Joyce Suhy

Tramiprosate in mild-to-moderate Alzheimer's disease - a randomized, double-blind, placebo-controlled, multi-centre study (the Alphase Study).

Introduction The aim of the study was to assess the clinical efficacy, safety, and disease-modification effects of tramiprosate (homotaurine, ALZHEMEDTM) in mild-to-moderate Alzheimer’s disease (AD). Material and methods Double-blind, placebo-controlled, randomized trial in 67 clinical centres across North America. Patients aged ≥ 50 years, with mild-to-moderate AD (Mini-Mental State Examination score between 16 and 26) and on stable doses of cholinesterase inhibitors, alone or with memantine. Intervention: 78-week treatment with placebo, tramiprosate 100 mg or tramiprosate 150 mg BID. Measurements: Alzheimer Disease Assessment Scale – cognitive subscale (ADAS-cog) and Clinical Dementia Rating – Sum of Boxes (CDR-SB) assessments were performed at baseline and every 13 weeks. Baseline and 78-week magnetic resonance imaging (MRI) hippocampus volume (HV) measurements were conducted in a subgroup of patients. Results A total of 1,052 patients were enrolled and 790 (75.1%) completed the 78-week trial. Patient discontinuation and reasons for withdrawal were similar across groups. Planned analyses did not reveal statistically significant between-group differences. Lack of adequate statistical validity of the planned analysis models led to the development of revised predictive models. These adjusted models showed a trend toward a treatment effect for ADAS-cog (P = 0.098) and indicated significantly less HV loss for tramiprosate 100 mg (P = 0.035) and 150 mg (P = 0.009) compared to placebo. The incidence of adverse events was similar across treatment groups. Conclusions The primary planned analyses did not show a significant treatment effect, but were confounded by unexplained variance. Post-hoc analyses showed a significant treatment-related reduction in HV loss. However, there was only a trend towards slowing of decline on the ADAS-cog and no slowing of decline on the CDR-SB. These results must be interpreted in consideration of the limitations of clinical and disease-modification outcome measures and their relationship, the heterogeneity of the disease and the impact of confounding demographic and clinical variables.

Steps to standardization and validation of hippocampal volumetry as a biomarker in clinical trials and diagnostic criterion for Alzheimer’s disease

The promise of Alzheimers disease biomarkers has led to their incorporation in new diagnostic criteria and in therapeutic trials; however, significant barriers exist to widespread use. Chief among these is the lack of internationally accepted standards for quantitative metrics. Hippocampal volumetry is the most widely studied quantitative magnetic resonance imaging measure in Alzheimers disease and thus represents the most rational target for an initial effort at standardization.

Standardization of analysis sets for reporting results from ADNI MRI data

The Alzheimers Disease Neuroimaging Initiative (ADNI) three‐dimensional T1‐weighted magnetic resonance imaging (MRI) acquisitions provide a rich data set for developing and testing analysis techniques for extracting structural endpoints. To promote greater rigor in analysis and meaningful comparison of different algorithms, the ADNI MRI Core has created standardized analysis sets of data comprising scans that met minimum quality control requirements. We encourage researchers to test and report their techniques against these data. Standard analysis sets of volumetric scans from ADNI‐1 have been created, comprising screening visits, 1‐year completers (subjects who all have screening, 6‐ and 12‐month scans), 2‐year annual completers (screening, 1‐year and 2‐year scans), 2‐year completers (screening, 6‐months, 1‐year, 18‐months [mild cognitive impaired (MCI) only], and 2‐year scans), and complete visits (screening, 6‐month, 1‐year, 18‐month [MCI only], 2‐year, and 3‐year [normal and MCI only] scans). As the ADNI‐GO/ADNI‐2 data become available, updated standard analysis sets will be posted regularly.

Prevalence of asymptomatic vasogenic edema in pretreatment Alzheimer's disease study cohorts from phase 3 trials of semagacestat and solanezumab

Cerebral vasogenic edema (VE) has been reported to occur during antiamyloid immunotherapy. VE may be associated with central nervous system pathology with blood–brain barrier disruptions; however, less is known about the prevalence of naturally occurring VE in patients with Alzheimers disease (AD).

1H MRSI predicts surgical outcome in MRI-negative temporal lobe epilepsy

Abstract—1H MRS imaging (MRSI) was performed on 15 patients with MRI-negative temporal lobe epilepsy (TLE) who underwent seizure surgery. The non–seizure-free patients (NSF) ipsilateral hippocampal N-acetylaspartate (NAA)/(Cr+Cho) z scores were lower than the contralateral scores (p = 0.04), and the NSF ipsilateral z scores were lower than the seizure-free patients’ (SF) ipsilateral z scores (p = 0.0049). Similarly, NSF contralateral scores were lower than contralateral SF (p = 0.02). These findings suggest NAA predicts the surgical outcome in patients with TLE without evidence of mesial temporal sclerosis on MRI.

Neuroradiological findings in vascular dementia

IntroductionThere are multiple diagnostic criteria for vascular dementia (VaD) that may define different populations. Utilizing the criteria of the National Institute of Neurological Disorders and Stroke and Association Internationale pour la Recherche et l’Enseignement en Neurosciences (NINDS-AIREN) has provided improved consistency in the diagnosis of VaD. The criteria include a table listing brain imaging lesions associated with VaD.MethodsThe different neuroradiological aspects of the criteria are reviewed based on the imaging data from an ongoing large-scale clinical trial testing a new treatment for VaD. The NINDS-AIREN criteria were applied by a centralized imaging rater to determine eligibility for enrollment in 1,202 patients using brain CT or MRI.ResultsBased on the above data set, the neuroradiological features that are associated with VaD and that can result from cerebral small-vessel disease with extensive leukoencephalopathy or lacunae (basal ganglia or frontal white matter), or may be the consequence of single strategically located infarcts or multiple infarcts in large-vessel territories, are illustrated. These features may also be the consequence of global cerebral hypoperfusion, intracerebral hemorrhage, or other mechanisms such as genetically determined arteriopathies.ConclusionNeuroimaging confirmation of cerebrovascular disease in VaD provides information about the topography and severity of vascular lesions. Neuroimaging may also assist with the differential diagnosis of dementia associated with normal pressure hydrocephalus, chronic subdural hematoma, arteriovenous malformation or tumoral diseases.

Coalition Against Major Diseases/European Medicines Agency biomarker qualification of hippocampal volume for enrichment of clinical trials in predementia stages of Alzheimer's disease

Regulatory qualification of a biomarker for a defined context of use provides scientifically robust assurances to sponsors and regulators that accelerate appropriate adoption of biomarkers into drug development.

The influence of biological and technical factors on quantitative analysis of amyloid PET: Points to consider and recommendations for controlling variability in longitudinal data

In vivo imaging of amyloid burden with positron emission tomography (PET) provides a means for studying the pathophysiology of Alzheimers and related diseases. Measurement of subtle changes in amyloid burden requires quantitative analysis of image data. Reliable quantitative analysis of amyloid PET scans acquired at multiple sites and over time requires rigorous standardization of acquisition protocols, subject management, tracer administration, image quality control, and image processing and analysis methods. We review critical points in the acquisition and analysis of amyloid PET, identify ways in which technical factors can contribute to measurement variability, and suggest methods for mitigating these sources of noise. Improved quantitative accuracy could reduce the sample size necessary to detect intervention effects when amyloid PET is used as a treatment end point and allow more reliable interpretation of change in amyloid burden and its relationship to clinical course.

Reduced extrahippocampal NAA in mesial temporal lobe epilepsy.

Summary:  Purpose: Structural and metabolic abnormalities in the hippocampal region in medial temporal lobe epilepsy (mTLE) are well described; less is known about extrahippocampal changes. This study was designed to characterize extrahippocampal metabolic abnormalities in mTLE with magnetic resonance spectroscopy in combination with tissue segmentation and volumetry of gray and white matter.

Spectroscopic metabolic abnormalities in mTLE with and without MRI evidence for mesial temporal sclerosis using hippocampal short-TE MRSI

Summary:  Purpose: Long echo time (TE) spectroscopy reliably identifies the epileptogenic hippocampus in mesial temporal lobe epilepsy. Short‐TE spectroscopy gives additional metabolic information but may have more artifacts. The aim of this study was to test (a) lateralization of the seizure focus by short‐TE spectroscopy, and (b) value of myoinositol (MI) in the identification of the epileptogenic hippocampus.