Increased intracranial pressure (ICP) is a serious condition that occurs when pressure inside the skull increases. The increased pressure can block blood flow to the brain and affect brain function and can cause damage to important brain structures. For this reason, ICP needs to be detected and treated as quickly as possible.
Changes to the volume of cerebrospinal fluid (CSF), blood within the brain and brain tissue may all cause an increase in pressure within the skull. The body adjusts to these changes by trying to maintain the pressure within the brain at a safe level. When the body is unable to do this, it can cause cerebral edema (swelling of the brain tissue). This swelling causes an increase in intracranial pressure.
Causes
Increased ICP in people with cancer is mainly caused by:
- tumour growth in the brain or meninges (the membranes that surround the brain)
- either a primary brain tumour or a metastatic tumour in the brain
- most common cause
- cancer treatment
- when brain tissue reacts to surgery or radiation
- infections of the brain (such as meningitis)
- bleeding within the brain
Signs and symptoms
The signs and symptoms of increased ICP often depend on the location of the lesion within the brain and may include:
- headache – often occurring early in the morning and made worse by coughing, bending or straining
- nausea
- vomiting
- dizziness
- vision problems
- difficulty speaking
- confusion
- restlessness
- drowsiness and decreased consciousness
- trouble with coordination
- loss of muscle strength
- loss of the ability to move a body part (paralysis)
- seizure
- coma
Symptoms become worse as the pressure within the skull increases.
Diagnosis
Increased ICP is usually diagnosed by doing a:
Treatment
People with increased ICP are monitored very closely. Intracranial pressure may be measured, sometimes by attaching a small device (called an intraventricular catheter) inserted into a tiny hole in the skull. Coughing, sneezing or bending over should be avoided as it can increase ICP. The head of the patient's bed is raised to help decrease pressure.
There are different treatments, depending on the cause and degree of increased ICP. Treatments are aimed at decreasing the pressure in the brain. Treating the underlying cause can often return the pressure to normal.
Treatment options for increased ICP may include:
- surgery
- to remove all or some of the tumour in the brain and to relieve pressure
- to insert a plastic tube (shunt) to drain CSF and relieve pressure
- to drain a brain abscess (a mass of cells, pus or other material within the brain tissue) caused by infection and inflammation
- anti-cancer treatments, such as radiation therapy or chemotherapy, if increased ICP is caused by a cancer
- corticosteroids to treat or prevent cerebral edema
- when they are no longer needed, corticosteroid drugs are gradually decreased before they are stopped altogether
- examples include:
- dexamethasone (Decadron) – most commonly used
- prednisone (Deltasone)
- methylprednisolone
- mannitol (an intravenous drug) to increase urine output and to reduce pressure
may be used along with a corticosteroid to quickly reduce ICP
may be used for recurrent edema that no longer responds to corticosteroids
- anticonvulsants (antiseizure medication) to treat seizures
- blood tests are done to check the level of anticonvulsant drug in the blood, because if the levels are too low there may not be enough drug in the body to effectively control seizures
- examples include:
- phenytoin (Dilantin) – the most commonly used
- phenobarbital
- carbamazepine (Tegretol)
- valproic acid (Depakane, Epival)
- antibiotic therapy if an infection is the main cause of increased ICP