Etiology of Headaches and Migraines
Headaches are a common complaint which affects the majority of the population at some point in their lives. Chronic or recurrent headaches or migraines, have been reported to be suffered by as high as 66% of the global population, representing a major health problem disturbing both quality of life and work productivity.
Headache Australia estimates the total cost of migraines alone on the economy is in excess of $1 billion. This includes direct treatment costs and indirect costs due to absenteeism and reduced effectiveness at work.
Traditional Headache and Migraine Classification Model
Classification of "headaches" are principally based on evaluation of headache symptoms and clinical testing. The International Headache Society revised classification of headache disorders (2004); classifies headaches into 14 groups and categorises these groups into four parts, with a total of over 270 possible differential diagnosis of headache and migraine. This classification systems views each diagnosis as a distinct entity with unrelated and often unknown patho physiological mechanisms. As a clinician managing these conditions, following this complex classification system to obtain a diagnosis can be a bit like a game of pin the tail on the donkey; akin to a best guess approach to help determine possible treatment strategies. You will often hear patients describe the different number of treatments that have been trialed, at times with little or no success, or with intolerable side effects.
Convergence Model and Headaches and Migraine
Recent research into migraines and headaches has found a common link between these conditions and concurrent central sensitisation of the trigeminocervical nucleus. This convergence model, developed by Roger Cady (2002), a world renowned headache specialist, shows that most headaches and migraines fall on a converged line of pain, meaning they are all relative expressions of the same underlying pathophysiology of sensitisation of the trigeminocervical nucleus.
This has created a shift in management strategies of headache and migraine away from a diagnostic classification model (primarily designed for research purposes), to identification and management of contributing influences to trigeminocervical nucleus sensitisation. In short, rather than managing the symptoms, we have started to manage the underlying pathophysiology.
The Trigeminocervical Nucleus
There are five major inputs into the trigeminocervical nucleus:
1. C1, C2 and C3 Afferents
2. Trigeminal Nerve Afferents from the face, jaw and teeth
3. Blood vessels within the brain
4. Diffuse Noxious Inhibitory Pathway
- A system that controls perception of pain in relation to other noxious stimuli
- Often lowered in chronic pain conditions
5. Serotonergic System
- Hormonal system that influences the bodies response to stress, environmental factors such as food and smells, and other hormones.
Under normal circumstances, information passes through this system and is filtered to provide relevant sensory awareness to the cortex. When sufficient levels of noxious stimuli are detected, and pass a certain threshold, pain is experienced. However, chronic noxious input from the cervical or trigeminal nerves can lead to habituation, or a lowering of the threshold required to provoke a pain response. This can be due to neck, jaw, ear, facial or tooth pain of any etiology. Previously benign stimulus eg, foods, bright lights, noises, bad posture, excessive talking or chewing, or even stress can trigger a pain response resulting in a headache or migraine.
The Headache, Neck & Jaw Clinic Approach
Our approach to treating this system is to systematically assess the craniocervical (upper neck and skull) and craniomandibular (jaw) neurological and kinematic systems for dysfunction or consequent sensitisation that may contribute to chronic central sensitisation of the trigeminocervical nucleus, thus contributing to priming the brain stem for lowered thresholds of provocation to generate a headache or migraine response. By correcting the dysfunction or sensitisation with specially refined manual treatment techniques, and providing a stable outcome through exercises and education, we can eliminate the noxious input to this system and help rectify the headache firing threshold.
Combining techniques to desensitise the trigeminocervical nucleus and correct underlying regional mechanical dysfunction with patient education and self management strategies has proven to provide meaningful and sustainable relief for countless of our headache and migraine clients. We look forward to the opportunity to assist you in helping manage these clients to provide optimal quality of life outcomes for them and their families.
Who should you refer?
Anyone who suffers from chronic recurrent headache or migraine symptoms should have their trigeminal and cervical systems expertly assessed for possible influence on or contribution to a sensitised trigeminocervical nucleus as a causative factor for headaches and migraines (red flags excluded).
Any relevant investigations or scans are always useful and we appreciate as much information as you can give us regarding presentation and previous management strategies, including medication and their effectiveness. We will always endeavour to report back to you after the initial consultation to inform you that your patient has attended and of any findings and planned treatment strategies. In some cases, we may contact you directly to acquire further information or discuss other management plans.
What should your patient expect?
At the Headache, Neck and Jaw Clinic, we strive to provide a high level of clinical expertise and client care. We believe in a quality patient journey and that best outcomes for our clients are achieved through this expertise and our sharing of knowledge with our clients.
All our techniques are safe. We do not perform any high velocity manipulations or joint cracking, and all due care is taken to screen out any potential contradicting factors to treatment prior to commencing any technique or exercise. Some techniques can involve some discomfort, including temporary reproduction of the patients headache or migraine symptoms. We stress that this is temporary, and it is a vital step in determining causation of central sensitisation from the structures we are assessing. We are careful to explain this process to patients so they can make informed decisions regarding their treatment.
If we are able to identify regional dysfunctions that are contributing to headache and migraine presentations, we expect to be able to make a measurable/meaningful change in the patients symptoms within the first 6 weeks of treatment. In some cases this can mean full resolution, but more commonly we aim for a marked decrease in frequency, intensity, duration and ease of provocation of headaches and migraines. Importantly, the patient will also be taught how to treat, control and prevent their own symptoms with relevant exercises and education addressing the underlying causes of their headaches. The goal is to enable them to sustain their improvement without requiring ongoing treatment.
Of course, we need to be ever aware of more sinister underlying pathologies when dealing with headache and migraine presentations. These include space occupying lesions, inflammatory conditions such as temporal arteritis and meningeal headaches, cerebro vascular headaches such as subarachnoid haemorrhages and severe hypertension, and side effects from medications. In our experience, it would be unusual for these conditions to present directly to physiotherapy. As first contact practitioners, we have to be aware of how these conditions present.
Red flag presentations include:
- Sudden onset of a new severe headache
- A recent worsening pattern of a pre-existing headache with no obvious cause
- Headache associated with systemic illnesses such as cancer or HIV
- Concurrent systemic symptoms such as fever or skin rash
- New onset of headache during or following pregnancy
- Moderate or severe headache triggered by cough, exertion, or bearing down
- Headache associated with focal neurologic signs excluding typical aura
Through thorough subjective and objective examination we can identify any potential risk to moving forward with treatment, and we will always refer on if any concerns are raised during assessment or treatment.