Neuropsychological recovery after TBI is not uniform across individuals and neuropsychological domains. For a subset of persons with moderate to severe TBI, neuropsychological recovery may continue several years after injury with substantial recovery. For other persons, measurable impairment remains 5 years after injury. Improvement was most apparent on measures of cognitive speed, visuoconstruction, and verbal memory.
Objectives-To examine patterns of brain activation while performing a working memory task in persons with moderate to severe traumatic brain injury (TBI) and healthy controls. It is well established that working memory is an area of cognition that is especially vulnerable to disruption after TBI. Although much has been learned about the system of cerebral representation of working memory in healthy people, little is known about how this system is disrupted by TBI. Methods-Functional magnetic resonance imaging (fMRI) was used to assess brain activation during a working memory task (a modified version of the paced auditory serial addition test) in nine patients with TBI and seven healthy controls. Results-Patients with TBI were able to perform the task, but made significantly more errors than healthy controls. Cerebral activation in both groups was found in similar regions of the frontal, parietal, and temporal lobes, and resembled patterns of activation found in previous neuroimaging studies of working memory in healthy persons. However, compared with the healthy controls, the TBI group displayed a pattern of cerebral activation that was more regionally dispersed and more lateralised to the right hemisphere. Differences in lateralisation were particularly evident in the frontal lobes. Conclusions-Impairment of working memory in TBI seems to be associated with alterations in functional cerebral activity. (J Neurol Neurosurg Psychiatry 2001;71:161-168)
Functional Near-Infrared Spectroscopy (fNIRS) is a neuroimaging technique that utilizes light in the near-infrared spectrum (between 700 and 1000 nm) to detect hemodynamic changes within the cortex when sensory, motor, or cognitive activation occurs. FNIRS principles have been used to study brain oxygenation for several decades, but have more recently been applied to study cognitive processes. This paper provides a description of basic fNIRS techniques, and provides a review of the rehabilitation-related literature. The authors discuss strengths and weaknesses of this technique, assert that fNIRS may be particularly beneficial to neurorehabilitation of cognitive disabilities, and suggest future applications.
The latent structure of the Wechsler Memory Scale-III was analyzed by confirmatory factor analysis using the covariance matrix based on the 11 primary subtests from the standardization sample. Omnibus fit indexes and individual parameter estimates were examined. Of the five models evaluated, a three-factor model (working memory, auditory memory, and visual memory) provided the best fit for the standardization sample (NNFI = .98, RMSEA = .05, GFI = .98, BIC = 429.42). Models that proposed separate immediate and delayed memory constructs were hampered by inadmissible parameter estimates that signaled model specification errors. R2 values for the Faces subtests were uniformly low for all five models that suggested that this subtest has insufficient commonality with the visual memory construct.
This randomized clinical trial utilized established techniques to improve new learning and memory performance in multiple sclerosis (MS) participants with learning impairment. Participants were 29 individuals with clinically definite MS with documented learning deficits, randomly assigned to the experimental or control group. The experimental group underwent eight sessions of the Story Memory Technique (SMT), while the control group participated in eight sessions of memory exercises. Neuropsychological assessment was conducted at baseline, immediately following treatment and 5 weeks later to assess outcome. When stratifying participants by degree of learning deficits, a significant treatment effect was noted. MS participants with moderate-severe impairment in learning showed a significant improvement in learning abilities when compared to controls, (t(19) =3.32, P<0.01) evident in 88% of participants in the experimental group. Little improvement was noted in MS participants with mild learning impairments. Significant self-reported improvements in memory were noted in MS participants that underwent treatment, but not those that did not undergo treatment (t(26) =2.55, P<0.01). Results indicate that learning and memory deficits in MS can be effectively treated through a memory rehabilitation program utilizing context and imagery to improve new learning. Appropriate patient selection is important, with moderately-severely impaired individuals showing significantly greater benefit from treatment.
Performance on the Trail Making Test is dependent upon multiple factors (e.g., motor speed, visual search, symbolic set shifting, capacity to sustain effort), many of which are difficult to assess differentially using the test's traditional administration, or with certain clinical populations (e.g., blind or grossly motor-impaired individuals). The present study investigated a motor-free, vision-free, oral version of the Trail Making Test in two groups of younger adults and one group of elderly adults. The results demonstrated that although there were age-associated differences in raw performance times, the comparability of oral and written performances, as assessed by oral-to-written ratios, was consistent across age groups. These results suggest that the oral version of the Trail Making Test yields results consistent with an individual's written performance in normal subjects, regardless of age. Findings are discussed with regard to the potential clinical application of this measure as an alternative for specific populations, and as a useful way of interpreting written Trail Making performances.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.