Imaging the Neural Network Connectivity on Patients With Mild Cognitive Impairment

Mild Cognitive Impairment Clinical Trial

Official title: Imaging the Neural Network Connectivity on Patients With Mild Cognitive Impairment

Status Completed

Clinical Trial Summary

The hypothesis tested if the diffusion properties in the base line, such as mean diffusivity or kurtosis, can differentiate two subtypes of MCI and predict the clinical outcome in Patients. The hypothesis further supports the correlation of the measured diffusion properties and the disease severity. We therefore proposed to investigate the potential value of diffusion properties as a possible tool to monitor the disease progression. The disease related changes in neural connectivity will be investigated.

1. The diffusion MRI could provide an improved diagnosis of Alzheimer's Disease and Mild cognitive Impairment.

Explanation:

The deposition of the macromolecules such as beta amyloid in the brain and the associated neuron death of the patient could lead to observable changes in tissue microenvironment. The related changes would lead to alterations in either the amplitude or distribution of water diffusion. In turn it could be detected in diffusion tensor and kurtosis.

2. aMCI is a preclinical state of AD and dMCI is from a different etiology, which can be differentially diagnosis by MRI. Diffusion Imaging could help to predict the clinical outcome Explanation

Clinical Trial Description

Mild Cognitive Impairment (MCI) referred to a decline of cognition in elder adults that are not of sufficient magnitude to meet the criteria for dementia. It is usually regarded as a transition state between patients of Alzheimer's Disease (AD) and the age matched healthy adults. It is a heterogeneous syndrome which can be divided into two subtypes: amnestic and dysexecutive. This 3 year proposal continues from a NSc funded project, in which we reported that the amnestic MCI could involve global white matter changes and therefore could be a preclinical status to AD. In contrast, no compromise in white matter status was found in patients of dysexecutive MCI. Therefore we proposed to further investigate the phenomena in this project.

The subjects will be divided into 3 groups: 30 patients with amnestic MCI, 30 with dysexecutive MCI and 30 healthy age-matched normal controls. Comprehensive neuropsychological examinations will be performed after detailed clinical history and physical screening, including Mini-Mental Status Examination, Clinical Dementia Rating and the Cognitive Abilities Screening Instrument. Successful candidate will be examined by 3T MRI, including diffusion imaging and high resolution T1 weighted anatomical images.

The current project proposed to examine the sensitivity and specificity of diffusion Magnetic Resonance Imaging, in the diagnosis of MCI and differential diagnosis of two subtypes. Both the conventional tensor derived indices and diffusion kurtosis will be compared. This is due to the fact that in a recently publication in Radiology, we reported an improved diagnostic performance on neurodegenerative disease from diffusion kurtosis than diffusion tensor. Secondly we will examine the regional changes of diffusion properties and correlated with the white matter involvement in patients. High resolution track density images will be implemented and compared with the susceptibility weighted imaging in an effort to address the underlying changes in pathophysiology. In the third year, the prognostic value of diffusion MRI will be determined. The optimal cutoff value of diffusion MRI in the prediction of conversion to Alzheimer's disease will be reported. The diffusion properties in patients with early conversion (the 2nd year) and late conversion (the 3rd year) will be compared.

It is expected that changes in diffusion can be used as an image based surrogate marker during the neurodegenerative process. The new insight into the temporal evolution of the diffusion MRI might help to understand the underlying etiology and pathophysiology between the amnestic and dysexecutive MCI patients, which can contribute to an early intervention strategy and might ultimately lead to an effective treatment. ;

Related Conditions & MeSH terms

• Cognitive Dysfunction
• Mild Cognitive Impairment

• NCT number: NCT01927653
• Study type: Observational
• Source: Chang Gung Memorial Hospital
• Status: Completed
• Start date: January 2011
• Completion date: February 2017