Cortical activation during rhythmic hand movements performed under three types of control: an fMRI study.

Echoplanar fMRI was used to measure changes in cortical activation during the performance of a simple hand movement task under three types of voluntary control. Each of three imaging series alternated a task with rest: passive (in which the experimenter moved the hand), voluntary against low resistance, and voluntary against higher resistance. Contralateral activation was observed in the supplementary motor area (SMA), the primary motor cortex (M1), and the somatosensory cortex (S1) in all three tasks in each subject, whereas ipsilateral activation differed in each cortical region for each task. SMA had the widest prevalence of ipsilateral activation in all three tasks. In the M1, ipsilateral activation was observed in all but 1 subject in the two voluntary tasks but in only a few subjects in the S1 in any of the tasks. Quantitative changes in signal intensity and spatial extent of activation differentiated the voluntary tasks from the passive task and were most pronounced in the S1.

Employment following severe traumatic brain injury: the utility of the Individual Ability Profile system (IAP).

The results of a survey of employment outcome and their relationship to psychometric indices indicated that competitive employment following severe traumatic brain injury is an ambitious endeavor. While 98% of the subjects sampled were either employed or in school premorbidly, 43% of the subjects were unemployed postinjury. Specifically, the Individual Ability Profile (IAP) ([Dean, 1982][Dean, 1983]) variables developed to assist in the clinical interpretation of the results of the WAIS-R were most highly related to employment outcome. A discriminant function analysis utilizing these variables yielded hit rates of 82% for the unemployed category and 92% for the full-time employment grouping. These results further highlighted the useful role of neuropsychological testing in assisting in vocational rehabilitation planning. Future research is required to further elucidate those neuropsychological abilities that subsequently affect employability following severe traumatic brain injury.

The scaling of the Katz Adjustment Scale in a traumatic brain injury rehabilitation sample.

Based on the KAS-R1 ratings completed by 88 relatives of clients who had enrolled in a post-acute rehabilitation programme, the 10 component groups discerned by Fabiano and Goran [1] were submitted to a classical analysis of tests. Seventy-nine items were found to contribute to the internal consistency of their respective component groups, resulting in alpha values ranging from 0.75 to 0.93 for the component groups. Intercorrelations between components suggested that while some degree of overlap existed between groups, they represented discrete categories of neurobehavioural functioning. Second-order components, as determined by principal-component analysis, discern two significant component groups. These two components correlated moderately, yielding a value of 0.49. The findings indicate that the revised KAS-R1 exhibits considerable potential for clinical utility. Further research is needed to investigate the validity of this instrument in accurately depicting behavioural manifestations of those who have incurred traumatic brain injury.

Scanning electron microscopic appearance of chronic ulcerative colitis with and without dysplasia.

This study was conducted to determine whether scanning electron microscopy of colonic mucosal biopsy specimens can help to detect dysplasia in patients with chronic ulcerative colitis. In the first phase of the study, using light microscopy as the standard for the diagnosis, the scanning electron microscopic appearance of specimens from patients with chronic ulcerative colitis and control patients was examined. Descriptive criteria were established to identify normal, atrophic, and dysplastic colonic mucosa. In the second phase, quantitative techniques were used to develop more objective criteria for the diagnosis of dysplasia in ulcerative colitis. Twenty-one coded colonic specimens from 11 patients were sequentially examined by scanning electron microscopy and by light microscopy. The three morphometric analyses performed on the surface epithelial cells were number of cells per unit area, number of microvilli per unit area, and percentage of microvilli with a normal width. The cell count and percentage of microvilli with a normal width were significantly reduced in the seven specimens with colonic dysplasia as compared with non-dysplastic tissues. Scanning electron microscopy may serve as an adjunct to light microscopy in the diagnosis of colonic dysplasia.

Esophageal dysplasia. Assessment by light microscopy and scanning electron microscopy.

This study was performed to determine the characteristics of esophageal dysplasia by scanning electron microscopy. A total of 82 esophageal biopsy specimens were taken from 30 patients who were divided into three groups. Group 1 patients had no known esophageal disease. Group 2 patients had squamous cell cancer. Group 3 patients had esophagitis. Mucosal biopsy specimens that had been diagnosed by light microscopy as normal, esophagitis, or dysplastic mucosa were examined by scanning electron microscopy. A characteristic appearance for each type of mucosa was recognized by scanning electron microscopy. A quantitative analysis of the scanning electron microscopy feature of microridge density showed a statistically significant difference not only between normal and dysplastic mucosa, but also between esophagitis and dysplastic mucosa. The addition of scanning electron microscopy to light microscopy may prove helpful in the diagnosis of dysplasia as well as in the understanding of the biologic behavior of dysplastic cells and possibly their relationship to esophageal carcinoma.