Combination of diffusion tensor and functional magnetic resonance imaging during recovery from the vegetative state.

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract Background The rate of recovery from the vegetative state (VS) is low. Currently, little is known of the mechanisms and cerebral changes that accompany those relatively rare cases of good recovery. Here, we combined functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) to study the evolution of one VS patient at one month post-ictus and again twelve months later when he had recovered consciousness. Methods fMRI was used to investigate cortical responses to passive language stimulation as well as task-induced deactivations related to the default-mode network. DTI was used to assess the integrity of the global white matter and the arcuate fasciculus. We also performed a neuropsychological assessment at the time of the second MRI examination in order to characterize the profile of cognitive deficits. Results fMRI analysis revealed anatomically appropriate activation to speech in both the first and the second scans but a reduced pattern of task-induced deactivations in the first scan. In the second scan, following the recovery of consciousness, this pattern became more similar to that classically described for the default-mode network. DTI analysis revealed relative preservation of the arcuate fasciculus and of the global normal-appearing white matter at both time points. The neuropsychological assessment revealed recovery of receptive linguistic functioning by 12-months post-ictus. Conclusions These results suggest that the combination of different structural and functional imaging modalities may provide a powerful means for assessing the mechanisms involved in the recovery from the VS.Published versio

HIV-associated neurocognitive disorders before and during the era of combination antiretroviral therapy: differences in rates, nature, and predictors

Combination antiretroviral therapy (CART) has greatly reduced medical morbidity and mortality with HIV infection, but high rates of HIV-associated neurocognitive disorders (HAND) continue to be reported. Because large HIV-infected (HIV+) and uninfected (HIV−) groups have not been studied with similar methods in the pre-CART and CART eras, it is unclear whether CART has changed the prevalence, nature, and clinical correlates of HAND. We used comparable methods of subject screening and assessments to classify neurocognitive impairment (NCI) in large groups of HIV + and HIV − participants from the pre-CART era (1988–1995; N = 857) and CART era (2000–2007; N = 937). Impairment rate increased with successive disease stages (CDC stages A, B, and C) in both eras: 25%, 42%, and 52% in pre-CART era and 36%, 40%, and 45% in CART era. In the medically asymptomatic stage (CDC-A), NCI was significantly more common in the CART era. Low nadir CD4 predicted NCI in both eras, whereas degree of current immunosuppression, estimated duration of infection, and viral suppression in CSF (on treatment) were related to impairment only pre-CART. Pattern of NCI also differed: pre-CART had more impairment in motor skills, cognitive speed, and verbal fluency, whereas CART era involved more memory (learning) and executive function impairment. High rates of mild NCI persist at all stages of HIV infection, despite improved viral suppression and immune reconstitution with CART. The consistent association of NCI with nadir CD4 across eras suggests that earlier treatment to prevent severe immunosuppression may also help prevent HAND. Clinical trials targeting HAND prevention should specifically examine timing of ART initiation

Demographically-Corrected Norms for the Grooved Pegboard Test and Finger Tapping Test in monolingual Spanish speakers from the US-Mexico Border Region

Abstract Objective We developed demographically-corrected norms for US-dwelling, Spanish-speaking Hispanics on two widely used tests of motor skills - the Grooved Pegboard Test (Pegs) and Finger Tapping Test (Tapping). We then examined the effects of applying established norms for non-Hispanic Caucasians (NH Whites) and non-Hispanic African Americans (NH Blacks) on motor test results from our Hispanic population. Participants and Method 254 participants living in the US-Mexico border region of San Diego, CA and Tucson, AZ completed Pegs, and a subset (n = 183) completed Tapping. Age ranged from 19-60 and education from 0-20 years, with 59% women. Raw test scores were converted to demographically-corrected T-scores with a fractional polynomial procedure and compared to a fitted curve for the original data. Results Findings included significant main effects of education on both tests (p < .001), and of age for Pegs (p < .001). There was a significant interaction of sex and age on Tapping, such that older age was associated with lower scores in men only (p = .02). The resulting normative T-scores were confirmed to be free from demographic influences. Using a T < 40 cut point, rates of impairment in the Spanish speaking normative sample for dominant (D) and nondominant (ND) hands, respectively, were 17% and 14% for Pegs, and 12% and 10% for Tapping. Applying existing norms for NH Whites and NH Blacks to the raw scores of Spanish speakers generally yielded lower impairment rates on all measures, with one exception, Pegs ND, for which NH White norms overestimated impairment (23%). Conclusions Normative standards from other groups are not a good fit for interpreting motor test performance in this Hispanic population, which in the current instance would have generally underdiagnosed fine motor impairment. These findings underscore the importance of appropriate, population-specific normative data- even for tests of motor ability