By John Leddy, MD
Joelle is an 18-year-old high school soccer player who sustained a head injury 3 months ago during a game. While going for a header, an opponent’s head struck her on the side of the head and knocked her on the ground. Observers on the sidelines saw how her head twisted to the opposite side prior to hitting the ground. Joelle has no independent recollection of this. All Joelle knows is that she continues to experience daily headaches, dizziness and difficulty with concentration and memory in school despite resting from sports and physical activity since the day of her injury. She has been told that she is suffering from post concussion disorder because her brain is not yet recovered from the injury. Upon close questioning, Joelle says that her headaches began from the top of her neck and radiate to the forehead and that her dizziness is exacerbated by looking right and left. She is having trouble concentrating and remembering things because she has a headache most of the day and she is not sleeping well. She has not tried to return to any physical activity and her parents have asked that the school make accommodates for her. Her brain MRI is normal and she has taken and passed a computerized neuropsychological (NP) test. Nonetheless, she does not feel ready to return to sports or even to recreational activities with her friends.
Patients who experience prolonged symptoms after concussion are classified as having post concussion disorder (PSD). It is, however, becoming more appreciated among medical professionals that prolonged symptoms after a head injury may not in all circumstances be related to the brain injury per se. This is because symptoms such as headache, dizziness and poor concentration are not specific to brain injury. Rather, they may represent other pathologies, some of which are related to the initial trauma and some of which may not be. The challenge for clinicians is to establish as best they can the underlying cause of the symptoms so that proper treatment can be initiated.
One cause of prolonged symptoms after head injury is concomitant neck injury. This may not be fully appreciated by the patient or by health care professionals because the focus is usually on the seriousness of the brain injury. Traumatic brain injury (TBI) often involves a whiplash or twisting mechanism that can also injure the neck. The upper cervical spine is particularly vulnerable to trauma because it is the most mobile part of the vertebral column with a complex proprioceptive system (Treleaven, Jull, & Sterling, 2003). Proprioception is defined as the sense of the relative position of neighboring parts of the body. The proprioceptive system of the cervical spine is particularly important since it tells us where our head is in space and has rich connections to the vestibular (balance) and visual systems of the brain (Treleaven, et al., 2003). The symptoms of whiplash injury can be prolonged, with the most common complaints being cervical pain, headache, vertigo and dizziness (Endo, Ichimaru, Komagata, & Yamamoto, 2006). Whiplash patients also endorse cognitive complaints such as poor concentration and memory deficits, even when no associated with concurrent brain injury (Sturzenegger et al., 2008). Futhermore, NP test results may not discriminate between whiplash patients and those with TBI (Taylor, Cox, & Mailis, 1996). Cervical proprioceptive disturbance might be an important factor in the maintenance, recurrence, or progression of various symptoms in patients with neck injury associated with TBI and may in fact be responsible for persistent symptoms thought to be due to PCD, even though the brain injury has resolved.
It is very important for clinicians to establish the mechanism of injury in patients with head injury and to realize that acceleration and deceleration of the head is often accompanied by a whiplash mechanism to the cervical spine. Clinicians should perform a careful physical examination of the neck in all patients with PCD. If a cervicogenic source is suspected to contribute whole or in part to ongoing symptoms after TBI, it is recommended that therapy be instituted that progressively addresses neck position and movement sense as well as cervicogenic oculomotor disturbances, postural stability, and cervicogenic dizziness (Kristjanson & Treleaven, 2009). There are no controlled trials of this form of therapy in those with persistent symptoms after concussion but anecdotal evidence indicates we can do a bread deal to assist in recovery.
The differential diagnosis of post concussion headache includes migraine, cervicogenic, and other types of post-traumatic headaches (Sallis & Jones, 2000). Treadmill testing using a standardized exercise treadmill protocol to establish physiologic recovery from concussion has recently been found to have very good inter-rater and sufficient re-test reliability for identifying patients with symptom exacerbation from concussion (Leddy, Baker, Kozlowski, Bisson, & Willer, 2011). This physiologic test can help with the differential diagnosis of physiologic PCD. Concussion symptoms, for example, are typically exacerbated by exercise prior to reaching full exercise capacity (Leddy et al., 2010). If patients can exercise to exhaustion without reproduction or exacerbation of headache or other concussion symptoms, and demonstrate a normal physiological response to exercise, then the symptoms are due to another problem, most commonly a cervical injury or a post-traumatic headache syndrome such as migraine. This information is vital to directing therapy to the cause of persistent symptoms.
Joelle exercised on a treadmill and reached physical exhaustion. She had some neck pain and headache that increased gradually in intensity but did not stop her from exercising. In fact, her symptoms improved by the end of the treadmill test. Joelle’s neck examination revealed upper cervical tenderness. The physical therapist found that Joelle had very abnormal cervical proprioception. Using a laser pointer taped to the side of her head, after having demonstrated the ability to hit a target with eyes open, Joelle could not consistently return to the spot on the target with her eyes closed. She kept missing wide to the left. After a course of cervical muscle strengthening and proprioceptive retraining, Joelle’s cervical proprioception improved and her headaches and dizziness subsided. Treating the cervical spine was the key to Joelle’s recovery from prolonged post concussion symptoms.
Endo, K., Ichimaru, K., Komagata, M., & Yamamoto, K. (2006). Cervical vertigo and dizziness after whiplash injury. Euro Spine J, 15(6), 886-890. doi: 10.007/s00586-005-0970-y
Kristjansson, E., & Treleaven, J. (2009). Sensorimotor function and dizziness in neck pain: implications for assessment and management. J Orthop Sports Phys There, 39(5), 364-377. dii: 2317 [pii] 10.2519/jospt.2009.2834
Leddy, J. J., Baker, J. G., Kozlowski, K., Bisson, L., & Willer, B. (2011). Reliability of a graded exercise test for assessing recovery from concussion. Clin J Sport Med, 21(2), 89-94, doi: 10.1097/JSM.0b-13e3181fdc72100042752-201102000-00003 [pii]