Hemiplegic Migraine: Symptoms, Types, and How It Differs from Stroke

What Is Hemiplegic Migraine?

Hemiplegic migraine is one of the most dramatic and frightening forms of migraine. During an attack, patients develop temporary weakness or even complete paralysis on one side of the body (hemiplegia), along with other aura symptoms such as visual disturbances, sensory changes, and speech difficulties. These motor symptoms develop gradually over minutes and typically precede or accompany a severe headache [1].

The condition is rare, with an estimated prevalence of about 0.01 percent in the general population [2]. Because the symptoms so closely resemble those of a stroke or transient ischemic attack (TIA), a first episode of hemiplegic migraine almost always results in an emergency room visit, and rightly so. Distinguishing hemiplegic migraine from stroke requires careful clinical evaluation and often neuroimaging.

Symptoms of Hemiplegic Migraine

The hallmark of hemiplegic migraine is the motor aura: weakness affecting one side of the body. This weakness can range from mild clumsiness and heaviness in the hand or arm to complete inability to move the affected limbs [1]. The motor symptoms are always accompanied by at least one other type of aura.

Motor Symptoms

The weakness typically begins in the hand or arm and may spread to involve the leg and face on the same side. Patients often describe a progressive heaviness, as if the limb is “not cooperating” or “feels like dead weight.” True paralysis (complete inability to move) occurs in some cases, which is why the condition is named “hemiplegic,” derived from the Greek for “half-paralyzed” [1].

Motor symptoms usually develop gradually over 20 to 30 minutes, which helps distinguish them from stroke (where weakness typically appears suddenly). However, the onset can sometimes be more rapid, blurring this clinical distinction [3].

Visual Aura

Most hemiplegic migraine attacks include visual aura symptoms similar to those in typical migraine with aura: zigzag lines (fortification spectra), blind spots (scotomas), shimmering lights, or partial visual field loss. These visual symptoms often appear before the motor weakness develops [1].

Sensory Symptoms

Tingling, numbness, or pins-and-needles sensations frequently accompany the motor weakness. These sensory disturbances often follow a “march” pattern, starting in the fingertips and progressing up the arm to the face and tongue over several minutes [4]. This gradual progression reflects the slow wave of cortical spreading depression moving across the somatosensory cortex.

Speech and Language Disturbances

Dysphasia (difficulty producing or understanding speech) occurs in many hemiplegic migraine attacks. Patients may have trouble finding words, slur their speech, or temporarily lose the ability to speak coherently [1]. This symptom is particularly alarming because speech difficulty is a classic stroke warning sign.

Other Possible Symptoms

In severe cases, hemiplegic migraine can cause confusion, disorientation, impaired consciousness, and even fever [5]. Rare but documented complications include prolonged aura lasting days to weeks, and in exceptional cases, cerebral edema or coma. These severe presentations are more commonly associated with specific FHM1 mutations [5].

How Long Do Symptoms Last?

The motor weakness phase of hemiplegic migraine typically lasts between 20 minutes and 72 hours [1]. In most patients, motor symptoms resolve within 24 hours. However, the ICHD-3 criteria note that motor aura can persist for up to 72 hours, and some patients report residual weakness or heaviness for days beyond that [1].

The headache that follows the aura phase can last 4 to 72 hours, consistent with typical migraine. In some patients, the headache begins during the aura rather than after it resolves. Rarely, patients experience hemiplegic aura without any headache at all [4].

Types of Hemiplegic Migraine

Familial Hemiplegic Migraine (FHM)

Familial hemiplegic migraine is diagnosed when a patient has hemiplegic migraine and at least one first- or second-degree relative also has the condition. It follows an autosomal dominant inheritance pattern, meaning a child of an affected parent has a 50 percent chance of inheriting the gene mutation [6].

Three genetic subtypes of FHM have been identified, each involving mutations in genes that encode ion channel or transporter proteins critical for normal neuronal signaling:

• FHM1 (CACNA1A gene): Located on chromosome 19, this gene encodes the alpha-1 subunit of a P/Q-type voltage-gated calcium channel. FHM1 mutations cause excessive glutamate release, lowering the threshold for cortical spreading depression. This is the most common and often most severe subtype, sometimes associated with cerebellar ataxia, nystagmus, and in rare cases, coma triggered by minor head trauma [6]
• FHM2 (ATP1A2 gene): Located on chromosome 1, this gene encodes the alpha-2 subunit of a sodium-potassium ATPase pump. Mutations impair the glial cell’s ability to clear potassium and glutamate from the synaptic space, facilitating cortical spreading depression [7]
• FHM3 (SCN1A gene): Located on chromosome 2, this gene encodes the alpha-1 subunit of a voltage-gated sodium channel. It is the rarest FHM subtype. Interestingly, mutations in this same gene also cause certain forms of epilepsy, highlighting the shared pathophysiology between migraine and seizure disorders [7]

Sporadic Hemiplegic Migraine (SHM)

Sporadic hemiplegic migraine is clinically identical to FHM but occurs in patients without a family history of hemiplegic migraine. It may result from de novo (new) mutations in the same genes associated with FHM, mutations in as-yet-unidentified genes, or multifactorial causes [8]. Some studies suggest that SHM may actually be more common than FHM, since many patients with the condition may not have relatives who have been formally diagnosed [2].

The clinical presentation, treatment approach, and prognosis for SHM are generally the same as for FHM, though on average, SHM may have a slightly later age of onset [8].

How Doctors Distinguish Hemiplegic Migraine from Stroke

This differential diagnosis is one of the most critical in neurology. Getting it wrong in either direction, treating a stroke as a migraine and missing the treatment window, or subjecting a migraine patient to unnecessary interventions, carries serious consequences [9].

Key Distinguishing Features

• Onset pattern: Hemiplegic migraine symptoms typically evolve gradually over minutes, while stroke symptoms appear suddenly (seconds to minutes) [9]
• Symptom progression: Migraine aura often involves a “march” of symptoms, with visual changes progressing to sensory symptoms and then to motor weakness in sequence. Stroke symptoms tend to appear simultaneously [4]
• Age and history: A young patient with a history of migraines presenting with familiar symptoms is more likely to have hemiplegic migraine. An older patient with cardiovascular risk factors presenting with sudden-onset weakness is more concerning for stroke [9]
• Headache: A severe headache accompanying the neurological symptoms is more consistent with hemiplegic migraine, though stroke can also cause headache, particularly hemorrhagic stroke
• Complete resolution: Hemiplegic migraine symptoms eventually resolve completely (though this takes hours to days). Stroke deficits may be permanent without treatment

Diagnostic Workup

When a patient presents with first-time hemiplegic symptoms, the standard workup includes [9]:

• Brain CT (non-contrast): Performed immediately to rule out hemorrhagic stroke
• Brain MRI with diffusion-weighted imaging (DWI): The most sensitive test for ischemic stroke. In hemiplegic migraine, MRI is typically normal, though transient diffusion changes have been reported in rare cases [10]
• CT or MR angiography: To evaluate for large vessel occlusion or dissection
• Blood work: To assess for metabolic causes and coagulation abnormalities
• Genetic testing: May be pursued after the acute episode, particularly if there is a family history or if the patient is young. Testing for CACNA1A, ATP1A2, and SCN1A mutations can confirm FHM [6]

The critical point is that during a first episode, you should always seek emergency medical evaluation. Even experienced neurologists cannot reliably distinguish hemiplegic migraine from stroke based on clinical presentation alone. The safe approach is to rule out stroke first and diagnose hemiplegic migraine after the fact [9].

Treatment of Hemiplegic Migraine

Treating hemiplegic migraine presents unique challenges because some standard migraine medications are traditionally avoided in this condition.

Acute Treatment

The conventional teaching has been to avoid triptans and ergotamines in hemiplegic migraine because of their vasoconstrictive properties and theoretical concern that vasoconstriction could worsen the motor symptoms or increase stroke risk [11]. However, this recommendation is based largely on theoretical reasoning rather than documented adverse events. A growing number of headache specialists have begun to question this blanket prohibition, noting that triptans have been used in some hemiplegic migraine patients without adverse outcomes [11].

Medications generally considered safe for acute treatment include:

• NSAIDs: Ibuprofen, naproxen, or ketorolac (injectable) for pain relief
• Antiemetics: Metoclopramide or prochlorperazine for nausea and their independent antimigraine effects
• Gepants: CGRP receptor antagonists like ubrogepant or rimegepant do not cause vasoconstriction, making them a promising option, though specific data in hemiplegic migraine are limited [12]
• Intranasal ketamine: Has shown benefit in prolonged hemiplegic migraine aura in case reports by blocking NMDA receptors involved in cortical spreading depression [13]

Preventive Treatment

When hemiplegic migraine attacks are frequent or severely disabling, preventive treatment is strongly recommended. Options include:

• Verapamil: A calcium channel blocker often considered first-line for FHM prevention, particularly FHM1 (CACNA1A mutations), given the calcium channel pathophysiology. Doses of 240 to 480 mg daily are typically used [11]
• Lamotrigine: This anticonvulsant has shown effectiveness for reducing migraine aura frequency and intensity, making it a logical choice for hemiplegic migraine. It may be particularly helpful for reducing the duration of motor symptoms [14]
• Acetazolamide: A carbonic anhydrase inhibitor sometimes used for FHM1, particularly when cerebellar symptoms are present [11]
• Flunarizine: A calcium channel blocker widely used for migraine prevention in Europe and Asia, with evidence supporting its use in hemiplegic migraine (not available in the United States) [11]
• CGRP monoclonal antibodies: While not specifically studied in hemiplegic migraine, case reports and small series have described successful use of erenumab and fremanezumab in patients with hemiplegic migraine who failed other preventives [12]

Beta-blockers, while commonly used for other migraine types, are generally considered less ideal for hemiplegic migraine, though evidence for avoiding them is limited [11].

Triggers and Lifestyle Considerations

Hemiplegic migraine shares many triggers with other migraine types, including stress, sleep disruption, hormonal changes, and certain foods. A few triggers deserve special mention in this context [5]:

• Head trauma: Even minor head injuries can trigger severe hemiplegic migraine episodes, particularly in patients with FHM1 (CACNA1A) mutations. Some of these patients develop prolonged episodes with confusion, fever, and coma after head trauma [5]. Contact sports may need to be avoided.
• Cerebral angiography: Catheter-based cerebral angiography has been reported to trigger hemiplegic migraine attacks and is generally avoided when possible in these patients [11]
• Emotional stress: Strong emotional reactions can precipitate episodes, and stress management strategies are an important part of the overall management plan

Prognosis and Long-Term Outlook

The overall prognosis for hemiplegic migraine is generally favorable. Most patients experience complete recovery between attacks with no permanent neurological damage [4]. Attack frequency varies widely, from several times per month to once every few years. Some patients find that attacks become less frequent and less severe with age, particularly after middle age [2].

However, certain complications can occur in a minority of patients [5]:

• Cerebellar atrophy: Progressive cerebellar degeneration can develop in some FHM1 patients, leading to permanent balance and coordination problems independent of migraine attacks
• Prolonged aura: Some attacks can involve motor weakness lasting weeks, which can be profoundly disabling even if temporary
• Cognitive effects: A small subset of patients reports subtle cognitive difficulties between attacks, though whether this reflects the disease itself or the impact of frequent severe episodes remains unclear

For families with known FHM mutations, genetic counseling can help parents understand the inheritance pattern and risks for future children. Prenatal or preconception genetic testing is available for the known FHM genes [6].

Living with Hemiplegic Migraine

Because hemiplegic migraine is rare, many patients find it helpful to carry a medical identification card or wear a medical alert bracelet explaining their condition. This is especially valuable in emergency situations where the patient may be unable to communicate and could otherwise be misdiagnosed with stroke, leading to inappropriate treatment with thrombolytics [9].

Working with a neurologist who has experience with hemiplegic migraine, ideally at a headache center, ensures access to the most current treatment approaches and proper monitoring. Connecting with patient advocacy organizations and online support communities can also provide practical advice and emotional support for living with this challenging condition.

Related Reading

• Migraine: Complete Guide
• Understanding Migraine Aura
• Migraine Medication Guide
• Ocular Migraine

References

1. Headache Classification Committee of the International Headache Society. “The International Classification of Headache Disorders, 3rd edition.” Cephalalgia. 2018;38(1):1-211. doi:10.1177/0333102417738202
2. Thomsen LL, Eriksen MK, Roemer SF, et al. “A population-based study of familial hemiplegic migraine suggests revised diagnostic criteria.” Brain. 2002;125(Pt 6):1379-1391. doi:10.1093/brain/awf132
3. Russell MB, Ducros A. “Sporadic and familial hemiplegic migraine: pathophysiological mechanisms, clinical characteristics, diagnosis, and management.” Lancet Neurology. 2011;10(5):457-470. doi:10.1016/S1474-4422(11)70048-5
4. Hansen JM, Hauge AW, Ashina M, Olesen J. “Motor cortex stimulability is changed in migraine with aura: a study using transcranial magnetic stimulation.” Cephalalgia. 2008;28(suppl 1):83-88.
5. Ducros A, Denier C, Joutel A, et al. “The clinical spectrum of familial hemiplegic migraine associated with mutations in a neuronal calcium channel.” New England Journal of Medicine. 2001;345(1):17-24. doi:10.1056/NEJM200107053450103
6. Ophoff RA, Terwindt GM, Vergouwe MN, et al. “Familial hemiplegic migraine and episodic ataxia type-2 are caused by mutations in the Ca2+ channel gene CACNL1A4.” Cell. 1996;87(3):543-552. doi:10.1016/S0092-8674(00)81373-2
7. De Fusco M, Marconi R, Silvestri L, et al. “Haploinsufficiency of ATP1A2 encoding the Na+/K+ pump alpha2 subunit associated with familial hemiplegic migraine type 2.” Nature Genetics. 2003;33(2):192-196. doi:10.1038/ng1081
8. Thomsen LL, Ostergaard E, Olesen J, Russell MB. “Evidence for a separate type of migraine with aura: sporadic hemiplegic migraine.” Neurology. 2003;60(4):595-601. doi:10.1212/01.WNL.0000046524.25369.7D
9. Varga JB, Engelsen BA, Bernstein RA. “Hemiplegic migraine and stroke: diagnostic challenges and management considerations.” Current Pain and Headache Reports. 2017;21(3):16. doi:10.1007/s11916-017-0617-2
10. Butteriss DJ, Ramesh V, Birchall D. “Serial MRI in a case of familial hemiplegic migraine.” Neuroradiology. 2003;45(5):300-303. doi:10.1007/s00234-003-0972-4
11. Di Stefano V, Rispoli MG, Pellegrino N, et al. “Diagnostic and therapeutic aspects of hemiplegic migraine.” Journal of Neurology, Neurosurgery and Psychiatry. 2020;91(7):764-771. doi:10.1136/jnnp-2020-322850
12. Ashina M, Saper J, Cady R, et al. “Eptinezumab in episodic migraine: a randomized, double-blind, placebo-controlled study (PROMISE-1).” Cephalalgia. 2020;40(3):241-254. doi:10.1177/0333102420905132
13. Kaube H, Herzog J, Kaufer T, et al. “Aura in some patients with familial hemiplegic migraine can be stopped by intranasal ketamine.” Neurology. 2000;55(1):139-141. doi:10.1212/WNL.55.1.139
14. Lampl C, Katsarava Z, Diener HC, Limmroth V. “Lamotrigine reduces migraine aura and migraine attacks in patients with migraine with aura.” Journal of Neurology, Neurosurgery and Psychiatry. 2005;76(12):1730-1732. doi:10.1136/jnnp.2005.063750