PHYSICAL THERAPY

Stereotactic Radiosurgery

Stereotactic radiosurgery is a non-invasive therapy that uses three-dimensional, computerized imaging to precisely deliver a targeted, highly-concentrated dose of radiation to an affected area of the brain. The technology allows surgeons to reach the deepest recesses of the brain and correct disorders not treatable with conventional surgery.

What Is Stereotactic Radiosurgery?

Stereotactic radiosurgery is similar to other forms of radiation treatment in that it does not excise (remove) the tumor, but alters the DNA of the tumor cells, rending them unable to reproduce. Benign tumors typically shrink within two years; malignant and metastatic tumors may shrink more rapidly, within several months of treatment. In the case of AVMs, this form of radiation treatment causes the blood vessels to thicken and close off, thus reducing the potential for bleeding.

Stereotactic radiosurgery treatment involves the delivery of a single high dose or smaller, multiple doses of radiation to the specific area of the brain in which the tumor/abnormality is located. Using a helmet-like device that keeps the head completely still, a rigid frame of reference called a stereotactic frame thats inserted into the helmet and held in place on the patients head with special pins and three-dimensional, computer-aided imaging software, stereotactic radiosurgery allows high doses of radiation to be delivered to the affected area with minimal exposure to the surrounding healthy tissue

There are three basic forms of stereotactic radiosurgery, cobalt-60 (Gamma Knife), linear accelerator (LINAC) and particle beam (proton) each of which incorporates a different mode of technology. There also are newer forms of the technology that allow for treatment without the use of a stereotactic frame.

Patients for whom this therapy may be recommended include those with:

• Arteriovenous malformations (AVMs) a tangle of abnormally or poorly formed arteries and veins that have a higher rate of bleeding than normal vessels.
• Arteriovenous fistulas (AVFs) an abnormal channel or passageway between an artery and a vein that disrupts normal blood flow patterns.
• Intracranial brain tumors both primary tumors such as chordomas, glioblastomas, hemangioblastomas and meningiomas, and tumors that have spread (metastasized) from other parts of the body.
• Trigeminal neuralgia a disorder of the fifth cranial nerve that causes intense, electric shock-like pain in the facial areas the nerve serves: the jaw, lips, eyes, nose, scalp and forehead.

Please talk to your doctor about whether this treatment option is most appropriate for your specific condition, and rely on his or her judgment.

Stereotactic radiosurgery is usually performed on an outpatient basis. You will not be put to sleep under general anesthesia; however, be prepared to spend up to 16 hours in the hospital. You also will need to have a family member or other support person accompany you, remain with you at the treatment facility and drive you home afterward.

Prior to treatment, please inform your doctor if you:

• Are taking medication to control diabetes
• Are allergic to contrast material, shellfish or iodine
• Have a pacemaker, artificial heart valve, defibrillator, or any other type of implanted medical device
• Are claustrophobic (fear closed-in spaces or the feeling of being confined)

Stereotactic radiosurgery treatment sessions are similar to those involved with receiving an X-ray, in that you will not be able to see, feel or hear the radiation beams. Before treatment, a technician will place an intravenous (IV) line in your arm or hand for delivery of medication, if needed, and a contrast material. Then, a local anesthetic will be injected in the front and back of your head, to numb your scalp and minimize any discomfort that may be involved with the attachment of the head frame. During placement of the head frame, you may feel pressure or tightness, which typically disappears within 15 minutes.

The treatment session should not be painful. If you experience any pain or discomfort from the way you’re positioned or from the head frame, notify your doctor or technician.

When the head frame is removed, there may be some minor bleeding from the pin sites that will be bandaged. After treatment, you also may experience nausea and/or a headache, which can be allayed with medication.

As with any spinal/neurosurgical procedure, stereotactic radiosurgery involves certain risks. Potential risks and complications associated with stereotactic radiosurgery may include:

• Local pain and swelling in the scalp
• Headache
• Skin reddening and irritation
• Nausea
• Seizure
• Local loss of hair in superficial lesions
• Local brain swelling in the treatment site
• Local necrosis in the treatment site
• Visual loss (very rare)
• Deafness (very rare)

Please consult your physician for a complete list of indications, warnings, precautions, adverse effects, clinical results and other important medical information that pertains to stereotactic radiosurgery.

Spinal cord stimulation (neurostimulation) is a procedure in which an electrical current is used to alleviate chronic back pain. It involves the implantation of a small pulse generator that transmits electrical impulses to the spinal cord, which in turn blocks the nerve signals to the brain responsible for the pain.

Neurostimulation delivers low-voltage electrical stimulation to the spinal cord or targeted peripheral nerve to block the sensation of pain.

One theory on how this technology works, the Gate Control Theory of pain developed by researchers Ronald Melzack and Patrick Wall, proposes that neurostimulation activates the body’s pain inhibitory system. According to this theory, there is a gate in the spinal cord that controls the flow of noxious pain signals to the brain. The theory suggests that the body can inhibit these pain signals or close the gate by activating certain non-noxious nerve fibers in the dorsal horn of the spinal cord. The neurostimulation system, implanted in the epidural space (the space outside the dura, or covering of the spinal cord, through which the spinal nerves extend into the rest of the body), stimulates these pain-inhibiting nerve fibers, masking the sensation of pain with a tingling sensation (paresthesia).1,2

Spinal cord stimulation may be appropriate for the management of severe, chronic back pain. Spinal cord stimulation typically is recommended for patients for whom:

• Conservative therapies have failed
• Spine surgery has failed (failed back syndrome)
• An observable pathology exists that is concordant with the pain complaint
• Further surgical intervention is not indicated
• No serious untreated drug habituation exists
• Psychological evaluation and clearance for implantation has been obtained
• No contraindications to implantation exist
• A screening test has been successful

Published studies of the therapy have shown that when used on carefully selected chronic pain patients, spinal cord stimulation may:

• Improve pain relief (a majority of patients may experience at least 50% reduction in pain)1,2,3
• Increase activity levels1,2,3,4
• Reduce use of narcotic medications 2,3,4

These results may also lead to reduced hospitalizations and surgical procedures, reduced healthcare costs, greater independence, and improved quality of life.2,3,4

There are two types of neurostimulation systems: one that is completely internal (surgically implanted) and one with both internal and external components. Each neurostimulation system consists of:

• One or two leads which deliver electrical stimulation to the spinal cord or targeted peripheral nerve
• An extension wire which conducts electrical stimulation from the power source to the lead
• A power source which generates the electrical stimulation

Both the power source (battery) and leads are surgically implanted for an internal system. A system with both internal and external components typically consists of a radiofrequency receiver and leads that are implanted and a power source that is worn externally. Batteries typically must be replaced every two to five years.

The neurostimulation system is typically implanted in a two-stage procedure. Stage 1 involves the implantation of a lead for trial screening. Stage 2 involves the implantation of the complete neurostimulation system.

Published studies of the therapy have shown that when used on carefully selected chronic pain patients, neurostimulation may:

• Improve pain relief (a majority of patients may experience at least 50 percent reduction in pain)3,4,5
• Increase activity levels3,4,5,6
• Reduce use of narcotic medications4,5,6

These results may also lead to reduced hospitalizations and surgical procedures, reduced healthcare costs, greater independence, and improved quality of life.4,5,6

As with any spinal procedure, there are certain risks and complications to consider. Potential risks associated with spinal cord stimulation may include:

• Scar tissue development around the electrode
• Pain extending beyond the reach of the stimulator
• Lead breakage/hardware failure
• Infection
• Spinal fluid leakage
• Headache
• Bladder impairment
• Reduced effectiveness over time

Please consult your physician for a complete list of indications, warnings, precautions, adverse effects, clinical results and other important medical information that pertains to spinal cord stimulation.