Pericranial muscle tenderness and exteroceptive suppression of temporalis muscle activity: a blind study of chronic tension-type headache.

The aim of the present study was to examine the ability of pericranial muscle tenderness and the second exteroceptive suppression period to distinguish chronic tension-type headache sufferers, migraine sufferers, and controls in a young adult population utilizing a blind design. The second exteroceptive suppression periods were assessed using the methodology recommended by the European Headache Federation and were scored with an automated computer software program designed in our laboratory to provide reliable, standardized, and precise quantification of exteroceptive suppression periods and eliminate any influence of experimenter bias that may occur with manual scoring. Our sample consisted of 45 subjects diagnosed according to IHS criteria: 25 with chronic tension-type headache and 20 with migraine without aura. Twenty-three headache-free controls were recruited. Consistent with our previous findings, abnormalities in pericranial muscle tenderness, but not in the second exteroceptive suppression period distinguished chronic tension-type headache sufferers from controls. The chronic tension headache sufferers exhibited the highest pericranial muscle tenderness and the control group exhibited the lowest tenderness (P < .001). Pericranial muscle tenderness was quite successful in distinguishing recurrent headache sufferers from controls, but failed to distinguish chronic tension-type headache sufferers from migraineurs. Our findings raise the possibility that pericranial muscle tenderness is present early in the development of chronic tension-type headache and migraine without aura, and thus might contribute to the etiology of headache disorders. Our findings also indicate that a shortened second exteroceptive suppression period is not a reliable marker for chronic tension-type headache in young adults.