Spinal Tap

A spinal tap may be done to check the spine for retinoblastoma that may have spread beyond the eyes. During a spinal tap, which is also called a lumbar puncture, a small amount of cerebrospinal fluid is removed and examined for cells displaying the retinoblastoma mutation. Depending on the age and disposition of the child, sedation or a local anesthetic may be given prior to the procedure.

Reason for Retinoblastoma Spinal Tap

A spinal tap is not among the tests that are typically given to diagnose retinoblastoma. The reason that a doctor may recommend a spinal tap is that retinoblastoma cells can often be found in the fluid that surrounds the brain and spinal cord if retinoblastoma has spread to the brain. This procedure carries a lower degree of risk than brain surgery, so it is preferred for diagnosis.

Retinoblastoma Spinal Tap Procedure

During the spinal tap, the child must stay very still, so sedation may be the best option in many cases. The patient typically lies facing sideways during this procedure, and doctors will either position the patient in a curled position or ask the patient to curl up to increase the amount of space between the vertebrae. The physician will then carefully insert a specific needle between two vertebrae and into a space that will contain cerebrospinal fluid. This exact spot may vary depending on the patient. The procedure typically takes around 30 minutes.

Spinal Tap Results

The cerebrospinal fluid is then examined by a pathologist that is experienced with retinoblastoma. The results are usually available within 48 hours. The results will be given to the treating physician, who will then go over the results and any action that must be taken with the parents. If retinoblastoma is evident in the spinal fluid, further testing may be done to determine the extent of the spread of the cancer on the brain. Treatment will begin as soon as possible.

Retinoblastoma Spinal Tap Risks

A spinal tap is considered to be a safe procedure, in most cases complications do not occur. In rare cases in which there is a tumor on the brain, removing cerebrospinal fluid may lead to compression of the brain stem. Excessive bleeding and infection are also risks inherent in any surgery. Anesthesia allergies may also pose a risk to the patient, particularly because most patients are five years of age or younger and may not have undergone sedation previously. Side effects after a spinal tap are common, but side effects generally diminish within a week.

Common side effects of a spinal tap may include:

• Back pain
• Leg pain
• Severe headaches
• Nausea
• Vomiting
• Dizziness