What the risks are:

Risks of lumbar puncture include:

• Hypersensitivity (allergic) reaction to the anesthetic
• Discomfort during the test
• Headache after the test
• Bleeding into the spinal canal

There is an increased risk of bleeding in persons who take blood thinners.

Brain herniation may occur if this test is done on a person with a mass in the brain (such as a tumor or abscess). This can result in brain damage or death. This test is not done if an exam or test reveals signs of a brain mass.

Damage to the nerves in the spinal cord may occur, particularly if the person moves during the test.

Cisternal puncture or ventricular puncture carry additional risks of brain damage and bleeding within the brain.

Special considerations:

This test should not be performed on people who have lesions that cause increased intracranial pressure. Others who should not have this test include patients with:

• Blood clotting problems
• Thrombocytopenia
• Risk of infection