effective in many cases	13 14
Prophylactic	Flunarizine, sodium valproate, lamotrigine, verapamil, acetazolamide	Used to reduce attack frequency	3 4 14 15
Other Prophylaxis	Topiramate, candesartan, pizotifen	Less evidence, may be tried	14
Beta-blockers	Propranolol	Controversial, not contraindicated	14
Supportive	Hospitalization for severe attacks	Especially with prolonged aura or impaired consciousness	4

Table 4: Treatment Approaches

Acute Treatment: Stopping the Attack

• First-line: Acetaminophen and NSAIDs are commonly used for pain relief 14 15.
• Triptans: Previously avoided due to concerns about vasoconstriction and stroke risk, but recent evidence suggests they are safe and effective in many patients without known vascular risk factors 13 14.
• Other options: No specific acute treatment for the aura (especially motor symptoms) is currently available. Supportive care and monitoring are vital during severe attacks 3 4 14.

Preventive (Prophylactic) Therapy

Given the potential for severe and frequent attacks, many patients benefit from preventive medication, especially if attacks are frequent or disabling:

• Calcium channel blockers: Flunarizine, verapamil 3 14 15
• Antiepileptics: Sodium valproate, lamotrigine 3 14
• Carbonic anhydrase inhibitors: Acetazolamide, particularly for patients with cerebellar features or prolonged aura 3 4 14 15
• Other options: Topiramate, candesartan, pizotifen may be considered if other agents fail 14

Special Considerations

• Beta-blockers (e.g., propranolol): Historically controversial, but not absolutely contraindicated; may be tried cautiously 14.
• Hospitalization: For severe attacks with prolonged aura, impaired consciousness, or diagnostic uncertainty, admission and observation are often warranted 4.

The Need for Individualized Care

Because hemiplegic migraine varies widely in severity and presentation, a trial-and-error approach to therapy is often necessary. Treatment plans should be tailored to each patient’s genetic background, frequency and severity of attacks, comorbidities, and preferences 14 15.

Avoiding Harm

• Neuroimaging and diagnostic tests: Used mainly to rule out stroke, epilepsy, or other conditions 4 14.
• Cerebral angiography: Contraindicated, as it can provoke attacks 14.
• Genetic counseling: Recommended for patients with familial forms or those considering family planning 14.

Conclusion

Hemiplegic migraine is a rare but dramatic disorder at the intersection of neurology and genetics, with unique symptoms and challenges. Here’s a summary of the key points:

• Symptoms: Include visual, sensory, and speech auras, but are defined by temporary weakness or paralysis on one side of the body. Attacks may also cause headache, ataxia, or even altered consciousness.
• Types: Two main forms—familial (with a family history and known genetic mutations) and sporadic (no family history, sometimes with mutations).
• Causes: Linked to specific mutations affecting ion channels in the brain, leading to abnormal neuronal signaling and cortical spreading depression. Hormones and environmental triggers may also play a role.
• Treatment: Involves acute pain management (acetaminophen, NSAIDs, triptans), preventive medication (flunarizine, valproate, verapamil, lamotrigine, acetazolamide), and supportive care for severe episodes. Treatment must be individualized, and ongoing research is needed to improve outcomes.

Key Takeaways:

• Hemiplegic migraine is rare but can mimic life-threatening conditions—prompt recognition is essential.
• Genetic testing can assist in diagnosis but does not exclude the disorder if negative.
• Treatment is based on limited evidence and should be tailored to each patient.
• Support and education for patients and families are critical for coping with this challenging migraine subtype.

If you or someone you know experiences symptoms of hemiplegic migraine, seek care from a neurologist familiar with this condition for accurate diagnosis and personalized treatment.