Morphological changes in cluster headache between attacks

Patients with cluster headache during an attack (in-bout) or between attacks (out-bout) had distinct cortical morphological changes. Both groups showed reduced grey matter volume in regions within the pain-processing network. These findings were obtained from voxel- and surface-based analyses from Taiwan [1].

Chronic pain and headache can alter brain morphology. Previous structural imaging studies in cluster headache used either volume- or surface-based morphometry to evaluate related morphological changes [2]. Studies often focused on comparing control subjects with patients with cluster headache that were either in the in-bout period of an attack or in the out-bout period of an attack [3]. Combining volume- and surface-based morphometry to evaluate cluster headache both during and between attacks may provide further insights into the pathophysiology of cluster headache.

To this end, the current study analysed 94 cluster headache patients (47 in-bout and 47 out-bout) and 47 age- and sex-matched healthy controls. Dr Kuan-Lin Lai (Taipei Veterans General Hospital, Taiwan) shared the results.

Age at onset and disease duration were comparable between in-bout and out-bout patients (P=0.059 and P=0.199, respectively) [1]. Total intracranial volume did not differ between groups (P=0.344). Volume-based morphometry showed a reduction of grey matter volume in multiple areas, confined to the pain matrix, in patients with cluster headache compared with healthy controls (P<0.05).

When grouping all patients with cluster headache, increased grey matter volume at bilateral putamen was observed. This was also found in in-bout patients but not out-bout patients. Similarly, surface-based morphometry showed reduced cortical thickness in anterior and middle cingulate, and bilateral insula cortices in all patients as a group and in in-bout patients, but not in out-bout patients. Additionally, the cortical thickness at the right insula negatively correlated with disease duration in patients during attacks. These findings are in line with previous studies [2,3]. Out-bout patients presented with reduced cortical thickness over bilateral insular and cingulate cortices and increased volume in bilateral putamen, suggesting that some of the morphological alterations may be a consequence of the perception of pain.

Combining structural and functional image analyses allowed researchers to show distinct morphological changes in patients with cluster headache during versus between attacks. These changes may be related to trait- and state-dependent effects.

1. Lai KL, et al. Cortical morphological changes in cluster headache between bouts: voxel- and surface-based analyses. AL06, IHC 2021, 8–12 September.
2. Arkink EB, et al. Cephalalgia. 2017;37(3):208–13.
3. Seifert CL, et al. Headache. 2012;52(9):1362–8.

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Posted on 8 November 202119 November 2021