Cluster headache is the most severe of the primary headaches. Positron emission tomography and functional MRI studies have shown that the ipsilateral posterior hypothalamus is activated during cluster headache attacks and is structurally asymmetric in these patients. These changes are highly specific for the condition and suggest that the cluster headache generator may be located in that brain area; they further suggest that electrical stimulation of that region might produce clinical improvement in chronic cluster headache sufferers refractory to medical therapy. In five patients with severe intractable chronic cluster headache, hypothalamic electrical stimulation produced complete and long-term pain relief with no relevant side-effects. We therefore consider it essential to propose criteria for selecting chronic cluster headache patients for hypothalamic deep brain stimulation before this procedure is undertaken at other academic medical centers.

Comment: This article describes the five patients operated on in Italy for chronic intractable cluster with the stimulator in the cluster hypothalamic generator with good results and “no relevant side-effects.” However, the authors' admonition for criteria for patient selection is now underlined by Dr. Schoenen's platform presentation at the American Academy of Neurology meeting in San Francisco in 2004, at which the Belgian experience was described: “The procedure was uneventful in 4/5 patients … Unfortunately, one patient developed massive brainstem and basal ganglia hemorrhage 4 hours after surgery and died after 2 days … In this small series, deep brain stimulation of posterior hypothalamus proved effective to control otherwise intractable chronic cluster headache … Serious adverse events can occur even with a single electrode … Pooling … patients with other deep brain stimulator procedures performed in our department (38 for Parkinson's disease, essential tremor, and generalized dystonia) … the overall rate of significant hemorrhage was 2.3%.”[Vendenheede M, Maertens de Noordhout AS, Remacle JM, Mouchamps M, Schoenen J. Deep Brain Stimulation of Posterior Hypothalamus in Chronic Cluster Headache. Neurology. 2004;62(suppl 5):A356.] This new information takes some of the enthusiasm out of everyone's initial reaction to this procedure. Obviously, hemorrhage and death are not consequences of the other surgical procedure for cluster that is often successful, radiofrequency trigeminogangliorhizolysis. —Stewart J. Tepper, MD