This is part 2 of my headache series and today’s discussion is all about Cervicogenic headaches. A headache that is caused by a dysfunction within the cervical region; this is what we call as chiropractors, a cervicogenic headache. As you may already know, most headaches come from a number of sources, Jaw pain, Hypertension, Dehydration and so on. What I will be discussing with you today, are some the causes, diagnoses, and treatments of a cervicogenic headache.
Cervicogenic headache usually starts in what we call the suboccipital area, which is that muscular area that is just under the occiput of the head. That pain starts there - it can be on one or both sides - and it tends to radiate up into the head and around the head. The easiest way to visualize it is to actually take the palm of your hand and place it on the back of the head and that really is where the pain spreads. More rarely, the pain can travel to the front of the head and behind the eye. Once again, that's not common and it is even less common for it to just appear in the front of the head or behind the eye, but it does happen.
What causes a Cervicogenic Headache?
In order to discuss the causes of cervicogenic headache, I need to take a step back for a second and talk about the anatomy cervical spine “neck”. What we're looking at here is the back of the head, the neck or cervical spine, and specifically what we're looking at is these little joints. Now these are facet joints - or zygapophysial joints – the hinge-like joints in the spine. Now, these joints are true joints - in other words, they have the synovial fluid, synovial capsule, cartilage - and they can react like any other joint; in other words, they can get irritated, inflamed, and can become painful. Now, what's important in this context is that the innervations for these joints comes from a very small branch - called medial branch - that comes around here and goes into the joint. At times, that branch continues on and becomes another nerve. The nerve we're concerned about specifically is called the third occipital nerve. This nerve crosses the C2-3 facet joints and the facet joints are named for the different vertebral bodies that are interfacing and forming that joint, so this is a C2 and C3. So a C2-3 is crossed by the third occipital nerve, then continues onto the occiput and around the scalp. If there is irritation at this joint, this nerve tends to transmit pain and cause the pain that we're discussing - the pain that actually encompasses the occiput and the back of the head.
Now, the causes of this, there are many to discuss. If we are to group them together, the most common cause is really similar to a whiplash injury. If you think about the joint itself as a hinge-like joint that provides the sliding motion. Whiplash is essentially an acceleration-deceleration injury grinding that joint. That usually is the first step to precipitating this cervicogenic headache because it irritates the joint, then the irritation drives the whole process.
Now, whiplash or acceleration-deceleration injury through that joint can mean motor vehicle accidents, can mean just falls - commonly falls on ice - that cause this motion of the head and that's usually more common in the younger population. When we talk about the older population and when arthritis becomes more of a problem, that arthritis in that same joint can also cause irritation, inflammation, and irritation to that nerve, causing that cervicogenic headaches. Of course, anything that would cause irritation to that nerve would cause the headaches and muscle spasms, grinding that joints, irritation to the joint from other causes, from the laxity of the joint, in different conditions that really predispose the hypermobility or increased mobility of that joint can also predispose to inflammation and irritation of that nerve, once again predisposing one to cervicogenic headaches.
How is a Cervicogenic Headache Diagnosed?
Diagnosing cervicogenic headache can be somewhat tricky because the headaches resemble a number of different headaches and to complicate the matter, they can trigger other headaches. So, for instance, patients can have cervicogenic headaches as another trigger for a migraine. Cervicogenic headache in itself can cause tension types of headache. But if there is suspicion for cervicogenic headache, the studies have shown that a very precise diagnostic procedure can be very accurate in diagnosing it.
The way this procedure is done is under controlled conditions and the guidance of an x-ray or fluoroscopy. A needle is actually placed at the joint at three separate spots - at the most likely places of this nerve - and anesthetic is placed very precisely at the location of the nerve. If this eliminates the pain, then that's a very positive indication that that's the source of the pain.
How is a Cervicogenic Headache Treated?
In discussing treatments for cervicogenic headaches, it's important to remember that we have to look at it as constellation of symptoms, even though we know that there is a third occipital nerve that gets irritated and that's what we have to treat, that resolves a part of the problem - a very important part of the problem - but from literature we know that we see the best outcomes by approaching it from several different directions. What I mean by that is: one of the main treatments for cervicogenic headaches is addressing the pain generator. So, reducing the inflammation at the joint and reducing the inflammation at that third occipital nerve is one of the first things to do. That can be done by placing medication right at the source of the inflammation and irritation. Another way to do this - and this is a very well-studied approach - is to use radiofrequency rhizotomy. Radiofrequency rhizotomy essentially eliminates those feeding nerve fibers and the way this is approached is a probe is placed along the path of this nerve and then radiofrequency energy is used in order to treat this area to eliminate those nerve fibers.
Besides using these techniques, what's important to remember is that chiropractic care and theruapeutic modalities such as Ice and Interferntial units to decrease inflammation and reduce pain, along with PNF stretching, or proprioceptive neuromuscular facilitation stretching, is a set of stretching techniques commonly used in clinical environments to enhance both active and passive range of motion in order to improve motor performance and aid rehabilitation. So, it is important to address this from a point of controlling the pain because, as we know, pain really drives a lot of the muscle spasms and prevents one from doing the exercises and manipulations that are necessary in order to get better. Once everything comes together and all of the components of the biomechanical chain are treated, the myofascial component is treated, the irritation and inflammation is eliminated, most patients tend to recover very well.