Gamma Light and Sound Stimulation to Prevent Dementia in Cognitively Normal People at Risk for Alzheimer's Disease

Eligibility Criteria

• 1. Between 55 - 90 years of age, inclusive.
• 2. Immediate family history of Alzheimer's disease.
• 3. Mini-Mental State Exam (MMSE) score of 27 or greater at baseline or expected score range for cognitively normal adjusted for education level.
• 4. Clinical Dementia Rating Global Score of 0 at baseline.
• 5. Delayed Recall score on the Logical Memory IIa subtest of 8 to 15 at baseline or expected score range for cognitively normal adjusted for education level.
• 6. Low serum amyloid levels at baseline.
• 7. Elevated fibrillar amyloid using 11C PiB PET at baseline between 20 - 70 CL.
• 8. Willing and able to undergo MRI brain and PET brain scans.
• 9. Adequate visual and auditory acuity to allow for neuropsychological testing.
• 10. Able to comply with neuropsychological testing and other study procedures in opinion of site PI.
• 11. Willing and able to complete baseline assessments, and willing to participate in 13-month study protocol.
• 12. Willing to provide blood samples at specified timepoints. Willing to consider contributing CSF samples at specified timepoints, if asked.
• 1. MRI contraindications, such as presence of pacemakers, aneurysm clips, artificial heart valves, ear implants, metal fragments, or foreign objects in the eyes, skin, or body.
• 2. High myopia \< -7 diopters, or untreated cataracts that affect vision.
• 3. Any significant systemic illness or unstable medical condition which could lead to difficulty complying with the study protocol.
• 4. For subjects agreeing to undergo lumbar punctures, history of bleeding disorders or laboratory results indicating low platelet levels are exclusionary for the procedure.
• 5. Concomitant medications:
• 1. Treatment with NMDA antagonists.
• 2. For subjects undergoing lumbar puncture, current use of warfarin or similar anti-coagulants is exclusionary for the procedure.
• 6. Clinical conditions:
• 1. History of seizure or medical diagnosis of epilepsy.
• 2. Female subjects who are pregnant or currently breastfeeding.
• 3. History of severe allergic or anaphylactic reactions.
• 4. Longstanding premorbid history (i.e., longer than 10 years) of alcohol or substance abuse with continuous abuse up to and including the time that the symptoms leading to clinical presentation developed.
• 5. Neurodegenerative disorder associated with cognitive impairment.
• 6. Renal disease.
• 7. MR imaging findings such as stroke, tumor, leukoencephalopathy that could preclude meaningful analyses of clinical and imaging data in the opinion of the site PI, such as:
• 1. Severe leukoencephalopathy seen on MRI.
• 2. Relevant structural abnormality (i.e., normal pressure or obstructive hydrocephalus, hypoxic ischemic lesions, hemorrhages, tumors, malformations).
• 3. Cerebral amyloid angiopathy, evidenced by T2\* or other susceptibility weighted-MRI.
• 8. Laboratory findings, if known (study does not perform testing) suggestive of systemic illness such as renal disease.
• 9. Site investigator's discretion, if s/he feels the subject cannot complete sufficient key study procedures. Exceptions to these guidelines may be considered on a case-by-case basis at the discretion of the Project Director.