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The late whiplash syndrome a biopsychosocial approach

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									722                                                                                       J Neurol Neurosurg Psychiatry 2001;70:722–726



NOSOLOGICAL ENTITIES?




                            The late whiplash syndrome: a biopsychosocial
                            approach

                            R Ferrari, H Schrader



                            Abstract                                               Medical Journal. The number of subjects and
                            Physicians and other therapists continue               characteristics of subjects who chose not to
                            to grapple in daily practice with the                  enter the study were not known.3 No control
                            controversies of the late whiplash syn-                population was utilised, and no consideration
                            drome. For decades much of the debate                  was given for the fact that the Swiss system
                            and the approach to this controversial                 encourages payments for reporting disability
                            syndrome has centred on the natural                    and time lost from work, and even if a patient
                            history of and progression to chronic pain             returns to work, they can be compensated for
                            after acute whiplash injury. Recognising               not returning to full time work or having the
                            that there is recent epidemiological data              potential for long term economic loss. The
                            that defines the natural history of the                 Swiss-type system (no fault system) may be less
                            acute whiplash injury outside of many of               harmful to outcome than a tort system, as a tort
                            the confounding factors occurring in                   system has been recently shown to delay recov-
                            many western countries, and the lack of                ery,4 but even a no fault system is associated
                            evidence for a “chronic whiplash injury”,              with compensation factors, and is not the best
                            this article will thus introduce the biopsy-           setting for prognostic or other studies of the
                            chosocial model, its elements, its advan-              natural history of the acute whiplash injury.
                            tages over the traditional model, and the              Indeed, no controlled study outside the medi-
                            practical application of this model. The               colegal context or studies avoiding other
                            biopsychosocial model recognises physi-                confounding factors in countries were the late
                            cal and psychological souces of somatic                whiplash syndrome is epidemic were identified
                            symptoms, but fundamentally recognises                 by the Quebec Task Force, nor was the obvious
                            that the late whiplash syndrome is not the             necessity for such studies mentioned. The
                            result of a “chronic injury”.                          authors recommended, however, that prognos-
                            (J Neurol Neurosurg Psychiatry 2001;70:722–726)        tic studies be performed to determine the risk
                                                                                   factors and the influence of compensation
                            Keywords: whiplash injury; neck sprain; biopsychoso-   incentives such as that seen in Switzerland and
                            cial                                                   other western countries. Since the Quebec
                                                                                   Task Force, prognostic studies have been
                                                                                   performed in Lithuania, Greece, and
                            The authors of the 1995 monograph of the               Germany.5–10 These studies were largely free of
                            Quebec Task Force on Whiplash-Associated               the problems involved in the Swiss eVorts and
                            Disorders,1 after reviewing over 10 000 publi-         other limited evidence previously available for
                            cations, could identify no acceptable study as a       understanding the natural history of the acute
                            suitable source for understanding the natural          whiplash injury.
                            history and prognosis of the acute whiplash
                            injury. The only studies available at the time         Lithuania
                            were those using highly selected patient popu-         Lithuania is a country in which there is no or
                            lations, without control groups and all per-           little awareness or experience among the
                            formed in countries where there exists a multi-        general population of the notion that a
                            tude of confounding factors including                  whiplash injury may cause chronic pain and
12779 -50 Street,           expectation of disability, eVects of intervention
Edmonton, Alberta,
                                                                                   disability. Collision victims view this as a
Canada T5A 4L8              by the therapeutic community, and possibilities        benign injury not requiring any medical atten-
R Ferrari                   for secondary gain. Typical examples include           tion. Possibilities for secondary gains are mini-
H Schrader                  the Swiss study by Radanov et al, conducted            mal. In a controlled historical inception cohort
                            almost a decade ago and published many times           study published in 1996,5 none of the 202 sub-
Correspondence to:          since.2 In this study, patients with whiplash          jects involved in a rear end car collision 1–3
Dr R Ferrari
rferrari@powersurfr.com     were recruited after a car collision, but only if      years earlier had persistent and disabling com-
                            they first sought contact with their primary            plaints that could conceivably be linked to the
Received 14 June 2000 and   care physician, and were then recruited as a           collision. There were no significant diVerences
in revised form
10 October 2000             non-consecutive cohort selectively achieved            between the collision victims and controls con-
Accepted 20 October 2000    through general advertisement in the Swiss             cerning prevalence of symptoms including


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Whiplash and the biopsychosocial model                                                                                          723


                              neck pain, headache, and subjective cognitive        than found in the general, uninjured popula-
                              dysfunction. In a later prospective controlled       tion.9 A prospective outcome study by Keidel et
                              inception cohort study,6 47% of 210 victims of       al of 103 subjects in another locale in Germany
                              rear end car collision consecutively identified       found the same good prognosis, recovery often
                              from the daily records of the traYc police had       within 3 weeks, and virtually all within 6
                              initial pain. The symptoms disappeared in            weeks.10
                              most cases after a few days. No subject
                              reported collision induced pain later than 3         Experimental and other voluntary
                              weeks. After 1 year, there were no significant        collisions
                              diVerences between the collision victim group        Experiences from experimental collisions, fair-
                              and the control group concerning frequency           ground bumper car driving, and car crashing
                              and intensity of both neck pain and headache.        contests also question the validity of a “chronic
                              In the historical cohort study,5 31 collision vic-   injury” model of the late whiplash syndrome.
                              tims recalled having had acute or subacute           Despite being able to readily produce acute
                              neck pain. This symptom lasted in most cases         symptoms thousands of experimental collisions
                              less than a week and only two subjects had neck      with volunteers have failed to produce a patient
                              pain for more than 1 month. Due to recall            with chronic symtoms. This is despite the use
                              problems, the true incidence of collision            of various vehicles, impact directions and
                              victims with acute symptoms such as neck pain        speeds, restraint systems, with or without head
                              or headache was unknown. The study has later         rests, with varying head inclinations and
                              been criticised for having insuYcient                rotation, with or without tensed neck muscles,
                              power.11–13 The authors of the criticism, how-       and more recently with a wide range of young
                              ever, confused the incidence of an acute whip-       and old, both sexes, non-military volunteers
                              lash injury—that is, the at risk population for      (for a comprehensive review see Ferrari14). The
                              chronic symptoms, with the number of colli-          collisions experienced in the fairground
                              sion victims who remembered having had neck          bumper cars have been shown to be of similar
                              pain shortly after the collision. According to       velocity changes to many apparently symptom-
                              the prospective study performed in a compara-        provoking rear end collisions with automobiles.
                              ble inception cohort, the 95% confidence lim-         Yet chronic symptoms are not reported.15 In
                              its for the true incidence of acute symptoms         studies of drivers in car crash contests or
                              were 40% and 54% giving an estimated                 demolition derbys, which bests replicate acci-
                              minimum of altogether about 180 subjects with        dental whiplash injury, none of the drivers
                              acute whiplash injury in both studies. As none       reported chronic disabling symptoms despite
                              of the collision victims seemed to have              the fact that the drivers had an average career
                              developed persistent and disabling symptoms          total of many hundred collisions.16 17
                              due to the collision, the studies either evaluated
                              alone or together have suYcient power to reject      Facet joint studies
                              estimates of the incidence of the so-called late     Zygapophysial joint pain has been claimed to
                              whiplash syndrome in previous, methodologi-          be the most common basis for chronic neck
                              cally inferior studies and to question the valid-    pain as a result of whiplash injury.18 In one
                              ity of the condition as a chronic physical injury.   study, 39 people with chronic neck pain were
                                                                                   investigated. Five of the 39 had not been in
                              Greece                                               motor vehicle accidents, but apparently had
                              The late whiplash syndrome seems to also be a        had neck injuries in other types of accidents.
                              rare event in Greece. Of 130 consecutive colli-      Two of 39 claimed that their chronic pain
                              sion victims, all had acute whiplash injury, 91%     began 3 months after an accident. Some of the
                              recovered in 4 weeks, the remainder having           accidents took place 44, 27, and 21 years
                              substantial improvement to the point where           before entering the study. Those in motor vehi-
                              their frequency of neck pain was similar to the      cle accidents are reported to have experienced
                              general population, and indeed recovering            high speed collisions, far higher than most
                              within 3 months.7 Extending this data to 180         whiplash victims.19 Looking for a cause of cur-
                              patients confirmed this result, not only for          rent neck pain in these subjects, the investiga-
                              recovery from neck pain, but from the other          tors found that the facet joint or nearby struc-
                              symptoms commonly reported as part of the            tures could be a source for current neck pain in
                              acute injury syndrome.8                              some members of this highly select, heteroge-
                                                                                   neous, non-representative group of what they
                              Germany                                              arbitrarily called “whiplash patients”. This
                              The prognosis of acute whiplash injury is also       indicates only that neck pain in some cases may
                              remarkably good in Germany, a country where          have a current physical cause. The results do
                              there is widespread awareness of the possibili-      not confirm that the current cause is also a past
                              ties of acute symptoms after whiplash in the         cause of the neck pain, or has been for, say, the
                              general population, but little expectation of        last 44 years. The results tell us nothing about
                              chronic disability. In a study of physiotherapy      the injury (if there was one) in these subjects
                              treatment, by 6 weeks the active treatment           and nothing about whether an acute injury can
                              group and control (healthy) groups were equal        develop into a chronic physical source of pain.
                              in their symptom reporting. Even the group           It is diYcult to exclude that a very small
                              given only a collar for 3 weeks and no other         proportion of subjects could have chronic
                              therapy recovered by 12 weeks. That is, the          structural damage in countries such as Lithua-
                              acute whiplash injury does not seem to confer        nia, and that current studies with background
                              a greater risk of reporting chronic symptoms         prevalence of chronic neck pain in the control


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724                                                                                             Ferrari, Schrader


      population of about 10% are not large enough         studies, radiological studies, and traumatologi-
      to distinguish an additional 2%-3%. Yet these        cal principles, the acute injury is in most cases
      additional patients are not the group of greatest    a muscle or ligament sprain.14 22 26 This may
      concern. It is the high percentage of patients       well vary, but it is less relevant than the fact that
      with chronic accident-attributed pain (50% in        the outcome of the acute injury is invariably
      Canada4 and 58% in Norway20) that provide            benign in some countries, and invariably leads
      the greatest health care and economic burden,        to epidemic proportions of chronic pain
      and facet joint studies are irrelevant to this       beyond 6 weeks in other countries. For the bet-
      larger group.                                        ter understanding of the epidemic of the late
         The facet joint studies illustrate that pa-       whiplash syndrome in western countries, it
      tients, and the researchers, are prepared to         seems neccessary to consider biological, psy-
      carry or place the label of “whiplash patient”       chological, and social factors together by a
      on anyone who wants to attribute their chronic       biopsychosocial approach.
      neck pain to an accident. What cultural factors
      promote this non-scientific decision to make          Elements in a biopsychosocial model
      such an attribution? Why can it be assumed           Whereas it can be accepted that some aspect of
      that a current cause of neck pain has any rela-      the symptoms these patients report arise as the
      tion to an accident 44 years ago? That such          somatic component of depression or anxiety
      assumptions were made is the greatest revela-        disorder, it is equally reasonable that many of
      tion of the facet joint research. Physical sources   the symptoms have physical sources. The fact is
      of pain can and do exist, but it is how people       that many of these same symptoms of patients
      interpret the significance of that pain in            with whiplash, with often unidentifiable causes,
      relation to other events that creates the            often occur in normal people.27 That being the
      problem. If these subjects attribute their neck      case, there is a substrate (symptom pool)
      pain to an accident, then they are “whiplash         immediately available, on which psychosocial
      patients”. If they choose to dismiss the attribu-    factors may act, and this leads to further
      tion, then they are not “whiplash patients”; the     behaviours that become “the illness”. Thus the
      label has such a limited and flimsy a basis that      first factor of the biopsychosocial model is that
      it can be, on a mere whim, dismissed or clung        there is a general symptom pool that includes
      to passionately.                                     headache, neck pain, back pain, numbness,
         Thus, less research is needed at trying to        fatigue, dizziness, joint or limb aches and pains,
      pinpoint an anatomical source for pain, and          limb stiVness, poor concentration, poor hear-
      more research at trying to find the cultural          ing, and sleep disturbance.27 Yet the cause of
      source for behaviour in response to an acute         these symptoms, even though at least some
      pain—a simple neck sprain.                           would be presumed to have a physical basis in
                                                           the healthy person, is largely unknown.
      The need for a biopsychosocial model                    We have the strong possibility that the symp-
      The need for the biopsychosocial model arises        toms of the late whiplash syndrome arise from
      primarily out of the epidemiology of the late        multiple sources (including physical ones), and
      whiplash syndrome. By showing that the               the more relevant aspect of the psychosocial
      prevalence of chronic symptoms after whiplash        factors (or psychological distress) is that they
      is of the same order of magnitude as in the          act on this substrate.
      general population, and indeed also after whip-         The first question is then how are these
      lash in other countries,21 the studies in Lithua-    symptoms perceived and acted on diVerently in
      nia, Greece, and Germany were the first to            patients with whiplash than in healthy people?
      eVectively document that both acute and              The second question is how does this maladap-
      chronic symptoms are genuine; although, the          tive behaviour create new sources of symp-
      issue arises as to the extent that chronic symp-     toms? This brings us to the other factors
      toms may be related to the accident injury. The      operative in the biopsychosocial model—
      issue thus remains how the acute injury is per-      symptom expectation, amplification, and attri-
      ceived to evolve into chronic pain in some           bution.
      countries and not in others. In view of the
      above evidence, it cannot simply be assumed          Expectation, amplification, and
      that the progression to chronic pain is a result     attribution
      of malingering or psychosomatic disorder in          In North America, as in many other countries
      most patients (although exaggeration of symp-        including Norway, there is overwhelming
      toms, underperformance in neuropsychologi-           information on the potential for chronic pain
      cal testing, and underreporting of pre-accident      outcomes after whiplash injury, with wide-
      symptoms may of course occur22–24). There is         spread knowledge of the expected symptoms
      until now no convincing evidence of a specific        even among people with no personal experi-
      neck injury that can be expected to commonly         ence of having a collision.28 29 This expectation
      cause chronic damage in the neck and continue        will in turn lead the person to become
      to generate chronic pain or other chronic            hypervigilant for symptoms, to register normal
      symptoms of the late whiplash syn-                   bodily sensations as abnormal, and to react to
      drome.14 22 25 26 Notwithstanding these observa-     bodily sensations with aVect and cognitions
      tions, given that in Lithuania, Greece, and          that intensify them and make them more
      Germany the acute whiplash injury commonly           alarming, ominous, and disturbing—symptom
      occurs with pain resolving within 6 weeks, the       amplification. It is noteworthy that in countries
      exact pathology of most acute whiplash injuries      such as Lithuania, Germany, and Greece,
      may be largely irrelevant. From engineering          where again the late whiplash syndrome is rare,


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Whiplash and the biopsychosocial model                                                                                          725


                              recent studies using the methodology of                 The final factor of this triad is thus symptom
                              Aubrey et al28 and Mittenberg et al29 in those       attribution. As a collision victim becomes
                              countries found a lack of expectation of chronic     hypervigilant for symptoms, and as the victim
                              symptoms—the whiplash injury is viewed as            may expect chronic symptoms, the problem of
                              benign (R Ferrari, unpublished data, 2000).          symptom attribution is a natural result. In the
                                 The circumstances of the collision immedi-        setting of amplification, previously unintrusive
                              ately create an impression that the minor injury     symptoms, largely ignored in daily life, become
                              is not benign. The patient’s fear may start when     far more intrusive after the collision. The
                              paramedics take him out of the car on a special      patient regards them as new (they are now
                              stretcher, apply a hard collar, and warn him not     being registered), and attributes them to the
                              to move. Symptoms are intensified when they           collision. The symptom pool for new symp-
                              are attributed to a serious disease than to more     toms is drawn on while the acute injury
                              benign causes such as lack of sleep, lack of         resolves. The pool arises from life’s aches and
                              exercise, or overwork. This is not to say that it    pains, occupational sources, symptoms from
                              is the psychological trauma of the accident          medication use, and potentially the symptoms
                              event that is operative, but rather of the           that arise from maladaptive postures and
                              perceived nature of the injury. In Lithuania,        changes in physical fitness that arise as patients
                              Greece, and Germany the accident itself, as a        withdraw from normal activities. It is true that
                              threat to existence in general, would be             it is expected that these various benign,
                              expected to, even there, have a certain degree of    physical sources would not be capable of caus-
                              psychological impact, as it would in any coun-       ing severe or significant pain (and they likely
                              try; yet despite this, there is a lack of chronic    did not in the past for the patient), but that is
                              pain as a result in Lithuania, Greece, and Ger-      the eVect of symptom amplification, to alter the
                              many. This suggests that psychological trauma        naturally benign appearance of the symptoms.
                              is not likely an independent or substantial fac-     A biopsychosocial model is therefore not a
                              tor in the progression from acute to chronic         “psychogenic model”—that is, a model which
                              pain.                                                assumes that the chronic pain has no physical
                                 Another aspect of symptom amplification            basis, but is merely the somatic expression of
                              occurs when others have the collision victim         psychological disorder. The biopsychosocial
                              repeatedly draw attention to the symptoms            model instead suggests that what the patient
                              (every time the patient sees a therapist, or is      expects, how they perceive symptoms, and how
                              asked to keep a diary of symptoms, etc). Atten-      they focus and attribute symptoms will in turn
                              tion to a symptom amplifies it, whereas               alter the character of those symptoms and the
                              distractions diminish it. Thus the more often        patient’s behaviour, and that the symptoms
                              patients are asked to rate their pain, the more      have various physical sources in some cases..
                              intense they rate it.                                Following this, entirely new physical problems
                                 This symptom expectation and amplification         may arise to contribute to the symptom pool.
                              may cooperate to alter a collision victim’s          Add whatever further contribution is made by
                              behaviour in a detrimental way. Feeling severe       anxiety, depression, and compensation sys-
                              pain and fearing future disability, they develop     tems, and the late whiplash syndrome evolves.
                              the cognitions and behaviours that lead to
                              withdrawal from activities after minor injury,       Summary
                              and, for example, develop maladaptive pos-           The late whiplash syndrome is not merely psy-
                              tures. Yet it is known, for example, that postural   chosomatic. At the same time, it is not the
                              abnormalities, if induced in healthy subjects,       result of a “chronic injury. The biopsychosocial
                              cause pain.14 The patients with whiplash, in         model that considers an eVect of cultural
                              response to their heightened pain and their          expectation, cultural factors that generate
                              anxiety have just created a new source of            symptom amplification and attribution, as well
                              pain—and a physical source at that. This new         as the possibility that physical and psychologi-
                              source forms a further part of the substrate on      cal causes for symptoms coexist seems more
                              which symptom amplification can act—the               helpful. It negates the concept of “chronic
                              patients not realising that they have a new          injury”, but at the same time takes away the
                              source of pain, but instead they feel they have a    stigmata of the psychiatric label, while explain-
                              “chronic injury”—such was their expectation.         ing that people’s behaviour in response to their
                              Psychosocial factors ultimately generate, in this    injury may generate much of the illness, and
                              example, a physical source for pain. Another         therefore the illness is not an incurable injury.
                              example of what this behaviour does includes            The psychosocial elements, which may
                              the use of medications. The patient, experienc-      amplify otherwise benign bodily symptoms, or
                              ing amplified and fearful symptoms, seeks             transform a minor injury into one that is
                              medications. Yet, the medications commonly           viewed as serious and generate anxiety, may set
                              used for pain have as their adverse eVects dizzi-    in motion the phenomenon of symptom expec-
                              ness, cognitive disturbance, etc, a new physi-       tation and amplification. These processes
                              ological source for symptoms that the patient        eventually lead a person to attribute new and
                              will be informed (from what they have read or        even previous symptoms to a “chronic injury”.
                              from the input of their therapist) is part and       This reattribution then further amplifies the
                              parcel of their injury eVects. This new source of    symptoms themselves, as they now take on a
                              symptoms is there to be amplified, there to be        diVerent significance, and become more in-
                              attributed to a “chronic injury”, and arises         tense, noxious, and worrisome. The concern
                              because of the initial behaviour of the collision    that a person is seriously injured, together with
                              victim and those in their environment.               medical scrutiny, and media induced attention


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726                                                                                                                    Ferrari, Schrader


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