What's hemiplegic migraine?
Hemiplegic migraine is a rare and severe form of migraine with aura whose defining feature is temporary weakness on one side of the body during an attack. The familial form is inherited in an autosomal dominant pattern.
| Also indexed as | ORPHA:569, MONDO:0018925 |
|---|---|
| Features mapped | 12 |
| Treatments mapped | 6 |
| Published sources | 9 |
| Last reviewed | 2026-08-04 |
Signs and symptoms
Diplopia
Double vision (diplopia) can occur during attacks in some people, among the broader range of aura symptoms.
Aphasia
During a hemiplegic migraine attack, speech can be affected as part of the aura, alongside the one-sided weakness. These speech symptoms typically come with the motor aura.
CSF pleocytosis
During severe hemiplegic migraine attacks the spinal fluid can show a rise in white cells (pleocytosis) even though there is no infection. This can make an attack look like meningitis or encephalitis and lead to unnecessary tests if the diagnosis isn't known.
Migraine with aura
Hemiplegic migraine is a subtype of migraine with aura. Visual, sensory, and speech symptoms typically come with the one-sided motor weakness, and a throbbing headache follows.
Decreased vigilance
Severe hemiplegic migraine attacks can reduce alertness and, rarely, cause loss of consciousness, sometimes with seizures and fever. These severe attacks can look like a stroke or brain infection and may need hospital care.
Paresthesia
The aura of hemiplegic migraine usually marches through several symptoms. Sensory changes such as tingling or numbness (paresthesia) commonly spread up a limb or across the face, typically along with visual and speech symptoms before or with the weakness.
Hemiparesis
In hemiplegic migraine, an attack involves temporary weakness on one side of the body that comes on as part of the aura. The weakness is reversible, though in some attacks it can last a long time before recovering.
Progressive gait ataxia
Some people with familial hemiplegic migraine also develop ataxia, meaning problems with balance and coordinated movement. It is described alongside the recurrent migraine and one-sided weakness that characterize the condition.
Hemiplegia
Hemiplegic migraine is named for the one-sided weakness or loss of movement that occurs as an aura symptom during an attack. This weakness is reversible.
Confusion
Severe hemiplegic migraine attacks, particularly the FHM2 form linked to ATP1A2, can cause a confused, encephalopathic state with reduced alertness, sometimes alongside seizures, that can last well beyond a typical migraine.
Vertigo
Some people with hemiplegic migraine have spinning dizziness (vertigo) during attacks, reflecting involvement of the brainstem and the ion-channel changes that drive the disorder. It can occur with double vision and ringing in the ears.
Tinnitus
Ringing or buzzing in the ears (tinnitus) can occur during hemiplegic migraine attacks as part of the brainstem aura symptoms, often alongside vertigo and double vision.
How it is diagnosed
Familial or sporadic hemiplegic migraine
Diagnosed using: ICHD diagnostic criteria.
“According to the diagnostic criteria of International Classification of Headache Disorders (ICHD-3β), 142 patients were diagnosed with…”
Familial or sporadic hemiplegic migraine
Diagnosed using: Genetic testing.
“Familial HM (FHM) is an autosomal dominant condition linked to mutations in CACNA1A, ATP1A2, and SCN1A…”
Familial or sporadic hemiplegic migraine
Diagnosed using: Whole-exome sequencing.
“Genetic testing with whole-exome sequencing (WES) confirmed an ATP1A2 mutation consistent with…”
Treatment and management
What the research describes, not a recommendation. Treatment decisions belong with your clinician.
This covers treatments that appear in the published research mapped here. Investigational and experimental therapies are not included, so their absence is a boundary of this map, not a sign they do not exist.
Verapamil
Verapamil, a calcium-channel blocker, is recommended as a preventive treatment for familial hemiplegic migraine and may also help in the sporadic form.
Used to help with: Familial or sporadic hemiplegic migraine.
“Oral verapamil is recommended for patients with familial hemiplegic migraine and may be effective in patients with sporadic hemiplegic migraine.”
Magnesium sulfate
Intravenous magnesium sulfate can be used to relieve the symptoms of a hemiplegic migraine attack in both the familial and sporadic forms.
Used to help with: Familial or sporadic hemiplegic migraine.
“…magnesium sulfate to relieve the symptoms in familial hemiplegic…”
Fremanezumab
Fremanezumab, an antibody that blocks the CGRP pathway, has been used as a preventive treatment and was followed by a reduced frequency of prolonged sporadic hemiplegic migraine attacks in a reported case.
Used to help with: Familial or sporadic hemiplegic migraine.
“Reduced Frequency of Prolonged Sporadic Hemiplegic Migraine Attacks Following…”
CGRP monoclonal antibodies
Recent evidence suggests that calcitonin gene-related peptide (CGRP)-targeting monoclonal antibodies may help prevent attacks in hemiplegic migraine, where preventive options have been limited.
Used to help with: Familial or sporadic hemiplegic migraine.
“…recent evidence supports the potential efficacy of calcitonin gene-related peptide-targeting monoclonal…”
Lamotrigine
Lamotrigine has been used as an initial treatment in a person with sporadic hemiplegic migraine before a preventive antibody was started.
Used to help with: Familial or sporadic hemiplegic migraine.
“…supported the diagnosis of sporadic hemiplegic migraine (SHM). Genetic testing revealed no mutations associated with familial HM. Initial treatment with…”
Nimodipine
Nimodipine, a calcium-channel blocker, has been reported in hemiplegic migraine, with improvement in consciousness and language described in one case, though its use remains controversial.
Used to help with: Familial or sporadic hemiplegic migraine.
“The patient improved in consciousness and language after nimodipine therapy but had persistent hemiplegia at…”
What changes how it shows up
The diagnosis is not the whole story. The factors and open questions below are described in the research mapped here as shaping whether, or how strongly, the condition shows up, or as points the field has not yet settled. They are not, on their own, its cause or its cure.
Autosomal dominant inheritance
Familial hemiplegic migraine is inherited in an autosomal dominant pattern, meaning a change in a single copy of the gene is enough to cause it and it can be passed down through a family.
Described as modulating: Familial or sporadic hemiplegic migraine.
“Familial hemiplegic migraine is caused by autosomal dominant mutations in the CACNA1A, ATP1A2, SCN1A, and PRRT2…”
CACNA1A / ATP1A2 / SCN1A / PRRT2 gene subtypes
The familial form of hemiplegic migraine can be caused by changes in the CACNA1A, ATP1A2, SCN1A, or PRRT2 genes. Which gene is involved defines the genetic subtype.
Described as modulating: Familial or sporadic hemiplegic migraine.
“Familial hemiplegic migraine is caused by autosomal dominant mutations in the CACNA1A, ATP1A2, SCN1A, and PRRT2…”
ATP1A2 (FHM2)
Hemiplegic migraine linked to the ATP1A2 gene is known as familial hemiplegic migraine type 2 (FHM2). This subtype may present with seizures, encephalopathy, or prolonged neurological deficits.
Described as modulating: Familial or sporadic hemiplegic migraine.
“FHM type 2 (FHM2), associated with ATP1A2 mutations, disrupts astrocytic Na⁺/K⁺-ATPase function and may present with seizures, encephalopathy, or prolonged neurological…”
How to read the evidence labels
Where this comes from
This guide is built from 9 published source(s). Every claim above links back to one of them. Click any source ID to read the original on PubMed.
Take it further
Printed, source-linked documents built from this condition's graph — ready to bring to an appointment or attach to a coverage request. Every claim carries its published source, the same as this guide.