Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a set of neurological disorders characterized by impaired social communication and interaction, as well as restricted, repetitive patterns of behaviour, interests and activities. It is commonly diagnosed at around the ages of 3 to 4 years, developing tools that could aid in obtaining a diagnosis as early as 6 or 12 months of age would allow an early therapy that could potentially increase the adaptation to society of children with ASD.

At the NIST, we have utilized voxel-wise image processing methods to investigate the brain development of children at high-risk of ASD during the first 2 years of life. This work has led to observations of significant differences in the growth trajectories of several regions in the brain between children who are diagnosed with ASD at 2 years of age and normal controls.

HIV Neurodegeneration

HIV enters the brain soon after seroconversion and potentially causes cognitive impairment. Although the incidence of severe dementia has been reduced, perhaps due to effective HIV treatment, the prevalence of mild to moderate cognitive impairment appears to be increasing. It has been reported that 30-50% of HIV+ patients with well-controlled infections show cognitive deficits. Several factors are thought to contribute to this brain injury. However, the literature has yet to produce a clear consensus of the mechanisms that may underlie brain injury.

HIV
Brain volume loss associated with a history of severe HIV-related immunosuppression.

At NIST, we have utilized novel neuroimaging methods with complementary strengths, deformation-based morphometry, voxel-based morphometry and cortical modeling, to investigate the effects HIV has on brain structure and function. Here, we observed regionally specific patterns of reduced cortical and subcortical volumes in the HIV+ group. White matter loss and subcortical atrophy was related a history of more severe immunosuppression, while cortical thickness reductions were related to poorer neuropsychological test performance. The findings suggest that distinct mechanisms may underlie cortical and subcortical injury, and argues for the potential importance of early HIV treatment in protecting long term brain health.

Abstracts and Conference Presentations:

R. Sanford, A.L. Fernandez Cruz, L.K. Fellows, B.M. Ances, D.L. Collins, Regionally Specific Cortical Thinning in HIV+ Patients in the cART Era, 2016 Conference on Retroviruses and Opportunistic Infections (CROI), February 2016, Boston, Massachusetts (pdf)

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