Hemiplegic migraine, familial

Hemiplegic Migraine, Familial

Familial hemiplegic migraine (FHM) is a rare subtype of migraine with aura that is characterized by the presence of motor weakness during the aura phase. It is a genetic disorder, meaning it is inherited in an autosomal dominant pattern. This condition is part of a group of disorders known as channelopathies, which are caused by dysfunctional ion channels.

Clinical Features

FHM is distinguished from other types of migraines by its unique aura symptoms, which include:

• Hemiparesis or Hemiplegia: Temporary weakness or paralysis on one side of the body.
• Visual Disturbances: Such as scintillating scotomas, which are shimmering or flickering lights in the visual field.
• Sensory Symptoms: Including numbness or tingling, often spreading from the hand to the arm and face.
• Speech Disturbances: Such as dysphasia or aphasia, where the patient has difficulty speaking or understanding language.

The aura typically precedes the headache phase, which can be severe and is often accompanied by nausea, vomiting, and sensitivity to light and sound.

Genetic Basis

FHM is associated with mutations in several genes that encode ion channels:

• CACNA1A: This gene encodes a subunit of a voltage-dependent calcium channel. Mutations in this gene are also associated with episodic ataxia and spinocerebellar ataxia type 6.
• ATP1A2: This gene encodes a subunit of the Na+/K+ ATPase pump, which is crucial for maintaining the electrochemical gradient across cell membranes.
• SCN1A: This gene encodes a subunit of a voltage-gated sodium channel, which is also implicated in some forms of epilepsy.

Diagnosis

Diagnosis of FHM is primarily clinical, based on the characteristic symptoms and family history. Genetic testing can confirm the diagnosis by identifying mutations in the associated genes. It is important to differentiate FHM from other causes of hemiparesis, such as stroke or transient ischemic attack.

Management

Management of FHM involves both acute treatment of migraine attacks and preventive strategies. Acute treatment may include:

• Analgesics: Such as nonsteroidal anti-inflammatory drugs (NSAIDs).
• Triptans: Although their use is controversial due to concerns about vasoconstriction.

Preventive treatment may involve:

• Calcium Channel Blockers: Such as verapamil.
• Antiepileptic Drugs: Such as topiramate or valproate.

Patients are advised to avoid known migraine triggers, such as certain foods, stress, and lack of sleep.

Prognosis

The prognosis for individuals with FHM varies. Some patients experience frequent and severe attacks, while others have infrequent episodes. The condition can be disabling, but it is not typically life-threatening. Long-term management and lifestyle modifications can help reduce the frequency and severity of attacks.

Also see

• Migraine with aura
• Channelopathy
• Episodic ataxia
• Spinocerebellar ataxia

edit 

WikiMD neurology

External links

• Comprehensive information from the National Institute of health.
  

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z