Frequent intermittent headache is prevalent in today's society. Differential diagnosis can be challenging in the common headache types of migraine, tension-type and cervicogenic headache, as there can be considerable symptomatic overlap. Cervical musculoskeletal dysfunction is considered to be the underlying cause of cervicogenic headache, but neck pain and tenderness are common accompaniments of migraine and tension-type headache. There is little knowledge of whether or not cervical musculoskeletal impairment is associated with the neck pain of these headache types, to justify the administration of treatments such as manipulative therapy and specific neck exercise.
The current physical impairment criteria for the classification of cervicogenic headache are largely non-specific. It was reasoned that diagnosis of this headache form might be improved with a more comprehensive understanding of the precise nature of impairment in the cervical articular, muscular and sensorimotor systems. The basic aims of this study were twofold namely, to investigate if there was a pattern of cervical musculoskeletal impairment which more precisely characterized cervicogenic headache and to investigate whether cervical musculoskeletal impairment accompanied other frequent intermittent headache types such as migraine and tension-type headache, whether suffered as a single headache or one of multiple headaches.
One hundred and ninety six subjects with frequent intermittent headache and 57 non-headache control subjects participated in this study. Eighty-eight subjects reported a single headache and 108 reported two or more headache types. All headache subjects completed a questionnaire inclusive of items for the classification of migraine, tension-type headache IHS (1988) and cervicogenic headache (Sjaastad et al 1998). Two investigators who were blind to the results of the physical examination later classified headaches independently. The tests of the cervical musculoskeletal system included measurement of range of movement and manual examination of the cervical segments, performance in the cranio-cervical flexion test (CCFT), the strength of the flexor and extensor muscles, cross sectional area (CSA) of the selected neck extensor muscles and a measure of cervical kinaesthetic sense.
Using the questionnaire, there was a 67% agreement between the two examiners for classification of subjects with a single headache and a 45% agreement for headache classification in the presence of multiple headaches. The analysis of the single headache cohort revealed significant differences in the measures of cervical musculoskeletal impairment between the cervicogenic headache subjects, those with other headache types and control subjects. Cervicogenic headache subjects were found to have a higher incidence of upper cervical joint dysfunction as determined by manual examination, reduced range of motion in extension and rotation, higher RMS EMG amplitudes in the sternocleidomastoid and scalene muscles in the CCFT, lesser cervical flexor and extensor strength and decreased muscle CSA in the rectus capitis posterior major and semispinalis capitis ipsilateral to pain (all p<0.001). No differences were found in tests of cervical kinaesthetic sense. Importantly, no differences were found in any test between the migraine, tension-type headache and control subjects (p>0.05). A pattern inclusive of upper cervical joint dysfunction, reduction in cervical extension and performance in the CCFT characterized cervicogenic headache with 100.0% sensitivity and 94.4% specificity. When the discriminant variables were applied to the data of the subjects with multiple headaches, it was found that musculoskeletal impairment was not present in multiple headaches unless a cervicogenic headache was one of the headache types.
This study has shown that cervicogenic headache is characterized by a pattern of musculoskeletal impairment which can enhance the accuracy for its classification in the presence of symptomatic overlap with other headache types. Cervical musculoskeletal impairment is not present in migraine and tension-type headaches and appears not to be the source of any neck pain or tenderness which might accompany these headaches. No support can be given to the use of manipulative therapy and specific neck exercises in the management of these latter frequent intermittent headache types.