Intracranial hypertension

Intracranial hypertension

    * Introduction
    * Clinical
    * Diagnostic Laboratory
    * Complications
    * Treatment
Intracranial hypertension occurs as a result of an imbalance between the anatomic and physiologic cranial and skull contents. Intracranial hypertension syndrome is characterized by frontal or occipital headache, eye disorders (diplopia, papilledema), vomiting and general feeling of discomfort. Intracranial hypertension is caused by a variety of causes: cerebral edema, the accumulation of cerebrospinal fluid in the skull, the cerebral vessels in hypertension, intracranial expansive processes (tumor, hematoma, abscess), strokes, infections (meningitis, encephalitis), hydrocephalus.
Contents skull is the brain with its layers, cerebrospinal fluid and meningo-cerebral vessels. Because the skull walls are not flexible, any change in volume of one of the components of content leads to increased intracranial pressure. Skull capacity is about 1350-1480 cm3.
Mean intracranial pressure is 110ml water column or 7 mmHg, with limits ranging between 80 and 150 ml water column or 2-12 mmHg. The full capacity of the skull, occupy 90% of brain volume. Intracranial cerebrospinal fluid quantity at any time is approximately 150 ml, being distributed in the brain ventricles, basal cisterns and subarachnoid space.
Cerebrospinal fluid is continuously secreted from the choroid plexus, it renews itself continuously being reabsorbed by vessels meningeene and Pacchioni granulations. This fluid acts as a protection against mechanical shocks, the role of nutrition and metabolic exchanges in the central nervous tissue. Cerebrospinal fluid circulation is as follows: secreted by the choroid plexus, it floods the lateral ventricles, third ventricle passes then, how goes the IV ventricle through the aqueduct of Silvius. The fourth ventricle, CSF passes through the holes of Magendie and Luschka in the basal cistern, cistern magna and subarachnoid space, where it is reabsorbed into general circulation through blood vessels and granulations Pacchioni meningeene.
Increased intracranial pressure over 200 ml water column indicate an alarm situation, and an increase in pressure above 400 ml column of water can endanger the patient's life by decreasing cerebral perfusion (intracranial pressure equalizes the blood pressure of the skull) and the compression of nerve brainstem level.
There are multiple causes of intracranial hypertension. Sistematizandu them, one can identify the following causes: - Birth defects: cranio-facial malformations such as craniostenozele or Crouzon's disease, malformations craniospinale as Arnold-Chiari malformation or Dandy-Walker syndrome. - Cranio-cerebral tumors, benign or malignant, both the primary and most metastatic. - Cranio-cerebral injuries such as fractures, clogging, intracranial subdural hematoma, epidural or intraparenchimatoase, cranio-cerebral wounds. - Parasitoses brain, including cysticercosis and hydatid cyst. - Vascular malformations, intracranial aneurysms that, primary intracranial hematoma. - Inflammatory diseases: brain abscess, tuberculomul cerebral gumma, inflammatory disease of viral etiology and evolution pseudotumoral. In patients infected with HIV clinical manifestations, most shows cerebral vascular lesions. - Allergies, poisoning, spinal compressions, which interfere with drainage of cerebrospinal fluid.
Pathological lesions in the brain that occur following an increase in intracranial pressure are ischemic in nature. Increased intracranial pressure in three ways: by the presence of a pathological process of replacement space (tumor, hematoma), the presence of a pathological process that causes the increase in volume of brain parenchyma (cerebral edema) and by increasing the amount of intracranial cerebrospinal fluid (by hypersecretion or by blocking the drainage). Any intracranial expansive process interferes with normal drainage of cerebrospinal fluid. It accumulates in the skull and result in increased pressure. While cerebrospinal fluid pressure does not exceed the pressure infusion, the patient's life is in danger. But if it equates to or exceeds, signs of cerebral ischaemia with poor prognosis. When cerebral perfusion pressure is below 20-30 mmHg, ischemic nerve cells are affected. Children develop slowly because of the elasticity of intracranial hypertension, especially in the skull bone sutures.