Migraine Familial Hemiplegic 4 C1843766
An inherited migraine disorder causing headaches with temporary weakness on one side of the body. It runs in families and requires careful trigger management. Treatment includes standard migraine medications.
Key facts at a glance
- ICD-10
- G40.909
- ICD-11
- 8A00.0
- Body system
- neurologic
- Severity
- severe
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Warning signs - seek immediate care
Transient hemiparesis during migraine attacks
Generalized symptoms
(neurologic)Significant symptoms that substantially affect daily functioning.
Frequency: Common at all stages
Severe headache with aura
(neurologic)Visual disturbances (scintillating scotoma)
(neurologic)Dysarthria during migraine attacks
(neurologic)Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
Acetazolamide
First-line prophylactic medication for FHM4, working as a carbonic anhydrase inhibitor to reduce neuronal hyperexcitability associated with ATP1A2 mutations.
Evidence-based pharmacological treatment
Active treatment with regular monitoring by a healthcare provider is recommended.
Ketogenic Diet Modification
Modified ketogenic dietary approach may help reduce neuronal excitability in some FHM4 patients by providing alternative metabolic substrates for brain energy metabolism.
Additional treatment options
Environmental Trigger Management
Avoidance of environmental triggers including bright lights, strong odors, and weather changes that may precipitate hemiplegic migraine attacks.
lifestyleVestibular Rehabilitation
Specialized physical therapy to address balance disturbances and proprioceptive deficits that may persist following hemiplegic migraine episodes.
physical_therapyPsychological Support and Counseling
Individualized psychological support to address the psychological impact of living with a severe, unpredictable neurological condition including anxiety and depression screening.
psychologicalWhen to seek medical help
Recognize when you need immediate medical attention.
See a doctor within 24 hours
Moderate to severe symptoms that may indicate worsening of this condition. Prompt medical evaluation is recommended.
Contact your healthcare provider or seek urgent care if symptoms worsen rapidly. Go to the emergency department for life-threatening symptoms.
Frequently asked questions
Common questions about this topic.
What is Migraine Familial Hemiplegic 4 C1843766?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalMedication Comparisons
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This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 26, 2026. · Read our editorial policy