Effects of Olfactory Training on the Brain Function in T2DM Patients With Mild Cognitive Impairment

Inclusion Criteria: * patients with type 2 diabetes mellitus; * Aged: 40 -75 years ; * Cognitive function assessment suggests mild cognitive impairment; * A stable glucose-lowering regimen for more than 2 months; * ≥6 years of education; * Right-handed. Exclusion Criteria: * Cognitive function assessment suggests normal cognition or dementia; * Other dementia related neurological diseases or depression, Mental dysplasia, mania, schizophrenia, etc in the past 2 years; Central nervous system diseases, including brain trauma, intracranial hemorrhage, acute cerebral infarction, etc; * Severe sinusitis, nasal cavity and sinus polyps, skull base or nasopharyngeal tumors and other space occupying lesions; * Congenital diseases and traumatic history of nose, maxillofacial and skull base affecting olfaction. * With symptoms of upper respiratory tract infection, including nasal congestion, runny nose, fever, etc. on the day of MR examination; * Diabetic Acute and chronic complications, including diabetic ketoacidosis, diabetic ketoacidosis; a hyperglycemic hyperosmolar state or severe hypoglycemic coma, etc. * Severe impairment of heart, liver, kidney and other organs; * Contraindications of MRI examination, such as implantation of metal prosthesis in vivo, claustrophobia, etc; * Pregnant and lactating women; * Receive other test drugs currently or within 3 months before participating in the project; * Known or suspected allergic history to essential oil; * Taking cognitive-related …