Intranasal Dexmedetomidine-esketamine on Sleep and Cognition in Older Adults With Mild-to-moderate Cognitive Impairment

Inclusion Criteria:

1. Aged ≥ 60 years.
2. Meeting the clinical diagnostic criteria for Alzheimer's disease, with mild cognitive impairment (MoCA score 18-25) or moderate cognitive impairment (MoCA score 10-17) due to Alzheimer's disease.
3. Comorbid with sleep disorders (Pittsburgh Sleep Quality Index [PSQI] score ≥ 7).
4. Signed informed consent.

Exclusion Criteria:

1. Cognitive impairment/dementia due to other causes (e.g., vascular dementia, frontotemporal dementia, Parkinson's disease dementia).
2. Unsuitable for intranasal administration due to nasal cavity diseases (e.g., rhinitis, nasal polyps, or nasal congestion of any cause).
3. Inability to communicate due to visual, auditory, language, or other reasons, or Mini-Mental State Examination (MMSE) score ≤ 9 or MoCA score ≤ 9.
4. History of schizophrenia, epilepsy, or Parkinson's disease, or confirmed diagnosis of glaucoma, hyperthyroidism, pheochromocytoma, or myasthenia gravis.
5. Confirmed diagnosis of restless legs syndrome or sleep apnea, or judged to be at high risk of moderate-to-severe sleep apnea according to STOP-Bang score, or Body Mass Index (BMI) > 30 kg/m2.
6. History of stroke or transient ischemic attack within 12 months prior to enrollment, confirmed intracranial aneurysm, or elevated intracranial pressure from any cause.
7. Uncontrolled hypertension (e.g., hypertensive crisis or systolic blood pressure > 160 mmHg and/or diastolic blood pressure > 100 mmHg prior to enrollment), myocardial infarction, unstable angina, revascularization surgery within 12 months prior to enrollment, or NYHA class III.
8. Sick sinus syndrome, severe sinus bradycardia (heart rate < 50 beats/min), atrioventricular block above degree II without a pacemaker, corrected QT interval (Fridericia-corrected QTcF) ≥ 450 ms, or other severe arrhythmias (e.g., frequent premature ventricular contractions).
9. Uncontrolled diabetes (e.g., HbA1c > 9%, diabetic ketosis, hyperglycemic coma, or hypoglycemia).
10. Severe hepatic dysfunction (Child-Pugh Class C), renal dysfunction (eGFR ≤ 30 ml/min/1.73m2), respiratory insufficiency (SpO2 < 93% on room air), or other severe diseases (e.g., frailty with inability to walk independently, advanced-stage tumors).
11. Alcohol or drug dependence (manifested as strong cravings, uncontrolled use, and withdrawal symptoms upon cessation), or use of contraindicated medications.
12. Major surgery under general anesthesia within 12 weeks prior to enrollment, or planned surgery within 12 weeks.
13. Allergy to dexmedetomidine and/or esketamine.
14. Participation in other interventional clinical studies.
15. Any other conditions deemed unsuitable for study inclusion by the investigator.