Overview.
因缺血引起的短暂性脑功能障碍，病程一般不超过24小时
主要由于血流动力学改变和微栓塞所致
主要表现为一侧肢体无力、感觉减退、眼前发黑等
常采取一般治疗、药物治疗、手术治疗
What is a transient ischemic attack?
Definition
Transient ischemic attack (TIA) is a transient neurological disorder caused by localized ischemia of the brain, spinal cord, and retina.
The “presence or absence of infarct lesions” is the only basis for the differential diagnosis of transient ischemic attack and cerebral infarction.
Classification
TIAs can be categorized into the following two groups, depending on the vessel and site of the attack.
TIA of the internal carotid artery system is caused by vascular lesions of the internal carotid artery, middle cerebral artery, anterior cerebral artery and their branches.
Vertebrobasilar system TIA, caused by vascular lesions of the vertebral artery, basilar artery, posterior cerebral artery and their branches.
Incidence
A national study conducted in 2010 estimated that there are 23.9 million patients with transient ischemic attacks in the country.
The prevalence of transient ischemic attack in adults in China is about 2.27 per 100 people.
It is more common in middle-aged and elderly people, and there are more men than women.
Questions you may be interested in
What is transient ischemic attack?
Transient ischemic attack is a transient neurological disorder caused by local ischemia of the brain, spinal cord and retina.
Clinical manifestations often include weakness of one side of the limb, loss of sensation, blackness in front of the eyes, etc. Symptoms usually do not last more than one hour and the longest time does not last more than 24 hours, and the related brain foci cannot be found in MRI and CT examinations.
On the contrary, if a clear brain lesion is found, it is not called transient ischemic attack.
Does a transient ischemic attack always lead to a stroke?
A transient ischemic attack does not necessarily progress to a stroke.
A stroke is a brain attack. There is a high risk of stroke in the early stages of a transient ischemic attack, but it does not necessarily become a stroke. Some of them may resolve spontaneously, some may reoccur and may develop into strokes, in addition to myocardial infarction and sudden death.
A shortening of the interval between attacks, a longer duration, and a gradual worsening of symptoms strongly indicate an impending development of a stroke.
What are the symptoms of transient ischemic attack?
The clinical manifestations of this disease vary depending on the vessel and site of the ischemic attack.
TIA of the internal carotid artery system may be characterized by weakness of one side of the limb, loss of sensation, lack of fluency in speech, and darkness in front of the eyes.
TIA of vertebrobasilar artery system may be characterized by dizziness, dizziness, unsteadiness, abnormal eye movement, double vision, facial numbness, limb weakness and sensory loss, as well as special manifestations such as fainting, falling and inability to recall what has just happened.
Causes
Causes
There are numerous doctrines regarding the etiology and pathogenesis of transient ischemic attacks, the main ones being the following.
Hemodynamic changes
On the basis of cerebral atherosclerosis or severe narrowing of the arteries, when sharp fluctuations and decreases in blood pressure occur, it can lead to a decrease in blood flow to the diseased vessels and transient cerebral ischemic symptoms. When the blood pressure rises back up and the local cerebral blood flow returns to normal, the symptoms may disappear.
Transient cerebral ischemia can also be caused by compression of the arteries supplying blood flow to the brain (e.g., the vertebral arteries in the cervical spine have a small lateral foramen, and if the vertebral arteries become sclerotic, they can become compressed when the neck is turned around), or spasm due to a variety of stimuli.
Microembolism
Obstruction of small arteries by microemboli can lead to ischemia in the brain tissue in the area of their blood supply. When the embolus breaks up and moves to the distal end or spontaneously dissolves, blood flow is restored and symptoms are relieved.
Microemboli mainly originate from unstable plaques of atherosclerosis or dislodged thrombus attached to the wall of the heart.
High risk factors
Having hypertension, hyperlipidemia, diabetes mellitus, hyperhomocysteinemia (blood homocysteine level higher than normal range), etc.
Long-term smoking and alcoholism.
Symptoms
Main Symptoms
Transient ischemic attack (TIA) often starts suddenly, and after a short period of time (usually not more than 24 hours), the symptoms disappear completely, and often recur.
The blood supply to the human brain consists of the internal carotid artery system and the vertebrobasilar system (including the vertebral artery and basilar artery, as well as their branches.) The clinical manifestations of TIAs vary according to the blood vessel and the location of the ischemic attack, as described below.
TIA of internal carotid artery system
大脑中动脉供血区缺血
Contralateral limb monoparesis, mild hemiparesis, facial paralysis and tongue paralysis.
It may be accompanied by hemiplegia (no perception of stimuli such as pain, temperature, touch, pressure, position, vibration, etc.), contralateral ipsilateral hemianopsia, aphasia, and spatial disorientation (inability to correctly recognize one’s own spatial location).
大脑前动脉供血区缺血
Personality and affective disorders and weakness of the contralateral lower limbs may occur.
颈内动脉的眼支供血区缺血
Most often, it is characterized by a sense of grayness, cloudiness, or blurred vision in front of the eyes.
In severe cases, there may be transient blackouts (blackness in front of the eyes).
颈内动脉主干供血区缺血
Transient blackout and blindness in one eye on the affected side, with or without contralateral hemiparesis and sensory disturbances.
TIA of the vertebrobasilar system
常见症状
Patients rarely have isolated symptoms and often have a combination of symptoms.
Vertigo, balance disorders, nystagmus and diplopia are common, and may be accompanied by facial and perioral numbness, contralateral limb paralysis, and sensory deficits.
特殊表现
Sudden weakness of the lower limbs and fall, no loss of consciousness, often can stand up quickly, mostly when the patient turns his head or tilts his head.
Short-term memory loss, usually the symptoms last for a few hours, and then completely improve.
Sudden or complete loss of vision in both eyes, which may be accompanied by visual field defects that resolve in minutes to hours.
Complications
Ischemic stroke
Numerous studies have shown that the risk of ischemic stroke is high in the early stages of TIA. the incidence of ischemic stroke ranges from 4% to 10% within 7 days of the onset of TIA, and from 10% to 20% within 90 days of the onset of TIA.
The main manifestations of TIA are headache, dizziness, impaired sensation in one limb (inability to perceive pain, temperature, etc.) or sudden weakness, blurred vision, choking on water, difficulty in eating, slurred speech or even aphasia.
In severe cases, coma and generalized convulsions may occur.
Consultation
Department of Medicine
Neurology
If you experience recurrent short-term symptoms such as dizziness, nausea, transient blackouts, memory loss, sudden weakness of the lower limbs, and numbness in the face and around the mouth, it is recommended that you consult a doctor promptly.
Emergency Department
If you experience coma, generalized convulsions, sudden blindness or other emergencies, we recommend that you consult the Emergency Department or call the “120” emergency number as soon as possible.
Preparation for medical treatment
Preparing for medical treatment: registration, information preparation, common problems
Tips for seeking medical treatment
Try to keep a record of the symptoms, duration and frequency of the attacks so that you can give your doctor more information.
Family members are recommended to accompany you to the doctor, and you should not drive or ride to the doctor by yourself.
Preparation Checklist
症状清单
Pay particular attention to the time of onset of symptoms, special manifestations, etc.
How often do you experience vertigo? How long does vertigo usually last?
Do you have problems moving your limbs? Do you have strength in your legs when walking?
Can you see clearly? Any transient blackouts?
Do you have numbness in the face and around the mouth?
病史清单
Do you suffer from hypertension, hyperlipidemia, diabetes, hyperhomocysteinemia, etc.?
Is there any long-term smoking or alcohol consumption?
检查清单
Test results in the last six months, which can be brought to the doctor’s office
Cranial CT, Cranial Magnetic Resonance Imaging (MRI)
Neck ultrasound
Echocardiography
Digital subtraction angiography
用药清单
Medication in the last 3 months, bring along medication box or package if available
Antiplatelet drugs: aspirin, clopidogrel
Anticoagulants: warfarin, rivaroxaban
Cerebral vasodilators: nimodipine, flunarizine hydrochloride
Diagnosis
Diagnosis is based on
Medical history
History of hypertension, hyperlipidemia, diabetes mellitus, hyperhomocysteinemia.
History of chronic smoking and alcohol consumption.
Clinical manifestations
症状
Vertigo, weakness of one limb, transient blackout, sudden loss of strength of lower limbs and fall are often seen repeatedly and transiently.
体征
A vascular murmur can be partially heard in the bilateral cervical triangle and above the clavicle. Generally, a high pitched and prolonged murmur suggests severe stenosis, but mild stenosis and complete occlusion can be preceded by no murmur due to slowed blood flow.
Funduscopic examination may reveal ischemia in some patients.
Laboratory tests
Including blood routine, blood glucose, liver and kidney function, electrolytes, blood lipids, coagulation function, homocysteine, myocardial injury markers, blood oxygen saturation and other tests.
It is conducive to the timely detection of risk factors, assessing the overall body condition and helping to determine the treatment plan.
During the course of treatment, some of the items may require regular checkups in order to monitor the body’s condition and assess the effectiveness of treatment.
Imaging
Symptoms and signs have disappeared by the time the vast majority of patients visit the clinic, so imaging tests are crucial to the diagnosis of the disease.
头颅CT及MRI
It can rule out small cerebral hemorrhages and other possible brain lesions, and is the most important initial diagnostic test, as well as helping to rule out other organic brain diseases.
The examination is mostly normal, and some can show transient ischemic foci early in the course of the disease by diffusion-weighted MRI.
颈部超声检查
These include carotid color Doppler flow imaging (CDFI) and transcranial Doppler ultrasound (TCD).
CDFI examination
可观察无名动脉、双侧颈总动脉、颈内动脉、颈外动脉、锁骨下动脉等血管。
可见动脉狭窄、粥样硬化斑块等。
TCD
可用于评估颅内基底动脉环（Wills环）、颈外动脉、眼动脉等血管的血流速度、搏动指数，脑动脉硬化程度，检测脑动脉内微栓子等。
在狭窄血管处可检测到血流速度增高。
数字减影血管造影
This examination can accurately indicate the length, degree, morphology and number of stenosis in different parts of the vessels and the blood supply of the brain parenchyma at the distal end of the stenosis; estimate the degree of cerebral ischemia and confirm whether there is any entrapment aneurysm or complication of other vascular lesions.
Cautions
检查的前6小时不要吃东西，也不要喝水或饮料。
检查前需要进行碘过敏试验。
保持检查部位皮肤清洁，不要过度紧张。
超声心动图
Helps to determine the presence or absence of cardiogenic emboli.
May detect multiple embolic sources such as cardiac appendage thrombus, anomalies of the interatrial septum, mitral valve redundancy, and coarctation of the aortic arch.
Differential Diagnosis
The following disorders can all present with symptoms similar to transient ischemic attacks and are usually differentiated by the physician through history, head CT, MRI, and digital subtraction angiography.
Partial epilepsy
It usually manifests as partial limb twitching, and the duration of the seizure is shorter than that of TIA.
EEG may be abnormal and head CT and MRI may reveal lesions.
Meniere’s disease
Symptoms of Meniere’s disease are similar to TIA of the vertebrobasilar system, but the seizures last longer, usually more than 24 hours, and may be accompanied by tinnitus, a feeling of ear obstruction, and hearing loss after repeated episodes.
Benign positional vertigo
Benign positional vertigo, also known as otolithiasis, is characterized by paroxysmal vertigo and nystagmus. The symptoms of vertigo are related to the change of head position, and the duration of each attack is usually less than 1 minute.
Physical examination, vestibular function examination and imaging examination are helpful for differentiation.
Treatment
General treatment
Actively treat pre-existing diseases, such as hypertension, hyperlipidemia, diabetes mellitus and hyperhomocysteinemia.
Cessation of alcohol and smoking, as well as avoiding passive smoking and staying away from smoking places.
Medication
Antiplatelet drugs
Can prevent the formation of new thrombus in the heart, prevent the proliferation and expansion of blood clots in blood vessels, and avoid worsening of symptoms.
Commonly used drugs include aspirin and clopidogrel.
Adverse reactions include gastrointestinal bleeding, abdominal pain, diarrhea and constipation.
Anticoagulation
Those with a combined hypercoagulable state, deep vein thrombosis and risk of pulmonary embolism need to be treated with prophylactic doses of anticoagulants.
Commonly used drugs include heparin, low molecular heparin, warfarin and rivaroxaban.
Cerebral vasodilators
Can prevent vasospasm, increase blood flow and improve circulation.
Commonly used drugs include nimodipine and flunarizine hydrochloride.
Fiber-lowering drugs
Applicable to people with obvious increase in fibrinogen.
Commonly used drugs include hypofibrinase, bacitracin, etc.
Surgery
Carotid endarterectomy or carotid stenting is often adopted.
It is suitable for patients with recent TIA combined with severe stenosis or moderate stenosis >70% of the ipsilateral extracranial segment of the carotid artery, or vertebral artery stenosis of 70% or more, with no establishment of collateral circulation on CT angiography, and poor perfusion of the posterior circulation detected on CT perfusion imaging, and where perioperative death and recurrence of stroke are expected to be <6%.
This treatment is not recommended for carotid extracranial segment stenosis <50%.
In patients who meet the indications for surgery and have no contraindications, surgery should be performed within 2 weeks.
Prognosis
Cure
Ischemic ischemic attack is usually effectively controlled by aggressive treatment in most patients.
Those who develop ischemic stroke have a poor prognosis and may even be life-threatening.
Hazards
Patients may experience transient blackout, limb weakness and other symptoms, and are prone to accidental injuries, such as falls, burns, traffic accidents and so on.
If ischemic stroke is caused, it is easy to increase the rate of death or disability, which seriously affects the daily life and work of patients and brings a heavy burden to society and family.
Daily
Daily Management
Dietary management
Balanced diet, choosing a variety of foods to achieve reasonable nutrition to ensure adequate nutrition and appropriate body weight.
Low-fat diet should be adopted to reduce the intake of fatty meat and fried food.
Steaming, boiling, mixing, water skimming, simmering and other cooking methods with less salt and oil should be used more often.
Control the intake of high-sugar foods, such as sugary drinks and desserts.
Do not eat dishes with high salt content or pickled products, such as salted meat, salted vegetables and smoked food.
Avoid drinking alcohol.
Exercise management
Suitable forms of exercise such as walking, tai chi, calisthenics, jogging, etc. can be chosen under doctor’s advice.
Family members need to accompany you when exercising to prevent accidents such as falling and falling out of bed.
Ensure the safety of the exercise environment, exercise to remove the surrounding sharp objects, do not allow debris to obstruct the route.
Choose the right time to exercise, fasting and full stomach after meals should not be trained immediately.
If you feel unwell during exercise, stop training immediately and relax at the right time.
Ensure that the training intensity is appropriate, and gradually increase the training frequency.
Life Management
Pay attention to rest and avoid exertion.
If vertigo occurs, sit down or lie down immediately to avoid falling.
If there is hemiplegia, lower limb weakness, etc., you should choose crutches, walking aids, etc. to carry out activities, or be supported by family members or pushed by wheelchair.
Quit smoking and avoid passive smoking.
Psychological support
Pay attention to the patient’s mental health, release pressure in time, avoid anxiety, depression and other bad emotions.
Family members should pay attention to the patient’s mental state, listen patiently and communicate and interact with the patient.
Disease monitoring
If symptoms worsen during treatment, or new symptoms appear, timely consultation is required.
For patients with high blood pressure and diabetes, daily monitoring and recording of blood pressure and blood glucose are recommended.
Prevention
Actively treat existing diseases, such as hypertension, hyperlipidemia, diabetes mellitus, hyperhomocysteinemia, etc., and follow the doctor’s instructions for regular medication.
Stop drinking and smoking, and avoid passive smoking.
Regular medical checkups should be conducted, and any abnormalities found should be promptly consulted and treated.
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