1.What is transient ischemic attack? Transient ischemic attack (TIA) is a transient cerebral blood circulation disorder with focal symptoms, characterized by recurrent episodes of transient aphasia, paralysis, or sensory disturbance, with signs and symptoms disappearing within 24 hours. Transient ischemic attack is a transient focal cerebral or retinal dysfunction in the corresponding region caused by ischemia in the internal carotid artery or vertebrobasilar artery, each attack lasts for several minutes and usually recovers completely within 30 min, but there are often recurrent attacks. 2.What diseases can cause TIA attacks? This disease is mostly related to hypertensive atherosclerosis, and its onset may be caused by a variety of factors. (1) Microthrombosis: When the attached thrombus, sclerotic plaque and the blood decomposition material and platelet aggregates in the internal carotid artery and the atherosclerotic stenosis of the vertebral aortic basilar system are free and dislodged, they block the arteries of the brain, and when the embolus breaks up or moves distally, the ischemic symptoms disappear. (2) Cerebral vasospasm: Atherosclerotic plaque in the internal carotid artery or vertebral a basilar artery system narrowed the lumen of the vessel, and the vortex flow of blood was generated there. When the vortex flow accelerated, it stimulated the vessel wall and caused vasospasm, and transient ischemic attack appeared, and the symptoms disappeared when the vortex decelerated. (3) Cerebral hemodynamic changes: When the carotid artery and vertebral basilar artery system is occluded or narrowed, if the patient suddenly has a transient hypotension, the attack of this disease will occur due to the reduction of cerebral blood flow; after the blood pressure rises, the symptoms disappear. The disease is more likely to occur when blood pressure fluctuates. In addition, cardiac arrhythmia, atrioventricular block, and myocardial damage can also cause the onset of the disease due to a sudden decrease in local cerebral blood flow. (4) When the carotid artery is twisted, overgrown, knotted or the vertebral artery is compressed by cervical vertebral bone growth and bone spur, the attack can be caused when the head is turned. 3 .What are the clinical features of TIA? It is more common in elderly people over 60 years old, and more men than women. It mostly develops under the circumstances of position change, excessive activity, sudden rotation or flexion and extension of the neck. (1) TIA of the carotid system is less frequent than TIA of the vertebral basilar system, but it lasts longer and is more likely to cause complete stroke. The most common symptoms are monoplegia, hemiplegia, hemianesthesia, aphasia, and monocular visual impairment. It may also lead to isotropic hemianopia and syncope. (2) TIA of the vertebrobasilar system is more common than TIA of the carotid system, and the number of episodes is also more frequent but shorter. The main manifestations are ischemia in the brainstem, cerebellum, occipital lobe, temporal lobe and proximal spinal cord. Symptoms of neurological deficit are commonly vertigo, nystagmus, unsteadiness in standing or walking, blurred or distorted vision, visual field defects, diplopia, nausea or vomiting, hearing loss, ball palsy, crossed paralysis, mild hemiparesis and mild bilateral paralysis. A few of them may have impaired consciousness or sudden collapse attack. 4. What is the prognosis of TIA? The disease is often a precursor of cerebral thrombosis. About half of the patients have a complete stroke within 1 month of the onset of carotid TIA and about 25-40% within 5 years; about 1/3 of the attacks disappear spontaneously or continue. The prognosis is affected by advanced age and frailty, hypertension, diabetes mellitus and heart disease. 5. What is the treatment plan for TIA? The disease can resolve on its own, and the treatment focuses on preventing recurrence. Blood pressure should be adjusted, cardiac function should be improved, effective blood circulation should be maintained, abnormal blood flow should be corrected, excessive neck flexion and extension should be avoided, and long-term oral platelet aggregation inhibitors, such as aspirin 0.05-0.1 g, 1 to 2 times/day, should be administered.