Whiplash - Recent Medical Evidence

First published in The Lawyers Weekly November 15, 2002, Vol. 22, No. 27

For all who are litigating and defending cervical whiplash, keeping up to date with key medical evidence is essential for optimal success.

Despite the commonness of whiplash injury, opportunities are limited for direct study of pathology in humans.

In lightly anesthetised non-human primates, severe whiplash without head injury causes organic brain damage.

The amount of physical damage to brain cells determines both the length of coma and the severity of subsequent neurological abnormalities and changes in behaviour.

In head-injured patients, Mild Traumatic Brain Injury (MTBI) with loss of consciousness and amnesia of 30-35 minutes has been shown to cause modest Diffuse Axonal Injury (DAI). DAI is the histopathological (tissue damage) marker for disruption of brain cells.

Prospective studies of MTBI without loss of consciousness and amnesia of up to 15 minutes have shown mild cognitive impairment lasting a few days.

There is presently no support for causation of brain cell injury by common human whiplash with only a few minutes of altered consciousness or amnesia.

Cognitive symptoms - forgetfulness, slowness, distractability and poor concentration - are common following MTBI.

They are also prevalent in otherwise similar patients who have not suffered TBI and in personal injury litigants without a history or claim of head injury.

Studies of normal populations show how common these symptoms are without any recognised illness or injury.

Similarly, diagnostic imaging abnormalities in blood-flow to the frontal lobes and anterior temporal region of the brain occur in depression, and the frontal lobe abnormalities are common to anxiety states also.

These disorders are, of course, very common in the aftermath of MTBI and whiplash.

There is presently no sound medical evidence on which to attribute these diagnostic imaging abnormalities to physical rather than psychological injury.

A recent Canadian study found no support for the claim that whiplash victims have a characteristic psychological profile.

On the contrary, patterns of symptoms such as anxiety and depression were similar to those of sufferers from chronic benign pain caused by other conditions.

There is some evidence that it is those who experience a greater severity of chronic pain that are most troubled by cognitive problems. Indeed, Mild TBI patients with chronic pain report greater ongoing cognitive difficulty than Severe TBI victims without associated pain.

Expectation and attitude appear to play a large role. Some patients react to injury with greater anxiety ("Will I ever get better?") or depression ("I'll never be the same.")

This response has been dubbed not psycho-somatic (the mind making the body sick) but rather somato-psychic (a psychological over-reaction to bodily injury).

Many physicians and lawyers seem to believe, despite considerable evidence to the contrary, that psychological health cannot adversely or beneficially influence physical healing. They remain uncertain whether, by taking thought, the claimant could not cure his/her psychological injury.

A practical medical response to this uncertainty is exhaustive diagnosis and treatment of the secondary psychological complications of head-injury or whiplash.

Known causes of disability in late whiplash are chronic headache, chronic pain, depression, anxiety disorders and Post Traumatic Stress Disorder.

Evidence-Based Medicine has shown that wearing the time-honoured soft collar delays recovery in comparison with active exercise.

By contrast, preliminary clinical research has found that administering high dosage corticosteroid medication within 8 hours of whiplash significantly reduced both disabling symptoms and prolonged sick leave.

To discredit a physical basis for late whiplash, Defence counsel often quote studies from Lithuania, where there is no compensation for motor vehicle injuries.

This earlier research found that, 1-3 years after rear-end collision, there was no increase in prevalence of neck symptoms compared with the uninjured population.

However, a more recent study in Sweden followed instead those who reported neck pain at the time of the MVA.

Those with immediate symptoms were three times as likely to be complaining of neck pain seven years later.

Previously, 14 clinical features were needed to forecast reliably those who would have a poor long-term outcome.

According to a new study, measured restriction of neck movement alone may be as accurate a predictor.

After a second whiplash, most patients reported recurrent or increased symptoms.

Almost all those who had apparently recovered completely after the first injury, developed persistent symptoms after the second accident.

Injuries to cervical facet joints and clefts in intervertebral discs are common and under-diagnosed.

Determining the anatomical pathological basis of soft tissue injuries that do not result in death generally depends on animal research.

Studies on primates that had been subjected to whiplash then sacrificed has now been supplemented by human studies of patients who probably suffered whiplash but died of an unrelated cause.

Two separate teams of researchers undertook autopsy studies of a total of 38 cervical spines from traffic accident victims who had died of Traumatic Brain Injury.

According to the autopsy studies, diagnostic imaging fails to detect the vast majority of soft tissue injuries following whiplash

Radiographs and Magnetic Resonance Imaging (MRI) that were taken during life or before post-mortem examination missed a number of spinal fractures and gross ligament disruption.

They also failed to detect the vast majority of the many injuries to the facet joints and intervertebral discs that were revealed by autopsy.

Where facet joints in the cervical spine are identified as a source of ongoing pain, interrupting the transmission of pain signals by radiofrequency neurotomy can dramatically improve pain within a couple of weeks.

The success rates of the procedure were not significantly different for litigants and non-litigants.

Furthermore, half of those litigants whose claims were settled within the study period had recurrence of pain after the settlement.

Other workers had previously shown that relieving pain by radiofrequency neurotomy also resulted in the resolution of psychological symptoms without the need for psychological treatment.