From the Guidelines
Hemiplegic migraine is diagnosed based on specific criteria that include at least two attacks of migraine with aura characterized by motor weakness and at least one additional aura symptom, with the motor weakness being fully reversible. The diagnostic criteria for hemiplegic migraine, as suggested by the most recent and relevant guidelines, prioritize the presence of motor weakness (hemiplegia) as a key distinguishing feature from other forms of migraine with aura [ 1 ].
Key Diagnostic Features
- At least two attacks of migraine with aura that include motor weakness (hemiplegia)
- At least one additional aura symptom, which can include visual disturbances, sensory symptoms, or speech/language disturbances
- The motor weakness must be fully reversible, although it may last from hours to days
- For familial hemiplegic migraine, there must be at least one first- or second-degree relative with identical attacks
Differential Diagnosis and Exclusion
Other potential causes of these symptoms, such as transient ischemic attack, stroke, or seizures, must be excluded through appropriate neuroimaging (MRI is preferred) and other diagnostic tests [ 1 ]. Genetic testing may support the diagnosis in familial cases, particularly for mutations in CACNA1A, ATP1A2, or SCN1A genes, though this is not required for clinical diagnosis.
Clinical Considerations
The condition is distinguished from typical migraine with aura by the presence of motor weakness, which is not a feature of standard migraine aura. It's also important to consider the management and potential risks associated with hemiplegic migraine, including the use of certain medications and the presence of comorbidities [ 1 ].
From the Research
Diagnostic Criteria for Hemiplegic Migraine
The diagnostic criteria for hemiplegic migraine are based on the International Classification of Headache Disorders (ICHD) criteria, specifically ICHD-II 2 and ICHD-3 3. The key features of hemiplegic migraine include:
- Transient hemiparesis during attacks
- Aura symptoms such as visual, sensory, or speech impairment
- Headache, which may not always be present
- Motor symptoms that usually last less than 72 hours
Types of Hemiplegic Migraine
There are two types of hemiplegic migraine:
- Familial hemiplegic migraine (FHM), which is an autosomal dominantly inherited subtype of migraine with aura
- Sporadic hemiplegic migraine (SHM), which occurs without a family history
Genetic Factors
Three genes have been identified as being associated with hemiplegic migraine: CACNA1A, ATP1A2, and SCN1A 2, 3, 4. However, other genes may also be involved, and genetic testing can confirm but not rule out the diagnosis.
Diagnostic Assessment
The diagnosis of hemiplegic migraine is clinical, with a genetic confirmation, and involves:
- Patient interview
- Neurological examination during attacks
- Exclusion of other disorders, such as epilepsy, stroke, encephalitis, and secondary headache syndromes
- Additional diagnostics, such as brain imaging, cerebrospinal fluid analysis, or electroencephalography, to exclude other causes of focal neurologic symptoms associated with hemiparesis and headache 3, 4
Differential Diagnosis
The differential diagnosis of hemiplegic migraine is broad and includes:
- Other types of migraine
- Conditions that can cause transitory neurological signs and symptoms, such as epilepsy, stroke, and encephalitis
- Secondary headache syndromes
Revised Diagnostic Criteria
A population-based study of familial hemiplegic migraine suggests revised diagnostic criteria, including:
- At least two aura symptoms, including motor weakness
- Aura symptoms that are similar in type to those in migraine with typical aura, but with a longer duration
- Basilar migraine symptoms in some cases 5