About this trial

Alzheimer's disease (AD) is the most common cause of dementia, affecting approximately 10% of individuals aged ≥ 65. Most available treatments aim at controlling symptoms at an early stage rather than providing a cure. Therefore, an accurate and early diagnosis of AD with appropriate management will slow the progression of the condition. Reduced cerebral glucose levels have been observed in patients with early AD. Glucose hypometabolism can be assessed by administering a radioactive glucose analogue, 2-deoxy-2-(18F) fluoro-D-glucose (18FDG), and imaging with PET (positron emission tomography). The high cost and limited availability of PET-CT (PET - computed tomography) still hamper its general clinical application. Moreover, the use of radioactive tracers in combination with the additional ionizing radiation of CT is not suitable for repeated measurements. Therefore, currently, the provisional diagnosis of AD is still based on the combination of clinical history, neurological examination, cognitive testing over a period of time, and structural neuroimaging. This has major time and resource implications.

A radically different and highly innovative means for imaging glucose with magnetic resonance imaging (MRI) has now been established, exploiting the interaction between hydroxyl protons in glucose and the protons in water; the method is termed glucose Chemical Exchange Saturation Transfer (glucoCEST). GlucoCEST MRI is a method that has no reliance on radiolabelled glucose analogues and could become widely implemented in clinic practice. We therefore aim to investigate the potential of glucoCEST MRI in Alzheimer's disease.

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

be > 18 years

consent to the study

not report problems with memory.

be ≥ 65 years,

Disqualifiers

have a history of diabetes,

have history of a major stroke (mini-stroke/Transient Ischaemic Attacks or lacunar stroke are acceptable),

have contra-indications to MRI scanning such as implantable cardiac devices

have family history in AD, to exclude possible gene mutations associated with AD

Trial population

Target population: For the methods development phase, 20 healthy volunteers (age 18 years and above) without contra-indications to MRI will be recruited. Twenty patients with clinically diagnosed AD and 20 age-matched controls (+/- 3 years) will be recruited to test the clinical feasibility of glucoCEST. As a feasibility study, the current work is unlikely to cover the full representative range of AD patients with diverse phenotypes. Its key purpose is to explore whether the proposed technique will show different glucose uptake between those with normal cognition and those with early AD. Further the purpose of future clinical use will be to detect AD in its early stage where clinical manifestations of AD are either subclinical or very mild. We will ensure that the sample is representative of the age range of AD patients, as well as sex balanced.

Trial design

Design model

Case-control

Time perspective

Prospective

Treatments tested in this trial

Magnetic Resonance Imaging (MRI)
Other intervention
Participants will be asked to lie in the MRI scanner while we collect 3D T1- and T2-weighted images and a 3D FLAIR image to exclude pathology (e.g. stroke). Participants will ingest a glucose solution (75 g Dextrose) so dynamic glucoCEST images can be acquired to measure glucose uptake and clearance.
Blood Glucose Assessment
Other intervention
A blood testing meter will be used to measure the blood sugar levels before and after the scans. Normal reading for a nondiabetic person after fasting is 70-99 mg/dl (3.9-6 mmol/L). If abnormal blood sugar levels are detected (sugar levels outside the above normal range), the participant will no longer be eligible for the study and they will be withdrawn.
Positron Emission Tomography (PET)
Other intervention
Participants will be administered a radioactive glucose analogue, 2-deoxy-2-(18F) fluoro-D-glucose (18FDG) through a canula inserted into a vein in the arm or hand and asked to sit quietly for 1 h. After 1 h they will be asked to lie quietly and without talking in the PET scanner and a PET brain scan will be performed.
Cognitive Assessment
Other intervention
Participants will be asked to undertake two cognitive tests (the Alzheimer's Disease Assessment Scale ADAS-cog test and the Mini Mental State Examination test - MMSE). These are standard clinical tests used to determine cognitive dysfunction in Alzheimer's disease.

Treatment groups

60 Participants

are divided into 4 treatment groups

Group A: Development Group 1 (N = 10) (Development Phase)2 interventions

Group B: Patients (N = 20) (Clinical Phase)4 interventions

Group C: Healthy Controls (N = 20) (Clinical Phase)4 interventions

Group D: Development Group 2 (N = 10) (Development Phase)2 interventions

Trial outcomes

Primary outcomes

1

PET glucose measurement

Dynamic frames from FDG-PET will be summed and normalised to the cerebellum using MATLAB (MathWorks Inc., USA). Standardised uptake values (SUVs) from PET will then be calculated. Regions of interests (ROIs) will derived from normalisation to the standard Desikan Killiany atlas. Average SUV from PET will be calculated from each ROI in MATLAB. Glucose uptake (maximum ΔS/So) with units of ratio. Clearance (rate of decrease of ΔS/So) values with units of ratio.

Time frame

2 years

2

CEST-MRI glucose measurement

Dynamic frames from CEST MRI will be summed and normalised to the cerebellum using MATLAB (MathWorks Inc., USA). Standardised uptake values (SUVs) will be calculated in regions of interests (ROIs) derived from normalisation to the standard Desikan Killiany atlas. Average SUV from each ROI, the glucose uptake (maximum ΔS/So) and clearance (rate of decrease of ΔS/So) values from patients and controls will be calculated using MATLAB. Glucose uptake (maximum ΔS/So) with units of ratio. Clearance (rate of decrease of ΔS/So) values with units of ratio

Time frame

2 years

3

Sensitivity and specificity of CEST-MRI glucose measurements

A neuroradiologist blinded to the diagnosis of each participant will be asked to report the scans in a similar way to an FDG-PET scan. Sensitivity and specificity of glucoCEST to detect AD by estimating the proportion of true positives and true negatives respectively will be determined. To demonstrate the feasibility of glucoCEST in differentiating AD patients from controls, group comparisons of glucose (paired samples t-tests as implemented by SPSS) uptake values between patients and controls and of glucose clearance values between patients and controls will be performed. Sensitivity and specificity values with units of ratio.

Time frame

2 years

4

Repeatability of CEST-MRI glucose measurement

To investigate the repeatability of MRI assessment, 10 out of 20 development phase healthy volunteers will be recruited to undergo a second repeated study assessment visit between 7 and 14 days after their first visit. Coefficient of variation values with units of percent.

Time frame

2 years

Detecting Early Alzheimer's Using MR

About this trial

Eligibility criteria

Qualifiers

Disqualifiers

Trial population

Trial design

Treatments tested in this trial

Treatment groups

Trial outcomes

Primary outcomes

Secondary outcomes

Other outcomes

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