What Is Hypertensive Encephalopathy?

Hypertensive encephalopathy means that when the blood pressure suddenly rises above the threshold for automatic adjustment of cerebral blood flow (central arterial pressure is greater than 140 mmHg), cerebral blood flow is hyperperfused, capillary pressure is too high, and permeability increases, leading to cerebral edema and intracranial Increased pressure, and even the formation of a hernia, cause a series of temporary cerebral circulation dysfunction.

Basic Information

English name

hypertensive encephalophy

Visiting department

Cardiology

Multiple groups

Patients with hypertension

Common causes

Hypertension with renal failure, hypertension during pregnancy, glomerulonephritis hypertension, etc.

Common symptoms

Severe headache, jet vomiting, restlessness, excitement, seizures, paroxysmal dyspnea, pain, etc.

Causes of Hypertensive Encephalopathy

Essential hypertension

Hypertensive encephalopathy occurs in about 1% of patients with essential hypertension, has a long history of hypertension, and is more likely to occur in patients with significant cerebrovascular sclerosis. Previously normal blood pressure and sudden hypertension, such as: patients with rapid hypertension and acute glomerulonephritis can also occur. Hypertensive patients with renal failure are also prone to hypertensive encephalopathy.

2. Secondary hypertension

Such as hypertension during pregnancy, glomerulonephritis, hypertension, renal artery stenosis, pheochromocytoma and other secondary hypertension are prone to hypertensive encephalopathy.

3. Certain drugs or foods induce hypertensive encephalopathy

Rarely, patients with hypertension who are taking monoamine oxidase inhibitors while taking rapam, methyldopa or post-node sympathetic nerve inhibitors can also cause symptoms similar to those of hypertensive encephalopathy. Eating amine-rich foods can also induce hypertensive encephalopathy.

4. After carotid endarterectomy

After carotid endarterectomy in patients with high carotid stenosis, sudden increase in cerebral perfusion can also cause hypertensive encephalopathy.

Clinical manifestations of hypertensive encephalopathy

Sudden onset, the condition develops very quickly.

1. Age of onset is related to etiology

Acute glomerulonephritis is more common in children, eclampsia is more common in young women, and cerebral arteriosclerosis is more common in elderly patients.

2. Increased arterial pressure

Depends on the degree and speed of the increase in blood pressure. It often occurs with aggressive hypertension and severe progressive hypertension. The latter is generally severe, and the blood pressure is significantly increased. It occurs only when the blood pressure reaches 250 / 150mmHg, and it can also occur in patients with acute hypertension who do not reach 200 / 130mmHg Hypertensive encephalopathy.

3. Increased intracranial pressure

Caused by cerebral edema. The patient had severe headache, jet vomiting, stiff neck, edema of the optic papilla, retinal arterial spasm with flame-like bleeding and arterial spasm, and villous exudate.

4. Disorder of consciousness

It can manifest as irritability, excitement, apathetic expression, stiffness, lethargy, and coma, as well as insanity.

5. Seizures

May be systemic localized seizures, and some continuous states of epilepsy.

6. Paroxysmal dyspnea

Caused by respiratory vasospasm, ischemia and acidosis.

7. Other symptoms of brain dysfunction

Such as aphasia, hemiplegia, hemianopia, blackness, temporary blindness, etc., about 32% of patients will have blurred vision. Renal insufficiency occurs in more than 50% of patients.

8. headache

It is often the early symptoms of hypertensive encephalopathy, which occurs in about 70% of patients. Most of them are headache or pain on the forehead, obvious headache when coughing and exertion, accompanied by nausea and vomiting. Headaches can be relieved when blood pressure drops.

9. Main symptoms of cerebral edema

Most patients have the three characteristics of headache, convulsions, and disturbance of consciousness, which is called the triad of hypertensive encephalopathy.

Hypertensive Encephalopathy Examination

Examination should be focused, that is, after considering the most probable disease or diseases based on the questionnaire materials, first check to confirm or deny some diagnosis as soon as possible. After the cause of the headache is clear, sometimes further examination is needed. The inspection methods are:

Fundus examination

Can be seen in different degrees of hypertensive fundus, retinal arterial spasm, sclerosis and even retina hemorrhage, exudate and papillary edema.

2.CT inspection

Mainly manifested as local or diffuse white matter edema, involving gray matter is rare, and may have a space effect. It can also range from negative, reversible posterior white matter edema to diffuse cerebral edema or even with bleeding and cerebral hernia.

3. EEG

If a diffuse slow wave appears, the brain tissue is edema.

4. Cerebrospinal fluid examination

Increased cerebrospinal fluid pressure (prohibited when the diagnosis is clear) and increased cell and protein content.

Hypertensive Encephalopathy Diagnosis

According to the symptoms of sudden and sudden increase of blood pressure and intracranial pressure in patients with hypertension, it should be considered when the following conditions are met:

1. Patients with hypertension suddenly have a rapid rise in blood pressure, with diastolic blood pressure greater than 120 mmHg as an important feature.

2. Clinical manifestations of neuropsychiatric abnormalities mainly with increased intracranial pressure and limited brain tissue damage: sudden and severe headache, often accompanied by vomiting, darkening, convulsions, and disturbance of consciousness, generally with a significant increase in blood pressure It occurred within 12 to 48 hours.

3. After the patient's emergency antihypertensive treatment, the symptoms and signs decreased with the blood pressure, which was significantly reduced or disappeared within a few hours without leaving any sequelae of brain parenchymal damage.

Differential diagnosis of hypertensive encephalopathy

If the blood pressure drops after treatment, and the brain symptoms and signs do not disappear for several days, it indicates that other diseases in the brain may exist and need to be distinguished from other acute cerebrovascular diseases.

1. bleeding or ischemic stroke

More common in middle-aged and elderly patients, blood pressure may not be high, headache symptoms may not be obvious, but there are symptoms and signs of intracranial localization, skull CT or MRI have clear lesions, EEG has signs of limited brain parenchymal damage.

2. Subarachnoid hemorrhage

Like hypertensive encephalopathy, there may also be sudden severe headache and vomiting meningeal irritation.Some patients may also have increased blood pressure. The consciousness disorder is usually mild, hemiplegia is rare, and the cerebrospinal fluid is homogeneous.It can be related to hypertension. Identification.

3. Intracranial space-occupying lesions

Although there is a severe headache, it is a slow-onset, non-abrupt occurrence. Other symptoms of increased intracranial pressure and focal neurological signs are also progressive. Although the blood pressure can be increased, it is not significantly higher than that of hypertensive encephalopathy. Cerebral angiography or CT to confirm the diagnosis.

Hypertensive Encephalopathy Treatment

Treatment principle: Patients should enter the intensive care unit, continuously monitor blood pressure and apply appropriate antihypertensive drugs as soon as possible. There is a need to alleviate the disease in the short term, improve the progressive damage to target organs, and reduce cardiovascular events and mortality. Intravenous infusion of antihypertensive drugs is often required, which can quickly reduce blood pressure to a safe level, but not excessively or too quickly, to avoid local or systemic hypoperfusion (especially renal, brain or coronary ischemia). The detailed treatment method can refer to the hypertension crisis.

Antihypertensive goal: to reduce blood pressure while ensuring cerebral blood flow perfusion, avoid using drugs that reduce cerebral blood flow. Generally, intravenous administration is the main method. The systolic blood pressure is reduced by 20% to 25% within one hour. The blood pressure drop cannot exceed 50%. The diastolic blood pressure is generally not less than 110mmHg. The selected drugs can be uradiadil, nicardipine, labelol, sodium nitroprusside, and the diastolic blood pressure can be changed to oral drugs after the diastolic blood pressure drops to 95-110 mmHg.

1. The following measures can be used to quickly lower blood pressure

(1) Ulladil Add 50ml of normal saline, and maintain the intravenous pump for 6-12 hours, or intravenous drip.

(2) Nicardipine is added with 50 ml of normal saline, and the intravenous pump is maintained for 6 to 12 hours, or intravenous drip.

(2) Labetolol Intravenous or intravenous drip.

(3) Intramuscular injection of 25% magnesium sulfate into deep muscle or slow intravenous injection after dilution with 20ml of 5% glucose. (Mostly used in patients with hypertension during pregnancy).

(4) Sodium nitroprusside is added to 500ml of 5% glucose solution, and it is dripped slowly and slowly. (Currently less clinical use).

(5) Reserpine intramuscular injection 1 to 2 times per day, this medicine has a slow and stable onset of action, and is suitable for maintaining blood pressure after rapid blood pressure reduction. (Currently less clinical use).

(6) Intramuscular injection or intravenous injection of phentolamine, or intravenous drip after dilution. (Currently less clinical use).

2. Recovery period can be changed to oral drugs.

3. Reduce intracranial pressure and eliminate brain edema

Furosemide and mannitol reduce intracranial pressure.

4. Stop convulsions

Diazepam or phenobarbital sodium.

5. Control epilepsy.

6. Etiology treatment

After the symptoms are controlled, dialysis treatment is feasible for those with renal failure, and labor should be induced for those with toxemia during pregnancy. Pay attention to screening patients for secondary hypertension.

Hypertensive Encephalopathy Prevention

Hypertensive encephalopathy is a very dangerous disease. Brain damage is the most prominent and must be rescued in time. Those with high blood pressure who have a sharp rise in blood pressure with severe headaches, and even those with altered consciousness and consciousness, should immediately go to the hospital for emergency treatment. The key to treatment is to quickly control blood pressure in a safe range and prevent or reduce brain tissue edema and damage. In addition, during the treatment process, excessive reduction of blood pressure should be avoided to prevent the blood perfusion of the brain, heart, and kidney. Systemic treatment of hypertension and primary disease, avoiding overwork and mental stimulation will help reduce the incidence of hypertensive encephalopathy. After the condition is stable, it should gradually transition to conventional antihypertensive treatment and adhere to long-term and regular treatment.

In addition, in patients with hypertension, especially intractable hypertension, attention should be paid to screening for secondary hypertension, and early diagnosis and treatment should be strengthened. At the same time, education for hypertension patients should be strengthened, blood pressure management models should be improved, and the treatment rate and control of hypertension should be improved. The rate is also the key to the prevention and treatment of hypertensive encephalopathy.