Acute hypothalamic stimulation and ongoing cluster headache attacks.

Long-term hypothalamic stimulation is effective in improving drug-resistant chronic cluster headache (CH). We assessed acute hypothalamic stimulation to resolve ongoing CH attacks in 16 patients implanted to prevent chronic CH, investigating 136 attacks. A pain intensity reduction of > or =50% occurred in 25 of 108 evaluable attacks (23.1%). Acute hypothalamic stimulation is not effective in resolving ongoing CH attacks, suggesting that hypothalamic stimulation acts by complex mechanisms in CH prevention.