CHARACTERISTICS OF WHITE MATTER HYPOINTENSITY IN NORMAL COGNITIVE VIETNAMESE ADULTS USING MRI

Objectives: access the white-matter hypointensity (WMHypo) volume characteristics in relationships with age. Methods: Analysing for volumes of cerebral WMHypo volumes from cranial magnetic resonance images taken from 455 normal cognitive Vietnamese subjects (males 47,03%), and ranging in age from 17 to 87 years. Results: The volumes of WMHypo were increasing with age in both male (p< 0,001) and female (p < 0,001). And regression analyses indicated that WMHypo volume increasing in cubic manners that relatively stable with age under 40-50 y.o then sharply increase from 60s. Conclusion: White matter hypointensity had appeared since youth and boosted from middle age, since any cognitive impairment could be detected as in elders, and and its growth rate coexists with atrophy in the cerebral degeneration process such as Alzheimer and Parkinson diseases.

Progressive Neurochemical Abnormalities in Cognitive and Motor Subgroups of Amyotrophic Lateral Sclerosis: A Prospective Multicenter Study

OBJECTIVE:To evaluate progressive cerebral degeneration in amyotrophic lateral sclerosis (ALS) by assessing alterations in N-acetylaspartate (NAA) ratios in the motor and prefrontal cortex within clinical subgroups of ALS.METHODS:Seventy-six ALS patients and 59 healthy controls were enrolled in a prospective, longitudinal, multicenter study in the Canadian ALS Neuroimaging Consortium (CALSNIC). Participants underwent serial clinical evaluations and MR spectroscopy at baseline, 4 and 8 months using a harmonized protocol across 5 centers. NAA ratios were quantified in the motor cortex and prefrontal cortex. Patients were stratified into subgroups based on disease progression rate, upper motor neuron (UMN) signs, and cognitive status. Linear mixed models were used for baseline and longitudinal comparisons of NAA metabolite ratios.RESULTS:Patients with ALS had reduced NAA ratios in the motor cortex at baseline (P < 0.001). Ratios were lower in those with more rapid disease progression and greater UMN signs (P < 0.05). A longitudinal decline in NAA ratios was observed in the motor cortex in the rapid progressing (P < 0.01) and high UMN burden (P < 0.01) cohorts. The severity of UMN signs did not change significantly over time. NAA ratios were reduced in the prefrontal cortex only in cognitively impaired patients (P < 0.05); prefrontal cortex metabolites did not change over time.CONCLUSIONS:Progressive degeneration of the motor cortex in ALS is associated with more aggressive clinical presentations These findings provide biological evidence of variable spatial and temporal cerebral degeneration linked to the disease heterogeneity of ALS. The use of standardized imaging protocols may have a role to play in clinical trials for patient selection or subgrouping.CLASSIFICATION OF EVIDENCE:This study provides Class II evidence that MRS NAA metabolite ratios of the motor cortex are associated with more rapid disease progression and greater UMN signs in patients with ALS.

The Canadian ALS Neuroimaging Consortium (CALSNIC) - a multicentre platform for standardized imaging and clinical studies in ALS

BackgroundAmyotrophic lateral sclerosis (ALS) is a disabling and rapidly progressive neurodegenerative disorder. Increasing age is an important risk factor for developing ALS, thus the societal impact of this devastating disease will become more profound as the population ages. A significant hurdle to finding effective treatment has been an inability to accurately quantify cerebral degeneration associated with ALS in humans. Advanced magnetic resonance imaging (MRI) techniques hold promise in providing a set of biomarkers to assist in aiding diagnosis and in efficiently evaluating new drugs to treat ALS.MethodsThe Canadian ALS Neuroimaging Consortium (CALSNIC) was founded to develop and evaluate advanced MRI-based biomarkers that delineate biological heterogeneity, track disease progression, and predict survival in a large and heterogeneous sample of ALS patients.FindingsCALSNIC has launched two studies to date (CALSINC-1, CALSNIC-2), acquiring multimodal neuroimaging, neurological, neuropsychological data, and neuropathological data from ALS patients and healthy controls in a prospective and longitudinal fashion from multiple centres in Canada and, more recently, the United States. Clinical and MRI protocols are harmonized across research centres and different MR vendors.InterpretationCALSNIC provides a multicentre platform for studying ALS biology and developing MRI-based biomarkers.

Multimodal longitudinal study of structural brain involvement in amyotrophic lateral sclerosis

ObjectiveTo understand the progressive nature of amyotrophic lateral sclerosis (ALS) by investigating differential brain patterns of gray and white matter involvement in clinically or genetically defined subgroups of patients using cross-sectional, longitudinal, and multimodal MRI.MethodsWe assessed cortical thickness, subcortical volumes, and white matter connectivity from T1-weighted and diffusion-weighted MRI in 292 patients with ALS (follow-up: n = 150) and 156 controls (follow-up: n = 72). Linear mixed-effects models were used to assess changes in structural brain measurements over time in patients compared to controls.ResultsPatients with a C9orf72 mutation (n = 24) showed widespread gray and white matter involvement at baseline, and extensive loss of white matter integrity in the connectome over time. In C9orf72-negative patients, we detected cortical thinning of motor and frontotemporal regions, and loss of white matter integrity of connections linked to the motor cortex. Patients with spinal onset displayed widespread white matter involvement at baseline and gray matter atrophy over time, whereas patients with bulbar onset started out with prominent gray matter involvement. Patients with unaffected cognition or behavior displayed predominantly motor system involvement, while widespread cerebral changes, including frontotemporal regions with progressive white matter involvement over time, were associated with impaired behavior or cognition. Progressive loss of gray and white matter integrity typically occurred in patients with shorter disease durations (<13 months), independent of progression rate.ConclusionsHeterogeneity of phenotype and C9orf72 genotype relates to distinct patterns of cerebral degeneration. We demonstrate that imaging studies have the potential to monitor disease progression and early intervention may be required to limit cerebral degeneration.

Salivary Redox Biomarkers in Selected Neurodegenerative Diseases

Neurodegenerative diseases (NDDs), such as Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease, are disorders, which cause irreversible and progressive deterioration of the central nervous system. The pathophysiology of NDDs is still not fully explained; nevertheless, oxidative stress is considered as a critical mediator of cerebral degeneration, brain inflammation, as well as neuronal apoptosis. Therefore, it is not surprising that redox biomarkers are increasingly used in the diagnosis of neurodegenerative diseases. As saliva is a very easy to obtain bioliquid, it seems promising to use this biomaterial in the diagnosis of NDDs. Saliva collection is easy, cheap, stress-free, and non-infectious, and it does not require the help of a specialised medical personnel. Additionally, the concentrations of many salivary redox biomarkers correlate with their content in blood serum as well as the degree of disease progression, which makes them non-invasive indicators of NDDs. This paper reviews the latest knowledge concerning the use of salivary redox biomarkers in the diagnosis and prognosis of selected neurodegenerative diseases.

Cerebral degeneration in amyotrophic lateral sclerosis

BackgroundWe investigated cerebral degeneration and neurochemistry in patients with amyotrophic lateral sclerosis (ALS) using magnetic resonance spectroscopy (MRS).MethodsWe prospectively studied 65 patients and 43 age-matched healthy controls. Participants were recruited from 4 centers as part of a study in the Canadian ALS Neuroimaging Consortium. All participants underwent single-voxel proton MRS using a protocol standardized across all sites. Metabolites reflecting neuronal integrity (total N-acetyl aspartyl moieties [tNAA]) and gliosis (myo-inositol [Ino]), as well as creatine (Cr) and choline (Cho), were quantified in the midline motor cortex and midline prefrontal cortex. Comparisons were made between patients with ALS and healthy controls. Metabolites were correlated with clinical measures of upper motor neuron dysfunction, disease progression rate, and cognitive performance.ResultsIn the motor cortex, tNAA/Cr, tNAA/Cho, and tNAA/Ino ratios were reduced in the ALS group compared with controls. Group differences in tNAA/Cr and tNAA/Cho in the prefrontal cortex displayed reduced ratios in ALS patients; however, these were not statistically significant. Reduced motor cortex ratios were associated with slower foot tapping rate, whereas only motor tNAA/Ino was associated with finger tapping rate. Disease progression rate was associated with motor tNAA/Cho. Verbal fluency, semantic fluency, and digit span forwards and backwards were associated with prefrontal tNAA/Cr.ConclusionsThis study demonstrates that cerebral degeneration in ALS is more pronounced in the motor than prefrontal cortex, that multicenter MRS studies are feasible, and that motor tNAA/Ino shows promise as a potential biomarker.

Texture Analysis to Detect Cerebral Degeneration in Amyotrophic Lateral Sclerosis

BackgroundEvidence of cerebral degeneration is not apparent on routine brain MRI in amyotrophic lateral sclerosis (ALS). Texture analysis can detect change in images based on the statistical properties of voxel intensities. Our objective was to test the utility of texture analysis in detecting cerebral degeneration in ALS. A secondary objective was to determine whether the performance of texture analysis is dependent on image resolution.MethodsHigh-resolution (0.5×0.5 mm2 in-plane) coronal T2-weighted MRI of the brain were acquired from 12 patients with ALS and 19 healthy controls on a 4.7 Tesla MRI system. Image data sets at lower resolutions were created by down-sampling to 1×1, 2×2, 3×3, and 4×4 mm2. Texture features were extracted from a slice encompassing the corticospinal tract at the different resolutions and tested for their discriminatory power and correlations with clinical measures. Subjects were also classified by visual assessment by expert reviewers.ResultsTexture features were different between ALS patients and healthy controls at 1×1, 2×2, and 3×3 mm2 resolutions. Texture features correlated with measures of upper motor neuron function and disability. Optimal classification performance was achieved when best-performing texture features were combined with visual assessment at 2×2 mm2 resolution (0.851 area under the curve, 83% sensitivity, 79% specificity).ConclusionsTexture analysis can detect subtle abnormalities in MRI of ALS patients. The clinical yield of the method is dependent on image resolution. Texture analysis holds promise as a potential source of neuroimaging biomarkers in ALS.

Acquired Hepato Cerebral Degeneration – An Atypical Finding in MRI of Brain mimicking Bilateral Ischaemic Stroke

Acquired Hepatocerebral Degeneration (AHD) produces a panel of neurological symptoms occurring in patients with chronic liver disease. These symptoms may mimic different neurological abnormalities e.g. abnormal movements, rigidity, parkinsonism, ataxia, neuropsychiatric and cognitive manifestations.[1] Acquired Hepatocerebral Degeneration is usually encountered in patients with CLD due to accumulation of manganese & other metabolic toxins in basal ganglia, following repeated episodes of liver failure[2] .The aim of this case report is to highlight the MRI finding of Acute Hepatocerebral Degeneration which often can be underappreciated owing to the possibility of diagnosing a relatively common condition that is Bilateral Ischemic stroke.[19].Bangladesh Crit Care J March 2016; 4 (1): 54-57