Familial Cluster Headache. Is Atypical Cluster Headache in Family Members Part of the Clinical Spectrum?

Abstract

Familial cluster headache (CH) was analysed in 21 Swedish families. Diagnosis was made according to The International Classification of Headache Disorders 2004. We identified 55 affected, of whom 42 had episodic or chronic CH, one had probable CH and 12 had atypical symptoms. The atypical cases did not fulfil the diagnostic criteria for CH, but had clinical symptoms with more resemblance to CH than to migraine or other trigeminal autonomic cephalgia syndromes. The overall male : female ratio was 1.8:1. The overall mean age at onset was significantly lower in the second/third generation than in the first generation (mean age at onset 22 vs. 31 years, SD +/- 7 vs. 13 years; P < 0.01). This may be anticipation or selection bias, since individuals with late age at onset from the second/third generation may not yet have symptoms. The prevalence of migraine was 24% (13/55), i.e. similar to the prevalence in the general population. The high incidence of atypical CH cases in the Swedish families with other members affected with CH may suggest that the spectrum of CH is broader than previously thought. We suggest that atypical CH in CH families may represent an expanded spectrum of the disease with a common aetiology, i.e. a common genetic background.

Cluster-migraine: Does it exist?

“…Therefore, it seems likely that progression of age is not the major factor in the development of cluster in migraine headache patients. The overall prevalence of migraine in patients with CH is comparable to that seen in the general population [24].…”

Prevalence of Familial Cluster Headache: A Systematic Review and Meta-Analysis

“…However, this may also be compounded by intra-familial clinical variability and presence of phenotypes atypical for CH. The documented preponderance of relatives with atypical CH in these studies complicates this further [39,40]. These cases are often omitted from epidemiological studies as they do not strictly fulfil diagnostic criterion, but perhaps represent part of a clinical spectrum associated with intergenerational genetic variation.…”

Epidemiology of cluster headache

“…Whichever genes turn out to be involved, there may be a predisposition toward anticipation. As mentioned earlier, a study by Sjostrand [23] demonstrated a signifi cantly lower mean age of onset in the second/third generation of families with CH than in the fi rst generation.…”

“…When looking at a familial cluster population, the mean age of onset was signifi cantly lower in the second and third generation (22 years) than in the fi rst generation (31 years), suggesting either genetic anticipation or selection/diagnosis bias to account for earlier age of presentation [23].…”