PONOS CLINIC · HEADACHE CENTRE · TACs
Hemicrania continua
A strictly unilateral, continuous headache that can easily be mistaken for chronic migraine.
What is it?
Hemicrania continua belongs to the trigeminal autonomic cephalalgias (TACs). The pain is typically unilateral and persistent, without truly pain-free intervals, with exacerbations of varying intensity.
Why it is often confused with migraine
Exacerbations may involve nausea, photophobia and phonophobia. If only the most intense phase is considered and the continuous background pain is overlooked, the condition can resemble chronic or treatment-resistant migraine.
Clinical features to look for
Continuous pain
Daily, persistent pain on one side of the head, with a variable background intensity.
Exacerbations
Periods of substantially increased pain, sometimes accompanied by restlessness and cranial autonomic signs.
Autonomic symptoms
Tearing, nasal congestion, a runny nose, ptosis or eyelid swelling may occur, particularly during exacerbations.
Response to indometacin
A complete response is a characteristic diagnostic feature and must be assessed in the appropriate clinical context.
Differential diagnosis
The main distinctions are from chronic migraine, cluster headache, cervicogenic pain, occipital neuralgia and secondary causes of continuous unilateral headache. Neuroimaging may be indicated in new or atypical presentations.
Treatment
Indometacin has a central diagnostic and therapeutic role. Dose selection, assessment of contraindications and gastrointestinal protection must be managed by a doctor.
For patients unable to take or tolerate it, alternatives generally have weaker supporting evidence and require individual assessment.
The role of interventional pain management
A procedure does not replace an accurate diagnosis of hemicrania continua, and indometacin remains the reference treatment in typical cases. Interventional pain management may nevertheless be considered for selected patients when pain remains clinically significant despite appropriate treatment, when indometacin is not tolerated or is contraindicated, or when a well-defined trigeminal-autonomic component coexists.
In these circumstances, pulsed radiofrequency of the sphenopalatine ganglion (SPG) may be considered as a neuromodulation technique. The indication must be individual and consistent with the clinical phenotype; where appropriate, selection may be supported by the response to a diagnostic sphenopalatine ganglion test. SPG PRF should therefore be understood as a specialist option for carefully selected refractory cases, rather than a first-line treatment for hemicrania continua.
Key references
Bahra A. Paroxysmal hemicrania and hemicrania continua: Review on pathophysiology, clinical features and treatment. Cephalalgia. 2023.
McClendon D, Riechers RG. A Comprehensive Review of Trigeminal Autonomic Cephalalgias. 2025.