Dan Murphy, DC
Private Practice of Chiropractic;
Diplomate American Board of Chiropractic Orthopedist;
Faculty Life Chiropractic College West;
Vice President ICA 2003-2009;
ICA Chiropractor of the Year 2009
INTRODUCTION
All headaches synapse in the Trigeminocervical Nucleus (1):
The 4 suboccipital muscles are innervated by the posterior primary rami of the C1 nerve root (1):
Three of the suboccipital muscles are directly and firmly attached to the spinal dura mater (2, 3, 4, 5, 6):
DISCUSSION
The apparent function of the attachment of the suboccipital muscles is to prevent the cervical spine Dura Mater from being mechanically irritated, injured or inflamed during spinal motions.
The cervical spinal Dura Mater is innervated with pain afferents (nociceptors) from the upper cervical spine nerve roots.
Upper cervical spine nerve root nociceptors synapse in the Trigeminocervical nucleus, and are therefore capable of initiating an electrical signal in the brain interpreted as being headache.
Mechanical dysfunctions of the upper cervical spine may compromise the ability of the suboccipital muscles to protect the Dura Mater from motion related stress, irritation, injury, and inflammation.
Whiplash extension injuries occur quickly, so that the suboccipital muscles do not have enough time to contract and pull the spinal Dura Mater to safety, resulting in injury and headache.
In chronic whiplash patients, injured suboccipital muscles may undergo atrophy and fatty infiltration, further compromising the ability of these muscles to protect the dura mater from irritation and inflammation during routine motions, resulting in headache (7).
DISCUSSION
Chronic upper neck postural stress and distortions that invoke contraction of the suboccipital muscles may cause chronic stress on the spinal dura mater, resulting in headache. This is particularly important in postural techniques, such as Chiropractic Biophysics.
Mechanical dysfunctions of the upper cervical spine may also irritate/inflame the spinal cord and its blood supply because the Dura Mater is attached to the vascular Pia Mater that surrounds the spinal cord (8).
There is biological plausibility for upper cervical spinal manipulation, occiput-atlas-axis chiropractic alignment, postural improvement, and suboccipital muscle myotherapy to be utilized in the cervicogenic headache patient.
References