This large series of PRES cases shows that atypical distributions and imaging manifestations of PRES have a higher incidence than commonly perceived, and atypical manifestations do not correlate well with the edema severity.

Background Persons with type 2 diabetes (T2D) are at risk for cognitive impairment and brain atrophy. The ACCORD Memory in Diabetes (MIND) Study investigated whether persons randomized to an intensive glycaemic therapeutic strategy targeting HbA1c to <6% had better cognitive function and a larger brain volume at 40 months than persons randomized to a standard strategy targeting HbA1c to 7%–7.9%. Methods ACCORD MIND was a double 2×2 factorial parallel group randomised trial conducted in 52 clinical sites in North America. Participants [age 55 – <80 years] with T2D, high HbA1c concentrations (>7.5%), and at high risk for cardiovascular events were randomised to treatment groups using a centralized web-based system. Clinic staff and participants were not blinded to treatment arm. The cognitive primary outcome, the Digit Symbol Substitution Test (DSST) score, was assessed at baseline, 20 and 40 months. Total brain volume (TBV), the primary brain structure outcome, was assessed with MRI at baseline and 40 months in a sub-set of 632 participants. All participants with follow-up data were included in the primary analyses. In February, 2008, increased mortality risk led to the termination of the intensive therapy and transition of those participants to standard glycaemic treatment. Results Randomised patients (n=2977; mean age 62.3 years) were consecutively enrolled; the final analysis included 1358 intensive and 1416 standard arm participants with a 20 or 40 month DSST score. Of the 614 with a baseline MRI, 230 intensive and 273 standard therapy participants were included in the analysis. There was no treatment difference in the DSST score. The intensive group had a greater TBV than the standard group (difference, 4.62; 95% CI 2.0 to7.3 cm3; p=0.0007). Interpretation Although significant differences in TBV favored the intensive therapy, cognitive outcomes were not different. Combined with the unfavorable effects on other ACCORD outcomes, MIND findings do not support using intensive therapy to reduce the adverse effects of diabetes on the brain in patients similar to MIND participants. (ClinicalTrials.gov number, NCT00182910).

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Spinocerebellar ataxia type 6 (SCA6) was recently identified as a form of autosomal dominant cerebellar ataxia associated with small expansions of the trinucleotide repeat (CAG)n in the gene CACNL1A4 on chromosome 19p13, which encodes the alpha1 subunit of a P/Q-type voltage-gated calcium channel. We describe clinical, genetic, neuroimaging, neuropathological, and quantitative oculomotor studies in four kindreds with SCA6. We found strong genetic linkage of the disease to the CACNL1A4 locus and strong association with the expanded (CAG)n alleles in two large ataxia kindreds. The expanded alleles were all of a single size (repeat number) within the two large kindreds, numbering 22 and 23 repeat units. It is noteworthy that the age of onset of ataxia ranged from 24 to 63 years among all affected individuals, despite the uniform repeat number. Radiographically and pathologically, there was selective atrophy of the cerebellum and extensive loss of Purkinje cells in the cerebellar cortex. In addition, clinical and quantitative measurement of extraocular movements demonstrated a characteristic pattern of ocular motor and vestibular abnormalities, including horizontal and vertical nystagmus and an abnormal vestibulo-ocular reflex. These studies identify a distinct phenotype associated with this newly recognized form of dominant SCA.

Functional magnetic resonance imaging (fMRI) was used to examine spatial working memory in 8-to 11-year-old children tested under three conditions. In the visual condition, children were asked to examine the location of a dot on a screen. In the motor condition, children were instructed to push a button that corresponded to the location of a dot presented on a screen. In the memory condition, children were asked to remember the location of a dot presented 1 or 2 trials previously. Subtracting the activation of the motor condition from the memory condition revealed activity in the dorsal aspects of the prefrontal cortex and in the posterior parietal and anterior cingulate cortex. These findings were also obtained in the analysis of the memory minus visual conditions except that motor cortex activation was also observed. These findings parallel those reported in comparable studies of adults and suggest that fMRI may be a useful means of examining function-structure relations in developmental populations.According to Baddeley (1986), working memory is the process of temporarily maintaining information in an active form so that it is available for further processing. Not surprisingly, this cognitive component may be involved in many common tasks such as planning, decision making, spatial navigation, and strategy use. In the context of development, it is likely that working memory may underlie the emergence of many abilities that are considered hallmarks of mature, higher level cognitive functions. In this article we explore the functional neuroanatomy of working memory in 8-to 11-year-old prepubescent children.In the adult, the neural substrate for working memory varies depending on what is required of the person (see Goldman-Rakic, 1996). For example, dorsal aspects of the frontal cortex (including the superior and middle frontal gyrus) may be disproportionately