Milena de Albuquerque

Spinal cord atrophy correlates with disease duration and severity in amyotrophic lateral sclerosis.

Abstract Our objective was to investigate spinal cord (SC) atrophy in amyotrophic lateral sclerosis (ALS) patients, and to determine whether it correlates with clinical parameters. Forty-three patients with ALS (25 males) and 43 age- and gender-matched healthy controls underwent MRI on a 3T scanner. We used T1-weighted 3D images covering the whole brain and the cervical SC to estimate cervical SC area and eccentricity at C2/C3 level using validated software (SpineSeg). Disease severity was quantified with the ALSFRS-R and ALS Severity scores. SC areas of patients and controls were compared with a Mann-Whitney test. We used linear regression to investigate association between SC area and clinical parameters. Results showed that mean age of patients and disease duration were 53.1 ± 12.2 years and 34.0 ± 29.8 months, respectively. The two groups were significantly different regarding SC areas (67.8 ± 6.8 mm² vs. 59.5 ± 8.4 mm², p < 0.001). Eccentricity values were similar in both groups (p = 0.394). SC areas correlated with disease duration (r = − 0.585, p < 0.001), ALSFRS-R score (r = 0.309, p = 0.044) and ALS Severity scale (r = 0.347, p = 0.022). In conclusion, patients with ALS have SC atrophy, but no flattening. In addition, SC areas correlated with disease duration and functional status. These data suggest that quantitative MRI of the SC may be a useful biomarker in the disease.

MRI Texture Analysis Reveals Deep Gray Nuclei Damage in Amyotrophic Lateral Sclerosis.

Amyotrophic Lateral Sclerosis (ALS) is characterized by extensive corticospinal damage, but extrapyramidal involvement is suggested in pathological studies. Texture analysis (TA) is an image processing technique that evaluates the distribution of gray levels between pixels in a given region of interest (ROI). It provides quantitative data and has been employed in several neurodegenerative disorders. Here, we used TA to investigate possible deep gray nuclei (DGN) abnormalities in a cohort of ALS patients.

Multimodal MRI-Based Study in Patients with SPG4 Mutations

Mutations in the SPG4 gene (SPG4-HSP) are the most frequent cause of hereditary spastic paraplegia, but the extent of the neurodegeneration related to the disease is not yet known. Therefore, our objective is to identify regions of the central nervous system damaged in patients with SPG4-HSP using a multi-modal neuroimaging approach. In addition, we aimed to identify possible clinical correlates of such damage. Eleven patients (mean age 46.0 ± 15.0 years, 8 men) with molecular confirmation of hereditary spastic paraplegia, and 23 matched healthy controls (mean age 51.4 ± 14.1years, 17 men) underwent MRI scans in a 3T scanner. We used 3D T1 images to perform volumetric measurements of the brain and spinal cord. We then performed tract-based spatial statistics and tractography analyses of diffusion tensor images to assess microstructural integrity of white matter tracts. Disease severity was quantified with the Spastic Paraplegia Rating Scale. Correlations were then carried out between MRI metrics and clinical data. Volumetric analyses did not identify macroscopic abnormalities in the brain of hereditary spastic paraplegia patients. In contrast, we found extensive fractional anisotropy reduction in the corticospinal tracts, cingulate gyri and splenium of the corpus callosum. Spinal cord morphometry identified atrophy without flattening in the group of patients with hereditary spastic paraplegia. Fractional anisotropy of the corpus callosum and pyramidal tracts did correlate with disease severity. Hereditary spastic paraplegia is characterized by relative sparing of the cortical mantle and remarkable damage to the distal portions of the corticospinal tracts, extending into the spinal cord.

MicroRNAs-424 and 206 are potential prognostic markers in spinal onset amyotrophic lateral sclerosis.

INTRODUCTION Skeletal muscle microRNAs (miRNAs) are potential candidate biomarkers for amyotrophic lateral sclerosis (ALS) that deserve further investigation. OBJECTIVES To identify miRNAs abnormally expressed in the skeletal muscle and plasma of patients with ALS, and to correlate them with parameters of disease progression. METHODS Expression profile of miRNAs in muscle was evaluated using an array platform. Subsequently we assessed the plasmatic expression of candidate miRNAs in a set of 39 patients/39 controls. We employed generalized estimating equations to investigate correlations with clinical data. RESULTS We identified 11 miRNAs differentially expressed in the muscle of ALS patients; of these, miR424, miR-214 and miR-206 were validated by qPCR in muscle samples. In plasma, we found only miR-424 and miR 206 to be overexpressed. Baseline expression of miR-424 and 206 correlated with clinical deterioration over time. CONCLUSION MiR-424 and miR-206 are potential prognostic markers for ALS.

Longitudinal evaluation of cerebral and spinal cord damage in Amyotrophic Lateral Sclerosis

Objective To evaluate MRI-based parameters as biomarkers of Amyotrophic Lateral Sclerosis (ALS) progression. Methods Twenty-seven patients and 27 controls performed two clinical and MRI acquisitions 8 months apart. ALSFRS-R scale was used to quantify disease severity at both time points. Multimodal analyses of MRI included cortical thickness measurements (FreeSurfer software), analysis of white matter integrity using diffusion-tensor imaging (tract-based spatial statistics-TBSS) and measurement of cervical spinal cord cross-sectional area (SpineSeg software). All analyses were corrected for multiple comparisons. The standardized response mean (SRM = mean score change / standard deviation of score change) was calculated for all methods herein employed and used for comparison purposes. Results There were 18 men and mean age at first examination was 51.9 years. Mean ALSFRS-R scores at baseline and follow-up were 34.0 and 29.0, respectively. There was no region with progressive cortical thinning, but there was significant brainstem volumetric reduction (p = 0.001). TBSS analyses revealed progressive increase of AD (axial diffusivity) and MD (mean diffusivity) at the corpus callosum (p < 0.05), whereas SpineSeg showed progressive cord area reduction (p = 0.002). Cervical spinal cord cross-sectional area reduction was the only MRI parameter that correlated with ALSFRS-R change (r = 0.309, p = 0.038). SRM for ALSFRS-R was 0.95, for cord area 0.95, for corpus callosum AD 0.62 and MD 0.65, and for brainstem volume 0.002. Conclusions Structural MRI is able to detect short term longitudinal changes in ALS. Cervical spinal cord morphometry is a promising neuroimaging marker to assess ALS course.