In adolescents with mild traumatic brain injury (MTBI) with Glasgow Coma Scale score of 15 and negative CT, diffusion tensor imaging (DTI) performed within 6 days postinjury showed increased fractional anisotropy and decreased diffusivity suggestive of cytotoxic edema. Advanced MRI-based DTI methods may enhance our understanding of the neuropathology of TBI, including MTBI. Additionally, DTI may prove more sensitive than conventional imaging methods in detecting subtle, but clinically meaningful, changes following MTBI and may be critical in refining MTBI diagnosis, prognosis, and management.

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The aim of this paper is to update the over 20-year-old normative data for the Benton Controlled Word Association (COWA) Test. In a sample of 360 normal volunteers, the age ranged between 16-70 years, and the educational level ranged from 7-22 years. Care was taken to ensure that the population was heterogeneous, yet the two stratifications of gender, four age, and three educational groups led to 24 cells with 15 individuals in each. Test-retest reliability was established by testing 30% of the sample after a 6-month delay, which represents a typical follow up duration between testings in a clinical setting. The two forms of the COWA revealed significant test-retest reliability. Generally, our updated values fall above the original normative values, which were derived from a less well-educated and rural sample. No major gender or age trends were noted, but the COWA test performances were influenced by education, i.e., as the level of education increased, the performance on the COWA increased. The only gender differences that were found were for the women in the highest educational group ( > 16 years), who performed significantly better that men in the highest educational group. An error analysis of repetitions or perseverations is provided, with cut-off scores according to age levels. Finally, the updated COWA norms are compared to the original norms as well as to other measures of word fluency.

Fifty patients who sustained mild to moderate closed head injury (CHI) underwent a CT scan, MRI, and neurobehavioural testing. At baseline 40 patients had intracranial hyperintensities detected by MRI which predominated in the frontal and temporal regions, whereas 10 patients had lesions detected by CT. Neurobehavioural data obtained during the first admission to hospital disclosed no distinctive pattern in subgroups of patients characterised by lesions confined to the frontal, temporal, or frontotemporal regions, whereas all three groups exhibited pervasive deficits in relation to normal control subjects. The size of extraparenchymal lesion was significantly related to the initial Glasgow Coma Scale score, whereas this relation was not present in parenchymal lesions. One and three month follow up MRI findings showed substantial resolution of lesion while neuropsychological data reflected impressive recovery. The follow up data disclosed a trend from pervasive deficits to more specific impairments which were inconsistently related to the site ofbrain lesion. These results corroborate and extend previous findings, indicating that intracranial lesions detected by MRI are present in most patients hospitalised after mild to moderate CHI.Individual differences in the relation between site of lesion and the pattern of nueropsychological findings, which persist over one to three months after mild to moderate CHI, remain unexplained.Since the application of MRI to neurosurgical patients several reports`7 and our quantitative study of 20 patients8 have shown that this technique is more sensitive than CT scanning in detecting intracranial abnormalities after closed head injury (CHI). In view of our preliminary description8 of individual patients with mild to moderate CHI exhibiting distinctive neurobehavioural sequelae associated with frontal v temporal lobe hyperintensities, we extended this study to 50 cases. We evaluated the neuroanatomical distribution of abnormalities visualised by MRI in patients sustaining mild to moderate CHI; resolution of these apparent lesions over one to three months; and the relation between cerebral site of lesion and neurobehavioural sequelae.