- Reasons of hypertensive encephalopathy
- Symptoms of hypertensive encephalopathy
- Treatment of hypertensive encephalopathy
Hypertensive encephalopathy is the neurologic dysfunction induced by malignant hypertensia. The term "hypertensive encephalopathy" was entered into use by Oppenheimer and Fishberg in 1928 to describe this specific type of encephalopathy.
This term (acute hypertensive encephalopathy) describes disorder of a brain (usually reverse) which is caused sudden and became the expressed increase in arterial pressure. Hypertensive encephalopathy meets at an eclampsia, acute nephrite and hypertensive crisis. Symptoms of hypertensive encephalopathy include: head pain, uneasiness, nausea, disturbance of consciousness, spasm, retinal apoplexy and papilledema. Damages of a brain can be connected with specific neurologic symptoms which consequence of influence the coma can be. Dysfunction is treated by means of the drugs reducing arterial pressure.
Reasons of hypertensive encephalopathy:
Hypertensive encephalopathy is caused by the increased blood pressure. Such sharp and long increase in arterial pressure can be caused by the following frustration: acute nephrite, eclampsia, hypertensive crisis, sharp termination of anti-hypertensive therapy. Besides, hypertensive encephalopathy can arise at a pheochromocytoma, Cushing's syndrome, fibrinferment of a renal artery.
The question that is the cornerstone of hypertensive encephalopathy disturbance of cerebral circulation remains disputable for today. As a rule, the brain blood stream is supported by the self-control mechanism which expands arteries in response to pressure decrease and leads to narrowing of arteries in response to increase in the ABP.
These autoregulyatsionny fluctuations at a hypertension become excessive. Because of such excessive regulation in response to an acute hypertension, there is a brain vasospasm that leads to ischemia of a brain and emergence of cytotoxic hypostases.
At disturbance of an autoregulyation, cerebral arterioles are forced to extend that leads to vazogenny wet brain.
Wet brain can be generalized or coordination. Cerebral cavities at the same time – contract, and cortical crinkles сплюскиваються.
Symptoms of hypertensive encephalopathy:
Hypertensive encephalopathy (acute) meets at the young people and middle-aged persons having arterial hypertension more often. Generally, this disease occurs very seldom, even at patients with hypertensia. Different doctors report that at 0,5-15% of patients with a malignant hypertension acute hypertensive encephalopathy develops.
With development of diagnostic methods and treatments of arterial hypertension, hypertensive encephalopathy began to arise more and more seldom.
Symptoms of hypertensive encephalopathy usually arise in 12-48 hours after sudden and long increase in arterial pressure. The first manifestation of these symptoms is the severe headache. It arises more than at 75% of patients. Besides, the patient becomes uneasy. In several hours the person can have disturbances of judgments and memory, confusion of consciousness, drowsiness and a sopor (deep oppression of consciousness with loss any and safety of reflex activity). If this frustration not to treat, then the above-stated neurologic symptoms can worsen and finally lead to a coma.
Treat other symptoms of hypertensive encephalopathy: acrimony, vomiting, spasms, convulsions and myoclonus of extremities. Extended among patients there are also problems with sight, especially, such as: vague image, defects of a field of vision, daltonism, cortical blindness (total or partial loss of sight). Such disturbances meet in 4 of 11 cases (Jelinek and other. 1964). The hemiparesis and aphasia are also possible, however they are less widespread. Elektroentsefalograficheskoye of a research, as a rule, shows lack of alpha waves that means consciousness disturbance. Patients with vision disorders, in occipital area have slow waves.
Treatment of hypertensive encephalopathy:
Acute cases of hypertensive encephalopathy demand urgent treatment which is performed preferential in intensive care units where the vital functions and elektroentsefalografichesky characteristics can be monitored. The first stage of treatment of such encephalopathy is – decrease in the ABP by means of medicines. At the same time it is necessary to remember that decrease in the ABP is controlled to prevent emergence of damages of vessels through their excessive reduction. The excessive sharp lowering of arterial pressure can lead to a heart attack of a brain, a blindness and cardiac ischemia.
Administration of diazoxide is effective for 80% of patients with hypertensive encephalopathy. This drug normalizes blood pressure within 3-5 min., and works within 6-18 hours. One of advantages of diazoxide is that it does not cause drowsiness, i.e. does not influence a condition of consciousness of the patient. The reflex tachycardia caused by this drug is its main shortcoming which does not allow to use it for treatment of patients with coronary heart disease. Furosemide is entered along with diazoxide to increase both anti-hypertensive effect, and its duration.
Gidralazin also enter intravenously or intramusculary for a lowering of arterial pressure. Its action similar to diazoxide, but it is less resistant.
Other drug used for a lowering of arterial pressure is Sodium nitroprussidum which is entered into an organism by intravenous injection.
For lowering of blood pressure at patients with hypertensive encephalopathy nitroglycerine is sometimes used.
Other class of the drugs used for a lowering of arterial pressure at hypertensive encephalopathy are ganglioblokator to which carry: лабеталол, пентолиниум (pentolinium), phentolamine and триметафан. These agents give bystry effect and do not cause drowsiness. However they can lead to emergence of serious side effects, such as an atony of intestines and bladder. These drugs, except for a labetalol, are not used if the hypertensive encephalopathy connected with a gestational eclampsia these drugs can do harm to a fruit.
Reserpinum, Methyldopum and the clonidine is applied much less often at extreme cases of a hypertension, they work much more slowly (effect of drug begins in 2-3 h after reception) and, besides they influence consciousness of the patient.
Oral anti-hypertensive drugs are accepted after at the patient the first heavy symptoms of frustration disappear and intravenous injections become not necessary.
Except anti-hypertensive drugs to patients with spasms anticonvulsant drugs, such as Phenytoinum are, as a rule, appointed. However, as a rule, anti-hypertensive drugs are, quite, enough for treatment of neurologic symptoms.