Functional Brain Imaging of Medication Treatment Response in Mild Alzheimer's Disease Patients

Functional Neuroimaging (fMRI) Biomarker of Allosteric Nicotinic Receptor Modulation in Mild Alzheimer's Disease Patients: A Razadyne vs. Aricept Dose Escalation Trial

The purpose of this study is to determine whether standard medications approved for Alzheimer's disease treatment differ in their action on brain functioning and whether any observed brain activity differences as result of treatment are associated with particular patterns of dementia improvement or reduced decline.

This study seeks to differentiate task-related and resting brain activity patterns captured via functional magnetic resonance imaging (fMRI) and associated with two common Alzheimer's disease (AD) medications, equivalent in acetylcholinesterase inhibition effect (AChEI) but differing with respect to allosteric nicotinic receptor modulation effect. It is the primary aim of this project to gain a better understanding of the brain mechanisms involved in the attentional and executive skills improvements associated with nicotinic receptor modulation in mild AD patients. To address this question, this 12-week continuous treatment, double-blind, head-to-head dose-escalation treatment trial seeks to visualize any treatment response unique to allosteric nicotinic receptor modulation and to associate these fMRI data with standard cognitive assessment outcomes. Using in-scanner tasks shown to reliably elicit brain activity in cortical regions important to memory and attention, this treatment trial will examine both resting and task-related BOLD signal characteristics in a well-characterized sample of 36 mild AD patients after periods of low dose and high dose AD dementia treatment with either galantamine hydrobromide (AChEI + nicotinic receptor modulation) or donepezil hydrochloride (AChEI only). Both the low and high dose imaging comparisons between treatment groups will be equivalent for 35% AChEI-effect, which may allow for the isolation of BOLD signal unique to allosteric nicotinic receptor modulation in both brain at rest and task-related brain states.

Alzheimer's Disease, fMRI, Functional Neuroimaging, Allosteric Nicotinic Receptor Modulation, Acetylcholinesterase Inhibition, Head to head, Dose escalation, Biomarker

4-weeks 8mg. Razadyne ER, then 4-weeks 16mg. Razadyne ER, and a subsequent 4-weeks of 24mg. Razadyne ER

Brain activity patterns, as collected via functional magnetic resonance imaging (fMRI), at rest and associated with task performance after 4 weeks of low-dose treatment and after 8-weeks of higher-dose treatment.

Differences in cognitive testing and functional status at pre-treatment baseline and after completion of the 12-week treatment trial.

Inclusion Criteria: Must meet diagnosis of mild Alzheimer's disease Must have a family member or caregiver who is willing to attend all study visits and provide information on your participation in the study If female, must be post-menopausal Must be able to swallow tablets Exclusion Criteria: Metal implants or medical devises unsafe for MRI use Pre-menopausal female HIstory of recent head injury Significant major, life-threatening illness or injury (e.g., stroke, AIDS, etc.) Vascular dementia or any dementia other than Alzheimer's Disease History of significant alcoholism or drug abuse History of seizure disorder, developmental delay or major psychiatric illness