Legal Update #15 The Neuropsychological Effects of Whiplash Injury: Fact or Fiction?

NLBC LEGAL UPDATE: January, 2002 - Issue #15

Sam Goldstein, Ph.D., Editor.
Complimentary Service of the Neurology, Learning and Behavior Center

THE NEUROPSYCHOLOGICAL EFFECTS OF WHIPLASH INJURY: FACT OR FICTION?

In my forensic work, perhaps no other issue invokes as much controversy and disagreement as the issue of neuropsychological impairments following whiplash injury. In this Legal Update, I will provide a brief overview of whiplash injury and the current state of knowledge concerning neuropsychological sequelae.

The term whiplash was first introduced in the 1920's when it was described as a sudden acceleration - deceleration force on the neck and upper trunk from external forces. The description was of a whip-like effect. Over a number of years the description itself became a diagnosis which has and continues to be criticized as vague and unscientific. There is no doubt that many individuals report a variety of symptoms secondary to a whiplash injury, particularly when the body receives sudden acceleration-deceleration of the trunk leading to excessive force to the neck. The nature and etiology, particularly of the neuropsychological complaints of these individuals, has been the cause of considerable debate.

The majority of researchers agree that acceleration, deceleration and rotational forces can and often do result in organic injuries. It has been estimated that at least 10% to 20% of individuals involved in rear-end car collisions suffer a whiplash injury. There is also a consensus that most realize a relatively good recovery within three to six months post-injury. The debate centers on the group of individuals who continue to be symptomatic beyond six months. This pattern of chronic whiplash syndrome is similar to the small group of individuals experiencing concussion leading to a chronic post-concussive syndrome. As with concussion, individuals who continue to be symptomatic following whiplash at six months are likely to develop a chronic pattern of impairment.

There continues to be disagreement as to the percentage of individuals experiencing whiplash who develop this chronic condition. Studies range from 0% to 50%. A number of studies suggest over a long period of time that at least a third of individuals suffering whiplash continue to experience chronic problems related to pain and cognitive difficulty. But the nature and etiology of these complaints has continues to be a source of controversy, not only in the scientific arena but in the forensic area as well.

The cluster of symptoms that have been associated with whiplash fall into one of three basic categories: (1) physical; (2) somatic; and (3) cognitive and affective problems. Physical symptoms have been noted to include headache, dizziness, nausea, auditory and visual problems and sleep disruption. Cognitive problems have included impairments in attention and concentration leading to a pattern of cognitive inefficiency in every day tasks. Affective symptoms have typically included the internalizing problems related to anxiety and depression with subsequent emotional lability. Children have been reported to experience a similar profile of problems.

It is accepted that whiplash can produce the rotational and acceleration/deceleration forces in the cranium that can result in the stretching and sheering of axons, ruptures or hemorrhages in small blood vessels, and a myriad of biochemical and neurotransmitter changes in the brain. Some professionals use the terms “closed head injury” and “whiplash injury” interchangeably because many of the symptoms are similar. However, an individual can experience a mild closed head injury without a change in brain structure or functioning. Alternately, research studies suggest that an individual can experience a change in brain physiology absent a blow to the head. As I have noted in past Legal Updates, the consensus of scientific research has defined the symptoms of concussion and the percentage of individuals experiencing accident related concussion but has yet to define all of the phenomena that ultimately shape symptom severity and chronicity for a particular individual. Even mild concussions have been demonstrated in some individuals to cause a change in brain function and ultimately every day activities. As Varney and Varney (1995) noted, non-impact brain injury can lead to “brain injury without head injury.” Animal studies have well demonstrated that whiplash type injuries cause changes in brain function and structure which can be identified on post mortem analyses.

Numerous studies have documented the somatic, cognitive and affective problems following whiplash with an increasing number of studies demonstrating that many of the symptoms of whiplash or post concussion can be caused by other non-traumatic problems.

The majority of individuals report several somatic, cognitive and emotional changes immediately following a whiplash injury or concussion. These symptoms decline over time. A subgroup of individuals continues to report these symptoms for several months or years post injury. Normal controls and patients with other conditions often report similar symptoms. On self-report alone there is a risk of over-diagnosis. During the course of litigation there is also a risk of malingering. Yet despite these phenomena, the strength of the scientific evidence allows the forensic neuropsychology expert to stand on firm footing when evaluating patients following whiplash injuries in which there are complaints of cognitive, physical and emotional changes.

When faced with litigation following a whiplash injury, it is reasonable for attorneys to conclude that most individuals will not experience persistent cognitive deficits. However, a small subset of individuals who sustain a whiplash injury will continue to present with cognitive complaints for several months or even years post injury, regardless of litigation. These should not be summarily dismissed as malingers, hysterics or people with flawed personalities. Although some of these factors may in part explain risk and vulnerability they do not in and of themselves explain failure to recover. To assume that individuals with chronic post whiplash problems cannot have residual cognitive impairments because the research demonstrates that most individuals make good recovery from these injuries, is poor science and unfair to these individuals. The challenge for the forensic neuropsychologist is to provide a reasoned and reasonable assessment, maintain current understanding and knowledge of research in the field, work cooperatively with medical specialties and most importantly, assist in designing treatment plans that facilitate maximum medical improvement.

Selected References

Alexander, M. (1998). In the pursuit of proof of brain damage after whiplash injury. Neurology, 51, 336-340.

Calaghan, M. & Abu-Arafeh, I. (2001). Chronic post traumatic headache in children and adolescents. Developmental Medicine and Child Neurology, 43, 819-822.

Evans, R.W. (1992b). The post-concussion syndrome and the sequelae of mild head injury. Neurologic Clinics, 10, 815-847.

Fisher, A.J.E.M., Huygen, P.L.M., Folgering, H.T., Verhagen, W.I.M. & Theunissen, E.J.J.M. (1995). Vestibular hyperactivity and hyperventilation after whiplash injury. Journal of the Neurological Sciences, 132, 35-43.

Frietag, P., Greenlee, M.W., Wachter, K., Ettlin, Th.M. & Radue, E.W. (2001). FMRI response during visual motion stimulation in patients with late whiplash syndrome. Neurorehabilitation and Neural Repair, 15, 31-37.

Gennarelli, T.A., Thibault, L.E., Adams, J.H., Graham, D.I., Thompson, C.C. & Marcincin, R.P. (1982). Diffuse axonal injury and traumatic coma in the primate. Annals of Neurology, 12, 564-575.

Miller, L. (1998). Motor vehicle accidents: clinical, neuropsychological, and forensic considerations. The Journal of Cognitive Rehabilitation, Jul/Aug, 10-23.
Pearce, J.M.S. (1994). Polemics of chronic whiplash injury. Neurology, 44, 1993-1997.

Radanov, B.P., Sturzenegger, M., & Schnidrig, A. (1994). A relationship between early somatic, radiological, cognitive and psychological findings and outcome during a one-year follow-up in 117 patients suffering from common whiplash. British Journal of Rheumatology, 33, 442-448.

Varney, N.R., & Varney, R.N. (1995). Brain injury without head injury: Some physics of automobile collisions with particular reference to brain injuries occurring without physical head trauma. Applied Neuropsychology, 2, 47-62.

The Neurology, Learning and Behavior Center provides multi-disciplinary, clinical and forensic assessment, case management, trial consultation and treatment services for children and adults with brain injury and dysfunction, Attention-Deficit Hyperactivity Disorder, language disorders, learning disability, developmental delay, emotional disorders, Autism and adjustment problems. The Center is dedicated to the provision of treatment services.