Acute hypothalamic stimulation and ongoing cluster headache attacks

Cluster headache (CH) is a primary headache characterized by excruciatingly severe strictly unilateral head pain attacks lasting 15 to 180 minutes, accompanied by agitation and ipsilateral autonomic phenomena.(1) PET studies have revealed activation in the ipsilateral posterior inferior hypothalamic gray matter during CH attacks,(2) whereas a voxel-based magnetic resonance morphometry study revealed increased neuronal density in the same area in patients with CH.(3) These findings reinforced the hypothesis of hypothalamic involvement in CH pathophysiology and led to the proposal that the cluster generator resides there.(2) Inhibition of hypothalamic activation may explain the efficacy of continuous hypothalamic stimulation in chronic drug-resistant CH.(4,5) We assessed the effect of acute hypothalamic stimulation on CH attacks in patients implanted to prevent chronic CH.