Ultrasonic Debris Clearance to Promote Brain Resilience

Inclusion criteria

1.1. Physician-reported amyloid positivity diagnosed by amyloid positron emission tomography (PET) OR historic CSF positivity of Abeta42, total tau, or phosphorylated tau OR positivity of plasma pTau-217.

1.2. Age ≥ 18 years. No gender/sex, racial, or ethnic preference. Subjects greater than 60 years of age will be assumed to be non-pregnant based on age and expected post-menopausal status. Female subjects under the age of 60 will complete a two-step assessment of pregnancy status (a self-reported assessment of menopause that proceeds to a urine human chorionic gonadotropin (hCG) test to confirm non-pregnancy, if the participant is not post-menopausal).

1.3. CDR Scale score less than or equal to 1.0, consistent with mild, very mild, or no dementia.

1.4. Ability and willingness to comply with the study procedures (six sessions sitting in a procedure chair for up to one hour for the procedure, with an ultrasound device placed on their scalp; additional time for the MRI assessment, blood draws, and cognitive assessments).

1.5. Ability to understand and the willingness to sign a written informed consent document.

Exclusion criteria

2.1. Dementia of moderate or higher severity (CDR > 1.0) 2.2. Intracranial tumors, acute or chronic hemorrhage (beyond petechiae/microhemmorhage), or other current or historic central nervous system specific pathology. Baseline MRI studies will be screened by the protocol director to ensure no exclusionary intracranial pathology is present.

2.3. Any other comorbidity that would prevent adequate interpretation of the study results per the treatment team (e.g. congenital brain malformations without clinical importance) 2.4. Ultrasound attenuators along the ultrasound beam path (metal, air, or bulky calcification) including thick hair or related adornments that cannot be undone for the study (e.g. turbans, dreadlocks, hairweaves/wigs) that would prevent adequate ultrasound gel coupling of the device to the scalp or could trap air in the ultrasound beam path.

2.5. Contraindications to MRI (unknown device, claustrophobia) or metallic hardware in the head that prevent adequate MRI visualization of the brain 2.6. Allergy or similar intolerance to the materials used for ultrasound device coupling (ultrasound gel, silicone) 2.7. Receipt of anti-amyloid monoclonal antibody therapy within 6 months prior to screening 2.8. Moderate or greater depressive symptoms at screening, defined as a Patient Health Questionnaire-9 (PHQ-9) total score >= 10.

2.9. Clinically significant suicidal ideation or behavior as assessed by the Columbia-Suicide Severity Rating Scale (C-SSRS) 2.10. Clinically significant hematologic abnormalities, defined as hematocrit < 35% for male or < 32% for female, absolute neutrophil cell count < 1500/uL, absolute lymphocyte count < 900/uL, or platelet count < 120,000/uL 2.11. Clinically significant hepatic, renal, respiratory, cardiovascular, or metabolic disease that increases risk or interferes with interpretation, defined as ALT/AST/ALP > 1.5 ULN, or eGFR < 50 mL/min/1.73m2, or recent MI/unstable angina/HF/cardiomyopathy within 6 months, 2.12. Significant bradycardia(<50/min) or tachycardia (>100/min) 2.13. Poorly controlled BP 2.14. Uncontrolled diabetes, defined as HbA1c > 7.5 2.15. Active clinically significant infection or other systemic illness affecting the CNS