Voxel-based morphometry (VBM) studies have reported abnormalities in brain regions involved in functions that are commonly impaired in autism spectrum disorders (ASD). However, little is known about brain structure anomalies in low-functioning (LF) young children with ASD. A VBM analysis was carried out to assess brain regions involved in ASD LF children, and a multiple regression analysis was used to examine the relationship between regional volume changes and autism symptom measures. Twenty-six LF ASD children (2-10 years) were compared with 21 controls. A VBM-Diffeomorphic Anatomical Registration analysis using Exponentiated Lie algebra (DARTEL) was used to evaluate gray matter (GM) and white matter alterations, covaried with Intelligence Quotient, age, and total brain volume. The resulting altered regions were correlated with Autism Diagnostic Interview (ADI)-Revised and Autism Diagnostic Observation Schedule (ADOS)-Generic scores. GM bilateral reduction was noted in the cerebellum (Crus II and vermis) and in the hippocampi in ASD group. GM reduction was also detected in the inferior and superior frontal gyri, in the occipital medial and superior gyri, and in the inferior temporal gyrus of the left cerebral hemisphere. In the right hemisphere, GM reduction was found in the post-central cortex and in the occipital inferior gyrus. Multiple regression analysis showed a correlation between alterations in GM volume in the cerebellum (Crus II and vermis) and ADI-communication and ADOS-total (communication and interaction) scores. These findings seem to confirm that the cerebellum is involved in integrating and regulating emotional and cognitive functions which are impaired in ASD.
The hippocampus is one of the earliest brain regions affected in Alzheimer's disease (AD) and tests of hippocampal function have the potential to detect AD in its earliest stages. Given that the hippocampus is critically involved in allocentric spatial memory, this study applied a short test of spatial memory, the 4 Mountains Test (4MT), to determine whether test performance can differentiate mild cognitive impairment (MCI) patients with and without CSF biomarker evidence of underlying AD and whether the test can distinguish patients with MCI and mild AD dementia when applied in different cultural settings. Healthy controls (HC), patients with MCI, and mild AD dementia were recruited from study sites in UK and Italy. Study numbers were: HC (UK 20, Italy 10), MCI (UK 21, Italy 14), and AD (UK 11, Italy 9). Nineteen UK MCI patients were grouped into CSF biomarker-positive (MCI+, n = 10) and biomarker-negative (MCI-, n = 9) subgroups. Behavioral data were correlated with hippocampal volume and cortical thickness of the precuneus and posterior cingulate gyrus. Spatial memory was impaired in both UK and Italy MCI and AD patients. Test performance additionally differentiated between MCI+ and MCI- subgroups (P = 0.001). A 4MT score of ≤8/15 was associated with 100% sensitivity and 90% specificity for detection of early AD (MCI+ and mild AD dementia) in the UK population, and with 100% sensitivity and 50% specificity for detection of MCI and AD in the Italy sample. 4MT performance correlated with hippocampal volume in the UK population and cortical thickness of the precuneus in both study populations. In conclusion, performance on a hippocampus-sensitive test of spatial memory differentiates MCI due to AD with high diagnostic sensitivity and specificity. The observation that similar diagnostic sensitivity was obtained in two separate study populations, allied to the scalability and usability of the test in community memory clinics, supports future application of the 4MT in the diagnosis of pre-dementia due to AD.
This study focused on the substantia nigra (SN) in Parkinson's disease (PD). We measured its area and volume, mean diffusivity (MD), fractional anisotropy (FA) and iron concentration in early and late PD and correlated the values with clinical scores. Twenty-two early PD (EPD), 20 late PD (LPD) and 20 healthy subjects (age 64.7 ± 4.9, 60.5 ± 6.1, and 61 ± 7.2 years, respectively) underwent 1.5 T MR imaging with double-TI-IR T1-weighted, T2*-weighted and diffusion tensor imaging scans. Relative SN area, MD, FA and R2* were measured in ROIs traced on SN. Correlation with Unified Parkinson Disease Rating Scale (UPDRS) scores was assessed. In LPD, the SN area was significantly reduced with respect to EPD (p = 0.04) and control subjects (p < 0.001). In EPD, the SN area was also significantly smaller than in controls (p = 0.006). Similarly, the SN volume significantly differed between LPD and controls (p = 0.001) and between EPD and LPD (p = 0.049), while no significant differences were found between controls and EPD. Both SN area (r = 0.47, p = 0.004) and volume (r = 0.46, p = 0.005) correlated with UPDRS scores. At 1.5 T, SN morphological measurements were sensitive to early PD changes and able to track the disease progression, while MD and FA measures and relaxometry did not provide significant results.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.