International Headache Society headache diagnostic patterns in pain facility patients

Objective: Previous studies have indicated that many patients with chronic pain (PWCP) referred to pain facilities for the treatment of neck and/or lo w back pain complain of associated headaches. The purpose of this study was to characterize the nature of these headaches according to International H eadache Society (IHS) headache diagnostic criteria. Design: In preparation for this study, a questionnaire that reflected MS he adache diagnostic criteria was developed. All consecutive patients admitted to our pain facility complaining of headache completed this questionnaire and received a physical and neurologic examination focused on key aspects o f headache. A headache interview was also conducted, using the questionnair e as a question guide. All questionnaires were entered in a computerized da tabase, and IHS diagnoses were arrived at for each patient. As many IHS dia gnoses as possible were assigned to each PWCP as long as IHS criteria were fulfilled. In addition, a frequency distribution for headache precipitants and neck-associated symptoms was developed and evaluated by discriminant an alysis to determine the diagnostic value of these factors in relation to ea ch IHS diagnostic group. Setting: Pain facility (multidisciplinary pain center). Patients: Consecutive PWCP. Results: Of 1,466 PWCP, 154 (10.5%) were identified as suffering from sever e headache interfering with function. Of these, 55.8% indicated that their headaches were related to an injury for which they were seeking treatment a nd 83.7% had neck pain, Migraine headache represented the most common diagn ostic group (90.3%), with cervicogenic headache representing the second mos t common (33.8%). Of the total group, 44.2% had more than one headache diag nosis, that is, there was overlap. Cervicogenic headache patients had the g reatest percentage of overlap (94.2%), with migraine patients being second (68.3%). The most frequent headache precipitant was mental stress, followed by neck position and activity/exercise. The migraine and cervicogenic head ache groups had a statistically significant greater number of neck-associat ed symptoms when compared with the remaining patients. Of the total headach e group, 74.6% complained that they had a tender point at the back of their neck. Cervicogenic, migraine, and tension PWCP had the greatest frequency of head or neck tender points. The discriminant analysis for neck-associate d symptoms yielded the following symptoms as the most common predictors of headache across Ii-IS diagnostic groups: clues to onset were severe headach e beginning at the neck or tender point and numbness in arms and legs; head ache brought on by neck position and arms overhead; and neck symptoms consi sting of a tender point in the neck and feeling severe headache in the neck . Conclusions: Headache can and should be considered a frequent comorbid cond ition in PWCP. Because of the overlap data, more precise diagnostic criteri a may be required to separate cervicogenic headache from migraine headache. Neck-associated symptoms seem to be important even to those PWCP diagnosed with migraine headache.