Most of us have suffered that blinding, nagging headache. Headaches are traditionally divided into two types: Tension headaches and Migraines. However, it is now believed that some headaches that were assumed to be falling into either of these categories are actually caused by damaged structures in the neck or cervical spine. Not all headaches, but quite a significant number of them seem to be originating in the neck. These headaches are called cervicogenic headaches.
How Neck Problem Can Cause Headaches
Cervicogenic headaches are usually felt in the neck region first and then tend to radiate up into and around the head. It also sometimes reaches the front of the head, temples or behind the eyes. These incapacitating, miserable headaches arise from problems or injuries in the upper cervical spine (upper neck).
How can neck pain result in a headache? Experts believe that this is because the nerve fibres from the upper neck converge with the nerve fibres branching off from the trigeminal nerve. Because of this shared platform, the brain can’t precisely interpret the location of the pain. Let’s dig into this a little deeper.
The entire spine, of which the neck is a part, is made up of individual bones stacked on top of each other forming a vertical hollow canal. Through this canal runs the very important spinal cord, an extension of brain that has many nerve roots branching off it.
When it comes to the anatomy of neck, it is a remarkably engineered structure made up of bones, nerves, muscles, ligaments and tendons. The neck has seven bones or vertebrae – C1, C2, C3, C4, C5, C6, C7 – originating at the base of the skull and extending down to the upper back. The three nerve roots of the cervical spine, more specifically located at C1, C2 and C3, share a common pain nucleus with the trigeminal nerve. This pain nucleus is responsible for routing pain signals to the brain.
Now, the trigeminal nerve is the largest cranial nerve and the main sensory nerve that runs through the brain. The nerve has three divisions branching off to the forehead and eye (ophthalmic nerve), cheek (maxillary nerve) and lower face and jaw (mandibular nerve) on the either side. The trigeminal nerve is responsible for transmitting sensations from the face to the brain. Besides sensory functions, the trigeminal nerve also activates the muscles used in biting and chewing.
Some nerve fibres of the trigeminal nerve descends into the neck where they interact with the sensory fibres emanating from the upper nerve roots of the cervical spine. This convergence of upper neck and trigeminal sensory pathways fools the brain so it can’t the pin-point source of the pain. “The trigeminocervical nucleus is a region of the upper cervical spinal cord where sensory nerve fibres in the descending tract of the trigeminal nerve (trigeminal nucleus caudalis) are believed to interact with sensory fibres from the upper cervical roots. This functional convergence of upper cervical and trigeminal sensory pathways allows the bidirectional referral of painful sensations between the neck and trigeminal sensory receptive fields of the face and head.” .
Referred Pain: Perceived in the head but with source in the neck
For this reason, a cervicogenic headache is also called referred pain, that arises from a distant part of the body other than its true source. So the pain in this case is referred to the head from either bony structures or soft tissues of the neck.
If there is any damage or injury to the bones in the neck, it can lead to pinched trigeminal nerve in this area. Since the nerve tracts for cervical nerves and the trigeminal nerve are shared, the brain misunderstands the pain signals and perceives this pain as being located in the head. What is happening is that when the trigeminal nerve transmits a message of pain to the brain, the brain can’t tell the pain source and ends up perceiving the pain in the head.
Cervicogenic headaches can be caused by damage to one or more structures in the neck including the nerves of the top 3 bones, joints, ligaments and muscles. Whiplash injuries, sport injuries, falls, herniated cervical disc and arthritis are some of the leading causes of damaged structures in the neck or the cervical spine. Certain neck movements, excessive twisting of neck or repetitive activities such as poor sitting postures can also trigger the damage. Sometimes the cause of damage can even be traced back to an injury suffered in the childhood like a nasty fall at the swing. So basically, anything that can cause inflammation or irritation to the trigeminal nerve can cause cervicogenic headaches, often misdiagnosed as migraines or tension headaches that ‘appear’ to be originating in the head and not in the neck.
Unfortunately, so many patients are misdiagnosed each year and as a result do not get the right treatment. A proper diagnosis and the subsequent treatment  can go a long way in relieving the debilitating pain and in improving the quality of life.
- David M. Biondi Cervicogenic Headache: A Review of Diagnostic and Treatment Strategies. The Journal of the American Osteopathic Association, April 2005, Vol. 105, 16S-22S.
- Phil Page. Cervicogenic Headaches: An Evidence-Led Approach to Clinical Management. International Journal of Sports Physical Therapy. 2011.