Psychological factors following whiplash

Bogdan P. Radanov, MD, Associate Professor of Psychiatry, Wilhelm Schulthess Hospital, Lengghalde 2, 8008 Zƒrich, Switzerland

    Introduction

            Different psychological symptoms have been documented during the course of whiplash injury. The principal focus of the present study was to evaluate the course of  psychological variables during a two-year follow-up using a non-selected sample of recently injured patients with common whiplash.

            Common whiplash in this study was considered a medical trauma leading to musculo-ligamental sprain or strain of the cervical spine due to hyperflexion/hyperextension, without fractures or dislocations or any head impact or traumatic loss of consciousness including posttraumatic amnesia.

         Patients and methods

            Physicians were asked to refer patients who had suffered whiplash injury within the shortest possible interval. Inclusion criteria were: i) injury according to the definition; ii) German as native language; iii) age less than 55 years; iv) no trauma to other parts of the body; and v) negative history of neurological dysfunctions (i.e., neuralgia, multiple sclerosis). The study investigated patients as soon as possibe after trauma and at 3, 6, 12 and 24 months. From a total of 164 referred patients 27 did not meet the criteria and 20 dropped-out at follow-ups. The final initial sample consisted of 117 patients (mean age=30.8ñ9.6, range 19 - 51 years, average educational attainment=12.7ñ2.7 years, women 58%). All patients underwent assessment of subjective complaints, neurological and physical investigation, radiological assessment of the cervical spine and, a detailed assessment of personal and family history focusing on factors possibly influencing illness behaviour. All patients at all investigations rated the intensity of neck pain and headache on a scale from 0 (no pain) to 10 points (maximal pain).

            Psychological assessment included:

Self-rated well-being was assessed using the well-being scale. The higher the score on the well-being scale the greater the impairment of the subjects' well-being. Scores greater than 17 (normal range 4 - 17 points) i.e., T-values greater than 56 reflect a significantly impaired well-being.

Personality traits were examined using the Freiburg Personality Inventory. The answer analysis reveals scores which are transformed into standardized values (STANINE). STANINE between 4 and 6 are comparable with 54% of a random sample, while scores above 6 are pathological. This inventory is comprised of the following scales: nervousness, spontaneous aggressiveness, depression, social withdrawl, irritability, reactive aggressiveness, inhibition, extraversion, neuroticism, and passivity (later three being considered to assess personality traits). Neuroticism has been shown to influence symptom reports.

Parallel versions of personality inventory, and well-being scale were used.

Evaluation strategy

For each patient, who still suffered from trauma-related symptoms at the end of the two-year follow-up (symptomatic group) an age, gender and education pair-matched counterpart was chosen from those individuals who were symptom free at the investigation 6 or 12 months following injury and in whom symptoms did not re-occur during follow-up period of two years (asymptomatic group). Thus, all patients considered for the present analysis were investigated at referral (T1) and at 3 (T2), 6 (T3) and 24 months (T4).

            Results

            Two years following initial trauma 21 patients still suffered from trauma-related symptoms (symptomatic group). Out of 96 individuals who had recovered 21 patients were pair-matched with regard to age, gender and education to establish group for comparison (asymptomatic group).

The symptomatic group initially (T1) on average scored with regard to neck pain intensity 5.3ñ2.2 and, at the final investigation (T4) 4.8ñ2.1. These same patients on headache rating initially on average scored 4.8ñ3.4 and at T4 5.6ñ2.5. Neither with regard to neck pain rating (z=-0.8928, p=0.372) nor hedache rating (z=-0.6097, p=0.542) a significant difference between the initial and final investigation. The presentation of respective results of theat T4 were competely recovered.

Scores for the two groups obtained at T1, T2, T3 and T4 regarding the well-being scale and three scales from the Freiburg Personality Inventory (i.e. nervousness, depression and neuroticism) were analysed. Furthermore, a one factor analysis of variance with repeated measures was employed to evaluate differences between the groups and the deviation of scores over time. This analysis included the following: i) for each patient the deviation from the average score over time has been calculated for every scale, i.e. well-being scale and the Freiburg Personality Inventory (TIME). The level of significance on this analysis (TIME) indicates a significant deviation of scores within the groups between the initial (T1) and final (T4) investigation. Whether this deviation is based upon an increase or decrease in scores must be analysed according to the respective scores; ii) for scores on the well-being scale and Freiburg Personality Inventory, symptomatic or asymptomatic groups were compared. The level of significance on this analysis (SYMPT) indicates that over the follow-up period groups significantly differed from each other. A level of significance for both analyses (SYMPT and TIME) suggests that groups differ significantly over time and one of the groups shows significant deviation regarding the initial (T1) and final score (T4); iii) furthermore, the interaction between the factors (TIMExSYMPT) was analysed. This analysis assesses whether scores of both groups over time are paralleled or overlap. The level of significance regarding this analysis indicates the inability to designate patients to one of the two groups (i.e. symptomatic or asymptomatic) according to test scores. In case a significant interaction between factors, a post-hoc analysis for determining the source of the interaction (i.e. T1, T2, T3 or T4) is calculated.

            Well-being scale

            A significant deviation over time and a significant difference between the groups was found on this scale. However, a significant interaction between factors could not be established.

Personality inventory

On nervousness-scale the symptomatic group on average showed increased scores during follow-up and there were significant deviation, significant difference between groups and significant interaction between factors for which T1 contributed (z=3.055, p<.003).

            Scores on the depression-scale showed a significant deviation over the follow-up period. However, the groups did not differ significantly from each other, and a significant interaction between factors could not be established. 

            For the extraversion, neuroticism or passivity scales, i.e. scales assissing personality traits, there was neither significant difference between groups, nor significant deviation over time nor significant interaction between factors.

            Conclusion

            These results highlight that patients' psychological problems are rather a consequence than a cause of somatic symptoms in whiplash.