Neck extensor muscular structure in cervicogenic headaches
Cervicogenic headache (CH) is an unrecognized yet relatively common chronic headache disorder that is often misdiagnosed as migraine or tension-type headache. It is widely excepted within the literature that CH is a syndrome characterized by chronic unilateral or bilateral pain that is referred to the head from either bony structures or soft tissues of the neck.
There is evidence that CH is disproportionately seen in elders and is comorbid with functional decline of the strength and endurance of the cervical musculature. There has been speculation as to whether the decline in function of the cervical musculature is related to the pathogenesis of the condition or whether it develops as a symptom secondary to another process. Yet, no studies have assessed the macroscopic qualities of the cervical musculature in individuals with CH.
A recent study used MRI imaging to assess the cervical musculature of 14 participants with diagnosed CH and 14 controls. Relative cross-sectional areas (rCSAs) and fatty infiltrate of the rectus capitis posterior major, rectus capitis posterior minor, multifidus, semispinalis capitis, splenius capitis, longus capitis/colli, and sternocleidomastoid muscles were assessed in both groups. The results of MRI analysis showed that the CH group had significantly less rCSA and higher level of fatty infiltration on the rectus capitis posterior major and minor and splenius capitis muscles, but no significant difference in the cervical flexors.
These data re-enforce the current paradigm that the cervical musculature plays a significant role in the course of and potentially the pathogenesis of cervicogenic headaches, and that there is likely to be widespread structural change in the cervical extensors in populations with CH.
It is also noted by the authors in the study that a causal relationship between the decreased muscle bulk and pathogenesis cannot be reliably established based upon these data, and further research is needed to confirm this relationship. As such, therapists should be aware of this, and emerging data on the subject so as to inform ongoing research, treatment techniques and modalities.
> From: Uthaikhup et al., Musculoskelet Sci Pract 29 (2017) (Epub ahead of print). All rights reserved to Elsevier Ltd. Click here for the online summary.