Intracranial hypertension is a syndrome of increased intracranial pressure. It can be idiopathic or develop with various brain lesions. The clinical picture consists of headache with pressure on the eyes, nausea and vomiting, sometimes — transient visual disturbances; in severe cases, there is a violation of consciousness. The diagnosis is made taking into account clinical data, the results of Echo-EG, tomographic studies, analysis of cerebrospinal fluid, intraventricular monitoring of ICP, cerebral vascular ultrasound. Treatment includes diuretics, etiotropic and symptomatic therapy. According to the indications, neurosurgical operations are performed.
G93.2 Benign intracranial hypertension
Intracranial hypertension is a syndromological diagnosis, often found in both adult and pediatric neurology. We are talking about an increase in intracranial (intracranial) pressure. Since the level of the latter directly affects the pressure in the cerebrospinal fluid system, intracranial hypertension is also called cerebrospinal hypertension syndrome or cerebrospinal hypertension syndrome. In most cases, intracranial hypertension is secondary and develops as a result of head injuries or various pathological processes inside the skull.
Primary, idiopathic, intracranial hypertension, classified according to ICD 10 as benign, is also widespread. It is a diagnosis of exclusion, i.e. it is established only after all other causes of increased intracranial pressure have not been confirmed. In addition, acute and chronic intracranial hypertension are isolated. The first, as a rule, accompanies traumatic brain injuries and infectious processes, the second – vascular disorders, slow—growing intracerebral tumors, brain cysts. Chronic intracranial hypertension is often a residual consequence of acute intracranial processes (injuries, infections, strokes, toxic encephalopathies), as well as brain surgery.
Causes and pathogenesis
The increase in intracranial pressure can be due to a number of reasons, which can be divided into 4 main groups. The first is the presence of a volume formation in the cranial cavity (primary or metastatic brain tumor, cysts, hematomas, cerebral vascular aneurysms, brain abscess). The second is cerebral edema of a diffuse or local nature, which develops against the background of encephalitis, brain injury, hypoxia, hepatic encephalopathy, ischemic stroke, toxic lesions. Edema not of the brain tissues themselves, but of the cerebral membranes in meningitis and arachnoiditis also leads to cerebrospinal hypertension.
The next group is the causes of vascular nature, causing increased blood filling of the brain. Excessive volume of blood inside the skull may be associated with an increase in its inflow (with hyperthermia, hypercapnia) or difficulty in its outflow from the cranial cavity (with dyscirculatory encephalopathy with impaired venous outflow). The fourth group of causes are cerebrospinal fluid disorders, which in turn are caused by an increase in cerebrospinal fluid production, a violation of cerebrospinal fluid circulation or a decrease in the absorption of cerebrospinal fluid (cerebrospinal fluid). In such cases, we are talking about hydrocephalus — excessive accumulation of fluid in the skull.
The causes of benign intracranial hypertension are not entirely clear. It develops more often in women and in many cases is associated with weight gain. In this regard, there is an assumption about the essential role of endocrine rearrangement of the body in its formation. Experience has shown that the development of idiopathic intracranial hypertension can be caused by excessive intake of vitamin A into the body, the intake of certain pharmaceuticals, the withdrawal of corticosteroids after a long period of their use.
Since the cranial cavity is a limited space, any increase in the size of the structures located in it entails an increase in intracranial pressure. The result is a pronounced compression of the brain to varying degrees, leading to dysmetabolic changes in its neurons. A significant increase in intracranial pressure is dangerous by displacement of cerebral structures (dislocation syndrome) with the insertion of the tonsils of the cerebellum into the large occipital foramen. At the same time, compression of the brain stem occurs, entailing a disorder of vital functions, since the respiratory and cardiovascular nerve centers are localized in the trunk.
In children, the etiofactors of intracranial hypertension can be abnormalities of brain development (microcephaly, congenital hydrocephalus, arteriovenous malformations of the brain), intracranial birth trauma, intrauterine infection, fetal hypoxia, asphyxia of the newborn. In younger childhood, the bones of the skull are softer, and the seams between them are elastic and malleable. Such features contribute to significant compensation of intracranial hypertension, which sometimes ensures its long subclinical course.
Intracranial hypertension symptoms
The main clinical substrate of the cerebrospinal hypertension syndrome is headache. Acute intracranial hypertension is accompanied by an increasing intense headache, chronic — periodically intensifying or constant. The localization of pain in the frontal-parietal areas, its symmetry and the accompanying feeling of pressure on the eyeballs are characteristic. In some cases, patients describe the headache as “bursting”, “pressing on the eyes from the inside”. Often, along with a headache, there is a feeling of nausea, soreness with eye movements. With a significant increase in intracranial pressure, nausea with vomiting is possible.
Rapidly increasing acute intracranial hypertension, as a rule, leads to severe disorders of consciousness up to coma. Chronic intracranial hypertension usually leads to a deterioration in the general condition of the patient — irritability, sleep disorders, mental and physical fatigue, increased weather sensitivity. It can occur with cerebrospinal hypertension crises – sharp rises in intracranial pressure, clinically manifested by severe headache, nausea and vomiting, sometimes short—term loss of consciousness.
Idiopathic cerebrospinal hypertension in most cases is accompanied by transient visual disturbances in the form of blurring, deterioration of image sharpness, double vision. A decrease in visual acuity is observed in about 30% of patients. Secondary intracranial hypertension is accompanied by symptoms of the underlying disease (general infectious, intoxication, cerebral, focal).
Cerebrospinal hypertension in children under one year manifests itself by a change in behavior (anxiety, tearfulness, capriciousness, rejection of the breast), frequent regurgitation “fountain”, oculomotor disorders, swelling of the fontanel. Chronic intracranial hypertension in children can cause mental retardation with the formation of oligophrenia.
Establishing the fact of an increase in intracranial pressure and assessing its degree is not an easy task for a neurologist. The fact is that intracranial pressure (ICP) fluctuates significantly, and clinicians still do not have a consensus on its norm. It is believed that the normal ICP of an adult in a horizontal position is in the range from 70 to 220 mm of water. In addition, there is not yet a simple and affordable way to accurately measure ICP. Echo-encephalography allows us to obtain only approximate data, the correct interpretation of which is possible only when compared with the clinical picture. An increase in ICP may be indicated by swelling of the optic nerves, detected by an ophthalmologist during ophthalmoscopy. With the long-term existence of cerebrospinal hypertension syndrome, so-called “finger depressions” are detected on the X-ray of the skull; children may experience a change in shape and thinning of the cranial bones.
Only direct insertion of a needle into the cerebrospinal space by means of a lumbar puncture or puncture of the ventricles of the brain can reliably determine intracranial pressure. Currently, electronic sensors have been developed, but their intraventricular injection is still quite an invasive procedure and requires the creation of a trepanation hole in the skull. Therefore, such equipment is used only by neurosurgical departments. In severe cases of intracranial hypertension and during neurosurgical interventions, it allows monitoring of ICP. In order to diagnose causal pathology, CT, MSCT and MRI of the brain, neurosonography through the fontanel, ultrasound of the vessels of the head, examination of cerebrospinal fluid, stereotactic biopsy of intracerebral tumors are used.
Conservative therapy of cerebrospinal hypertension is carried out with its residual or chronic nature without marked progression, in acute cases — with a slow increase in ICP, lack of data for dislocation syndrome and serious disorders of consciousness. The basis of treatment is diuretic pharmaceuticals. The choice of the drug is dictated by the level of ICP. In acute and severe cases, mannitol and other osmodiuretics are used, in other situations, furosemide, spironolactone, acetazolamide, hydrochlorothiazide are the drugs of choice. Most diuretics should be used against the background of the administration of potassium preparations (potassium asparaginate, potassium chloride).
In parallel, the treatment of causal pathology is carried out. With infectious and inflammatory brain lesions, etiotropic therapy (antiviral drugs, antibiotics) is prescribed, with toxic – detoxification, with vascular — vasoactive therapy (aminophylline, vinpocetine, nifedipine), with venous stagnation — venotonics (dihydroergocristine, horse chestnut extract, diosmin + hesperidin), etc. To maintain the functioning of nerve cells in conditions of intracranial hypertension, neurometabolic agents (gamma-aminobutyric acid, piracetam, glycine, pig brain hydrolysate, etc.) are used in complex therapy. Cranial manual therapy can be used to improve venous outflow. In the acute period, the patient should avoid emotional overload, exclude working at the computer and listening to audio recordings with headphones, sharply limit watching movies and reading books, as well as other activities with a strain on vision.
Surgical treatment of intracranial hypertension is applied urgently and planned. In the first case, the goal is to urgently reduce ICP in order to avoid the development of dislocation syndrome. In such situations, neurosurgeons often perform decompression trepanation of the skull, according to indications — external ventricular drainage. Planned intervention is aimed at eliminating the cause of the increase in ICP. It may consist in the removal of an intracranial volume formation, correction of a congenital anomaly, elimination of hydrocephalus with the help of cerebral bypass surgery (cystoperitoneal, ventriculoperitoneal).
Prognosis and prevention
The outcome of the cerebrospinal hypertension syndrome depends on the underlying pathology, the rate of increase in ICP, the timeliness of therapy, compensatory abilities of the brain. With the development of dislocation syndrome, a fatal outcome is possible. Idiopathic intracranial hypertension has a benign course and usually responds well to treatment. Prolonged cerebrospinal hypertension in children can lead to a delay in neuropsychiatric development with the formation of debility or imbecility.
Prevention of intracranial pathology, timely treatment of neuroinfections, dyscirculatory and cerebrospinal disorders allows to prevent the development of intracranial hypertension. Preventive measures include compliance with the normal daily routine, labor rationing; avoidance of mental overload; adequate management of pregnancy and childbirth.