Author: E. Paul Giersch

The ubiquitous whiplash injury continues to raise a variety of medical and legal issues which have far-reaching implications for modern society. Basic among these issues is whether the chronic whiplash condition can be confirmed with reasonable scientific certainty. Vigorous efforts by the insurance and risk management industries to challenge the validity of chronic whiplash have enormous economic and health care access repercussions for those suffering its effects. Interested parties must therefore rely heavily on scientific research from around the world to identify and describe the disorder with clarity and objectivity.

Two recently published studies, quite different in subject and focus, may contribute significantly to further understanding of chronic whiplash.

Surface Electromyography Measurements of Upper Trapezius Muscles

In the August 2000 issue of Spine appears the report of a study from The Netherlands which investigated whether surface electromyography assessment of the upper trapezius muscles could be used to distinguish chronic whiplash patients from healthy control subjects. ( Nederhand M, IJzerman M, et al. Cervical muscle dysfunction in the chronic whiplash associated disorder grade II (WAD II). Spine 2000; 25: 1938-43.) Eighteen whiplash patients who reported neck, head or shoulder pain for more than six months were compared with nineteen healthy control subjects. Surface EMG activity of the upper trapezius muscles was recorded during three static postures, during a unilateral dynamic manual exercise, and during relaxation after the manual exercise. The whiplash patients showed higher co-activation levels during physical exercise and a decreased ability to relax muscles after exercise. The authors suggest that SEMG assessment of muscle dysfunction may be a more useful testing measure than palpation in identifying patients with chronic whiplash (since palpation has questionable inter-examiner reliability).

In the medical-legal context, this study may be valuable in two ways. It adds to the body of research establishing chronic whiplash disorder as a valid diagnostic entity through objective measurement. Moreover, in certain situations SEMG may provide treating and examining doctors with objective evidence to confirm the accuracy of their examination findings and diagnostic assessments in chronic whiplash patients.

Saccadic Eye Movement Disturbance in Chronic Whiplash Patients

Researchers from the Departments of Neurology and Physchiatry at the University of Berne, Switzerland, in the April 2000 issue of Brain, reported their findings after examining the horizontal eye movements of chronic whiplash patients. (Mosimann V, Muri R, et al. Saccadic eye movement disturbances in whiplash patients with persistent complaints. Brian 2000; 123: 828-35.)

Symptomatic subjects were compared with a second group which had recovered from whiplash injury, and a control group of healthy volunteers. The symptomatic group had reported persistent dizziness, poor concentration, and neck pain or headache, for an average of 2.8 years. Individuals with traumatic brain injury where excluded from the study.

The researchers studied the performance of reflexive and intentional saccade tasks. No significant difference in performance was appreciated between the recovered group and the control group. The symptomatic group, however, showed dissociation of their performances of reflexive and intentional tasks. Specifically, performance in reflexive tasks was normal, but performance was impaired with regard to the intentional tasks. The appearance of impaired inhibitory function (impairing the ability to intentionally ignore a suddenly appearing visual target) suggests dysfunction of prefrontal and frontal cortical structures, according to the authors.
Parenthetically, all three groups of subjects had been evaluated for emotional functioning using the Beck Depression Inventory. Although no signs of major depression where found in any of the groups, the authors note that the mean overall BDI scores where significantly elevated in the symptomatic group. Nevertheless , the authors suggest that depression is not a likely explanation for the oculographic findings of the study.

Quite apart from the larger questions suggested by this study relating to possible links between altered brain function and whiplash, the results provide further evidence useful in identifying and describing chronic whiplash as a disorder. They also suggest potential forensic value of eye movement studies in the medical-legal arena.

Conclusion
A number of insurance medical examiners, many with impressive credentials, routinely and under oath deny the existence of chronic whiplash disorder altogether. Accumulating research, typified by the two studies discussed above, make it increasingly difficult for these insurance industry partisans to maintain credibility in the medical/legal arena. For those who work in the legal and therapeutic realms, these kinds of research studies should provide encouragement and support.

Very truly yours,
ADLER GIERSCH, P.S.

E. Paul Giersch
Attorney at Law