A proposed etiology of cervicogenic headache: The neurophysiologic basis and anatomic relationship between the dura mater and the rectus posterior capitis minor muscle

Abstract

Objective: To examine the neurophysiologic basis and anatomic relationship between the dura mater and the rectus capitis posterior minor muscle in the etiologic proposition of cervicogenic headache. Data Source: On-line searches in MEDLINE and the Index to Chiropractic Literature, manual citation searches, and peer inquiries. Results: Connective tissue bridges were noted at the atlanto-occipital junction between the rectus capitis posterior minor muscle and the dorsal spinal dura. The perpendicular arrangement of these fibers appears to restrict dural movement toward the spinal cord. The ligamentum nuchae was found to be continuous with the posterior cervical spinal dura and the lateral portion of the occipital bone. Anatomic structures inervated by ceervical nerves C1–C3 have the potential to cause headache pain. Included are the joint complexes of the upper 3 cervical segments, the dura mater, and spinal cord. Conclusion: A sizable body of clinical studies note the effect of manipulation on headache. These results support its effectiveness. The dura-mascular, dura-ligamentous connections in the upper cervical spine and occipital areas may provide anatomic and physiologic answers to the cause of the cervicogenic headache. This proposal would further explain manipulation's efficacy in the treatment of cervicogenic headache. Further studies in this area are warranted to better define the mechanisms of this anatomic relationship. (J Manipulative Physiol Ther 1999;22:534–9).

Introduction

The pain and discomfort experienced from headaches are significant indicators that anatomic and physiologic changes have taken place. Headaches can result from cervical spine joint complex dysfunction,¹ vascular disease, metabolic dysfunction, brain tumors, and trauma. The severity of this disorder leads to more than 18 million annual office visits in the United States.² The Nuprin Report has documented that, “156 million full-time work days are lost each year because of headaches, at an estimated cost of 25 billion dollars in lost productivity.”³ Headaches are also found to be the most common reason for the use of over-the-counter analgesic medication.⁴ The extensive impact of headaches on a patient's quality of life far exceeds that of other chronic conditions such as osteoarthritis, hypertension, and diabetes.⁵ Health care practitioners find headaches to be one of the most commonly addressed complaints. One study found that 27% of those reporting a headache have used a form of alternative management. Chiropractic was found to be the most common practitioner-based health care sought.⁶

The diverse nature of headaches and their symptoms have allowed for great disparity in the literature as to causation and management of resulting conditions. The failure to accurately determine the cause of chronic benign headaches (eg, cervicogenic, migraine, or tension type) has led to a variety of management techniques and treatment options that may or may not address the true nature of the patient's complaint. Studies conducted by the International Headache Society suggest that cervicogenic headaches account for approximately 15% to 20% of all recurrent benign headaches.⁷ The neurophysiologic basis for the cervicogenic headache is the convergence that takes place in the trigeminocervical nucleus between receptive fields of cervical nerves C1–C3 and the nociceptive afferents from the trigeminal nucleus. Structures innervated by the first 3 cervical nerves have shown a potential for causing a cervicogenic headache.⁸ The neurophysiologic basis and recent anatomic disclosure by Hack et al⁹ will be thoroughly examined in this review. This finding may provide anatomic evidence that implicates cervical spine joint complex dysfunction as a cause of cervicogenic headache. He reported a connective tissue bridge between the rectus capitis posterior minor muscle and the posterior spinal dura at the atlanto-occipital junction⁹ (Fig 1).

This recent discovery, along with the suggested neurophysiologic mechanism, may provide significant evidence relating headache to the cervical spine joint complex dysfunction.

This overview and subsequent correlation of the literature will examine the recent anatomic finding and apply this knowledge to the proposed neurophysiologic mechanism involved in the cervicogenic headache.

This article consists of a qualitative and critical review of reports on the treatment of chronic benign headaches by spinal manipulation. Studies that reported only on those individuals designated as benign headache patients were used. Single-participant case studies were excluded from this review. Five independent studies were examined in the confirmation of the connective tissue bridges at the atlanto-occipital junction between the rectus capitis posterior minor muscle and the posterior spinal dura. One study was also included that revealed a connection between the ligamentum nuchae and the posterior spinal dura. The search strategy in these reports included on-line searches in medical databases (MEDLINE, Index to Chiropractic Literature), manual citation searches, and peer inquiries.