Sporadic hemiplegic migraine presenting as acute encephalopathy

Area of Science:

• Neurology
• Genetics
• Pediatrics

Background:

• Sporadic hemiplegic migraine (SHM) is a rare subtype of migraine with aura, often associated with mutations in specific genes.
• SHM typically presents with transient neurological deficits, primarily hemiplegia, during migraine attacks.

Observation:

• A 10-year-old boy with developmental delay experienced acute hemiplegia, fever, and altered consciousness, initially mimicking encephalopathy.
• Neuroimaging showed left temporo-occipital swelling, restricted diffusion, and transient cortical atrophy, with elevated cerebrospinal fluid interleukin-6.
• The patient later developed recurrent migraine attacks and transient left hemiplegia, alongside persistent hypoperfusion in the left posterior cortex.

Findings:

• Genetic analysis revealed a de novo CACNA1A gene mutation (c.1997 C>T, p.T666M) in the patient.
• The clinical presentation and neuroimaging findings suggest an unusual evolution of SHM with acute encephalopathic features.
• Elevated interleukin-6 indicates a potential inflammatory component contributing to the neurological manifestations.

Implications:

• This case expands the phenotypic spectrum of SHM and CACNA1A mutations.
• It underscores the importance of considering SHM in children presenting with hemiplegic episodes and encephalopathic symptoms.
• The findings suggest a potential role for migraine-related inflammatory processes in the pathogenesis of severe neurological events in SHM.