Confirmation of the distinction between chronic migraine and chronic tension-type headache by the McGill Pain Questionnaire.

Objective: To investigate if the McGill Pain Questionnaire confirms the distinction between chronic migraine and chronic tension-type headache.

Background: It has been suggested that different categories of chronic daily headache should be distinguished; in particular, chronic migraine and chronic tension-type headache.

Methods: The McGill Pain Questionnaire and a visual analog scale were administered to 40 patients with chronic daily headache, 85 patients with migraine, and 47 patients with episodic tension-type headache. The patients with chronic daily headache were subdivided, according to criteria described by other authors, into those with chronic migraine (n=29) and those with chronic tension-type headache (n=11). Weighted McGill Pain Questionnaire item scores, subscales, total pain rating indexes, and choice frequency of the descriptors were calculated. The data of chronic migraine and chronic tension-type headache were compared and tested for significant differences (Student t test). The same was done for migraine and episodic tension-type headache. Data were also processed through the Self-organizing Map, a system based on a counter-propagation neural network.

Results: In the chronic migraine group, compared with the chronic tension-type headache group, scores were higher in 17 of 20 McGill Pain Questionnaire items (significantly in 5) and for the sensory and affective subscales (significantly). In the migraine group, compared with the episodic tension-type headache group, scores were higher for 18 McGill Pain Questionnaire items (significantly in 7), and for the sensory, affective, and mixed affective-evaluative subscales, total pain-rating index, and visual analog scale (all significantly). The coincidence of descriptors of first choice was low between chronic migraine and chronic tension-type headache, but it was high between chronic migraine and migraine and between chronic tension-type headache and episodic tension-type headache. After Self-organizing Map analysis, chronic migraine and chronic tension-type headache were prevalently distributed in 2 different areas of the map.

Conclusions: In the disorders characterized by a daily and near-daily headache, the McGill Pain Questionnaire consistently can discriminate between those evolving from migraine and those evolving from tension-type headache, indirectly confirming the validity of a distinction between these 2 clinical conditions. The differences are similar to those observed between patients with migraine and patients with episodic tension-type headache. This seems to be independent of the pain level since the difference of the total pain-rating index and the visual analog scale between chronic migraine and chronic tension-type headache was not statistically significant.