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Dr. Rapoport: Do you commonly see patients who present with symptoms of both central and peripheral symptoms in practice?
Dr. Romero-Reyes: Yes, I see patients that present with temporomandibular disorders (TMD) and headache comorbidity, as well as patients with migraine, tension-type headache, and cervicogenic headache with myofascial pain.
Dr. Rapoport: Why do you think this condition is so challenging to treat?
Dr. Romero-Reyes: I think this is because of the lack of understanding and awareness that in addition to the multifactorial nature of headache disorders, other types of disorders that are not neurovascular in origin may influence trigeminovascular nociception, and these types of non-neurovascular disorders involve the skill and knowledge of other expertise.
Headaches receiving inputs from extracranial structures such as in TMD (temporomandibular joint [TMJ] and muscles of mastication) and/or cervical structures (cervical spine, cervical muscles) require multidisciplinary evaluation and management. In these cases, the management should involve a neurologist specialized in headache disorders, a dentist trained in TMD and orofacial pain disorders, and a physical therapist with special training in craniofacial and cervical Therapeutics. Multidisciplinary communication is key for successful management.
Another reason is that myofascial pain (MFP) is often overlooked in patients with headache disorders. In my experience, patients with episodic and chronic migraine, episodic and chronic tension-type headache, cervicogenic headache, and patients presenting TMD and headache comorbidity can present trigger points in the craniofacial and cervical muscles, an indication of MFP. It has been reported that these patients present a higher disability impact. The presence of MFP may be contributing to the activation of the trigeminovascular system and therefore facilitate, exacerbate, and perpetuate headache symptomatology and may accelerate the progression to a more chronic form of the disorder.
Dr. Rapoport: In your opinion, is this considered a controversial topic? Why or why not?
Dr. Romero-Reyes: Yes, I think it is necessary to clarify that tenderness in the back of the head or of neck muscles present in headache patients does not necessarily imply that it is due to a nerve compression. This could also be caused by local myalgia but more commonly, from latent or active myofascial trigger points present in the muscles of the area being palpated, or by referred pain beyond the area of the muscle being palpated. Suboccipital muscles (in the occiput area) are not the only muscle group that is associated with headache and neck pain symptomatology. For example, the trapezius muscle, which is an overlooked source of tension- type and cervicogenic headache, can present trigger points that can refer pain to the shoulder, neck, head, face and the eye. In addition, other craniofacial and cervical muscles such as the sternocleidomastoid (SCM) and temporalis muscles have been shown to be associated with headache symptomatology in the migraineur, as well as the chronic tension-type headache patient. Other muscles that also refer to the craniofacial area and can elicit headache and neck pain symptomatology include the masseter, occipitofrontalis, splenius capitis, splenius cervicis, semispinalis capitis, semispinalis cervicis and multifidi (cervical). The presence of trigger points in these muscles do not support or warrant the need to be removed or managed with non-conservative approaches.
Myofascial trigger points can result from muscle injury and overload, parafunctional activity, and poor head and neck posture. MFP is characterized by a regional pain and presence of localized tender areas (trigger points) in muscle, fascia or tendons that reproduce pain when palpated, and produce a pattern of regional pain spreading along the muscle palpated, or beyond the location boundary of the muscle palpated. It has been shown by microdyalisis that inflammatory mediators and neuropeptides are present in the area of an active trigger point. In addition, an increase of electromyography activity has been shown in trigger points in patients with chronic tension-type headache when compared with controls.
The importance of an evaluation by a skilled clinician in the craniofacial and cervical area to verify the source of pain is critical. The patient may be reporting pain in one area, but the source of the pain is in another area, and this is typical symptomatology present when there are active trigger points. In addition, an assessment of any contributing factors arising from the cervical spine (eg, poor posture) and craniofacial area (eg, TMD) that may exacerbate headache symptomatology is vital to proper diagnosis.
In my experience, patients with migraine, tension-type headache, cervicogenic headache, and TMD and headache comorbidity present MFP perpetuating headache symptomatology. MFP is not managed by surgical interventions. This perpetuating factor can be managed effectively with conservative measures. The plan is tailored for each patient’s needs. In general, the plan of management may include trigger point injections in the muscle with anesthetics, dry needling, and a physical therapy plan that may include education regarding habits and posture, exercises and physical therapy modalities, which are crucial to relieve pain and increase function. In cases of TMD and headache comorbidity, an occlusal appliance (stabilization appliance) can be included if necessary. We should also consider behavioral therapies (especially EMG biofeedback training) and some oral anti-inflammatories or muscle relaxants in the beginning of management, together with the plan of management mentioned above.
With these approaches to manage the MFP component in headache patients, I have been able to see that in migraineurs with MFP, the frequency and severity of the attacks decrease significantly. The patient may still experience migraine attacks, but feel happy to have the possibility to reduce medication intake and be in more control of their pain. In patients with tension-type headache, I have seen this even more dramatically.
This is telling us that headache pathophysiology involves a “conversation” between the peripheral and central nervous system, which influence each other. Peripheral nociceptive input coming from extracranial structures can induce trigeminovascular activation and therefore exacerbate a headache disorder and vice versa. Chronic myofascial pain may be the result of central sensitization due to the protracted peripheral nociceptive input (eg, poor posture, neck strain, parafunctional activity), therefore perpetuating the headache disorder even more.
Dr. Rapoport: Do you have any other comments about the article Treatment Challenges When Headache Has Central and Peripheral Involvement that you would like to share with our readers?
Dr. Romero-Reyes: It is simplistic to say migraine is either a peripheral or a central disorder, or that symptoms are either peripheral or central. Beyond thinking about migraine pain, migraine is fundamentally a brain (central) disorder. Its associated symptoms (nausea, phonophobia, photophobia) tell us this. Migraine headache is complex, and most likely the result of central mechanisms that can be influenced by peripheral inputs from the craniofacial and cervical region.
Embarking on surgical interventions for the management of headache disorders warrants a caution since it is still an experimental research question and the need of such therapies should be evaluated against conservative management. We are in a very exciting and hopeful time for migraine management. New evidence-based options from biological agents, such as anti-calcitonin gene-related peptide (CGRP) therapies, to non-pharmacological approaches, such as neuromodulation, can be offered to the patients. If the patient is experiencing pain in the neck area or other craniofacial area, it is recommended to have a thorough evaluation by a physical therapist with special training in cervical and craniofacial therapeutics and/or a dentist trained in TMD and orofacial pain disorders to work in consultation with a neurologist to elaborate a personalized management plan. Do not overlook the contribution of myofascial pain (trigger points) as well as TMD in the symptomatology of headache disorders. Few patients need to undergo surgical measures of peripheral nerves and muscles for improvement. An exhaustive evaluation must be undertaken first.
Resources for patients:
AHS
https://americanheadachesociety.org/
https://americanheadachesociety.org/wp-content/uploads/2018/06/Choosing-Wisely-Flyer.pdf
AAOP
https://aaop.clubexpress.com/content.aspx?sl=1152088466
PTBCTT