ABSTRACT
Mild cognitive impairment (MCI) may predict future development of dementia in Parkinson's disease (PD). We aimed to examine the extent of subcortical brain atrophy in patients with early PD with and without MCI compared to normal controls (NC). Participating in a population-based study were 43 early, drug-naïve PD patients and 41 NC. Eleven patients were classified with MCI (MCI PD) and 32 patients without (non-MCI PD). Volumetric segmentation of 3D-T1 weighted brain MRI was performed using FreeSurfer. Groups were compared applying MANCOVA corrected for total intracranial volume, age, and sex. Results showed that left inferior lateral ventricle and third ventricle volumes were significantly larger in MCI PD than in non-MCI PD and NC. Fourth ventricular size in MCI PD was significantly different from NC and highly correlated with memory performance in MCI PD patients. This suggests that cognitive dysfunction in early PD may be associated with ventricular enlargement.
Subject(s)
Cognition Disorders/pathology , Lateral Ventricles/pathology , Parkinson Disease/pathology , Third Ventricle/pathology , Aged , Analysis of Variance , Cognition Disorders/physiopathology , Disease Progression , Female , Humans , Image Processing, Computer-Assisted , Lateral Ventricles/physiopathology , Magnetic Resonance Imaging , Male , Middle Aged , Neuropsychological Tests , Parkinson Disease/physiopathology , Severity of Illness Index , Third Ventricle/physiopathologyABSTRACT
PURPOSE: To investigate the associations between the rs2030324 SNP of brain-derived neurotrophic factor (BDNF) and neuropsychological (NP) test measures in multiple sclerosis (MS) patients. BACKGROUND: BDNF regulates the survival of neuronal and non-neuronal cells and plays a critical role in neurochemical processes underlying learning and memory. METHODS: A total of 209 MS patients (161 females; 48 males) underwent brain MRI and genotyping for BDNF rs2030324. The NP testing (n=108) assessed processing speed, working memory, new learning and executive control. The MRI measurements included T1 and T2 lesion volume, whole brain, white and gray matter volumes, magnetization transfer imaging and regional subcortical brain volumes. RESULTS: The T/T rs2030324 genotype group performed poorly on the Brief Visuospatial Memory Test-Revised (p=0.031) and the Symbol Digit Modalities Test (p=0.045) compared to the C/C genotype group. Because these NP tests both involve visual processing, the relationship with the volume of the thalamus was assessed. The BDNF rs2030324 genotype was associated with the volume of the left thalamus (p=0.036). There were no significant associations with whole brain lesional and atrophy MRI measures. CONCLUSIONS: The C allele of BDNF rs2030324 is associated with protection against visual cognitive processing deficits via mechanisms that appear associated with the volume of the thalamus.
ABSTRACT
Cortical and subcortical atrophy occurs in multiple sclerosis (MS) and relates to clinical outcomes. FreeSurfer, a voxel-based automated software for brain reconstruction was used to investigate the extent of subcortical and cortical atrophy in 71 MS and 17 clinically isolated syndrome (CIS) patients, and 38 normal controls (NC), and to relate group differences to disease type and severity. Segmentation was performed on 3D SPGR T1-weighted MRI 1.5T images. Region-specific subcortical tissue volumes were calculated in mm(3) and cortical thickness in mm. Logistic regression and general linear model analyses, adjusted for age and intracranial volume, examined differences between NC, MS and CIS patients and disease subtypes. The MS group was characterized by significantly lower volumes of thalamus (left and right p<0.0001), left inferior lateral ventricle, third ventricle (p<0.0001), ventral diencephalon, pallidum and putamen bilaterally, as well as of right accumbens and brainstem with corresponding bilateral increase in volumes of lateral ventricles (p<0.01). Focal cortical atrophy areas in the thalamus, inferior parietal lobule of left hemisphere and in right precuneus were also significant in the MS sample. Versus CIS patients, RR or progressive MS patients showed significantly lower volumes of subcortical regions and cortical thinning. Hippocampal atrophy appeared only in advanced disease stages. Cerebellum WM volumes were significantly lower in MS and CIS patients vs. NC. Subcortical and cortical atrophy correlated with higher disability as measured by EDSS. This study confirmed selective deep gray matter atrophy (mostly thalamic), revealed cerebellum WM atrophy from the earliest clinical stages, and showed that cortical thinning advances with disease progression.
