PET Imaging of Cluster Headache
November 1, 1998 less than 1 minute read
PET Imaging of Cluster Headache
abstract & commentary
Source: May A, et al. Hypothalamic activation in cluster headache attacks. Lancet 1998;352:275-278.
May and colleagues report on the pet findings in patients with cluster headache. H2O15 PET was used to study cerebral blood flow changes in 17 patients with a history of cluster headache. Nine subjects with nitroglycerine-induced cluster headache were compared to eight pain-free controls. In the acute pain state, activation was seen in the ipsilateral inferior hypothalamus, contralateral ventroposterior thalamus, bilateral anterior cingulate cortex, bilateral insulae, and cerebellar vermis. The observed activation in the cingulate, insulae, and thalamus was consistent with areas known to be involved with pain processing and previously described in other PET studies of somatic and visceral pain. However, activation in the ipsilateral hypothalamus appears to be a unique and distinguishing feature of cluster headache. In contrast to migraine, no brainstem activation was found during the acute attack.
Commentary
There are several striking features of cluster headache that would seem to suggest a role for the hypothalamus. The circadian rhythmicity of repeat attacks that often follow predictable seasons and daily clocks is one example. The associated autonomic dysregulation including Horner’s Syndrome is equally suggestive. The results of this study clearly differentiate cluster from other primary headache disorders, such as migraine. But how activity in the hypothalamus leads to similar pain in the trigeminal-vascular system remains to be explored.
You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
- Award-winning Medical Content
- Latest Advances & Development in Medicine
- Unbiased Content