ObjectiveTo evaluate MRI-based parameters as biomarkers of Amyotrophic Lateral Sclerosis (ALS) progression.MethodsTwenty-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.ResultsThere 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.ConclusionsStructural MRI is able to detect short term longitudinal changes in ALS. Cervical spinal cord morphometry is a promising neuroimaging marker to assess ALS course.

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.

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.

Machado-Joseph disease (SCA3) is the most frequent spinocerebellar ataxia worldwide and characterized by remarkable phenotypic heterogeneity. MRI-based studies in SCA3 focused in the cerebellum and connections, but little is known about cord damage in the disease and its clinical relevance. To evaluate the spinal cord damage in SCA3 through quantitative analysis of MRI scans. A group of 48 patients with SCA3 and 48 age and gender-matched healthy controls underwent MRI on a 3T scanner. We used T1-weighted 3D images to estimate the cervical spinal cord area (CA) and eccentricity (CE) at three C2/C3 levels based on a semi-automatic image segmentation protocol. The scale for assessment and rating of ataxia (SARA) was employed to quantify disease severity. The two groups-SCA3 and controls-were significantly different regarding CA (49.5 ± 7.3 vs 67.2 ± 6.3 mm(2), p < 0.001) and CE values (0.79 ± 0.06 vs 0.75 ± 0.05, p = 0.005). In addition, CA presented a significant correlation with SARA scores in the patient group (p = 0.010). CE was not associated with SARA scores (p = 0.857). In the multiple variable regression, we found that disease duration was the only variable associated with CA (coefficient = -0.629, p = 0.025). SCA3 is characterized by cervical cord atrophy and antero-posterior flattening. In addition, the spinal cord areas did correlate with disease severity. This suggests that quantitative analyses of the spinal cord MRI might be a useful biomarker in SCA3.

Spinocerebellar ataxia type 1 (SCA1) is an autosomal dominant disorder caused by a CAG repeat expansion, characterized by progressive cerebellar ataxia and pyramidal signs. Non-motor and extracerebellar symptoms may occur. MRI-based studies in SCA1 focused in the cerebellum and connections, but there are no data about cord damage in the disease and its clinical relevance. To evaluate in vivo spinal cord damage in SCA1, a group of 31 patients with SCA1 and 31 age- and gender-matched healthy controls underwent MRI on a 3T scanner. We used T1-weighted 3D images to estimate the cervical spinal cord area (CA) and eccentricity (CE) at three C2/C3 levels based on a semi-automatic image segmentation protocol. The scale for assessment and rating of ataxia (SARA) was used to quantify disease severity. The groups were significantly different regarding CA (47.26 ± 7.4 vs. 68.8 ± 5.7 mm2, p < 0.001) and CE values (0.803 ± 0.044 vs. 0.774 ± 0.043, p < 0.05). Furthermore, in the patient group, CA presented significant correlation with SARA scores (R = -0.633, p < 0.001) and CAGn expansion (R = -0.658, p < 0.001). CE was not associated with SARA scores (p = 0.431). In the multiple variable regression, CA was strongly associated with disease duration (coefficient -0.360, p < 0.05) and CAGn expansion (coefficient -1.124, p < 0.001). SCA1 is characterized by cervical cord atrophy and anteroposterior flattening. Morphometric analyses of the spinal cord MRI might be a useful biomarker in the disease.