# Hemiplegic Migraine

Hemiplegic migraine is a rare and severe form of migraine. Its distinguishing feature is in the name: *hemiplegia* — temporary weakness on one side of the body — accompanies the migraine. It is the only kind of migraine in which motor weakness is part of the picture.

## What an episode is like

A hemiplegic migraine episode usually has two stages.

**The aura.** Before — and sometimes during — the headache, the person experiences neurological symptoms that build up over minutes. These can include:

* visual changes (flashing lights, blind spots, zigzag patterns),
* sensory changes (tingling or numbness on one side, often spreading from a hand up the arm to the face),
* difficulty speaking or understanding language, and
* **weakness on one side of the body** — the defining feature.

The weakness can be partial (a heavy arm, a clumsy hand) or more pronounced. It typically affects the same side as the sensory symptoms.

**The headache.** A severe headache usually follows, often with nausea, light sensitivity, and sound sensitivity — the familiar features of migraine.

Aura symptoms typically resolve within hours, though in some cases the weakness can last longer. The headache may last a day or more.

## Why it can be alarming

A hemiplegic migraine attack can look very much like a stroke — sudden one-sided weakness, sensory changes, speech difficulty. The crucial difference is that hemiplegic migraine is **reversible**. Symptoms build, then resolve. But because of the resemblance, a first episode often leads to emergency evaluation — which is appropriate. Stroke must always be ruled out.

## How PRRT2 fits in

Familial hemiplegic migraine has been linked to several genes, and **PRRT2 is one of them**. In families carrying a PRRT2 variant, hemiplegic migraine may appear alongside the movement and seizure phenotypes — or as the only manifestation in a particular relative.

The mechanism fits. As described in [The Sodium Channel Connection](/prrt2-gene-overview/sodium-channel-connection.md), PRRT2 helps restrain the electrical excitability of neural circuits. Migraine, and especially hemiplegic migraine, is thought to involve **cortical spreading depression** — a slow wave of altered electrical activity that moves across the surface of the brain. A weaker brake on neural excitability makes it easier for such a wave to start and to spread.

## Treatment and care

Treatment of hemiplegic migraine requires some specialist care. Certain standard migraine medications are typically avoided in hemiplegic migraine, and management often focuses on preventive treatment and identifying triggers. The medication side is covered in [Treatments & Management](/treatments-and-management/how-treatment-works.md).

{% hint style="success" %}
**🧭 PRRT2.org Perspective**

*PRRT2.org's own perspective — our synthesis and lived experience, offered alongside the established science, not as established medical fact.*

Hemiplegic migraine is sometimes the only PRRT2 symptom a person ever has — and it may not appear until adulthood. That makes it one of the most easily missed parts of the spectrum.

If a relative has had what seemed like an isolated severe migraine with one-sided weakness, and other relatives have had unexplained childhood seizures or paroxysmal movement episodes, PRRT2 may be the thread running through all of it. The *pattern* across the family is often the clue — not any single attack on its own.
{% endhint %}

## Sources

The established science on this page is drawn from:

* [MedlinePlus Genetics — PRRT2 gene](https://medlineplus.gov/genetics/gene/prrt2/) — U.S. National Library of Medicine, NIH
* [GeneReviews — Familial Paroxysmal Kinesigenic Dyskinesia](https://www.ncbi.nlm.nih.gov/books/NBK1460/) — University of Washington / NCBI
* [OMIM — Entry 614386](https://omim.org/entry/614386) — Johns Hopkins University

For the complete set of authoritative references, see [Official Resources](/resources/official-resources.md).

## Continue reading

* [The PRRT2 Spectrum](/associated-conditions/prrt2-spectrum.md) — the full set of conditions
* [The Sodium Channel Connection](/prrt2-gene-overview/sodium-channel-connection.md) — why migraine fits a network-stability problem
* [Inheritance & Genetics](/prrt2-gene-overview/inheritance-and-genetics.md) — how the gene moves through families


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