Francomichele Puca†

The association between headache and sleep disorders has been observed for more than a century though the nature of this relationship is still to be completely understood. Several attempts were made to classify the possible types of comorbidity between these conditions as summarised in Tables 1–3, but a general agreement on this topic has not been reached until now [1–3]. One of the troubles often encountered in the evaluation of comorbidity between sleep and headache disorders is that patients referring to tertiary headache centres are mainly con-cerned about their pain and generally do not tend to spon-taneously report their possible sleep problems. But when they are specifically asked, very interesting data do emerge. In a sample of 464 adult headache outpatients, the insomnia prevalence reached the value of 56.03%, without difference according to gender (58.80 % in females, 48.80 % in males, Chi Square test: n.s.) [4]. This percent-age of insomnia is surely higher than 19.00 % correspond-ing to the value found in the general population [5]. As shown in Fig. 1, insomnia was more prevalent in the group of patients whose attacks fulfilled the diagnostic criteria for both migraine and tension-type headache. In most cases (75.01%) insomnia was long term, lasting more than three weeks [6]. Short term insomnia, having a duration o