Post-Traumatic Cephalalgia: Perspectives on a Major Pain

By: Nathan D. Zasler, MD, FAAPM&R, FACRM, FAADEP, DAAPM, CBIST, Concussion Care Centre of Virginia.

Headache and neck pain are the most common physical complaints following concussion (mild brain injury) and are experienced early after injury by up to 70% of persons with these types of injuries. Headache also occurs after more severe brain injury; however, it tends to be a much less common phenomena in this group of patients when compared with the incidence following mild traumatic brain injury. I have suspected for some time that cervical injuries serve as a primary pain generator for PTHA and that in more severe TBI PTHA is inadvertently prophylaxed to an extent through bedrest and chemical paralyzation; thereby decreasing its relative incidence when comparted with MTBI related PTHA. From this clinician’s perspective, a diagnostis of "post-traumatic headache" alone is non-specific and does not provide any elaboration as to the pain generator(s) and with no real information regarding the appropriate treatment or prognosis.

Although the majority of headache following MTBI is most likely benign relative to the fact that these conditions do not require surgical treatment, there are, on occasion, complications that occur, as is more commonly seen with more severe brain injury and associated headache, that may require surgical intervention. Specifically, certain more serious complications may occur after TBI that result in persistent headache including subdural and epidural hematomas, carotid cavernous fistulas, traumatic carotid arterty dissection, cavernous sinus thrombosis, as well as post-traumatic ICP abnormalities (including shunt related complications).     

The experienced clinician should be able to determine the underlying cause for the post-traumatic headache condition through an adequate history and physical exam. Based on the findings of the aforementioned, any necessary diagnostic testing should be ordered but shotgun approaches avoided. Once the appropriate diagnosis is made, treatment should be instituted in a holistic fashion with a sensitivity to maximizing the benefit/risk ratio of any particular intervention including drug prescription.

Education of the patient with PTHA is crucial to optimizing treatment success and decreasing distress and poor adaptation to pain, particularly when chronic. One of the most important pieces of education is making sure the patient understands their disease process and the expectations of treatment. Another very important area is making sure the patient and their family/caregiver understands how to take the medication and the potential detrimental effects of non-compliance and/or over-use (e.g. drug induced headache and more importantly, rebound headache).

Categorization

The major types of headaches seen following trauma include: musculoskeletal headache (including direct cranial trauma, cervicogenic headache and TMJ disorders), neuromatous and neuralgic (nerve) headache, tension type headache, neurovascular (migraine) headache, as well as more uncommon causes of headache including dysautonomic headaches, seizures, pneumocephalus (air in the head), cluster and paroxysmal hemicrania, post-traumatic sinus infections, drug induced headache (whether primary from the medicine itself or due to rebound phenomena) and the surgical conditions previously mentioned. In my extensive clinical experience, the most common cause of headache or head pain following trauma is musculoskeletal relating to referred myofascial pain and/or other cervical headache disorders such as occipital neuralgia and vertebral somatic dysfunction.

Etiology

There are multiple sources of head and neck pain, both inside and outside of the head. The brain itself, interestingly, is not a source of pain. Headache typically results from six major physiologic phenomena: displacement of intracranial (within the skull) structures; inflammation; ischemia and/or metabolic changes; myodystonia (increased muscle tone); meningeal irritation (inflammation/irritation of the thin layers of tissue "coating" the brain) and increased or decreased intracranial pressure.

Natural History, Prognostic Factors, Outcomes

There are inadequate evidence based studies to stipulate dogmatically the natural history, prognostic factors and outcome of post-traumatic cephalalgia (headache) PTHA, in part, because PTHA is not one single pathophysiological disorder but rather a symptom descriptor that may involve multiple pain generators. One can examine the most recent literature and be surprised to find a lack of concordance across studies in the incidence of particular post-traumatic headache sub-types such as tension headache, migraine and cervicogenic headache, as well as the time course of onset. There are major methdological flaws in the existing literature relative to lack of prospective, controlled studies in this patient population.

There are multiple methodological challenges in studying an impairment that is predominantly based on subjective patient report including issues of misattribution bias, recall bias, secondary gain as well as issues germane to adverse psychological and medical effects of stress as related to the symtpom of headache. The majority of the studies to date have not based conclusions on comprehensive physical assessments that integrate neurological and musculoskeletal assessment and/or additionally link specific exam findings with current headache classification systems; the latter which have been criticized relative to their lack of applicability and relevance in this particular disorder (i.e. IHS criteria).  Studies to date have also traditionally not used validity or response bias measures for headache pain reporting, making it difficult if not impossible to gauge the realities of PTHA incidence, frequency and severity.

Studies have demonstrated that ongoing litigation has little to no effect on the   persistence of headache complaints. Specifically, studies have shown that patients still continue to report significant symptoms even after litigation has ended. A small number of patients, seemingly regardless of the headache etiology, will develop intractable post-traumatic headache. When properly diagnosed and treated, most PTHA is able to be modulated and some even cured. It is rare for PTHA to be disabling over the long term; that is, it is highly unlikely that appropriately diagnosed and treated PTHA should result in substantive functional and vocational disability.

PTHA prognosis must be based on an exact understanding of headache etiology,   response to historical treatment and consideration of whether appropriate treatment for the pain generator was even ever instituted.

Cognitive Behavioral Issues in PTHA

Due to the nature of chronic pain due to PTHA, a variety of techniques including medications, various physical modalities including but not limited to physical therapy, chiropractic and/or osteopathic treatment; interventional pain management techniques such as trigger point injections, nerve blocks, facet blocks, among others; psychological therapies including cognitive behavioral therapies, stress inoculation therapies, pain adaptation and/or disability counseling, and pain cope groups may be prescribed.  It is quite common that persons with chronic pain develop emotional difficulties such as depression and/or anxiety which may further increase their perception of their pain and their subjective level of distress.  Persons with PTSD are at even greater risk with concurrent pain issues which tend to perpetuate their PTSD symptoms. Interestingly, headache is the most common somatic complaint in persons with PTSD.

Many times referral to a psychologist or pain specialist may be indicated to help the person with the headache condition learn to deal better with their pain. Biofeedback, stress management and cognitive-behavioral therapies do help many patients with headache including those without evidence of gross psychological problems. Such interventions should be provided by persons adept at chronic pain management, as well as, familiar with issues germane to working with persons with TBI and their families.

Pain associated with PTHA can interfere with thinking in terms of decreased attention and concentration with perceived memory problems. Such interference can often produce false positive diagnoses of mild TBI in persons following cranial or cervical trauma with significant PTHA related pain (including as related to blast type injuries as seen in military personnel).  Pain can also disrupt sleep, as well as, behavior; in the latter scenario, this typically manifests as irritability, depression and/or anxiety.

Evaluation

All too often, patients are simply given a diagnosis of post-traumatic headache (PTHA) and no further elaboration is made relative to the problem causing the pain. Often PTHA is treated as vascular or migraine headache, when, in fact, the great majority of these headaches are not due to migraine‑like phenomena. It is therefore not surprising that persons treated in this manner often do not respond to the prescribed treatment regimen. It is important for the examining clinician to keep the different mechanisms of PTHA in mind. Additionally, the mechanism of injury responsible for the initial insult should also be investigated. Specifically, inquiry regarding history pertaining to three main phenomena: brain injury; cranial or cranial/adnexal trauma (damage to the head or structure in the head but outside the brain); and cervical acceleration/deceleration (CAD) insult (also called whiplash injury).

One of the major clues for the examiner relative to the origin of the headache should come from establishing the symptom profile for that particular headache, as well as the patient's pre-injury history of headache. Just because an individual had headache pre-injury does not mean that he or she could not develop a different type of headache or a worsening of the pre-injury condition following trauma. The major questions relative to the headache profile that need to be asked are expressed in the pneumonic "COLDER": Character, Onset,Location, Duration, Exacerbation, and Relief. Other descriptors including the frequency, severity, associated symptoms, and presence/absence of aura, degree of functional disability associated with headache episodes, as well as, the time of day that headaches come on are all important parameters to inquire about. A good history regarding the patient’s pre-injury headache status, as well as any genetic loading risk factors for headache (i.e. particularly migraine) in the family should also be sought.

Adequate physical examination is paramount to an appropriate diagnosis and should include inspection, palpation, auscultation and percussion as appropriate. The neurological exam should be a centerpiece of this assessment, however, adequate examination of cranial and cervical (i.e. neck) structures including inspection, percussion and palpation of the head, neck and shoulders, as appropriate, is a crucial yet often overlooked aspect of a complete exam for PTHA.  All to often, I have seen patients over the years who tell me no one actually ever laid hands on them...a sad fact, but apparently more true than many of us may want to believe.

Treatment Caveats

PTHA does not occur in a vacuum. Rather, it occurs in a biological system within specific psychological and social contexts. It reflects an interaction of organic and emotional factors. While often similar to non-traumatic headaches in clinical presentation of subtypes and biochemical mechanisms, often times inadequate assessment in terms of history and physical exam lead to inappropriate diagnoses and treatments.

Inappropriate medication management may lead to unwanted side effects (e.g., adverse effects on sleep, mental alertness, sexual functioning, work performance) and certainly does not address adaptation to chronic pain through development of new coping skills. Conversely, PTHA patients have been reported to exhibit minimal response to psychological or physical treatments when utilized in a non-holistic fashion. Treatments that target not only the pain generator(s), but also the patient's reaction to pain within their daily life typically fare better than treatments with a more narrow focus (e.g., medication management or non-drug therapies alone). Understanding vulnerability issues as predictors of poor chronic pain adaptation is also critical in this context. Currently, multicomponent treatment packages are the preferred treatment choice for PTH.

Conclusions

PTHA is a complex post-injury phenomena and one that is quite manageable in the majority of cases using a holistic approach to both evaluation and treatment. There remains a significant need for multicenter, prospective, randomized trials on PTHA involving incidence, prevalence, prognosis, assessment and treatment in both civilian and military personnel.

Suggested Readings

  • Davidoff RA: Trigger points and myofascial pain: toward understanding how they affect headches. Cephalalgia. 18(7): 1998.
  • Evans RW:  Peristent post-traumatic headche, post-concussion syndrome, and whiplash injuries: the evidence for a non-traumatic basis with an historical review. Headache. 50(4):716-724, 2010..
  • Freund B, Schwartz M: post-traumatic myofascial pain of the head and neck. Curr pain heache Rep. 6(5):361-269, 2002.
  • Fernandez-de-Las-Pensas C, Simons D, Cuadrado ML, Pareja J: The role of myofascial trigger points in musculoskeletal pain syndromes of the head and neck. Curr Pain Heache Rep. 11(5):365-372,2007.
  • Martelli, M.F., Zasler, N.D.: Post-traumatic pain disorders: Psychological Assessment and Management. In: Brain Injury Medicine: Principles and Practice. N. Zasler, D. Katz, R. Zafonte (Eds.). New York. Demos Publishers. 2007.
  • Nampiaparampil, DE: Prevalence of chronic pain after traumatic brain injury. JAMA. 300(6):711-719, 2008.
  • Neely Et, Midgette LA, Sher AI: Clinical review and epidemiology of headache disorders in US service members: with emphasis on post-traumatic headche. Headche. 49(7):1089-1096, 2009.
  • Walker WC, Seel RT, Curtiss G, Warden DL: Headache after moderate and severe traumatic brain injury: a longitudinal analysis. Arch Phys Med Rehabil. 86(9):1793-1800, 2005.
  • Zasler, ND & Martelli, MF. Post-traumatic headache: Practical approaches to diagnosis and treatment. In: R.B. Weiner (Ed.): Pain Management: A Practical Guide for Clinicians, 6th edition. Boca Ratan, FL: St. Lucie Press, 313-344, 125-138, 2002.
  • Zasler, N.D. Martelli, M.F., Nicholson, K.: Pain Issues in TBI. In: J.M. Silver, S.C. Yudofsky, T.W. McAllister (Eds.): "Neuropsychiatry of Traumatic Brain Injury", 2nd Edition. 2004.
  • Zasler, N.D., Horn, L., Martelli, M.F. Nicholson K: Post-traumatic pain disorders: Medical Assessment and Management. In: Brain Injury Medicine: Principles and Practice. N. Zasler, D. Katz, R. Zafonte (Eds.). New York. Demos Publishers. 2007.

About the author

Dr. Zasler is CEO & Medical Director, Concussion Care Centre of Virginia, Ltd., as well as, CEO & Medical Director, Tree of Life Services, Inc. He is an adjunct Professor, VCU Department of Physical Medicine and Rehabilitation, Richmond, Virginia and an adjunct Associate Professor, Department of Physical Medicine and Rehabilitation, University of Virginia, Charlottesville, Virginia. He is also an adjunct Professor in the Graduate School of Psychology, Touro College, New York, NY. Dr. Zasler is Associate Editor of the NeuroTrauma Letter and Chief Editor (along with Dr. Jeffrey Kreutzer) of both Brain Injury (the IBIA endorsed scientific journal) and NeuroRehabilitation. His email address is: nzasler@cccv-ltd.com