Normal intracranial pressure is a prerequisite for ensuring adequate blood supply to the brain, and, accordingly, its functional activity. There are three most common causes of incremental pressure.
Content
Internal pressure on intracranial pressure
Brain fabric is very gentle and sensitive to various mechanical impacts that occur under the action of environmental factors. It is in order to save this gentle substance of the wise nature and placed the human brain into a protective liquid medium (subarachnoid liquid spaces) and supplied it with internal liquid cavities (ventricles). Thus, the brain is actually weighed in a special liquid - liquor (it is also a cerebrospinal fluid). Likvor is in the skull cavity under certain pressure. It is the pressure of the lycvore on the brain and is called intracranial pressure.
Intracranial pressure - pressure in the skull cavity (in venous sinus of the brain, brain ventricles, in epidural and subarachnoid spaces), created by dynamic equilibrium volumetric blood flow, cerebrospinal fluid and brain tissue.
Normal intracranial pressure - a necessary condition for ensuring adequate blood supply to the brain, its metabolism and functional activity. Intracranial pressure is ensured by complex pressure regulation mechanisms, tone of brain vessels, volumetric cerebral blood flow, product speed and destruction of cerebrospinal fluid and.D.
Normal is the level of intracranial pressure in the range from 7.5 to 15 mm RT. Art. (from 1 to 2 kPa). In physiological conditions, a change in one of the factors affecting the maintenance of intracranial pressure determines the inclusion of compensatory mechanisms aimed at its normalization, for example, a decrease and increase of average systemic blood pressure in the range of 60 to 150 mm. RT. Art. (from 8 to 20 kPa) causes a rapid expansion or narrowing of the vessels of the brain, as a result of which there is no significant change in bulk brain blood flow and intracranial pressure.
The normal level of intracranial pressure is very important for human well-being, so neuropathologists pay great attention to the inspection and normalization of intracranial pressure in patients with neurological problems.
The relationship between the total volume of tissues and liquid media in the skull cavity and pressure is non-linear, since an increase to certain limits of one of the volumes (for example, the volume of brain tissue due to edema) is accompanied by simultaneous decrease in the volume of cerebrospinal fluid due to a compensatory reduction of its products or an increase in resorption. Intracranial pressure at the same time can remain within normal quantities. In the exhaustion of compensatory mechanisms, even a slight increase in intracranial volume can lead to a significant rise in intracranial pressure.
Causes of increasing intracranial pressure
All liquid spaces and ventricles are interconnected by ducts. Likvor is constantly circulating. In some sections of the brain, it stands out, and then flows through the liquor ducts to other brain departments, where it is absorbed into the bloodstream. Full renewal of the liquor occurs on average 7 times a day.
Excessive cluster of the liquor causes an increase in its pressure on the brain substance. This is called an increase in intracranial pressure (intracranial hypertension).
Three frequent causes of chronic increase in intracranial pressure:
- Likvora allocated too much
- Likvor is not fully absorbed
- Violated the passability of liquor circulation paths
Any of these reasons can be a consequence:
- transferred to the brain injury (even very long, right up to the generic injury)
- meningitis or encephalitis
- Congenital features of the structure of the central nervous system (anomalia of Arnold-Kiaari, idiopathic intracranial hypertension, etc.)
- Violation of the outflow of venous blood from the skull cavity
- Hypoxia (oxygen starvation)
- Strong poisoning
If intracranial pressure is increased significantly and long in time, liquid brain cavities can expand, this expansion is called hydrocephalus. Since the skull cavity is a closed space, the expansion of the liquid cerebral cavities occurs due to the reduction of the mass of the brainstant. It is clear that this process can negatively affect health.
