What is a TIA? The body’s blood flows through the brain’s blood vessels minute by minute, supplying nutrients such as oxygen and glucose, and carrying out waste products such as carbon dioxide. If the lumen of a cerebral artery becomes narrowed or occluded due to some lesion, if the blood becomes sticky or easily clotted for some reason, or if the blood pressure in the artery that maintains the flow of blood to the brain drops suddenly, cerebral blood flow can decrease or even stop. If the amount of blood flowing through an artery in the brain is drastically reduced, the ischemic part will not be able to work properly and some so-called localized brain deficits will appear, such as slurred speech, paraplegia and paralysis. If the ischemia is short-lived, the cerebral deficits will last only for a short period of time and will not leave ischemic necrosis (cerebral infarction) in the brain. The medical term for such transient neurological deficits caused by localized brain or retinal ischemia is transient ischemic attack (TIA), also known as mini-stroke. Who is at risk for TIA? Smokers, alcoholics, and middle-aged and elderly people with hypertension, diabetes, hyperlipidemia, atrial fibrillation, coronary artery disease, and myocardial infarction are more likely to have TIA, as are patients with true erythrocytosis, and people with one or more of these risk factors are known as individuals at high risk for cerebrovascular disease and should be more alert for TIA. The manifestations of TIA: stereotypy and diversity The localized brain deficit manifestations of TIA are characterized by transient (usually lasting from a few minutes to about 20 minutes, usually no more than an hour) and reversible (no infarct lesions or residual symptoms in the brain) features. When a patient has a series of frequent seizures, the form of his seizure presentation is usually fixed, a characteristic called stereotypy. In contrast, for different patients, the presentation of cerebral deficits is diverse due to the different arteries where the obstruction occurs and the different sites of cerebral ischemia. An analogy to this stereotype and diversity can be drawn with road traffic blockages: the consequences of a road blockage to the airport are usually fixed, i.e., delaying our flight, while blockages occurring on different roads in the city can have various effects on our life and work. Understanding the diversity of the manifestations of TIA episodes will help us to determine the condition and respond to it in a timely and correct manner. I would like to introduce some of the common manifestations of TIA for your readers. Abnormal vision Sudden loss of vision in one eye, as if suddenly covered by a black curtain. After a few minutes, the black curtain gradually fades away and vision is restored as before. Blurred vision, inability to see objects on one side of the eye in front of you, such as walking without being able to avoid and repeatedly bumping into obstacles on one side of the body, indicates a visual field defect on that side of both eyes. Double vision when looking at things. A normal person may also see double shadows when looking at a lateral or upper or lower target for a long time, and this condition is not considered TIA. Feeling objects in front of the eyes or feeling one’s body rotate in a certain direction, often accompanied by nausea and vomiting symptoms. You may have experienced this sensation, called vertigo, when you suddenly stopped in the middle of a rapid rotation in place during childhood games. Dyskinesia A feeling of loss of strength and dominance of one side of the face, upper and lower extremities, as well as a slanting mouth, salivation, difficulty lifting the arm, dropping objects from the hand, walking with one foot dragging on the ground, or even inability to stand and walk. Sudden paralysis of all four limbs. Sudden loss of strength in both legs and falling to the ground. Unstable standing and walking, or unstable and inaccurate movements of upper limbs, appearing uncoordinated. Sensory impairment A tingling sensation or numbness in one side of the face and limbs (dullness of sensation) Speech impairment Slurred speech, feeling of a stiff tongue. Speech slows down and often stops because of the inability to find the right words. Difficulty in writing and reading. Depending on the site of ischemia, patients with TIA may present with one or more of the above symptoms. It should be noted that most of the above symptoms are not unique to TIA, but other disorders may also present with similar symptoms and need to be differentiated. TIA needs to be distinguished from the following diseases Epilepsy: Epilepsy is also characterized by seizure-related brain dysfunction, which is caused by abnormal and excessive discharge of nerve cells in the brain. Some types of seizures behave very similarly to TIA and need to be examined in the hospital to be judged by a doctor. Migraine aura: Migraine is a disease with episodic headache as the main manifestation. Some patients may experience aura manifestations such as blurred vision, double vision, or numbness in the migraine body before the attack, followed by headache. Sometimes, the aura can come on alone. Hypoglycemia: It is common in diabetic patients taking glucose-lowering drugs, and in most cases is accompanied by panic attacks, hand tremors, sweating, weakness, and a feeling of hunger. Symptoms improve rapidly after eating or drinking sugar water. Multiple sclerosis: An autoimmune disease of the central nervous system with multiple lesions, often with multiple relapses and remissions. It is mostly seen in young adults and is more common in women. The disease is relatively uncommon in China except in some cold regions. The disease requires brain and spinal cord MRI as well as cerebrospinal fluid examination for differentiation. In addition, dizziness that lasts only one or two seconds, as well as isolated generalized fatigue, dizziness, or shaking of the limbs, are usually not manifestations of TIA attacks. Although TIA attacks come and go without seeming to cause permanent physical damage, they are a manifestation of severe abnormalities in the body’s cerebral blood circulation. Approximately one-third of patients experience cerebral infarction one after another within a year thereafter, with most of them occurring within a month of the TIA attack. Therefore, TIA is also known as a warning stroke. We hope that this article will help those patients with risk factors for cerebrovascular disease and their family members, as well as readers who are concerned about their own cerebrovascular health, to understand the common manifestations of TIA so that they can be accurately identified and promptly diagnosed, and thus receive timely and effective treatment.