Pain and behaviour in cluster headache. A prospective study and review of the literature.

Cluster headache (CH) has also been called "suicide headache" on account of the extremely severe pain that characterizes its attacks. It is indeed well known that CH sufferers exhibit peculiar behaviours during attacks. The purposes of our study were: i) to investigate prospectively prodromes and clinical pain features and behaviour of patients during typical, spontaneous attacks of CH defined according to the International Headache Society classification criteria; and ii) to investigate retrospectively the premonitory signs and symptoms preceding onset of the cluster period. Forty-two episodic CH patients consecutively referred to the University of Parma Headache Centre were asked to fill in a questionnaire soon after a "typical" CH attack. In the questionnaires, the patients were requested: a) to describe in their own words the type of pain experienced during the attack; b) to rate peak pain intensity on a visual analogue scale (VAS); c) to indicate the time elapsing between headache onset and peak pain intensity; d) to report the signs and symptoms preceding the attack (prodromes), choosing them from a 65-item list; and, e) to describe in their own words their behaviour during the attack. Each patient was also requested to report any signs and/or symptoms preceding onset of the cluster period (premonitory symptoms). Data analysis showed that the clinical features of pain were very complex and varied widely among patients. In 85.7% of cases, patients rated their peak pain intensity (reached on average within 8.9 minutes of attack onset) at between 8 and 10 on the VAS. Most (88.1%) exhibited typical signs of pyschomotor agitation (restlessness) during the attack. Prodromes were reported by almost all the patients in our sample (97.6%), and premonitory symptoms by only 40.5%. The results of our study suggest: i) that the pain in CH cannot be described either as vascular- or as neuralgic-type; ii) that a traditional three-item scale (mild, moderate, severe) does not allow adequate categorization of pain intensity, and should be replaced by the VAS in order to reflect a broader spectrum of pain intensity; iii) that restlessness during attacks is so frequent that it should become a CH diagnostic criterion; and, iv) that prompt and accurate reporting of prodromes and/or premonitory symptoms could be helpful in establishing early treatment.