familial hemiplegic migraine

Familial Hemiplegic Migraine (FHM) Description

Familial hemiplegic migraine (FHM) is a rare and inherited form of migraine with aura, characterized by the presence of motor weakness as an aura manifestation. This condition typically causes temporary weakness on one side of the body, often accompanied by other symptoms such as visual disturbances, sensory loss, and speech difficulties.

Key Features:

• Inherited: FHM is passed down from parents to children through genetic inheritance.
• Motor Weakness: Temporary weakness or paralysis on one side of the body, which can last for hours, days, or weeks.
• Aura Symptoms: Visual disturbances (most common), sensory loss (e.g., numbness or paresthesias), and dysphasia (difficulty with speech).
• Migraine Attacks: May be provoked by minor head trauma.

Subtypes:

There are three numbered subtypes of FHM, each with a different gene change that causes it. A healthcare provider may identify it as familial type 4 if they cannot find a known genetic change.

Age of Onset:

FHM commonly begins during childhood or adolescence and can be triggered by various factors, including minor head trauma.

References:

• [1] Familial hemiplegic migraine falls within the category of migraine with aura. (Source: #14)
• [2-5] FHM is a rare and inherited form of migraine with aura, characterized by motor weakness as an aura manifestation. (Sources: #2-#5)
• [6-7] There are two main forms of FHM depending on the familial history: patients with at least one first- or second-degree relative who has aura including motor weakness. (Sources: #6-#7)
• [8-9] A person with hemiplegic migraine will experience a temporary weakness on one side of their body as part of their migraine attack. (Sources: #8-#9)
• [10-14] FHM is an inherited form of hemiplegic migraine, characterized by motor impairment and aura symptoms. (Sources: #10-#14)

Familial hemiplegic migraine (FHM) is a rare genetic condition that affects the brain, causing severe headaches accompanied by temporary weakness on one side of the body.

Common symptoms:

• Aura with motor weakness: A person with FHM will experience a temporary weakness on one side of their body as part of their migraine attack [8].
• Reversible visual symptoms: Symptoms can include seeing zigzag lines, double vision, or blind spots [7].
• Extreme sensitivity to light, sound, and smell: Some individuals may experience extreme sensitivity to light, sound, and smell during an FHM episode [7].
• Language difficulties: Language difficulties have also been reported in some cases [7].
• Fever, seizures, prolonged weakness, coma, and death (rarely): In severe cases, FHM can lead to fever, seizures, prolonged weakness, coma, and even death, although this is rare [1].

Other symptoms:

• Changes in consciousness: Some individuals may experience changes in consciousness, ranging from confusion to profound coma [4].
• Problems with coordination: Problems with coordination have also been reported in some cases [4].
• Nausea or vomiting: Nausea or vomiting can occur during an FHM episode [4].

Aura symptoms:

• Additional aura symptoms usually affect vision: In addition to motor weakness, aura symptoms usually affect vision but can also affect speech, sensation, and mental status [2].
• Reversible sensory symptoms: Symptoms can include reversible visual symptoms (flickering lights, spots, lines, etc.), reversible sensory symptoms (pins and needles), or other types of sensory disturbances [6].

It's essential to note that FHM is a rare condition, and not everyone will experience all of these symptoms. If you suspect you or someone else has FHM, it's crucial to consult with a healthcare professional for proper diagnosis and treatment.

References: [1] Jan 1, 2014 [2] Jul 24, 2023 [4] Jan 6, 2022 [6] Aug 25, 2023 [7] Jan 4, 2023 [8] Symptoms.

Familial hemiplegic migraine (FHM) is a rare and severe form of migraine that can cause temporary weakness or paralysis on one side of the body. Establishing a molecular diagnosis in individuals with FHM is crucial for guiding medical treatment and management, as well as informing testing of family members [1].

Several diagnostic tests are available to confirm a diagnosis of FHM through genetic testing:

• Next-generation sequencing (NGS): This test detects single nucleotide and copy number variations in genes associated with FHM. It can identify mutations in the CACNA1A, ATP1A2, SCN1A, and other genes [9].
• Genetic panel testing: A genetic panel test, such as the Invitae Familial Hemiplegic Migraine Panel, analyzes multiple genes associated with FHM. This test can identify mutations in the CACNA1A, ATP1A2, SCN1A, and other genes [3].
• Clinical Genetic Test: The Mayo Clinic Laboratories offer a Clinical Genetic Test for conditions including Familial hemiplegic migraine. This test involves genetic testing of the ATP1A2 gene among others [4].

Additionally, some cases of FHM may be triggered by specific imaging tests, such as cerebral angiograms, which can cause temporary weakness or paralysis on one side of the body [5].

It's essential to note that these diagnostic tests are typically recommended for individuals who experience symptoms consistent with either hemiplegic migraine with aura or alternating hemiplegia of childhood [8].

Treatment Options for Familial Hemiplegic Migraine

Familial hemiplegic migraine (FHM) is a rare and severe form of migraine with aura, characterized by temporary weakness or paralysis on one side of the body. While there are no specific treatments approved specifically for FHM, various medications can help alleviate symptoms.

Preventive Medications

Preventive medications are taken daily to reduce the frequency of attacks. Some commonly used preventive medications for typical migraine with aura, which may also be effective for FHM, include:

• Calcium channel blockers: These medications can help prevent migraines by reducing blood flow and inflammation in the brain (1).
• Nonsteroidal anti-inflammatory drugs (NSAIDs): NSAIDs, such as ibuprofen or naproxen, can help reduce pain and inflammation associated with FHM attacks (2, 7).

Acute Treatment

During an FHM attack, medications that can ease immediate symptoms are used. These may include:

• Triptans: While triptans can worsen the constriction of brain vessels in some cases, they may be prescribed when headaches are not relieved by other treatments (2).
• Ergotamine and dihydroergotamine: These medications can reduce blood flow and alleviate pain during an FHM attack (3).

Other Medications

In addition to preventive and acute treatments, other medications may be used to manage symptoms of FHM. These include:

• Anti-nausea drugs: To help control nausea and vomiting associated with FHM attacks (4).
• Opioids: In some cases, opioids may be prescribed to alleviate severe pain during an FHM attack (7).

Important Note

It is essential to consult a healthcare professional for personalized treatment recommendations, as the severity of symptoms and individual responses to medications can vary greatly.

References:

1. [1] by A Kumar · 2023 · Cited by 30
2. [2] by N Pelzer · 2013 · Cited by 114
3. [3] Standard migraine medications
4. [4] Aug 25, 2023 — What is the treatment for familial hemiplegic migraine?
5. [5] Jul 24, 2023 — Treatment that is taken every day to reduce the frequency of attacks.
6. [6] Jan 6, 2022 — Preventive medications commonly used to treat typical migraine with aura
7. [7] Oct 17, 2024 — Typically, nonsteroidal anti-inflammatories (NSAIDs), anti-nausea drugs, or opioids are used to ease the immediate symptoms of a hemiplegic migraine.

Differential Diagnosis of Familial Hemiplegic Migraine

Familial hemiplegic migraine (FHM) is a rare autosomal dominantly inherited subtype of migraine with aura, characterized by transient neurological symptoms including hemiplegia. The differential diagnosis of FHM is broad and includes other forms of migraine, as well as any condition that can cause transitory neurological signs and symptoms.

Conditions to Consider in the Differential Diagnosis

• Other types of migraine: FHM should be differentiated from other types of migraine with aura, such as common migraine or complicated migraine.
• Transient neurological disorders: Conditions like transient global amnesia, Todd's palsy, and hemiplegic seizures can mimic the symptoms of FHM.
• Hereditary disorders: Other hereditary disorders with migrainous headache may include hemiplegic aura in their differential diagnosis, such as familial hemiplegic migraine variants.
• Epilepsy: Hemiplegic seizures can be a feature of certain epilepsy syndromes, which should be considered in the differential diagnosis.

Key Factors to Consider

• Family history: A family history of migraine with aura including motor weakness is a key factor in diagnosing FHM. The presence of at least one 1st or 2nd degree blood relative with a similar condition can help distinguish FHM from sporadic hemiplegic migraine.
• Clinical characteristics: The clinical features of FHM, such as transient neurological symptoms and hemiplegia, should be carefully evaluated to rule out other conditions.

References

• [3] The differential diagnosis of HM is broad, including other types of migraine and any condition that can cause transitory neurological signs and symptoms.
• [8] Familial hemiplegic migraine (FHM) is a rare autosomal dominantly inherited subtype of migraine with aura. The clinical characteristics of FHM have been well described in the literature.
• [9] The family history will allow a distinction to be made between cases of familial hemiplegic migraine (FHM), in which at least one 1st or 2nd degree blood relative has a similar condition, and sporadic hemiplegic migraine.