Caroline Andrews

A proton magnetic resonance spectroscopic study in ALS: Correlation with clinical findings

Objective: To evaluate neuronal dysfunction in the motor region subcortical white matter in ALS using volumetric localized proton magnetic resonance spectroscopy (1H-MRS). Methods: Sixteen patients with El Escorial definite, probable, or possible ALS and eight healthy age-matched control subjects were studied. The ALS patients were divided into those with limb onset (n = 8) and those with bulbar onset (n = 8). Measurements of the metabolic ratios N-acetylaspartate (NAA)/creatine and phosphocreatine (Cr+PCr), NAA/choline (Cho), and Cho/(Cr+PCr) were correlated with clinical assessments. Results: We found no differences in the metabolic peak area ratios in the motor region when comparing the total ALS group and the control subjects. However, correlations were found between the NAA/(Cr+PCr) ratio and the El Escorial category (p = 0.03), the ALS severity scale (p = 0.01), and the Medical Research Council score (p = 0.06). No correlations were found between the NAA/(Cr+PCr) ratio and the Ashworth Spasticity Scale, reflex score, or disease duration (p > 0.16). Bulbar-onset patients had a lower NAA/(Cr+PCr) ratio in the motor region compared with limb-onset patients (p = 0.03). Conclusion: In vivo 1H-MRS of the subcortical white matter in the motor region is unlikely to be sensitive enough to detect early disease changes in ALS because there is considerable overlap between the metabolic peak area ratios from patients with ALS and normal control subjects. However, changes in the NAA/(Cr+PCr) metabolic peak area ratios correlate with clinical measures of disease severity, and this measure may be useful in monitoring disease progression.

Neural correlates of working memory in a visual letter monitoring task: an fMRI study.

Complex mental operations rely on the coordinated activity of widely distributed brain regions constituting neurocognitive networks. Using multislice echoplanar functional magnetic resonance imaging (fMRI) we have contrasted regional brain activity during a control and an experimental condition which differed with respect to the demands placed on verbal working memory. Subjects were seven right-handed healthy male volunteers. Analysis of group and individual data revealed activation in the anterior and posterior parasagittal cortex in all subjects, left parietal cortex (six subjects) and left dorsolateral prefontal cortex (five subjects). These results suggest that verbal working memory is subserved by a neurocognitive network comprising cortical regions involved in attention, executive function and short term mnemonic processes.

Choice of ADNI MPRAGE volume and RF coil affects brain segmentation comparability

Background: The ROSAS study is a monocentric observational study run in Toulouse, France, designed to identify AD biomarkers by collecting samples from Normal Controls (NC), Mild Cognitive Impairment (MCI) and AD subjects and following them over up to 4 years. Methods: 408 subjects of 65 years old or greater were enrolled in the study, including 110 NC (no memory complaints, MMSE 26 and CDR1⁄40), 100 MCI (MMSE 24 and CDR1⁄40.5, memory impairment based on Rey Auditory Verbal Learning Test and that did not meet DSM IV criteria for AD dementia) and 198 AD (12 MMSE 26 and CDR 0.5 and meeting DSM IV criteria). Subjects with other types of dementia and/or non-AD grounds for cognitive issues were not offered to participate. Clinical data, neuropsychological tests and biomarkers (blood, urine and CSF whenever possible) will be collected at Baseline and every 6 months until Month 48. MRI scans (3DT1, 3DT2, FLAIR, SWI, DWI and DTI) will be collected up to 3 times between Baseline and Month 48, using a Philips Achieva 3T scanner, for consenting subjects (n1⁄4158). The volume of intracranial cavity (ICV), left and right hippocampi (HCV), lateral ventricles (LVV) and whole brain (WBV) were assessed at Baseline using an automated multi-atlas segmentation algorithm. Descriptive statistics of