Increased intracranial pressure

Increased intracranial pressure

Definition:

A condition in which the pressure of the cerebrospinal fluid or brain matter within the skull exceeds the upper limits for normal pressure.

Alternative Names:

ICP; Intracranial pressure - increased

Causes, incidence, and risk factors:

Increased intracranial pressure is almost always indicative of severe medical problems. The pressure itself can be responsible for further damage to the central nervous system by decreasing blood flow to the brain or by causing the brain to herniate (push through) the opening in the back of the skull where the spinal cord is attached. Sudden herniation through the foramen magnum (back of the skull) is fatal.

Many conditions can cause increases in the intracranial pressure including metabolic, toxic, traumatic, infectious, neoplastic and idiopathic. Common causes include:

severe head injury
battered child syndrome
subdural hematoma
intraventricular hemorrhage
meningitis
meningoencephalitis
lead poisoning
Reye's syndrome
hypervitaminosis A
diabetic ketoacidosis (during treatment)
water intoxication (psychogenic polydipsia)
decerebrate posture
decorticate posture
fontanelles - bulging

Symptoms:

Infants:

bulging fontanelle
separated sutures

Older children and adults:

vomiting
headache
changes in behavior
progressive decreased consciousness, may become coma
seizures

Note: Slow increases are tolerated fairly well in young children before they become symptomatic. Adults tolerate increased intracranial pressure less well.

Signs and tests:

Intracranial pressure is measured in millimeters of mercury (mm Hg) and the normal range is 8-12 mm Hg. The average is 10 mm Hg. Intracranial pressure may be measured during a spinal tap (lumbar puncture) or may be measured directly by attaching a device referred to as a bolt to a small hole in the skull.

Treatment:

This condition is critical. The affected person will be in the hospital, possibly in an intensive care unit. They will be monitored and treated aggressively with a breathing tube (intubation), medication, and close monitoring.

Home care instructions will be sent home after the condition that caused the increased pressure has been resolved.

Expectations (prognosis):

Herniation of the brainstem can be fatal. Slow increases may be tolerated fairly well if the condition causing the increase can be controlled.

Complications:

brainstem herniation

Calling your health care provider:

Children and adults with increased intracranial pressure are, by the time the diagnosis is made, in the hospital.

Prevention:

Use proper precautions to avoid head injury. See the individual causes above for other preventive measures.

Review Date: 11/28/2001
Reviewed By: Victoria Kennedy, RN, A.D.A.M. editorial (11/28/2001). Previous review: Lyle J. Dennis, MD Fellow in Critical Care Neurology and Epilepsy and Electroencephalography Columbia-Presbyterian Medical Center. Review provided by VeriMed Healthcare Network (5/8/2000).

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