Rehabilitation of Attention Following TBI
Rehabilitation of Attention Following Traumatic Brain Injury: A Model of Methylphenidate
Lead Organisation: Monash University
VNI Funding: $37,979
Project Dates: 1 November 2006 - 31 October 2007
Background:
Traumatic brain injury (TBI) results in disabling impairments of attention and speed of information processing. Methylphenidate (MP) primarily acts upon dopaminergic and noradrenergic neurotransmitter systems which mediate attentional processes. These processes are disrupted by TBI. Previous treatment study findings with MP (Ritalin®) in this population have been mixed, and have largely been conducted many years post-injury. This study investigated the efficacy of MP in the amelioration of attention deficits during the acute rehabilitation phase.
Aims:
The central aim of the present study was to investigate the efficacy of the central nervous system stimulant MP in the rehabilitation of attention deficits following TBI. Firstly we aimed to identify the nature of attentional deficits in the early stages following TBI by comparing performances of those with TBI and healthy Controls on a range of measures. The next step was to recruit patients into the MP trial whilst they were still participating in inpatient rehabilitation, based on the notion that the drug may facilitate the patient's ability to actively participate in therapy. Finally we aimed to identfy those most likely to “respond” to treatment with MP following TBI. It was hypothesised that TBI participant’s performance on selected neuropsychological measures, and rating scales of attentional behaviour, would be improved by MP administration compared to placebo.
Methods:
Forty participants with moderate-severe TBI sustained on average two months previously, and 40 healthy Control subjects participated in a one-off baseline assessment session in order to identify which domains of attention are disrupted following TBI. Subsequently, the TBI participants were recruited into a randomised, crossover, repeated measures, double-blind, placebo controlled drug trial. MP was administered at a dose of 0.3mg/kg bd over two weeks. Neuropsychological measures included standardized clinical tests and experimental reaction time (RT) measures. The Rating Scale of Attentional Behaviour was completed by therapists.
Results:
Patients in the acute rehabilitation phase after TBI demonstrate globally slowed speed of information processing. Their speed and accuracy of performance was further compromised by increasing working memory requirements, and the greater demands of controlled processing on certain tasks. The drug exerted its effect on speed of information processing, the aspect of attention which was most consistently impaired in these patients. Less impact was evident in terms of enhancing accuracy of performance or performance on tasks with complex working memory demands, possibly reflecting the fact that these aspects of performance were less impaired relative to Controls. In summary, pharmacological augmentation of the dopaminergic and noradrenergic neurotransmitter systems in this way routinely enabled participants with TBI to process and respond more quickly to stimuli in their environment.
Conclusions:
There are a number of unique aspects to this study which highlight its contribution to the field. It is the first to compare the MP trial TBI participants’ performance on neuropsychological tasks to that of healthy controls in order to determine which elements of attention are impaired. This is the largest randomized, placebo controlled study of the efficacy of MP in the early rehabilitation phase, as the majority of previous studies have investigated the effects of the drug many years post-injury. This study has demonstrated that the application of MP in the early rehabilitation phase is safe, paving the way for larger clinical trials.
Other Grants:
2004 - Seeding grant from The Wenkart Foundation, a division of Macquarie Health.
Publications (As of October 2009):
WILLMOTT C, PONSFORD J (2008). Efficacy of methylphenidate in the rehabilitation of attention following traumatic brain injury: A randomized, crossover, double-blind, placebo controlled inpatient trial. Journal of Neurology Neurosurgery and Psychiatry; December, doi:10.1136/jnnp.2008.159632
Presentations (As of October 2009):
Conferences
WILLMOTT C, PONSFORD J, REDMAN J. Pharmacological approaches to traumatic brain injury rehabilitation: A model for methylphenidate. Annual Meeting of the Australian Society for the Study of Brain Impairment; 2003 April 3-5, Sydney, Australia. (Oral)
WILLMOTT C, PONSFORD J, HOCKING C. Rehabilitation of attention following traumatic brain injury: A model for methylphenidate. Abstract. 36th Annual Meeting of the International Neuropsychological Society; 2008 February 6-9, Hawaii, USA. (Oral)
WILLMOTT C, PONSFORD J, HOCKING C. Efficacy of methylphenidate in the early rehabilitation of attention following traumatic brain injury: A randomised, double-blind, placebo controlled trial. IBIA 7th World Congress on Brain Injury; 2008 April 9-12, Lisbon, Portugal. (Oral)
WILLMOTT C, PONSFORD J, HOCKING C. Efficacy of methylphenidate in the early rehabilitation of attention following traumatic brain injury: A randomised, double-blind placebo controlled trial. Combined Conference of the Australasian Faculty of Rehabilitation Medicine and the AFO&EM; 2008 May 6-9 Adelaide, South Australia. (Oral)
WILLMOTT C. Efficacy of Methylphenidate in the Rehabilitation of Attention following Traumatic Brain Injury: A Randomized, Crossover, Double-Blind, Placebo Controlled Inpatient Trial. 32nd Annual Brain Impairment Conference (ASSBI); 2009 May, Sydney, Austarlia.
Education Sessions
WILLMOTT C. Attention following TBI: Indications for pharmacological interventions. The Wenkart Foundation; 2006 August 11, Sydney, Australia.
WILLMOTT C, PONSFORD J, HOCKING C. Efficacy of methylphenidate in the early rehabilitation of attention following traumatic brain injury: A randomised, double-blind, placebo controlled trial. National Trauma Research Institute Allied Health Symposium; 2007 November 7, Melbourne, Australia.
WILLMOTT C. Efficacy of methylphenidate in the early rehabilitation of attention following traumatic brain injury, as part of Session 1 – From Bench to Beside. VNI Research Seminar Series; 2008 March 11, Melbourne, Australia.
WILLMOTT C. Pharmacological rehabilitation of cognitive impairment following traumatic brain injury: what works and why. Department of Psychology, Monash University; 2008 May 27, Melbourne, Australia.
Researchers on this project attended the following conferences through the VNI conference support scheme:
- IBIA Seventh World Congress on Brain Injury, Lisbon, Portugal, 9 April 2008
- Combined Conference Australasian Rehab & Occ Medicine, 6 May 2008
