Answer: Brain Injury Source, Volume 2, Issue 2, Ask the Doctor
By Nathan Zasler, MD, FAAPM&R, FAADEP, CIME

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; for some reason that has not yet been unidentified, headache tends to be a much less common phenomena. Post-traumatic headache (PTHA) may be quite persistent; however, it cannot be positively correlated with severity of injury. Often, injured persons will seek medical care following concussion and/or cervical whiplash injury only to be diagnosed with "post-traumatic headache".

Although the majority of headache following mild brain injury is most likely benign relative to the fact that these conditions do not require surgical treatment, there are, on occasion, complications that occur. These complications are more commonly seen with severe brain injury and associated headache that may require surgical intervention. Specifically, certain serious complications may occur after a closed head injury that result in persistent headache including subdural and epidermal hematomas (blood collecting between the brain and the skull), abscesses and carotid cavernous fistulas (abnormal communication between the venous blood flow and arterial blood flow). Through appropriate clinical examination and additional diagnostic tests, these types of conditions can be ruled out.

There are multiple sources of head and neck pain, both inside and outside of the head. Interestingly enough, the brain itself is not a source of pain. Headache typically results from six major physiologic phenomena:

• Displacement of intracranial (within the skull) structures
  
• Inflammation
  
• Ischemia (decreased blood flow) and/or metabolic changes
  
• Myodystonia (increased muscle tone)
  
• Meningeal irritation (inflammation/irritation of the thin layers of tissue "coating the brain")
  
• Increased intracranial pressure
  
  

All too often, an individual is simply given a diagnosis of PTHA and no further elaboration is made relative to the problem causing the pain. Many times, PTHA is treated as vascular or migraine headache, when, in fact, the great majority of these headaches are not due to migraine-like phenomena. Therefore, it is 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, clinicians should research the past history of the individual in regards to three main phenomena:

brain injury

cranial or cranial/adnexal trauma (damage to the head or structure in the head, but outside the brain)

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 individual’s pre-injury history headache. Merely because an individual experienced headache prior to the injury does not mean that he/she could not develop a different type of headache or a worsening of the pre-injury condition following the trauma. The major questions relative to the headache profile that need to be asked are expressed in the mnemonic "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 and the time of day that headaches come on are all important parameters to inquire about.

The major types of headaches following trauma include: musculkeletal headache (including TMJ disorders), neuroma and neuralgic (nerve) headaches, tension type headache, chronic daily headache, post-traumatic sympathetic nerve dysfunction and vascular (migraine) headache. There are also more rare causes of headache including: seizure disorders, pneumocephalus (air in the head), cluster and paroxysmal hemicrania and the surgical conditions previously mentioned. In this clinician’s experience, the most common cause of head pain (headache) after trauma is musculoskeletal relating to so-called myofascial pain syndromes secondary to cervical acceleration-deceleration insult (whiplash) with referred pain into the head. Iatregenic or "physician-caused" headache must also be ruled-out. The most common cause of iatrogenic headache is rebound headache, caused by the individual over-using certain prescribed and/or over-the-counter-headache-medications.

Post-traumatic migraine accounts for up to 20% of chronic post-traumatic headache. This condition is generally treated with methods similar to the ones used to treat non-traumatic migraine. Two types of atypical post-traumatic migraine variants (which may not necessarily present with headache per se) include basilar artery migraine and transient cortical blindness, the latter much more commonly seen in children than adults.

By taking an appropriate amount of time to complete an adequate pre-injury and post-injury history, conducting a careful clinical evaluation and ordering the necessary and appropriate diagnostic testing, the experienced clinician should be able to determine the underlying cause for the post-traumatic headache condition. Once the appropriate diagnosis is made, treatment should 1) be instituted in a holistic fashion with a sensitivity to maximizing the benefit/risk ratio of any particular intervention, 2) prescribe treatment that can be optimally complied with and 3) educate the individual and family regarding the condition, its treatment and prognosis.

Multiple studies, some of which have only been completed in the last 3-5 years, demonstrate that ongoing litigation has little to no effect on the persistence of headache complaints. Specifically, studies have shown that individuals still continue to report significant symptoms even after litigation. A small number of individuals will develop intractable post-traumatic headache. However, it is this practitioner’s experience that with proper treatment, most instances of PTHA will not result in long-term or permanent disabilities. In summation, prognosis must be based on an exact understanding of headache etiology, rather than on a "garbage can" diagnosis of PTHA. As a case manager, do not accept a diagnosis of "post-traumatic headache." This type of diagnosis simply suggests that the clinician does not know what is causing the headache.

Look for a future issue on post-traumatic headache in the Journal of Head Trauma Rehabilitation due out later this year.

Suggested Reading

Cephalagia: An International Journal of Headache. 17 (S19): October, 1997. ICD-10 Guide for Headaches.

Packard RC & Ham LP: Posttraumatic headache: determining chronicity.

Headache. 33(3): 133-134, 1993.

Packard RC: Posttraumatic headache: permanency and relationship to legal settlement. Headache. 32 (10) : 496-500,1992.

Zasler ND: Post-traumatic headaches and brain injury. Highways to Healing Series. Booklet and Pamphlet. Brain Injury Association, 1996.

Zasler ND: Neuromedical diagnosis and management of post-concussive disorders. In: Medical Rehabilitation of Traumatic Brain Injury. L Horn & ND Zasler (Eds.). Hanley & Belfus, Inc., Philadelphia, 1996.

Zasler, ND (Guest Ed): Journal of Head Trauma Rehabilitation. Issue on Post-traumatic headache. (In preparation).