What is intracranial pressure
Inside the skull are the brain, blood and cerebrospinal fluid. If the volume of one of the components increases and the compensatory capabilities are exhausted, the pressure increases. In an adult, cerebrospinal fluid pressure during lumbar puncture in the supine position above 25 cm of water column is considered increased. Short-term fluctuations in pressure when coughing or straining are normal and are not a disease. A sustained increase disrupts the blood supply to the brain and damages the optic nerves.
- Secondary - with tumor, hemorrhage, hydrocephalus, meningitis
- For thrombosis of the venous sinuses
- Idiopathic - no apparent reason
- Acute - develops over hours
- Chronic - develops over weeks and months
Causes and risk factors
Secondary intracranial hypertension develops with space-occupying formations, hemorrhages, cerebral edema after injury, impaired outflow of cerebrospinal fluid, and inflammation of the meninges. Venous sinus thrombosis is associated with pregnancy, taking hormonal contraceptives, infections, and coagulation disorders. The idiopathic form is more common in obese women of childbearing age, especially those with recent weight gain. It can be provoked by some tetracycline antibiotics, retinoids, excess vitamin A, or withdrawal of corticosteroids.
- Brain tumors and cysts
- Hydrocephalus
- Traumatic brain injury, hemorrhage
- Meningitis and encephalitis
- Venous sinus thrombosis
- Obesity, taking tetracyclines, retinoids, excess vitamin A
Symptoms
Headache with increased intracranial pressure is usually daily, pressing, aggravated by lying down, in the morning, with coughing and straining, and may be accompanied by nausea. Characteristic are short-term episodes of blurring or darkening of the eyes for a few seconds, especially when standing up, pulsating tinnitus in rhythm with the heart, double vision. Long-term swelling of the optic discs gradually narrows the visual field, and vision loss may be irreversible. In infants, signs include bulging and tension of the large fontanel, rapid growth of head circumference, vomiting, and lethargy.
- Daily headache, worse in the morning and while lying down
- Nausea, vomiting
- Brief blurred vision
- Pulsatile tinnitus
- Double vision
- In infants - bulging fontanelle, rapid head growth
Diagnostics
The key examination is an examination of the fundus by an ophthalmologist: swelling of the optic discs is the main objective sign. Perimetry and optical coherence tomography assess the extent of optic nerve damage. MRI of the brain with contrast excludes tumor and hydrocephalus, MR venography excludes thrombosis of the venous sinuses. Then, in the absence of contraindications, a lumbar puncture is performed with pressure measurement and cerebrospinal fluid analysis. Rheoencephalography, echoEG, EEG and ultrasound of the vessels of the head do not allow measuring intracranial pressure, and this diagnosis is not made using them.
- Fundus examination
- Perimetry, optical coherence tomography
- Brain MRI with contrast
- MR venography
- Lumbar puncture with measurement of cerebrospinal fluid pressure
- Blood tests according to indications
Treatment
In case of secondary hypertension, the cause is treated: the tumor is removed, hydrocephalus is eliminated, anticoagulant therapy is carried out for sinus thrombosis, and meningitis is treated. An acute increase in blood pressure with depression of consciousness requires treatment in intensive care. In the idiopathic form, the most important thing is weight loss, which often leads to remission. Discontinue provoking medications. The neurologist prescribes drugs from the group of carbonic anhydrase inhibitors, which reduce the production of cerebrospinal fluid. If there is a threat of vision loss, shunt operations, stenting of the venous sinus or fenestration of the optic nerve sheath are performed. Diuretics “for pressure in the head” should not be taken without a confirmed diagnosis.
- Treating the underlying cause
- Weight loss in idiopathic form
- Discontinuation of provoking drugs
- Carbonic anhydrase inhibitors as prescribed
- Regular vision checks by an ophthalmologist
- Surgical treatment for vision hazards