Hemicrania Continua: An Update

Approach to the Patient With Headache

OBJECTIVE

The evaluation of patients with headache relies heavily on the history. This article reviews key questions for diagnosing primary and secondary headache disorders with a rationale for each and phrasing to optimize the information obtained and the patient's experience.

LATEST DEVELOPMENTS

The availability of online resources for clinicians and patients continues to increase, including sites that use artificial intelligence to generate a diagnosis and report based on patient responses online. Patient-friendly headache apps include calendars that help track treatment response, identify triggers, and provide educational information.

ESSENTIAL POINTS

A structured approach to taking the history, incorporating online resources and other technologies when needed, facilitates making an accurate diagnosis and often eliminates the need for unnecessary testing. A detailed yet empathetic approach incorporating interpersonal skills enhances relationship building and trust, both of which are integral to successful treatment.

Hemicrania Continua: An Update

PURPOSE OF REVIEW

Hemicrania Continua (HC) is a rare and disabling primary headache disorder that is characterized by persistent, unilateral headache with ipsilateral, cranial autonomic symptoms and restlessness or agitation. The diagnosis requires patients to experience an absolute response to therapeutic doses of indomethacin.

RECENT FINDINGS

HC is diagnosed in in about 1.8% of adult patients who were evaluated for headache in tertiary care services, albeit this estimate should be interpreted with caution. The most prevalent accompanying symptoms appear to be lacrimation, conjunctival injection and restlessness or agitation. However, the available literature is limited by methodologic issues, and the current diagnostic criteria lack clarity on what defines absolute response to indomethacin. More rigorous studies are thus needed to improve our understanding of HC which, in turn, will facilitate better disease management in clinical practice. Here, we provide a comprehensive overview of HC, including its epidemiology, clinical presentation, diagnostic evaluation, and management.

Prevalence and clinical features of hemicrania continua in clinic-based studies: A systematic review and meta-analysis

OBJECTIVE

To estimate the relative frequencies of hemicrania continua and its clinical features in adult patients who were evaluated for headache in a clinic-based setting.

METHODS

PubMed and Embase were searched for observational, clinic-based studies published between 1 January 2004 and 1 February 2022, that reported on the relative frequencies of hemicrania continua and its clinical features. Two independent investigators (HMA and SA-K) screened titles, abstracts, and full text-articles. A random-effects meta-analysis was conducted to estimate pooled relative frequencies of hemicrania continua and its clinical features across clinic-based studies.

RESULTS

Eleven clinic-based studies were deemed eligible for inclusion. Of these, eight studies reported on the relative frequency of hemicrania continua among adult patients (n = 9854) who were evaluated for headache in a tertiary care unit. The pooled relative frequency of hemicrania continua was found to be 1.8% (95% CI; 1.0-3.3). Considerable heterogeneity was noted across studies (I² = 89.8%). The three most common symptoms associated with hemicrania continua were lacrimation (72.3%), conjunctival injection (69.8%), and restlessness/agitation (60.2%).

CONCLUSION

The findings of this meta-analysis suggest that there is limited epidemiologic data on the relative frequencies of hemicrania continua and its clinical features. Standardized data acquisition and reporting are needed to estimate prevalence rates more accurately and to better understand epidemiologic patterns. This, in turn, should increase awareness of the impact that hemicrania continua has in clinical practice.