Asymptomatic cerebral infarction

Asymptomatic cerebral infarction Asymptomatic cerebral infarction, also known as resting cerebral infarction, is a special type of cerebral infarction. It is generally believed that elderly patients have no history of cerebral infarction, no clinical symptoms of the nervous system, no signs of nervous system localization in the nervous system, brain CT scans, brain MRI examinations have found cerebral infarction lesions, clinically known as asymptomatic cerebral infarction. Some scholars believe that this disease also includes cerebral infarction found at autopsy, and its symptoms may not be recognized, or forgotten by patients, or only transient ischemic symptoms. basic knowledge The proportion of illness: 0.005% Susceptible people: no special people Mode of infection: non-infectious Complications: Hypertension Diabetes

Asymptomatic cerebral infarction

(1) Causes of the disease

Cerebrovascular disease is the most common disease in neurology. The etiology is complicated and affected by many factors. Generally, cerebrovascular diseases are classified into vascular wall lesions, blood component changes and hemodynamic changes according to the etiology.

In addition, many people in the clinic have no cerebrovascular disease even if they have risk factors for cerebrovascular disease, but some people who do not have risk factors for cerebrovascular disease have cerebrovascular disease, indicating that the occurrence of cerebrovascular disease may be related to other factors. Relevant, such as genetic factors and bad hobbies.

Asymptomatic cerebral infarction is roughly the same risk factor as cerebral infarction, such as hypertension, diabetes, hyperlipidemia, atrial fibrillation, TIA, carotid stenosis, smoking, etc.

Coronary heart disease, myocardial infarction patients with high incidence of asymptomatic cerebral infarction, reported in different places, Tanaka et al reported 92 cases of coronary heart disease, brain CT scan found 26 cases of asymptomatic cerebral infarction, the incidence rate was 28.26%, domestic Korea Feng et al reported 289 cases of hypertension, including 180 cases of coronary heart disease and 20 cases of asymptomatic cerebral infarction, accounting for 10.1%. Liu Wei et al reported that there were 23 cases of asymptomatic cerebral infarction in 84 cases of myocardial infarction, the incidence rate was 27.38. %, indicating the incidence of asymptomatic cerebral infarction in patients with coronary heart disease and myocardial infarction.

(two) pathogenesis

The pathogenesis of asymptomatic cerebral infarction is the same as atherosclerotic cerebral infarction. The reason why the clinically asymptomatic brain CT scan or MRI has cerebral infarction lesions may be because: 1 infarct is located in the non-primary functional zone or non-dominant hemisphere of the brain. 2, the damage caused by cerebral infarction develops slowly, the brain tissue produces a compensatory mechanism, 3 infarcts are generally small, generally less than 1.5cm, not involving the sensory or motor conduction beam, and in the static or non-dominant side of the brain, 4 Although there are transient symptoms, because the patient may ignore or forget the medical history, or explain it for other reasons, 5 some people think that the symptoms of cerebral infarction may occur during the patient's sleep, and the patient may be relieved after the patient is awake or the infarct is small, which is a cavity. Infarction.

Asymptomatic cerebral infarction may be a multi-factorial disease, related to age, gender, hypertension, diabetes, smoking, abnormal lipid metabolism, left atrial enlargement, carotid stenosis, etc., according to the scope of the study, the conclusions drawn It is also different.

Tanaka et al believe that coronary atherosclerosis is an important risk factor for asymptomatic cerebral infarction. As the coronary artery stenosis increases, the incidence of asymptomatic cerebral infarction increases. Feinberg et al believe that the age of the left atrium is greater than 5.0 cm. Valvular disease, atrial fibrillation patients with high incidence of asymptomatic cerebral infarction, Mounier-Vehier et al also believe that older than 65 years old and left atrial enlargement are independent risk factors for asymptomatic cerebral infarction, 16 medical centers of the US Department of Veterans Affairs Prospective studies confirm that age, history of hypertension, active angina, and elevated systolic blood pressure are risk factors for asymptomatic cerebral infarction.

Silent prevention of cerebral infarction

Asymptomatic cerebral infarction is a precursor to symptomatic cerebrovascular disease, or a risk factor for cerebrovascular disease. It needs to attract the same attention as cerebral infarction, and actively seek the cause of asymptomatic cerebral infarction. The focus of treatment is prevention and active search for cerebrovascular disease. Risk factors for the disease and control of risk factors.

Hypertensive patients

The systolic blood pressure is controlled below 21.33 kPa (160 mmHg), the diastolic blood pressure is controlled below 12 kPa (90 mmHg), and blood pressure should be gradually and gently controlled.

2. Hyperlipidemia patients

Blood lipids should be lowered and the diet controlled.

3. Diabetic patients

Control blood sugar levels at normal or normal slightly higher levels.

4. Heart disease patients

Targeted treatment, such as cardioembolic emboli, has been confirmed to be effective in preventing cerebral embolism.

5. Anti-platelet aggregation

The most commonly used is aspirin, in addition to dipyridamole (dipyridamole), ticlopidine, etc., ticlopidine can act on platelet membrane to reduce platelet aggregation induced by ADP and other substances, effective for both men and women However, about 5% of patients have serious side effects that need to be discontinued.

6. Patients with carotid stenosis

Carotid endarterectomy or internal carotid artery stent is feasible.

7. Change bad lifestyles

Quit smoking, avoid alcohol abuse, adjust the diet, promote proper sodium intake and adequate potassium-containing foods.

8. Sports activities

Increase physical activity and physical exercise as far as you can.

9. Keep your mood comfortable.

In addition, the elderly should pay attention to the signs of cerebrovascular disease, any discomfort or newly added symptoms, although there is no signs of nervous system positioning, it should also be highly valued, such as sudden dizziness, headache, limb numbness, weakness and weakness, Sudden dementia, or abnormal sleep, abnormal mood, brain tissue ischemia, hypoxia, etc., should be suspected of cerebrovascular disease, timely brain CT scan or brain MRI.

Asymptomatic cerebral infarction Complications, hypertension, diabetes

Because patients with asymptomatic cerebral infarction often have history of hypertension, diabetes, heart disease, etc., they often have clinical manifestations of primary disease, such as clinical manifestations of hypertension, clinical manifestations of diabetes, and clinical manifestations of heart disease.

Asymptomatic cerebral infarction symptoms Common symptoms Neuralgia "three-biased" sleep disorders vascular dementia dizziness dementia depression myocardial infarction pseudo-bulbaric paralysis

1. Common symptoms: Asymptomatic cerebral infarction is not a symptom. According to careful medical history, most patients are symptomatic, such as headache, dizziness, limb numbness, memory loss, sleep disturbance, head trauma, peripheral facial paralysis, Trigeminal neuralgia, mental disorders, or other symptoms and diseases, including headaches with high incidence of dizziness, whether these "symptoms" as a diagnostic clue or part of the basis, remains to be explored, but asymptomatic cerebral infarction can cause or exacerbate mental retardation, Multiple asymptomatic cerebral infarction can develop into multifocal infarction, and the clinical manifestations of multifocal infarction are mainly vascular dementia and/or pseudobulbaric palsy, so the study of asymptomatic cerebral infarction should be strengthened.

2. Depression performance: It is reported that depression is one of the main manifestations of asymptomatic cerebral infarction. It is generally considered that the infarct is small or located in the brain where the symptoms are not easy to be found, although asymptomatic cerebral infarction does not cause clear Neurological symptoms and signs, but may cause or aggravate depression or mental retardation, and it is reported that about 1/3 of patients with asymptomatic cerebral infarction have depression.

Infarction can occur in the cerebral cortex, subcortical, cerebellum and other parts of the infarction, which is related to the number of lacunar infarcts. Asymptomatic cerebral infarction is more common in multifocal infarction, and multifocal lacunar infarction The incidence of depression is significantly higher than that of single-infarction infarction. Multifocal and subcortical infarction can cause loss of white matter myelin, which destroys the neural connection of the emotional circuit of the limbic system, and ischemic necrosis can be directly or Indirectly leads to the synthesis and metabolism of neurotransmitters involved in emotional responses and information transmission disorders of neurotransmitters, such as norepinephrine, dopamine, serotonin, etc., which may be the anatomical and physiological basis of depression, in short, depression Emotion is one of the more common manifestations of asymptomatic cerebral infarction. Early is easy for clinicians to ignore, and with the increase of age and the course of hypertension, the incidence of depression increases, so for the elderly, especially with high blood pressure, Those with a history of diabetes and heart disease should pay attention to the occurrence of depressive symptoms and perform imaging examination if necessary.

3. Can develop into symptomatic cerebral infarction: asymptomatic cerebral infarction can exist alone, and there may be symptoms of cerebral infarction.

The incidence of asymptomatic cerebral infarction is reported in different literatures. Due to the lack of focal symptoms and signs of the nervous system, the clinical diagnosis rate is low. The asymptomatic cerebral infarction diagnosed by brain CT scan accounts for 10% of acute ischemic stroke. 38%; asymptomatic cerebral infarction diagnosed by brain MRI can be as high as 47%. As the age increases, the incidence of asymptomatic cerebral infarction increases, and the presence of asymptomatic cerebral infarction may cause symptomatic cerebral infarction. The condition is aggravated and the risk of recurrence of cerebral infarction is increased. Therefore, early diagnosis and active prevention are of great significance.

4. Clinical classification: According to the CT scan of the brain in asymptomatic cerebral infarction, some scholars divided the asymptomatic cerebral infarction into lacunar infarction, cortical infarction and borderline infarction.

It is generally believed that hypertensive microangiopathy is the main cause of lacunar infarction. Cortical infarction is mostly caused by cardiac abnormal emboli, while border infarction is related to systemic hypotension and hypovolemia. Liu et al. In asymptomatic cerebral infarction, lacunar infarction is the most common, and cortical infarction is second.

Therefore, any diagnosis of coronary heart disease, myocardial infarction, especially those with hypertension, if conditions permit, should do regular brain CT scan or brain MRI, which for early detection, actively treat asymptomatic cerebral infarction, prevent its evolution into Symptomatic cerebral infarction and vascular dementia or pseudobulbaric paralysis have important clinical implications.

Asymptomatic cerebral infarction

For patients with asymptomatic cerebral infarction should pay attention to find the cause, generally should be blood sugar, blood lipids, blood rheology examination.

1. Brain CT scan: Asymptomatic cerebral infarction may exist alone or in combination with symptomatic cerebrovascular disease, but the presence of asymptomatic cerebral infarction may aggravate the onset of symptomatic cerebral infarction and increase the recurrence of cerebral infarction. Dangerous, asymptomatic cerebral infarction brain CT scan is characterized by small infarct size, occurs in the subcortical white matter, lesions are limited to one cerebral lobe, single or multiple infarction, usually multiple, the literature reports that single lesions occur mostly on the right side The cerebral hemisphere, the non-dominant hemisphere, the infarct site of asymptomatic cerebral infarction is common in the basal ganglia and the internal sac, and can also be found in other parts. The lesion range is generally small, the diameter is less than 1.5cm, and the other lesions are larger under the cortex. In the quiet zone, focal signs and symptoms of the nervous system are often not found, and it is easy to be ignored by the clinic. Some patients have brain CT scans showing that fresh lesions and old lesions coexist, and lacunar infarction is more common. Some scholars have asymptomatic cerebral infarction. The CT findings of the brain were classified into lacunar infarction, cortical infarction and infarction in the border zone.

2. Brain MRI examination: For asymptomatic cerebral infarction, because the lesion is generally small, the clinical lack of focal symptoms and signs of the nervous system, brain MRI examination is superior to brain CT scan, infarct is mostly located in the basal ganglia and internal capsule , that is, next to the caudate nucleus, the lateral anterior horn of the lateral ventricle or the external side, the lateral side of the internal capsule, the globus pallidus, the internal capsule, the frontal lobe, the parietal lobe, the temporal lobe, the cerebellum, and the number of lesions may be a single lesion, Can be multiple lesions, according to brain MRI examination can be divided into the following 2 types: 1 lacunar infarction: the cause is mostly caused by hypertensive microangiopathy, the lesion diameter <1.5cm, the lesion is mostly located in the deep perforating blood supply area, often involving Basal nucleus and internal capsule, due to small lesion range, mild symptoms or no clinical symptoms, easy to be ignored, 2 non-chamber cerebral infarction: the cause is mostly caused by cardiac emboli, the lesion diameter is >1.5cm, the lesion often involves the brain The cortex is common in the frontal area and the occipital area. The lesion is mostly located in the parietal lobe or occipital lobe. Because it is located in the subcortical area, it is not close to the important structure, so it often lacks complaints, which is easily ignored by patients and physicians. Brain MRI examination Asymptomatic brain The diagnosis of brain death is better than CT scan, brain stem, cerebellar infarction can clearly and accurately found.

3. EEG topographic map or EEG: The abnormal rate of EEG topographic map of cerebral infarction is 80%93%, and the abnormal rate of EEG can reach 40%70%. EEG has high sensitivity to cortical ischemia. It may indicate impaired cortical function and localization to confirm early clinical diagnosis, guide treatment, acute brain tissue ischemia, edema, abnormal neuronal activity, so the positive rate of EEG topography is high, and after acute phase, diseased tissue The regression of edema and the establishment of collateral circulation and partial functional compensation make the abnormal rate of EEG topographic map decrease. Therefore, EEG topographic map has certain clinical application value for early diagnosis of asymptomatic cerebral infarction. EEG topographic map can be quantitatively located. The ground shows changes in brain function, so the positive rate of detection of asymptomatic cerebral infarction is higher than EEG, and can be diagnosed earlier than brain CT scan or brain MRI.

4. Fundus examination: There are many manifestations of retinal atherosclerosis, that is, the arterial lumen becomes thinner, the reflection of the arterial wall is enhanced, and the reflective band is widened, which can be expressed as a copper wire-like change. In severe cases, the artery is stiff and silvery. Change and present the arterial white sheath. There are two white lines on both sides of the retinal arterial blood column called the vascular white sheath, which is also a manifestation of the decrease of the transparency of the blood vessel wall. The white blood sheath of the blood vessel occurs at the intersection of the artery and the vein below the secondary blood vessel, and is also an artery. The manifestation of sclerosis, arteriovenous cross-indentation, veins can be pressed like a pen tip, and severe veins are interrupted or misplaced by compression.

5. Other examinations: According to the patient's condition, the corresponding examination can be selectively performed, such as DSA, brain MRA, transcranial Doppler ultrasonography, the main purpose is to find the cause of vascular disease of cerebrovascular disease, transcranial Doppler ultrasound Check the price is cheap, convenient, can find large vascular abnormalities early, brain MRA examination is simple and convenient, can rule out vascular lesions of larger arteries, help to understand the location and extent of vascular occlusion, DSA can find smaller vascular lesions, and can Timely application of interventional therapy.

Diagnosis and diagnosis of asymptomatic cerebral

diagnosis

The diagnosis of asymptomatic cerebral infarction mainly depends on brain CT scan, brain MRI and other imaging examinations. The first brain CT scan or brain MRI examination can detect lacunar infarction or periventricular white matter lesions. The CT scan rate is 10% to 38%. MRI can reach 47%, the main lesion is under the cortex, and in the vicinity of the basal ganglia, the general lesion range is small, 0.5 ~ 1.5cm, most asymptomatic cerebral infarction is a single infarct (80%).

Differential diagnosis

Mainly associated with transient ischemic attack, multiple sclerosis, lacunar infarction, depression, brain tumors, etc.

1. Transient ischemic attack: different from asymptomatic cerebral infarction, that is, there are signs of transient nervous system localization, brain CT scan or brain MRI without lesions, transient ischemic attack refers to the transient with focal symptoms The cerebral blood circulation disorder is characterized by recurrent episodes of transient aphasia, delirium or sensory disturbances. The onset is sudden, symptoms and signs last for several minutes to several hours, most of them recover completely within 24 hours, and most patients have symptoms gradually after repeated episodes. Exacerbation, if not effectively treated, often develops into complete cerebrovascular disease.

2. Multiple sclerosis: This disease is different from asymptomatic cerebral infarction. This disease occurs mostly in young, young, common in women, complicated in clinical manifestations, and widely distributed in neurological function. The main clinical features are multiple parts and time. The course of the disease is prolonged, irregular, and often characterized by remission and recurrence. A few patients with progressive exacerbations after onset, the lesion is mainly the central nervous system, and the lesion is multiple, often with brain, cerebellum, brainstem, and spinal cord. Symptoms and signs of lesion damage occurring in two or more different periods of optic nerve, etc., are multifocal inflammatory demyelinating plaques coexisting with new and old lesions. Brain CT scans are seen in white matter, optic nerve, brainstem and cerebellum. Low-density plaques, except for the acute phase, were enhanced without enhancement. Brain MRI showed T1 weighted low signal, T2 weighted high signal, and asymptomatic cerebral infarction more common in the elderly, with a history of hypertension, brain CT scan found Infarcts in the deep perforating area of the cerebral blood vessels.

3. Lacunar infarction: It is also a cerebrovascular disease that seriously harms the health of middle-aged and elderly people. At present, it mainly relies on brain CT scan and brain MRI to confirm the diagnosis. Lacunar infarction refers to the diameter of the lesion below 15~20mm. Fresh or old deep brain infarction, after occlusion of these small arteries, can cause multiple brain softening lesions of different sizes, which are later removed by macrophages leaving irregular large and small cavities due to infarction Different blood vessels, often showing different neurological symptoms, the most common clinical symptoms are headache, dizziness, insomnia, forgetfulness, limb numbness, movement disorder, difficulty in pronunciation - clumsy syndrome, severe dementia, hemiplegia, aphasia, etc. For many patients with lacunar infarction, no signs of focal signs, or no symptoms at all, should be asymptomatic cerebral infarction.

4. Depression: Depression has clear clinical manifestations and depressive personality, brain CT scan, normal brain MRI, and antidepressant treatment.

5. Brain tumors: The main symptoms of brain tumors are increased intracranial pressure and signs of nervous system localization. Increased intracranial pressure can lead to clinical syndrome characterized by headache, vomiting, optic disc edema, and headache caused by increased intracranial pressure. It is often characterized by persistent headache and increased paroxysmalness. For patients with early brain tumors, there may be no clear signs of nervous system localization. Therefore, brain CT scan and even brain MRI examination are important for definite diagnosis. If necessary, strengthen brain CT scan or enhanced brain MRI, while asymptomatic cerebral infarction is more common in the elderly, generally does not cause increased intracranial pressure and signs of nervous system localization.

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