Comment on ‘The use of Radiolabelled Human serum Albumin and SPECT/MRI Coregistration to Study Inflammation in the Cavernous Sinus of Cluster Headache Patients’ by Schuh-Hofer et al.

Dear Sir   I have read with great interest the study by Schuh-Hofer et al. in the last issue of Cephalalgia (1), showing that 99mTc-HSA SPECT shows no abnormal inflammation in the cavernous sinus loggia in cluster headache.

The authors omit to mention the study we published in 1994 (2), which showed essentially similar results by using Gallium SPECT. There was indeed no difference in labelling of the cavernous sinus between cluster headache patients within a bout and those who were in remission, nor between cluster patients and migraineurs. The present study adds the fact that there is equally no abnormal labelling during NTG-induced cluster attacks.

Our study was prompted by a report by Gawel et al. (3), which mentioned abnormal Gallium SPECT findings in the cavernous sinus during active cluster in three out of six patients and which is also not cited in Schuh-Hofer et al.'s article.