When we hear the term headache, we don’t usually think about the neck. Rather, we focus on the head, more specifically, “…what part of the head hurts?” But, upon careful questioning of patients, we usually find some connection or correlation between neck pain and headaches.
The key to this connection can be found in looking at the anatomy of the neck. There are 7 vertebrae that make up the cervical spine and 8 sets of nerves that exit this part of the spine and innervate various parts of the head, neck, shoulders and arms, all the way to the fingers. Think of the nerves as electric wires that stretch between a switch and a light bulb. When you flip on the switch, the light illuminates. Each nerve, as it exits the spine, is like a switch and the target it travels to represents the light bulb. So, if one were to stimulate each of the nerves as they exit the spine, we could “map” exactly where each nerve travels (of course, this has been done). When we look specifically at the upper 3 sets of nerves that exit the spine (C1, C2, and C3), we see that as soon as they exit the spine, they immediately travel upwards into the head (the scalp). Like any nerve, if enough pressure is applied to the nerve, some alteration in nerve function occurs and usually a sensory change is noted (numbness, tingling, pain, burning, etc.). If the pressure continues, these symptoms can last for a long time. These types of headaches are often called “cervicogenic headaches” (literally meaning headaches that are caused by the neck). These can be caused by the nerves getting pinched by tight muscles through which they travel as they make their way to the scalp.
Another connection between the neck and headaches includes the relationship between 2 of the 12 cranial nerves and the first three nerves in the neck described above. These types of headaches usually only affect one half of the head – the left or right side. One of the cranial nerves is called the trigeminal nerve (cranial nerve V). Because the trigeminal nerve innervates parts of the face and head, pain can also involve the face. Another cranial nerve (spinal accessory, cranial nerve IX) can also interact with the upper 3 cervical nerve roots, resulting in cervicogenic headaches. People with cervicogenic headaches will often present with an altered neck posture, restricted neck movement, and pain when pressure is applied to the base of the skull or to the upper vertebrae. Other than a possible numbness, there are no clinical tests that we can run to “show” this condition, though some patients may report scalp numbness or, it may be found during examination.
Though medication, injections, and even surgical options exist, manipulation applied to the small joints of the neck, especially in the upper part where C1-3 exit, works really well so why not try that first as it’s the least invasive and, VERY EFFECTIVE! In some cases, a combination of approaches may be needed but many times, chiropractic treatment is all the patient needs for a successful outcome.