Concussion management – don’t forget about the neck

Concussion is a growing area of sports medicine and becoming a highly prevalent and recognised issue, with over 100,000 cases presenting annually according to the Australian Institute of Sport (1).

A concussion is a mild Traumatic Brain Injury (TBI) and is caused by biomechanical forces from a blow to the body or head, causing a rapid acceleration and deceleration of the brain inside the skull. The rapid movement of the brain creates shearing forces on the nerve cells, causing a complex cascade of metabolic events inside the brain and depleting brain energy levels (6).

Cervical injury, on the other hand, involves persistent impairments caused by dysfunction of the somatosensory system of the cervical spine. This is likely caused by strain on the soft tissues during the whiplash movement of the neck seen in concussion. This disrupts the pathways that relay information from the neck to the brain (4). Cervical spine injury or impairment is often seen alongside concussion.

Managing concussion is much more than waiting for symptoms to subside before returning to sport. Areas to address can include graded return to cognitive load (study/work), exercise tolerance, vestibular impairments, visual function, psychological factors and cervical spine issues. Addressing these areas, combined with allowing adequate time post-concussion for the brains’ energy levels to replenish fully, forms the best practice management of concussion (1, 5).

In this blog, we will explore cervical spine injury associated with concussion specifically, and why and how it should be addressed to adequately rehabilitate patients following concussion.

If you’d like to see exactly how expert physio Julia Treleaven assesses the cervical spine, watch her full Practical HERE. With Practicals, you can be a fly on the wall and see exactly how top experts assess and treat specific conditions – so you can become a better clinician, faster. Learn more HERE.

How is the cervical spine affected in concussion?

Firstly, let’s look into some of the pathophysiology behind cervical spine injury and concussion symptoms.

Concussions require approximately 70-120g’s of force to occur. On the other hand, a whiplash injury to the neck, involving strain of the soft tissues of the cervical spine, can occur with under 5g’s of force (2, 3). Therefore, a concussion will always involve an element of whiplash or cervical spine injury.

Afferent feedback from the cervical spine provides somatosensory information for head and neck position. This is integrated with the sensory and motor nuclei of the brainstem, as well as with visual and vestibular information in the cerebellum. Interaction of these afferent signals helps coordinate important reflexes for gaze stability, postural stability and visual responses (4).

When the upper cervical spine (C1-C3) is injured in the whiplash mechanism during a concussion, the accuracy and speed of these signals to the brain can be impaired. When these faulty signals from the neck combine with correct signals from the vestibular system, this can lead to symptoms of dizziness, unsteadiness and balance issues, as the brain isn’t sure which information is correct.

So how do we know how much the cervical spine is contributing to concussion-related symptoms? Common symptoms across both pathologies can include but are not limited to:

• Dizziness
• Headaches
• Neck pain and stiffness
• Balance problems
• Blurred vision

Fortunately, there are a number of tests we can use to assist in determining the degree that the cervical spine injury is contributing to a patient’s symptoms. Impairments in the following tests indicate issues with cervical sensorimotor control and/or head-eye movement control, motor control and range of motion (4).

1. Cervical joint-position-error test (JPET)
2. Smooth-pursuit neck torsion test (SNPTT)
3. Head-neck differentiation test (HNDT)
4. Cervical flexion-rotation test
5. Motor control assessment of deep cervical flexors/extensors
6. Physical examination of the cervical spine

While we won’t fully cover these assessments in depth in this blog, they can be watched in detail in Julia Treleaven’s Practical.

Why do we need to address cervical spine impairments post-concussion?

While other strategies such as sub-symptom threshold aerobic exercise are crucial to concussion recovery, numerous studies have also shown the benefits of cervical spine treatment in patients with concussion, to reduce symptoms, shorten return to play timeframes and reduce risk of persistent concussion symptoms.

Schneider et al found that participants who underwent combined vestibular and cervical spine rehabilitation were almost 4x more likely to return to participation in under 8 weeks compared to those who didn’t have the same treatment (5).
Additionally, injury to the cervical neck musculature has been linked to reduced neck joint position sense, which may increase risk for future neck and other musculoskeletal injury, due to deficits in postural stability (4).

How do we address these impairments?

After a concussion, the patient’s Central Nervous System (CNS) is in overdrive and hyperactive, due to the shearing of neurons in the brain during the injury and the subsequent massive exchange of ions causing an energy imbalance. For this reason, any cervical spine treatment in the first 7-10 days post injury, such as light soft tissue work and joint mobilisation should be low-key to avoid winding up the CNS further and aggravating symptoms.

After this period of time, in which we are letting the initial acute symptoms settle and guiding a gradual return to cognitive load and light exercise, more progressive cervical therapy may begin, with treatment targeted at impairments based on our assessment findings.

With impairments of sensorimotor control, we can work on aiming to improve joint-position error using a target and laser, like Julia Treleaven does in the video below. Without a laser, we could use a piece of blue-tack on a mirror instead to get a similar outcome, where we are aiming to return the head to the starting neutral neck position with the eyes closed, to challenge and improve the cervical muscle spindle’s proprioceptive ability. Watch Julia demonstrate in this short clip from her hands-on Practical:

Issues with head-eye movement control can be improved with visual tracking and gaze stability exercises such as smooth pursuit training. To challenge this further in those with impairments on the SPNTT, we can challenge the patient further by having them perform visual tracking with the neck in rotation. See the below video from Julia’s Practical:

If we find deficits in range of motion in the cervical flexion-rotation test as well as increased soft tissue tone and reduced joint mobility on physical examination, manual therapy through soft tissue techniques and joint mobilisation can be used to reduce pain, symptoms and muscle tone and improve movement. This might be combined with exercises such as deep neck flexor training, if for example the patient has poor motor control of cranio-cervical flexion, causing overactivity of larger superficial muscles.

Wrapping up

Concussion is a complex pathophysiological process and can heavily involve the cervical spine, due to the nature and degree of forces required for whiplash and concussion. Whilst a progressive return to cognitive load and physical exercise are cornerstones of concussion management, accurately assessing and managing cervical spine impairments can significantly assist in identifying the cause and rehabilitating ongoing symptoms such as dizziness, balance issues and headaches.

For more details on cervicogenic dizziness assessment and management, check out Julia Treleaven’s full Practical.