Hemicrania Continua: Functional Imaging and Clinical Features With Diagnostic Implications

Area of Science:

• Neurology
• Neuroscience
• Headache Medicine

Background:

• Hemicrania continua (HC) is a complex headache disorder.
• Understanding its pathophysiology and clinical presentation is crucial for accurate diagnosis and management.
• Existing diagnostic criteria may not fully encompass the spectrum of HC manifestations.

Purpose of the Study:

• To review pivotal research enhancing the understanding of hemicrania continua's pathophysiology.
• To summarize clinical features of HC patients, highlighting implications for diagnostic criteria.
• To advocate for revisions in the clinical diagnostic criteria for HC.

Main Methods:

• Review of two key articles: one functional imaging study and one prospective cohort study of HC patients.
• Analysis of brain regions activated during HC attacks using functional imaging.
• Evaluation of clinical characteristics, including autonomic signs, pain features, and patient-reported symptoms.

Main Results:

• Functional imaging identified activation in the dorsal rostral pons and posterior hypothalamus during HC attacks.
• A prospective cohort revealed a broader range of autonomic signs than currently recognized, including absence in some patients.
• High frequency of migrainous features, restlessness, and variations in pain characteristics (location, duration, description) were observed.

Conclusions:

• The dorsal rostral pons and posterior hypothalamus are implicated in HC pathophysiology.
• Current International Headache Society criteria for HC may be too narrow.
• Clinical diagnostic criteria for hemicrania continua should be widened and modified to include a broader spectrum of symptoms and signs.