Functional Magnetic Resonance Imaging of Brain Activity in Patients With Painful Diabetic Neuropathy

Inclusion Criteria: * Voluntary participation and signing informed consent * 18 to 60 years old with junior high school education or above * meeting the 1999 WHO type 2 diabetes diagnostic criteria: having symptoms of diabetes (polydipsia, polyphagia, polyuria and unexplained weight loss) plus one of the following 3 items: (1) random blood glucose more than 11.1 mmol/L; (2) fasting blood glucose more than 7 mmol/L; (3) after 2 hours glucose load, the blood sugar more than 11.1 mmol/L * The diagnosis of diabetic peripheral neuropathy (at the same time meets the following three items, of which painful neuropathy patients have pain symptom): (1) neuropathy occurs not earlier than the diagnosis of diabetes; (2) having clinical manifestations of pain, numbness, and abnormal sensation; (3) any abnormality in the following 5 examinations: ankle reflex, vibratory sensation, pressure sensation, temperature sensation, and acupuncture pain Exclusion Criteria: * left-hand writers * neuropathy caused by other causes, such as cervical spondylosis, cerebral infarction, Green Barre syndrome; severe arteriovenous disease; neurotoxic changes caused by drugs and renal insufficiency * patients with severe cerebral vascular disease * diagnosed mental disorders such as depression, anxiety and Alzheimer's disease * patients who can't accept head magnetic resonance imaging, such as those with metal (stents, metal dentures, internal fixation plates, etc.), and claustrophobic space phobias