Research in Focus - Whiplash Associated Disorder: A Dilemma or a Primary Care Opportunity?

  •   September 3, 2014
  •  By: Ashley Smith, PT, FCAMPT, PhD(c)

 

Whiplash associated disorder (WAD) is the term used to describe the symptoms arising from a whiplash injury, which is commonly associated with a cervical acceleration/deceleration mechanism during a motor vehicle collision.1 Individuals sustaining a whiplash injury may present with a variety of physical and psychological manifestations. The predominant symptom is neck pain but headaches, upper limb paraesthesia, dizziness and lumbar spine pain are also reported. Individuals may also report symptoms involving difficulties with cognitive tasks and mood disturbances. Psychological manifestations include post-traumatic stress symptoms, psychological distress, pain catastrophization and fear of movement.

As most physiotherapists know, many individuals sustaining a whiplash injury do not necessarily recover in a timely fashion, with approximately 50% continuing to report symptoms 12 months after the date of the collision. Approximately 20-30% of those who do not recover present with moderate to severe symptoms.2 Generally, those who do recover do so within the first 8-12 weeks. Thus, the challenge for physiotherapists is to determine which individuals may transition into chronicity and to apply appropriate treatment and management strategies accordingly.
 

Predicting chronicity

Various systematic reviews and meta-analyses have been performed to assist with determination of prognosis for individuals sustaining a whiplash injury.3

  • Initial pain and disability
    High initial pain (>5.5/10) and disability (Neck Disability Index >14/50) consistently demonstrate poor prognosis in a variety of cohorts.
  • Cold hyperalgesia
    The presence of cold hyperalgesia has also emerged as a feature that can predict poor prognosis.4 Within a clinical environment, application of ice for approximately five seconds over the cervical spine region with concurrent report of pain (>5/10) is indicative of cold hyperalgesia.5 It is generally thought that hypersensitivity to stimuli such as cold are as a result of augmented nociceptive processing (otherwise known as central hyperexcitability).
  • Psychological manifestations
    Various psychological manifestations also consistently demonstrate poor prognosis. These include presence of post-traumatic stress symptoms, pain catastrophizing and depressed mood.6
    • Post-traumatic stress symptoms
      A score of >26 on the Impact of Events Scale (IES) demonstrates the presence of moderate  post-traumatic stress symptoms.7
    • Pain catastrophizing
      A score of >24 on the Pain Catastrophization Scale (PCS) is indicative of clinically significant pain catastrophization.8
    • Depression
      The presence of depression can be gauged with a positive response to either of the first two questions on the PHQ-91. However, recently Reme and associates demonstrated that a positive response to the question: “have you been affected by sadness/depression during the last month” was also indicative of the presence of depression.9 Expectations of recovery are also related to prediction of recovery, with those individuals not expecting to recover generally not recovering.10

 

How these measures help determine prognosis

It is important to capture these measures within a clinical environment to assist with determination of an individual’s prognosis (improvement within the first 90 days of the initial injury). That is not to say that all measures need to be captured for each individual at the outset of treatment. For example, elevated levels on the IES and PCS tend to improve in the first month, especially in those with improving levels of pain and disability. In fact, some authors assert that elevated PCS scores occur with concurrent high pain and disability levels.11

However, if an individual is not demonstrating improvement in the first month, the above prognostic indicators need to be formally evaluated to assist with appropriate treatment options being delivered to optimize health outcomes for that individual. It is also of assistance to notify the insurer of these poor prognostic indicators to assist with appropriate management of these individuals.

 

Factors that have low evidence of predicting chronicity

Physical measures such as restricted range of motion (ROM), poor performance of the cranio-cervical flexion test and sensori-motor disturbances (head relocation in space) generally do not predict poor prognosis.12 That is not to say that these impairments should not be addressed by physiotherapists during rehabilitation. However, deficits in these measures don’t consistently demonstrate poor prognosis.

Other factors such as crash related factors and compensation factors (individual is involved in litigation) also generally do not predict poor recovery.3 Similarly, other psychological factors such as personality traits, psychological distress, life control, social support, well-being and psychosocial work factors are not related to poor prognosis.6 Inconsistent evidence exists for factors such as age, income levels and education levels.

 

Does physiotherapy improve outcomes?

Limited research is available in regard to this question, although unfortunately, a recent multi-professional trial aimed at treatment of these poor prognostic indicators did not reduce the rate of chronicity.13 Similarly, in a large cohort trial in the UK, multimodal care provided by physiotherapists was no better than a pamphlet in reducing the rate of chronicity.14

 

Psychological manifestations of WAD

Psychological factors can have a significant effect on the physical presentation of a patient. Stress system dysregulation has been described in post-traumatic stress disorder, a factor that occurs concurrently with central hyperexcitability/sensitization in some individuals.15 Patients may demonstrate elevated blood pressure, heart rate and gastro-intestinal disturbance arising from these effects. Moderate associations between cold pain thresholds and both psychological distress and catastrophization (PCS) have also been demonstrated.16

These findings indicate that psychological factors play a role in the sensory presentation of whiplash but do not support the assumption that psychological factors are the only or main factors responsible for central hyperexcitability. In particular, spinal cord hyperexcitability (hyperalgesic response to Brachial Plexus Provocation Test – bilateral restriction of elbow extension > 30°) appears not to be affected by the psychological factors that were evaluated in these studies.17 Thus, management of both psychological factors and central hyperexcitability is required to improve patient health outcomes.

 

Are outcomes improved if we reduce psychological manifestations?

A recent systematic review provided conflicting evidence on the effectiveness of psychological management in reducing symptom severity and improving health outcomes in chronic WAD.18 In chronic WAD, evidence supports the use of Cognitive Behavioural Therapy (CBT) to reduce work-related disability.19 Individuals with elevated fear of movement, catastrophization and pain-related disability all demonstrated greater reductions of pain and increased rate of return to work when they underwent this 10-week program (in comparison to “standard physiotherapy”). This program focuses on graded exposure to activities in conjunction with thought recording, monitoring and reappraisal to resume life roles.19 Physiotherapists have been trained to provide this role within this program.

A recent RCT (performed by a clinical psychologist) demonstrated the efficacy of CBT in reducing disability and post-traumatic stress symptoms in individuals with chronic WAD (although limited improvement in pain resulted).20 Emerging evidence is also present for Acceptance and Commitment Therapy (ACT – a form of CBT) in individuals with chronic WAD who have an ineffective struggle to control pain at the expense of valued life activities. ACT involves mindfulness training in an effort to display a willingness/openness to cope with pain. Clarification of life values and values-based action is also emphasized.21

The question arises as to the role of a physiotherapist in managing these psychological manifestations. Certainly, a physiotherapist is well qualified to apply screening questionnaires to assist with referral to appropriate health professionals experienced with treating such manifestations. However, it is not within a physiotherapist’s scope of practice to provide mental health diagnoses, such as post-traumatic stress disorder, depression or generalized anxiety disorder. Thus, an appropriate referral is required to a clinical psychologist experienced in the management of these disorders within the context of an initiating traumatic event.

However, an emergent opportunity exists for willing physiotherapists. The improved health outcomes achieved when modulating psychological manifestations can be performed by physiotherapists trained to provide CBT. Physiotherapists have been shown to be efficacious in treatment fidelity when delivering a standardized pain coping skills program. This indicates that there is great potential for psychologically informed practice performed by physiotherapists to be a feature of effective health-care delivery.22

 

Can reducing pain improve psychological outcomes?

Essentially, the above psychological treatments (CBT) demonstrate efficacy in reducing event-related distress with limited improvement in pain-related distress resulting from the original injury. To that end, our laboratory recently performed a series of studies in an effort to determine if reducing pain would also assist with improved psychological health outcomes.23 We were able to demonstrate reductions in psychological distress and pain catastrophization, but not post-traumatic stress symptoms.

This was done by ablating the medial branches of the dorsal rami in individuals with previous response to diagnostic facet joint injections.23 Improvement in these psychological manifestations (in conjunction with pain and disability and quality of life) were demonstrated for approximately 10-12 months.24 Thus, improvements in pain-related distress measures were noted, with limited improvement demonstrated in event-related distress (post-traumatic stress symptoms).  Perhaps a combination treatment directed at effectively reducing pain (e.g., radiofrequency neurotomy) and also concurrently addressing the event-related stress (e.g., CBT) would significantly improve health outcomes. This requires further investigation.

Thankfully, other research performed in our laboratory has also demonstrated the ability of physiotherapists to accurately determine which individuals would benefit (or not benefit) from diagnostic facet joint injections. This assists with determination of suitability for referral for radiofrequency neurotomy and effective longer term relief of symptoms.25 A combination of physical examination findings commonly performed within the clinic has been demonstrated to be reliable and possess high sensitivity and specificity when determining suitability of referral for these procedures. Given that this is the only validated treatment for individuals with chronic WAD, knowledge of these skills would seem important.

 

Conclusion

With knowledge of neuropathic pain mechanisms13, and the above knowledge of physical and psychological manifestations in WAD, physiotherapists can move the treatment forward for this complex condition. However, with an increased role to play, an increased responsibility awaits. Physiotherapists are well placed to welcome this expanded primary care challenge.

 

About the Author: Ashley recently completed his research-based PhD through the University of Queensland in Australia (as a remote student performing the research in Calgary, Alberta, Canada). His PhD investigated the effects of peripheral nociceptive generators on the physical and psychological presentation of individuals with persistent WAD symptoms. Ashley achieved the designation of Clinical Specialist in Musculoskeletal Physiotherapy in 2011 and pursues his work as a clinician at Evidence Sport and Spinal Therapy in Calgary. He was admitted as a Fellow in the Canadian Academy of Manipulative Physiotherapy in 2001. Ashley is also certified through the American Board of Independent Medical Examiners (ABIME), performing numerous independent medical examinations. Ashley has been an invited speaker, and his peer-reviewed publications on the cervical and lumbar spine and pain mechanisms, have been accepted, at numerous international conferences/congresses.

 


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