Energy crisis : prevalence, severity, treatment and persistence of fatigue after mild traumatic brain injury : a dissertation presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Psychology at Massey University, Palmerston North, New Zealand

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The objectives of this research were to investigate the prevalence and severity of post-mild traumatic brain injury (MTBI) fatigue in a non-litigant New Zealand sample and to evaluate the effectiveness of a treatment programme. Subsequently, a third objective evolved – the investigation of the natural history of post-MTBI fatigue and the degree to which reliable clinically significant change occurred over time regardless of intervention type. The research took the form of two studies where analysis was based on group data followed by analysis of the Study Two data at an individual participant level. Study One, a longitudinal prospective study examined fatigue prevalence, severity, predictors and co-variates over six months post mild traumatic brain injury (MTBI). Participants completed the Fatigue Severity Scale (FSS), Rivermead Postconcussion Symptoms Questionnaire (RPSQ), Hospital Anxiety and Depression Scale (HADS) and the Short Form 36 Health Survey-Version 2 (SF-36v2). Complete data were available for 159 participants. Key measures; prevalence - RPSQ Item 6: severity - FSS. The effect of time on fatigue prevalence and severity was examined using ANOVA. Multiple regression analysis identified statistically significant covariates. The study found post-MTBI fatigue prevalence was 68%, 38% and 34% at 1 week, 3 and 6 months respectively. There was a strong effect for time over the first three months and moderate to high correlations between fatigue prevalence and severity. Early fatigue strongly predicted later fatigue. Depression, but not anxiety, was a predictor. Fatigue was seen as laziness by family or friends in 30% of cases. Conclusions for Study 1 were that post-MTBI fatigue is a persistent postconcussion symptom, exacerbated by depression but not anxiety. It diminishes in the first three months and then becomes relatively stable, suggesting the optimum intervention placement is at three months or more post-MTBI. Study Two was a quasi-experimental longitudinal prospective controlled study which had a two by three, treatment by time, repeated measures research design. Participants with a history of MTBI were recruited from three Concussion Clinics. Post-MTBI fatigue was identified through Item 6 of the Rivermead Postconcussion Symptoms Questionnaire (RPSQ) and the outcome measures were the FSS, Fatigue Assessment Scale, RPSQ, Hospital Anxiety and Depression Scale and Sydney Psychosocial Re-integration Scale. All treatment group participants (N = 18) came from the same Concussion Clinic as the principal researcher, and control participants (N = 23) came from other Concussion Clinics. The question of whether the participants thought their significant others perceived them as lazy was also explored in Study Two. A 12 week manualised programme (PERT) was developed specifically for Study Two and was delivered by either a clinical psychologist or occupational therapist through a combination of personal and phone sessions. No significant time by group effect was found for any of the outcome measures. A time effect was found for all of the outcome measures. During the search for explanations for these findings it was discovered that the two conditions were more similar than expected. The majority (85.7%) of the control group had, in accordance with current rehabilitation practice, engaged in exercise and/or received interventions similar to the treatment group which presented a confound to the study. The data from the two groups was combined and analysed for information regarding reliable clinically significant change RCSC in individual participants. No significant correlations with demographic variables such as time since injury, age, gender, level of education, work type and injury type were found. Female gender was related to positive RCSC at three months post-baseline but not at six months post-baseline. Fatigue severity was significantly positively related to participants’ belief that relatives perceived them as lazy. Study Two provided no evidence to support this treatment for post-MTBI fatigue. Prevalence and severity of post-MTBI fatigue reduced over the six months of Study Two, however on examination of individual data the majority of the participants showed no reliable clinically significant change, supporting the need for further research into finding an effective post-MTBI fatigue treatment. The small sample size and the similarity of the treatment and control group conditions were major factors in confounding the findings of the study. There is a comparatively large percentage of individuals reporting prevalence and severity of post-MTBI fatigue in New Zealand samples and, although the combined psychoeducation and aerobic exercise approach could not be evaluated, the postconcussion and general literature suggests there is merit in continuing research into its effectiveness in treating post-MTBI fatigue.
Content of this thesis previously published as: Norrie, J., Heitger, M., Leathem, J., Anderson, T., Jones, R., & Flett, R. (2010). Mild traumatic brain injury and fatigue: A prospective longitudinal study. Brain Injury, 24(13-14), 1528-1538.
Mild traumatic brain injury, Wounds and injuries, Patients, Rehabilitation, Fatigue