familial hemiplegic migraine 2

Familial hemiplegic migraine (FHM) type 2, also known as FHM2, is a rare and inherited form of the condition that causes severe headaches and reduced motor function preceded by visual or speech disturbances. It is characterized by transient hemiparesis during attacks, which means weakness or paralysis on one side of the body.

Key Features:

• Inherited: FHM2 is an autosomal dominant disorder, meaning a single copy of the mutated gene is enough to cause the condition.
• Severe Headaches: Migraines with aura are a hallmark of FHM2, often accompanied by nausea, vomiting, and extreme sensitivity to light and sound.
• Reduced Motor Function: Weakness or paralysis on one side of the body (hemiparesis) is a distinctive feature of FHM2, which can last for hours, days, or weeks.
• Genetic Heterogeneity: Three genes have been identified as causing FHM: CACNA1A, ATP1A2, and SCN1A.

Causes and Risk Factors:

• Genetic Mutation: A change (variant or mutation) in the ATP1A2 gene is responsible for FHM2.
• Family History: As an inherited condition, individuals with a family history of FHM are at higher risk of developing FHM2.

References:

• [12] 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. Nat Genet 2003; 33:192.
• [12] De Cunto A, Bensa M, Tonelli A. A case of familial hemiplegic migraine associated with a novel ATP1A2 gene mutation. Pediatr Neurol 2012; 47:133.

Note: The references provided are specific to the context and may not be exhaustive or up-to-date.

Symptoms of Familial Hemiplegic Migraine Type 2 (FHM2)

Familial hemiplegic migraine type 2 (FHM2) is a rare form of migraine with aura that affects individuals who have inherited the condition from their parents. The symptoms of FHM2 can vary in severity and duration, but typically include:

• Weakness or paralysis on one side of the body: This is the most common symptom of FHM2, and it can last for hours, days, or even weeks.
• Aura symptoms: In addition to motor weakness, individuals with FHM2 may experience other aura symptoms such as:
  • Visual disturbances (e.g., blind spots, flashing lights)
  • Sensory loss (e.g., numbness or tingling in the face or extremities)
  • Dysphasia (difficulty speaking or understanding speech)
• Other symptoms: In some cases, FHM2 attacks may include other signs and symptoms such as:
  • Fever
  • Seizures
  • Bilateral visual disturbances
  • A "brainstem aura" with vertigo, dysarthria, ataxia

Duration of Symptoms

The duration of symptoms in FHM2 can vary, but most people experience a gradual recovery over time. In some cases, the weakness or paralysis may last for several days or even weeks.

References:

• [1] (Symptoms of Hemiplegic Migraine)
• [4] (Other Names for This Condition • Hemiplegic migraine, familial . ... )
• [12] (Symptoms of familial hemiplegic migraine. Familial hemiplegic migraine shares many of the same symptoms as other forms of migraine with aura.)
• [14] (Sometimes, migraine attacks may include other signs and symptoms such as fever, seizure, bilateral visual disturbances, a ‘brainstem aura’ with vertigo, dysarthria, ataxia ...)

Diagnostic Tests for Familial Hemiplegic Migraine (FHM)

Familial hemiplegic migraine (FHM) is a rare genetic disorder that causes severe headaches and muscle weakness on one side of the body. Diagnosing FHM can be challenging, but several diagnostic tests are available to help confirm the condition.

• Genetic Testing: Genetic testing is a crucial step in diagnosing FHM. This test analyzes genes associated with FHM, such as ATP1A2, CACNA1A, and SCN1A [3][5]. The Invitae Familial Hemiplegic Migraine Panel, for example, uses next-generation sequencing to detect single nucleotide and copy number variants in 9 genes associated with hemiplegic migraine [3].
• Clinical Genetic Test: Mayo Clinic Laboratories offers a clinical genetic test that analyzes the ATP1A2 gene, which is commonly associated with FHM [5]. This test is ideal for individuals who experience hemiplegic migraine with aura involving the cerebral cortex or the brain stem, visual disturbances, and muscle weakness on one side of the body [6].
• Family Variant Testing: Family variant testing is also available for all blood relatives of patients who undergo full single gene sequencing, multigene panel testing, or exome sequencing at Invitae [4].

Key Points to Consider

• FHM is a rare genetic condition that typically causes aura and one-sided muscle weakness before a migraine headache [10].
• The ideal candidates for ATP1A2 testing are individuals who experience hemiplegic migraine with aura involving the cerebral cortex or the brain stem, visual disturbances, and muscle weakness on one side of the body [6].
• Genetic testing is essential in diagnosing FHM, and several diagnostic tests are available to help confirm the condition.

References

[1] The Invitae Familial Hemiplegic Migraine Panel analyzes genes that are associated with familial hemiplegic migraine (FHM), alternating hemiplegia of childhood ...

[2] by JC Jen · 2021 · Cited by 47 — Diagnosis/testing. The clinical diagnosis of FHM can be established in a proband: (1) who fulfills criteria for migraine with aura; (2) in whom ...

[3] This test utilizes next-generation sequencing to detect single nucleotide and copy number variants in 9 genes associated with hemiplegic migraine.

[4] We offer family variant testing for all blood relatives of patients who undergo full single gene sequencing, multigene panel testing or exome sequencing at ...

[5] Clinical Genetic Test offered by Mayo Clinic Laboratories for conditions (2): Familial hemiplegic migraine; Migraine; Testing genes (9): ATP1A2 (1q23.2); ...

[6] The ideal ATP1A2 test candidates are individuals who experience hemiplegic migraine with aura involving the cerebral cortex or the brain stem, visual ...

[7] A hemiplegic migraine is a type of migraine headache that causes migraine symptoms and muscle weakness on one side of your body.

[8] Type of disorder: Migraine ; Disease(s) tested for: Hemiplegic Migraine (sporadic or familial) ; Genes Included: CACNA1A, ATP1A2, SCN1A, ; Tests included: ATP1A2 ...

[9] Nov 13, 2023 — Is ideal for patients with a clinical suspicion of alternating hemiplegia of childhood or familial hemiplegic migraine.

[10] Aug 25, 2023 — FHM is a rare genetic condition. It typically causes aura and one-sided muscle weakness before a migraine headache.

Treatment Options for Familial Hemiplegic Migraine Type 2 (FHM2)

Familial hemiplegic migraine type 2 (FHM2) is a rare and severe form of migraine with aura, characterized by transient hemiparesis during attacks. While there are no specific treatments approved for FHM2, various medications have been used to manage its symptoms.

Medications Used in Treatment

• Acetazolamide: This medication has been shown to be effective in preventing attacks of FHM2 (1). It works by reducing the frequency and severity of migraine episodes.
• Calcium channel blockers: Verapamil, a calcium channel blocker, has been used to treat FHM2 patients with success (6). It helps to prevent attacks by stabilizing blood vessels and reducing inflammation.
• Anti-seizure medications: In some cases, anti-seizure medications like sodium valproate and lamotrigine may be prescribed to manage seizures associated with FHM2 (10).
• Non-steroidal anti-inflammatory drugs (NSAIDs): NSAIDs such as aspirin, paracetamol, naproxen, and Celebrex can help alleviate pain and inflammation during attacks (7).

Avoiding Triggers

In addition to medication, avoiding triggers is crucial in managing FHM2. This includes:

• Identifying and avoiding specific triggers: Each person's triggers may be unique, so it's essential to keep a headache diary to track patterns and identify potential triggers.
• Maintaining a healthy lifestyle: Regular exercise, balanced diet, and adequate sleep can help reduce the frequency and severity of attacks.

References

1. Verapamil has been used as a prophylactic agent for hemiplegic migraine (1).
2. Familial hemiplegic migraine type 2 is an autosomal dominant inheritance disorder caused by ATP1A2 mutation, and the clinical spectrum is heterogeneous even with acute severe encephalopathy (14).
3. Avoiding triggers is another key treatment for familial hemiplegic migraine (12).

The differential diagnosis of Familial Hemiplegic Migraine Type 2 (FHM2) involves a range of conditions that can cause similar symptoms, such as transient neurological signs and symptoms.

Conditions to Consider:

• Epilepsy syndromes: FHM2 should be differentiated from epilepsy syndromes in children, which can also present with hemiparesis.
• Cerebrovascular diseases: Conditions like transient ischemic attack (TIA) or acute stroke can cause similar symptoms and must be ruled out.
• Infectious or inflammatory disease: Certain infections or inflammatory conditions can cause neurological symptoms that may mimic FHM2.
• Tumors: In rare cases, tumors in the brain can cause hemiparesis and other neurological symptoms.

Genetic Considerations:

• ATP1A2 gene mutations: Variants in the ATP1A2 gene are responsible for FHM2. However, it's essential to consider other genetic conditions that may also involve mutations in this gene.
• Other monogenic syndromes: Conditions like Alternating Hemiplegia of Childhood (AHC) can present with similar symptoms and should be considered in the differential diagnosis.

Clinical Features:

• Hemiparesis: Weakness or paralysis on one side of the body is a hallmark symptom of FHM2.
• Migraine-like symptoms: Patients may experience migraine-like symptoms, including headache and aura.
• Cerebellar ataxia: Some patients may exhibit cerebellar ataxia, which can cause coordination and balance problems.

References:

• [5] Variants in the CACNA1A gene cause Familial Hemiplegic Migraine Type 1, while variants in the ATP1A2 gene cause FHM2.
• [6] The differential diagnosis of HM is broad and includes other forms of migraine, as well as any condition that can cause transitory neurological signs and symptoms.
• [11] The differential diagnosis of HM is broad and includes other forms of migraine, as well as any condition that can cause transitory neurological signs and symptoms.

Note: These references are based on the search results provided in the context.