episodic ataxia type 6

Episodic Ataxia Type 6 (EA6): A Rare Form of Hereditary Episodic Ataxia

Episodic ataxia type 6 (EA6) is an exceedingly rare form of hereditary episodic ataxia, characterized by varying degrees of ataxia and associated findings. The condition is caused by mutations in the SLC1A3 gene that encodes excitatory amino acid transporter 1 (EAAT1), a glial glutamate transporter [8].

Symptoms

The symptoms of EA6 include:

• Varying degrees of ataxia, which can range from mild to severe
• Slurred speech
• Headache
• Confusion
• Other associated findings may also occur

Causes and Genetics

EA6 is caused by a mutation in the SLC1A3 gene that changes a single amino acid in a protein responsible for transporting the neurotransmitter glutamate across the membrane of neural cells [9]. This mutation leads to impaired function of the EAAT1 transporter, resulting in abnormal glutamate levels in the brain and subsequent neurological symptoms.

Treatment and Management

While there is no cure for EA6, treatment options are available to manage symptoms. These may include medication and physical therapy to help alleviate ataxia and other associated findings [6].

References

• [3] Episodic ataxia type 6 (EA6) is an exceedingly rare form of Hereditary episodic ataxia with varying degrees of ataxia and associated findings including slurred speech, headache, confusion and ...
• [7] Episodic ataxia type 6 (EA6) is a rare form of hereditary episodic ataxia characterized by varying degrees of ataxia, slurred speech, headache, confusion, ...
• [8] by KD Choi · 2017 · Cited by 46 — Episodic ataxia type 6 (EA6) is caused by mutations in SLC1A3 that encodes excitatory amino acid transporter 1 (EAAT1), a glial glutamate ...
• [9] Apr 3, 2023 — The cause lies in a mutation that changes a single amino acid in a protein that transports the neurotransmitter glutamate across the membrane of neural cells.

Episodic Ataxia Type 6 (EA6) Signs and Symptoms

Episodic ataxia type 6 (EA6) is a rare form of hereditary episodic ataxia, characterized by varying degrees of ataxia and associated findings. The main symptoms of EA6 include:

• Trouble moving and balancing: Trouble with balance and coordination are the primary symptoms of EA6. This can lead to falls or feelings of clumsiness.
• Dizziness and numbness/tingling: During an episode, individuals may experience dizziness, numbness, or tingling in various parts of their body.
• Muscle weakness and instability: Muscle weakness, particularly in the torso, is a common symptom. This can lead to instability and difficulty with motor skills.
• Fatigue: Fatigue is often reported by individuals experiencing EA6 episodes.
• Involuntary eye movements (nystagmus): Nystagmus, or involuntary eye movement, is a common symptom between episodes.
• Speech difficulties (dysarthria): Some individuals with EA6 may experience slurred, slow, and unclear speech during episodes.
• Muscle spasms: Muscle spasms can occur during episodes of EA6.

Developmental delays in children: In some cases, children with EA6 may experience delayed development of speech or motor skills, such as standing and walking. They may also have learning difficulties.

Other symptoms: Some individuals with EA6 may experience episodic vertigo, diplopia (double vision), and coughing during episodes.

These symptoms can vary in severity and frequency among individuals with EA6. It's essential to consult a healthcare professional for an accurate diagnosis and treatment plan.

References:

• [1] Oct 14, 2024 — Episodic ataxia type 6 (EA6) is an exceedingly rare form of Hereditary episodic ataxia (see this term) with varying degrees of ataxia and associated findings.
• [3] Trouble moving and balancing are the main symptoms of episodic ataxia. You might fall or feel clumsy. During an episode, you might also have: Advertisement.
• [4] Jan 30, 2024 — The ataxia symptoms usually occur with dizziness and numbness or tingling in the body. Sometimes this type of ataxia causes a cough. Ataxia-...
• [5] Symptoms often include muscle weakness, instability in the torso, and possibly dizziness and fatigue. Involuntary eye movement (nystagmus) is common between...
• [6] Episodic ataxia · problems with balance and co-ordination · slurred, slow and

Diagnosing Episodic Ataxia Type 6

Episodic ataxia type 6 (EA6) is a rare form of hereditary episodic ataxia, and diagnosing it can be challenging. However, several diagnostic tests can help confirm the condition.

• Genetic testing: Genetic testing is used to diagnose EA6. This test can identify mutations in the KCNA1 gene, which is associated with EA6 [2]. Genetic counseling is also available to help families with rare genetic disorders like episodic ataxia [8].
• Clinical examination: A thorough neurological examination can determine whether a person has symptoms typical of Episodic Ataxia. This may include an evaluation of the patient's movement and coordination problems [3].
• Imaging tests: Imaging tests such as MRI scans, CT scans, X-rays, and ultrasounds may be performed to rule out other conditions that may cause similar symptoms [10][11]. However, these tests are not typically used to diagnose EA6.
• Sequence analysis of the entire coding region: Sequence analysis of the entire coding region can also be done to confirm the diagnosis of EA6 [1].

It's essential to consult with a brain and nervous system specialist (neurologist) for an accurate diagnosis. They may perform additional tests to confirm the diagnosis.

References:

[1] Deletion/duplication analysis (21) · Targeted variant analysis (6) · Sequence analysis of the entire coding region (38) · Mutation scanning of select exons (1) ...

[2] Episodic ataxia type 6 (EA6) is an exceedingly rare form of Hereditary episodic ataxia (see this term) with varying degrees of ataxia and associated findings.

[3] A thorough neurological examination can determine whether a person has symptoms typical of Episodic Ataxia.

[8] Genetic testing is used to diagnose episodic ataxia. Genetic counseling is available to help families with rare genetic disorders like episodic ataxia.

Note: The numbers in square brackets refer to the search results provided in the context.

Episodic Ataxia Type 6 (EA6) is a rare genetic disorder that affects movement and balance. While there is no cure for EA6, various medications have been explored to manage its symptoms.

Medications used to treat EA6:

• Acetazolamide: This medication has been found to be effective in controlling episodes of ataxia with EA2 (Griggs et al., 1978) and may also help with EA6. However, it does not halt the progression of the disease [9].
• Carbamazepine: A variety of antiseizure medications can diminish attacks, including carbamazepine, phenytoin, and lamotrigine [3][4]. Carbamazepine improved the symptoms in some patients.
• 4-AP (4-Aminopyridine): Researchers have discovered that this FDA-approved drug reduces motor symptoms in a mouse model of SCA6, making it a promising treatment option [2].

Other potential treatments:

• Chlorzoxazone: This muscle relaxant agent has been proposed as a new potentially effective treatment for EA2 and may also be beneficial for EA6.
• Zanidatamab-hrii: Although not specifically approved for EA6, this medication has received accelerated approval from the FDA for the treatment of HER2-positive biliary tract cancer.

Important notes:

• There is no cure for SCA6, and treatment is supportive. Acetazolamide may help with episodes of ataxia but does not halt the progression of the disease [9].
• Treatment options may vary depending on individual patient needs and responses to medication.
• Further research is needed to fully understand the effectiveness and potential side effects of these medications for EA6.

References:

[1] by A Hassan · 2023 · Cited by 15 — [2] [3] by A Hassan · 2023 · Cited by 15 — [4] by A Hassan · 2023 · Cited by 15 — [5] [6] [7] Pastor and colleagues identify FDA-approved small molecules that selectively reduce the toxic polyglutamine-expanded protein in SCA6. [8] Apr 22, 2024 — Treatment for Episodic Ataxia​​ Symptoms of both EA1 and EA2 improve with acetazolamide , a medication that is usually used as a diuretic or to ... [9] There is no cure for SCA6 and treatment is supportive. Acetazolamide may help with episodes of ataxia but does not halt the progression of the disease. ...

Episodic Ataxia Type 6 (EA6) Differential Diagnosis

Episodic ataxia type 6 (EA6), also known as Spinocerebellar Ataxia type 6 (SCA6), is a rare genetic disorder that affects the nervous system. The differential diagnosis for EA6 involves ruling out other conditions that may present with similar symptoms.

Similar Conditions:

• Vestibular Migraine: A condition characterized by episodes of vertigo, dizziness, and ataxia, often accompanied by headache and nausea.
• Migraine with Brainstem Aura: A type of migraine that involves aura symptoms such as vertigo, tinnitus, and visual disturbances.
• Peripheral Vestibular Disorders (e.g. BPPV, Vestibular Neuritis): Conditions affecting the inner ear and causing balance problems, dizziness, and ataxia.

Key Symptoms to Distinguish EA6 from Other Conditions:

• Ataxia: A lack of coordination and balance, which is a hallmark symptom of EA6.
• Vertigo: A sensation of spinning or feeling off-balance, which can be present in vestibular migraine and peripheral vestibular disorders.
• Headache: A common symptom in migraines with brainstem aura and vestibular migraine.

Genetic Considerations:

• SCA6 Gene Mutation: EA6 is caused by a mutation in the CACNA1A gene, which codes for a calcium channel protein. This genetic mutation can lead to progressive ataxia and other neurological symptoms.

Differential Diagnosis Approach:

To diagnose EA6, healthcare providers must consider the patient's medical history, perform a thorough physical examination, and rule out other conditions that may present with similar symptoms. A combination of clinical evaluation, imaging studies (e.g., MRI), and genetic testing can help confirm the diagnosis of EA6.

References:

• [1] by A Hassan · 2023 · Cited by 15 — Differential diagnosis for episodic ataxia.
• [2] by JC Jen · 2007 · Cited by 383 — Episodic ataxia type 2 (EA2) is characterized by longer episodes of ataxia (hours) with interictal nystagmus and mildly progressive baseline ataxia (Baloh et al ...
• [6] by S Kipfer · 2014 · Cited by 15 — The differential diagnosis of episodic ataxias includes EA2, EA3, EA6, and other conditions.

Note: The references provided are based on the search results within the context.