The majority of individuals, approximately 60-70%, who sustain a concussion will recover within 4 weeks. While many strive to be among this majority, about 30-40% of concussion patients will experience post-concussive symptoms (PCS) that persist beyond the typical metabolic healing period. (1,2,3,4,5)

Identifying the source of a patient’s symptoms, known as “symptom generators,” can be challenging due to the wide variability of symptoms following a concussion. 

Without a clear plan for assessing PCS, clinicians may misinterpret patient symptoms for the wrong concussion subtype. Determining the precise “symptom generator” is crucial for accurate diagnosis and effective treatment.

In this part of the series on concussion flavors, we will discuss the specific subtype related to the cervical spine. Our goal is to help you identify if your patient’s specific concussion subtype is one of cervical spine origin and develop a targeted treatment plan based on your findings.


Cervical Spine Involvement “The Cervicogenic Patient”.

Patients with a vestibulospinal or cervicogenic concussion “symptom generator” typically present with characteristic symptoms. Those with cervical spine involvement commonly report:

  • Imbalance
  • Lightheadedness 
  • Cervical/Neck pain
  • Headaches that tend to be tension-type (rather than migrainous)

While these symptoms are common in patients with cervical dysfunction, they may also appear with other symptom generators, such as visual or autonomic dysfunction. Differentiating between these reported symptoms can provide the first clue in identifying the correct concussion subtype.

Patients may also provide insights through key triggers that provoke their symptoms. Those with a cervical spine subtype often report the following triggers:

Reported Triggers:

  • Head or neck movement
  • Worsening symptoms during exercise
  • Increased symptoms while driving

Why Does Cervical Dysfunction Occur Following Concussion?

#1 Cervical Sprain/Strain: Musculoskeletal Origin

The forces generated in a concussion injury (70-120 G’s) are sufficient to cause a cervical spine sprain or strain (4.5 G’s). (6)

Whiplash injuries and concussions are closely related in terms of symptom presentation. In fact, if clinicians were unaware of the specific injury, it would be nearly impossible to differentiate between the two based on symptoms alone.

This similarity arises from dysfunction in the cervical spine, particularly in the suboccipital region and surrounding neck muscles. This leads to a decreased range of motion, increased muscular tension, and proprioceptive dysfunction.

Common Concussion AND Whiplash Symptoms 

  • Neck pain 
  • Neck tightness/ decreased range of motion
  • Dizziness 
  • Blurred vision 
  • Mental/Cognitive fatigue 
  • Headache
  • Memory/Concentration Impairment

#2 Cervical Proprioceptive Neural Injury 

The upper cervical spine houses millions of proprioceptive organs densely populated within the facet joints and surrounding musculature. These proprioceptors relay constant information to the brain about the head’s position in space.

The intricate connection between neck muscles, joint proprioception, and other mechanisms means that injury to these structures can result in proprioceptive misinformation sent to the brain, leading to disequilibrium, dizziness, and balance issues. (7)

#3 Structural Integrity  

With head injuries, the cervical spine can be impacted to an extent that poses a significant risk to its structural integrity. This includes the potential for cervical fractures, ligamentous injuries, and vascular incidents, all of which should be carefully considered.

Following head and cervical spine trauma, there’s a possibility of cervical spine instability and other injuries, such as occipital neuralgia, emerging. Therefore, special attention should be given to assessing and addressing these potential complications.


Cervical Spine Assessment.

When assessing a patient suspected of having cervical spine involvement, adopting a systematic approach is crucial. Before initiating a cervical spine assessment, it’s essential to consider the various dysfunctions that may be at play.

Conducting a comprehensive patient history can aid clinicians in identifying the specific mechanism of cervical spine dysfunction.

The three main categories outlined in the preceding section, “Why Does Cervical Dysfunction Occur,” encompass the typical presentations of patients with complaints related to the cervical spine.

  • Compromise to Structural Integrity (Ruling out red flags)
  • Musculoskeletal Injury 
  • Proprioceptive Dysfunction 


Structural Integrity and Red Flags 

The close relationship between reported symptom cross-over, location, and implications for severe injury to the cervical spine should be thoroughly assessed before further evaluation and treatment can start.

Some key structures require specific attention when assessing the cervical spine for structural integrity and red flags. 

Fracture (Canadian C Spine Rules)

In assessing a patient for potential cervical spine fracture, clinicians should adhere to the “Canadian C Spine Rules.” These rules provide specific criteria for identifying suspected fracture risk in individuals following trauma. With a sensitivity of 99.4% and a specificity of 45.1%, the Canadian C Spine Rules are highly effective at ruling out fractures. If a fracture is suspected based on these criteria, the next step would be to refer the patient for radiographic imaging. (8)

Ligamentous Integrity 

Spinal stability is a critical factor to consider following trauma, particularly when deciding whether to implement treatments such as manual therapy and rehabilitative movement.

Various tests are available to evaluate the structural integrity of the cervical spine. (9,10,11,12)

  • Right and Left Alar ligament test 
  • Sharp Purser Test (Integrity of Transverse ligament)
  • Spurling’s Test (Cervical radiculopathy)

Vascular Incident and Cranial Nerves 

Vascular incidents, such as post-traumatic fistulas or dissections, may arise following significant head or neck trauma. During the initial examination, auscultation for bruits over the temporal arteries, mastoids, carotids, and with closed eyes can help assess for vascular turbulence that may indicate such occurrences.

Irrespective of the concussion subtype, a thorough neurological assessment is essential for clinicians to diagnose or exclude the possibility of additional pathology. Trauma to the neck is a known cause of occipital neuralgia, and a detailed evaluation of the cranial nerves can reveal structural abnormalities that warrant further investigation. (12)


Musculoskeletal Injury

Symptoms of an isolated cervical spine injury and concussion exhibit a significant overlap, often presenting similarly. Musculoskeletal injuries can even induce concussion-related symptoms that many patients may not attribute to a neck injury, such as dizziness, a sense of being off-balance, mental fatigue, and visual dysfunction. (7)

Headaches and neck pain are the most common symptoms associated with a genuine cervical spine injury, often leading to the onset of other related symptoms.

During a physical examination of the cervical spine, emphasis should be placed on assessing range of motion and palpation for tenderness and muscle spasms in the neck. Suboccipital muscles frequently bear the brunt of trauma to the head and neck and warrant thorough examination.

Musculoskeletal Assessment 

  • Cervical Range of Motion (Passive and Active) 
  • Palpation of muscle tenderness and spasm 
  • Specific trigger point palpation for pain referral patterns  
Special Consideration For Headache Symptoms  

Headaches are a common symptom to present after a concussion. Due to the high incidence of headaches, clinicians need to use clear physical examination techniques to differentiate headache subtypes. In 2016, Delphi et al. outlined the most effective techniques physical therapists employ to detect headaches. (13)

Delphi determined the following as the most effective methods for the detection of headaches

  • Craniocervical flexion test 
  • Cervical flexion rotation test 
  • Active range of cervical motion 
  • Trigger point palpation 
  • Muscle test of the shoulder girdle 
  • Passive physiological intervertebral movements 
  • Thoracic spine screening 
  • Combined movement test 

Cervicogenic Headache Test Cluster 

Combining the above tests can effectively rule out specific cervical spine dysfunctions. In the context of diagnosing cervicogenic headaches, a cluster of tests has demonstrated strong accuracy and high reliability. (14-15)

  • Cervical flexion rotation test 
  • Smooth pursuit neck torsion test (SPNTT)
  • Cervical-joint reposition error test (JPET) 


Proprioceptive Injury 

Given the dense concentration of proprioceptive structures in the cervical spine, particular attention should be paid if a patient exhibits dizziness, balance dysfunction, and disequilibrium sensations.(7)

The cervical-joint reposition error test (JPET) pinpoints dysfunction of the muscle spindles in the upper cervical spine.

Furthermore, the smooth-pursuit neck torsion test (SPNTT) is valuable for assessing cervico-ocular dysfunction.

Enhanced understanding of the mechanisms underlying a patient’s concussion subtype can greatly aid clinicians in developing a more precise and personalized treatment plan.


Cervical Spine Treatment.

The primary objective in treating patients with a concussion subtype involving cervical spine dysfunction is to restore the patient to a state of normal function in both cervical spine biomechanics and proprioceptive function.

In instances where cervical spine dysfunction involves a significant musculoskeletal component, manual therapy, and rehabilitation techniques can yield beneficial outcomes. 

Chiropractors and physical therapists, with their specialized expertise and training, are well-equipped to facilitate recovery through manual therapy techniques such as: 

  • Soft tissue/ Myofascial work 
  • Joint Manipulation 
  • Dry Needling 
  • Trigger point therapy 
  • Stabilization exercises  

If a proprioceptive dysfunction is identified as significantly impacting the examination, clinicians can utilize various rehabilitative techniques to aid patients in reintegrating this system and fostering a more comprehensive recovery. 

Treatment Options for Cervical Spine Proprioceptive Input 

  • Cervical JPET (as rehab)
  • Smooth Pursuits
  • Smooth Pursuits with neck torsion (SPNTT as rehab)
  • Bess H Exercise 
  • Walking with Head Turns exercise 

Bottom Line.

Neck pain and headaches frequently accompany concussion injuries, often signifying cervical spine involvement. However, the cervical spine can elicit other less typical symptoms, confusing clinicians attempting to identify the true “symptom generator” in their patients’ cases.

Having a clear and accurate plan for evaluation and detection can significantly impact treatment times and patient outcomes. 


REFERENCES
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