Course of disease in cluster headache is reflected by distinct gray matter transformation

Objective: To identify gray matter changes in episodic and chronic cluster headache. Background: Cluster headache (CH) is a rare primary headache disorder and usually follows a distinct course of disease with pain free episodes (outside bout) and periods with headache attacks attacks (inside bout). Some patients have no pain free episodes and are considered to have chronic CH (CCH). A pivotal role of the hypothalamus in the pathophysiology of CH was suggested, but data are controversial. The involvement of other parts of the pain network and especially changes in regard to different states of disease is hardly i…