The Effect of Cognitive Rehabilitation Therapy on Traumatic Brain Injury in a Single-Subject Design Study

Studies conducted on cognitive rehabilitation therapy (CRT) following traumatic brain injury (TBI) have shown significant efficacy in remediating deficits of attention, prospective memory, and executive functioning. The efficacy of CRT has been consistently demonstrated in individuals within the acute, sub-acute and very early chronic stages of TBI. Consequently, the case study depicted, was designed to determine if CRT treatments that are efficacious in the acute, sub-acute and early chronic stages of TBI are effective in generating functional gains in an individual well into the chronic stage of TBI and furthermore, to determine if an intensive schedule of CRT can produce results in this population. Additional goals are to examine whether or not such functional improvements might be associated with evidence of neuroplasticity consistent with what is known of structure-function relationships in the brain. A case study was conducted over the course of eleven-weeks to determine the behavioral and neuroplastic effects of intensive CRT on an individual with severe TBI. The single, male, subject (age 56) was six years post injury and demonstrated impairments in the domains of attention, prospective memory and executive functioning. Pre-treatment repeated baseline testing was performed during the first four weeks, followed by three weeks of intensive CRT on Mondays through Thursdays, with Fridays reserved for repeated measures and neuroimaging. At the completion of the seventh standardized testing session (occurring at the end of the third and final treatment week) a four-week hiatus was introduced, followed by standardized testing and neuroimaging one month post-treatment. Thus, five neuroimaging sessions were conducted in total on the Fridays of weeks 4, 5, 6, 7 and 11 of the study. Standardized measures administered both pre- and post-CRT included both functional measures such as the Functional Assessment of Communication Skills for Adults (ASHA FACS) and the World Health Organization Quality of Life-BREF (WHOQOL-BREF), as well as standardized psychometric measures such as the Delis-Kaplan Executive Function System (D-KEFS). Repeated measures included standardized tests such as the Memory for Intentions Screening Test (MIST), the Attention Process Training (APT-III), Conners’ Continuous Performance Test (CCPT II), and the (WAIS-IV), as well as daily logs kept by the subject. Improvements were observed in the domain of executive functioning via the D-KEFS and non-standardized functional measures conducted by the student clinician. The participant also reported functional improvement as a result of metacognitive strategy instruction (MSI) intervention. Results of intervention in the domains of prospective memory and attention were inconclusive. Additionally, neuroimaging data suggest neuroplastic changes consistent with functional gains. This study provides initial evidence for the possible efficacy of CRT in eliciting functional and neuroplastic changes for individuals with TBI several years post-injury, as well as the efficacy of an intensive schedule of treatment in this stage. Further research expanding beyond the single-subject design is needed to evaluate the efficacy of intensive CRT in the chronic stage of TBI