Is Diffusion Tensor Imaging a Good Biomarker for Early Parkinson's Disease?

Objectives: To assess white matter abnormalities in Parkinson's disease (PD). Methods: A hundred and thirty-two patients with PD (mean age 60.93 years; average disease duration 7.8 years) and 137 healthy controls (HC; mean age 57.8 years) underwent the same MRI protocol. Patients were assessed by clinical scales and a complete neurological evaluation. We performed a TBSS analysis to compare patients and controls, and we divided patients into early PD, moderate PD, and severe PD and performed an ROI analysis using tractography. Results: With TBSS we found lower FA in patients in corpus callosum, internal and external capsule, corona radiata, thalamic radiation, sagittal stratum, cingulum and superior longitudinal fasciculus. Increased AD was found in the corpus callosum, fornix, corticospinal tract, superior cerebellar peduncle, cerebral peduncle, internal and external capsules, corona radiata, thalamic radiation and sagittal stratum and increased RD were seen in the corpus callosum, internal and external capsules, corona radiata, sagittal stratum, fornix, and cingulum. Regarding the ROIs, a GLM analysis showed abnormalities in all tracts, mainly in the severe group, when compared to HC, mild PD and moderate PD. Conclusions: Since major abnormalities were found in the severe PD group, we believe DTI analysis might not be the best tool to assess early alterations in PD, and probably, functional and other structural analysis might suit this purpose better. However it can be used to differentiate disease stages, and as a surrogate marker to assess disease progression, being an important measure that could be used in clinical trials. HIGHLIGHTS DTI is not the best tool to identify early PDDTI can differentiate disease stagesDTI analysis may be a useful marker for disease progression.

Exploratory structural assessment in craniocervical dystonia: Global and differential analyses.

INTRODUCTION: Our goal was to investigate the cortical thickness and subcortical volume in subjects with craniocervical dystonia and its subgroups. METHODS: We studied 49 subjects, 17 with cervical dystonia, 18 with blepharospasm or oromandibular dystonia, and 79 healthy controls. We performed a whole group analysis, followed by a subgroup analysis. We used Freesurfer software to measure cortical thickness, subcortical volume and to perform a primary exploratory analysis in the craniocervical dystonia group, complemented by a region of interest analysis. We also performed a secondary analysis, with data generated from Freesurfer for subgroups, corrected by false discovery rate. We then performed an exploratory generalized linear model with significant areas for the previous steps using clinical features as independent variables. RESULTS: The primary exploratory analysis demonstrated atrophy in visual processing regions in craniocervical dystonia. The secondary analysis demonstrated atrophy in motor, sensory, and visual regions in blepharospasm or oromandibular dystonia, as well as in limbic regions in cervical dystonia. Cervical dystonia patients also had greater cortical thickness than blepharospasm or oromandibular dystonia patients in frontal pole and medial orbitofrontal regions. Finally, we observed an association between precuneus, age of onset of dystonia and age at the MRI exam, in craniocervical dystonia; between motor and limbic regions and age at the exam, clinical score and time on botulinum toxin in cervical dystonia and sensory regions and age of onset and time on botulinum toxin in blepharospasm or oromandibular dystonia. CONCLUSIONS: We detected involvement of visual processing regions in craniocervical dystonia, and a pattern of involvement in cervical dystonia and blepharospasm or oromandibular dystonia, including motor, sensory and limbic areas. We also showed an association of cortical thickness atrophy and younger onset age, older age at the MRI exam, higher clinical score and an uncertain association with longer time on botulinum toxin.

Cerebellar Gray Matter Alterations in Huntington Disease: A Voxel-Based Morphometry Study.

Neuropathological and neuroimaging studies in Huntington disease (HD) have suggested a role for the cerebellum. Our goal was to perform a detailed evaluation of cerebellar morphology. We performed the Unified HD rating scale (UHDRS) and Montreal cognitive assessment (MOCA) in 26 HD patients and 26 healthy controls. We created a two-sample test to analyze cerebellar gray matter (GM) differences between groups and another to correlate GM alterations with UHDRS and MOCA, corrected for age, expanded cytosine-adenine-guanine repeats, and disease duration using the spatially unbiased atlas template (SUIT)-SPM-toolbox which preserves anatomical detailing. We found increased GM density in the anterior cerebellum compared to controls. Higher GM density in the postero-superior lobe correlated with mood symptoms. Worse motor function and better cognitive function correlated with GM changes in the posterior cerebellum (false discovery rate (FDR) correction p < 0.05 and k > 100 voxels). In this detailed study of the in vivo cerebellar morphology in HD, we observed GM changes in regions involved in sensorimotor integration, motor planning, and emotional processing, supporting cerebellar involvement in the neuropathological process of HD.

Does Side of Onset Influence the Pattern of Cerebral Atrophy in Parkinson's Disease?

BACKGROUND: Imaging studies have revealed widespread neurodegeneration in Parkinson's disease (PD), but only a few considered the issue of asymmetrical clinical presentations. OBJECTIVE: To investigate if the side of onset influences the pattern of gray matter (GM) atrophy in PD. METHODS: Sixty patients (57.87 ± 10.27 years) diagnosed with idiopathic PD according to the U.K. Brain Bank criteria, 26 with right-sided disease onset (RDO) and 34 with left-sided disease onset (LDO), were compared to 80 healthy controls (HC) (57.1 ± 9.47 years). We acquired T1-weighted images on a 3 T scanner. Images were processed and analyzed with VBM8 (SPM8/Dartel) on Matlab R2012b platform. Statistic assessments included a two-sample test (family-wise error p < 0.05) with extent threshold of 20 voxels. RESULTS: Compared to HC, LDO patients had GM atrophy in the insula, putamen, anterior cingulate, frontotemporal cortex, and right caudate, while the RDO group showed atrophy at the anterior cingulate, insula, frontotemporal, and occipital cortex. CONCLUSION: This study revealed widespread GM atrophy in PD, predominantly in the left hemisphere, regardless of the side of onset. Future investigations should also consider handedness and side of onset to better characterize cerebral involvement and its progression in PD.

White Matter Microstructure in Idiopathic Craniocervical Dystonia.

BACKGROUND: Dystonias are hyperkinetic movement disorders characterized by involuntary muscle contractions resulting in abnormal torsional movements and postures. Recent neuroimaging studies in idiopathic craniocervical dystonia (CCD) have uncovered the involvement of multiple areas, including cortical ones. Our goal was to evaluate white matter (WM) microstructure in subjects with CCD using diffusion tensor imaging (DTI) analysis. METHODS: We compared 40 patients with 40 healthy controls. Patients were then divided into subgroups: cervical dystonia, blepharospasm, blepharospasm + oromandibular dystonia, blepharospasm + oromandibular dystonia + cervical dystonia, using tract-based spatial statistics. We performed a region of interest-based analysis and tractography as confirmatory tests. RESULTS: There was no significant difference in the mean fractional anisotropy (FA) and mean diffusivity (MD) between the groups in any analysis. DISCUSSION: The lack of DTI changes in CCD suggests that the WM tracts are not primarily affected.

Clinical predictors of cognitive impairment and psychiatric complications in Parkinson's disease.

OBJECTIVE: To estimate the clinical and demographics aspects that may contribute to cognitive impairment and psychiatric symptoms in Parkinson's disease (PD). METHOD: All patients answered a structured standardized clinical questionnaire. Two movement disorders specialists performed the following scale: Unified Parkinson's disease rating score (UPDRS), the modified Hoehn and Yahr staging, Schwab and England Scale, SCOPA cognition (SCOPA-COG), SCOPA-Psychiatric complications (SCOPA-PC) and Non-Motor Symptoms Scale (NMSS). We built a generalized linear model to assess predictors for the SCOPA-COG and SCOPA-PC scores. RESULTS: Almost 37% of our patients were demented as per SCOPA-COG scores. Level of education and the UPDRS-Subscale III were predictors of cognitive impairment. Higher scores in domain 3 of NMSS and male gender were associated with psychiatric complications as assessed per the SCOPA-PC. CONCLUSION: Level of education and disease severity are predictors of dementia in PD. Psychiatric complications are more commonly observed in men.

Clinical predictors of cognitive impairment and psychiatric complications in Parkinson’s disease / Preditores clínicos de transtorno cognitivo e complicações psiquiátricas na doença de Parkinson

Objective To estimate the clinical and demographics aspects that may contribute to cognitive impairment and psychiatric symptoms in Parkinson’s disease (PD). Method All patients answered a structured standardized clinical questionnaire. Two movement disorders specialists performed the following scale: Unified Parkinson’s disease rating score (UPDRS), the modified Hoehn and Yahr staging, Schwab and England Scale, SCOPA cognition (SCOPA-COG), SCOPA-Psychiatric complications (SCOPA-PC) and Non-Motor Symptoms Scale (NMSS). We built a generalized linear model to assess predictors for the SCOPA-COG and SCOPA-PC scores. Results Almost 37% of our patients were demented as per SCOPA-COG scores. Level of education and the UPDRS-Subscale III were predictors of cognitive impairment. Higher scores in domain 3 of NMSS and male gender were associated with psychiatric complications as assessed per the SCOPA-PC. Conclusion Level of education and disease severity are predictors of dementia in PD. Psychiatric complications are more commonly observed in men. .

Objetivo Estimar aspectos clínicos e demográficos que podem contribuir para o comprometimento cognitivo e sintomas psiquiátricos na doença de Parkinson (DP). Método Todos pacientes responderam questionário clínico padrão. Duas especialistas em distúrbios do movimento aplicaram as seguintes escalas: Unified Parkinson’s disease rating score (UPDRS), Hoehn and Yahr estágios, Schwab and England Scale, SCOPA cognição (SCOPA-COG), SCOPA-Complicações psiquiátricas (SCOPA-CP) e Escala de sintomas não motores (NMSS). Utilizamos análise multivariada, para avaliar os preditores relacionados ao SCOPA-COG e SCOPA CP. Resultados Aproximadamente 37% dos nossos pacientes foram classificados como dementes utilizando-se os valores obtidos no SCOPA-COG. Nível educacional e a parte III do UPDRS foram preditores de comprometimento cognitivo. Escores elevados no domínio 3 do NMSS e sexo masculino associaram-se com complicações psiquiátricas quando acessadas pelo SCOPA-CP. Conclusão Nível educacional e gravidade de doença são preditores de demência na DP. Complicações psiquiátricas são mais comumente observadas em homens. .