Whiplash Associated Disorders

"Whiplash" is defined as an acceleration-deceleration mechanism of energy transfer to the neck that results from rear-end or or side impact motor vehicle collisions. It can also derive from diving accidents or other similarly occurring impacts that result in bony or soft tissue injuries. These injuries can in turn lead to a variety of clinical manifestations. The collection of clinical manifestations has been called "Whiplash Associated Disorders" or WAD.

The Quebec Task Force WAD classification according to clinical presentation is as follows:

Grade Clinical Presentation

0 No neck complaints and no physical sign(s)

I Neck pain, stiffness or tenderness and no physical sign(s)

II Neck complaint and musculoskeletal sign(s)

III Neck complaint and neurologic sign (s)

IV Neck complaint and fracture or dislocation

The Gargan and Bannister classification of symptom severity is as follows:

Group Symptons

A Asymptomatic

B Mild Symptons not affecting work or leisure activities

C Intrussive symptons interfering with work or leisure. Frequent use of analgesics, orthosis, or physiotherapy.

D Severe problems: lost job, continual reliance on analgesics, orthosis. Repeated medical consultations.

The epidemiology of Whiplash Associated Disorders varies from country to country. The incidence has been reported as highest, 188/100,000 in the Netherlands to lowest, 39/100,000 in Australia.

Early ideal treatment involves the general rules of assessment for major trauma at the initial site and time of the accident. These involve preservation of life and prevention of further damage to the spine and cord and preservation of spinal function. This has been laid out in the US National Acute Spinal Cord Injury Study. The key is to assume spinal instability until proven otherwise.

In the Emergency Department Acute Traumatic Central Cord Syndrome (ATCCS) must be excluded. This is a complex spinal cord syndrome which presents with incomplete neurological deficits such as the ability to walk but not move hands, and sensory changes such as burning hands or urinary retention. MRI generally shows white matter involvement but no hemorrhage. The prognosis is generally good.

Fractures are ruled out by xrays.However if the xrays are normal but the patients persists in having severe pain special x ray views are indicated. If persisting severe pain without any abnormality being found then a hard collar is applied and an MRI is done within24-48 hours showing flexion/extension views to rule out ligamentous injury.These xrays and imaging are all however open to a variety of pitfalls requiring expert interpretation.

Once major injuries are ruled out the normal approach to WAD (Whiplash Associated Disorder) is reassurance and education, no soft collar, Non steroidal anti inflammatory medication such as ibuprofen or naproxens, and early mobilization. Rest and cervical collars can have a detrimental effect on the outcome.

This said nearly 75% of injured patients report immediate symptons such as cervical pain, painful neck movement, painful back, shoulder pain, disturbance of consciousness and dizziness. Examination may show paresthesias, ie unusual sensations, and weakness. Later patients may have visual disturbance, problems with concentration, fatigue, sleep impairment, as well as irritability and anxiety and depression. Interestingly studies show that the anxiety and depression are most directly related to the presence of symptons such as pain and disability. Anxiety and depression do not appear in contrast in those who are early asymptomatic.

While it is important to remember that approximately 10 to 30 % of the general population who have not had an injury report chronic neck symptons, studies show that 15 to 40 % of the WAD patients have chronic neck pain with 10% reporting this as severe. Studies have showed that there can be little alteration of in symptons by three months and stabilizing at 2 years. Authors in prospective study showed little alteration in sympton severity for the majority of patients (64%) between 3 months and 7.5 years . Between 3 months and 2 years the symptons fluctuated significantly and prognosis based on this were unreliable. Therapeutically the greatest benefit for influencing outcome was in those first three months. One interesting study showed that high dose methylprednisone resulted in earliest return to work.

There have been many issues raised relative to the prognosis or eventual outcome of the injury. This has been difficult because there is no clear definition of what is recovery. At best crude measures of symptons or disability have been used along with such matters as 'return to work', 'discontinuation of treatment', or 'conclusion of litigation' .

That said, a systematic review of prospective cohort studies done in Pain 2003 concluded that "strong evidence was found for high initial pain intensity, and strong evidence for no prognostic value for older age, female gender, high acute psychological response, angular deformity of the neck, rear-end collision and compensation". Limitted evidence was found for some physical, psychosocial, neuropsychological, crash related and treatment related factors in terms of prognosis.

References:

Initial assessment of whiplash patients, Dr. R Gunzburg, M. Szpalski, J. Van Goethem,Pain Res Manage Vol 8 No 1 Spring 2003

Fluctuation in recovery following whiplash injury, 7.5 year prospective review, P.J. Tomlinson, M.F. Gargan, G.C. Bannister, Injury, Int. J. Care Injured (2005) 36, 758-761

Sensory hypersensitivity occurs soon after whiplash injury and is associated with poor recovery, Michele Sterling, Gwendolen Jull, Bill Vicenzino, Justin Kenardy, Pain 104 (2003) 5009-517

Prognostic factors of whiplash-associated disorders: a systematic review of prospective cohort studies, Gwendolijne G.M. Scholten-Peeters, Arianne P. Verhagen, Geertruida E. Bekkering, Danielle A.W.M. van der Windt, Les Barnsley, Rob A.B. Oostendorp, Erik J.M. Hendriks, Pain (104 (2003)303-322