Safety and Efficacy of Remote Ischemic Conditioning on Cerebral Amyloid Angiopathy. (RIC-CAA)

Inclusion Criteria:

1. Age≥55 and ≤85.
2. The diagnosis of probable CAA and probable CAA with supporting pathology by the Bostoncriteria.
3. Signed and dated informed consented is obtained.

Exclusion Criteria:

1. Familial hereditary CAA or other hereditary small-vessel disorders.
2. Previous intracranial hemorrhage caused by other reasons, such as tumor, cerebralcavernous angioma, ruptured aneurysm, arteriovenous malformation, venous sinusthrombosis and so on.
3. A history of stroke within 3 months.
4. The degree of intracranial or extracranial large artery stenosis >50%.
5. Clinical diagnosis of probable AD by National Institute of Neurological andCommunicative Diseases and Stroke/Alzheimer's Disease and Related DisordersAssociation (NINCDS-ADRDA) criteria.
6. Significant cognitive impairment (defined as Mini-mental State Examination (MMSE)score of ≥20 (primary school) or ≥24 (junior school or above) or other diseasesresulting from severe cognitive impairment.
7. Inability to walk 6m unaided or other conditions that affected gait performance, suchas Parkinson.
8. Illiteracy and patients with severe visual or hearing impairment.
9. Contraindication to MRI scan, such as intracranial metal implants, cardiac pacemaker,severe claustrophobia, history of seizures and so on.
10. Patients with missing or poor-quality MRI sequences at baseline and follow-up.
11. Patients with a pre-existing neurological deficits (modified Ranks scale score >2) orpsychiatric disease that would confound the neurological or functional evaluations.
12. Alcohol dependence and other psychoactive substance abuse
13. Contraindication for remote ischemic conditioning: severe soft tissue injury, limbdeformities, fracture, atrial fibrillation or peripheral vascular disease in the upperlimbs.
14. Life expectancy of less than 1 year due to co-morbid conditions.
15. Severe, sustained hypertension (SBP > 180 mmHg or DBP > 110 mmHg).
16. Severe renal or hepatic disease.
17. Known pregnancy (or positive pregnancy test), or breast-feeding.
18. Concurrent participation in another research protocol for investigation of anotherexperimental therapy.
19. Any condition which, in the judgment of the investigator, might increase the risk tothe patient.