Prescription and Safety Information
Read this section to gather important prescription and safety information.
Intended Use This neurostimulation system is designed to deliver low-intensity electrical impulses to nerve structures. The system is intended to be used with leads and associated extensions that are compatible with the system.
Indications for Use The St. Jude Medical™ deep brain stimulation system is indicated for unilateral or bilateral stimulation of the ventral intermediate nucleus (VIM) of the thalamus for the management of tremor; the internal globus pallidus (GPi) or the subthalamic nucleus (STN) for the management of intractable, chronic dystonia, including primary and secondary dystonia; the unilateral or bilateral stimulation of the thalamus, internal globus pallidus (GPi), or subthalamic nucleus (STN) in patients with levodopa-responsive Parkinson’s disease.
Contraindications: Implantation of this neurostimulation system is contraindicated for the following:
- Patients for whom test stimulation is unsuccessful.
- Patients who are unable to properly operate the system.
The following procedures are contraindicated for patients that have been implanted with a DBS system:
Diathermy: Short-wave diathermy, microwave diathermy, or therapeutic ultrasound diathermy (all now referred to as diathermy) should not be used on patients implanted with a DBS system. Energy from diathermy can be transferred through the implanted system and can cause tissue damage at the location of the implanted electrodes, resulting in severe injury or death. Diathermy is further prohibited because it may also damage the DBS system components. This damage could result in loss of therapy, requiring additional surgery for system replacement. Injury or damage can occur during diathermy treatment whether the DBS is turned on or off. All patients are advised to inform their healthcare professional that they should not be exposed to diathermy treatment.
Magnetic resonance imaging (MRI): Full-body radiofrequency (RF) coil or other extremity coils should not be used on patients implanted with a DBS system. Because energy from MRI can be transferred through the implanted system, the potential for heat generation at the location of the electrodes exists. This isolated temperature rise may cause tissue damage at the location of the implanted electrodes, possibly resulting in severe injury or death. Injury can occur during MRI treatment whether the DBS system is turned on or off. All patients are advised to inform their healthcare professional that they should not be exposed to MRI. In the instance that MRI must be performed, the guidelines provided in the clinician’s manual accompanying the IPG must be followed.
The following warnings apply to these components.
Poor surgical risks. Neurostimulation should not be used on patients who are poor surgical risks or patients with multiple illnesses or active general infections.
Implanted cardiac devices. Physicians need to be aware of the risk and possible interaction between a neurostimulation system and an implanted cardiac system, such as a pacemaker or defibrillator. Electrical pulses from a neurostimulation system may interact with the sensing operation of an implanted cardiac system, causing the cardiac system to respond inappropriately. To minimize or prevent the implanted cardiac system from sensing the output of the neurostimulation system, (1) maximize the distance between the implanted systems; (2) verify that the neurostimulation system is not interfering with the functions of the implanted cardiac system; and (3) avoid programming either device in a unipolar mode (using the device’s can as an anode) or using neurostimulation system settings that interfere with the function of the implantable cardiac system.
Theft detectors and metal screening devices. Certain types of antitheft devices, such as those used at entrances or exits of department stores, libraries, and other public establishments, and airport security screening devices may affect stimulation. Patients should use caution when approaching such a device and should request assistance to bypass the device. If they must proceed through the device, patients should move through the detector quickly and then check the IPG to verify that it is turned on or off.
Motor vehicles, machinery, and equipment. Patients should not operate motor vehicles, potentially dangerous machinery, or power tools or engage in any activity that would be potentially unsafe if their symptoms were to return unexpectedly.
Device components. The use of non-St. Jude Medical components with this system may result in damage to the system and increased risk to the patient.
Case damage. Do not handle the IPG if the case is pierced or ruptured because severe burns could result from exposure to battery chemicals.
Cremation. The IPG should be explanted before cremation because the IPG could explode. Return the explanted IPG to St. Jude Medical.
IPG disposal. Return all explanted IPGs to St. Jude Medical for safe disposal. IPGs contain batteries as well as other potentially hazardous materials. Do not crush, puncture, or burn the IPG because explosion or fire may result.
Charge density. A risk of tissue damage exists with stimulation parameter settings of high amplitudes and wide pulse widths. Higher amplitude and pulse width settings required to achieve therapy may indicate a system problem or suboptimal lead placement. Parameter values exceeding the charge density limit of 30 μC/cm2 should only be programmed with due consideration of the warnings concerning charge densities. Charge density can be reduced by lowering the stimulation amplitude or pulse width.
Low frequencies. Stimulation frequencies less than 30 Hz may be programmed; however, these frequencies may cause tremor to be driven (i.e., occur at the same frequency as the programmed frequency). For this reason, programming at lower frequencies is not recommended.
The following precautions apply to these components.
Surgeon training. Implanting physicians should be experienced in stereotactic and functional neurosurgery.
Clinician selection. Clinicians should be familiar with deep brain stimulation therapy and be experienced in the diagnosis and treatment of the indication for which the deep brain stimulation components are being used.
Patient selection. Select patients appropriately for neurostimulation.
Infection. Follow proper infection control procedures. Infections may require that the device be explanted.
Electromagnetic interference (EMI). Some equipment in home, work, medical, and public environments can generate EMI that is strong enough to interfere with the operation of a neurostimulation system. Patients should avoid getting too close to these typesof EMI sources, which include the following examples: commercial electrical equipment (such as arc welders and induction furnaces), communication equipment (such asmicrowave transmitters and high-power amateur transmitters), high-voltage power lines, and some medical procedures (such as therapeutic radiation and electromagnetic lithotripsy).
Sterilization and Storage
Single-use, sterile device. The implanted components of this neurostimulation system are intended for a single use only. Sterile components in this kit have been sterilized using ethylene oxide (EtO) gas before shipment and are supplied in sterile packaging to permit direct introduction into the sterile field. Do not resterilize or reimplant an explanted system for any reason.
Storage environment. Store components and their packaging where they will not come in contact with liquids of any kind.
Handling and Implementation
Expiration date. An expiration date (or “use-before” date) is printed on the packaging. Do not use the system if the use-before date has expired.
Care and handling of components. Use extreme care when handling system components prior to implantation. Excessive heat, excessive traction, excessive bending, excessive twisting, or the use of sharp instruments may damage and cause failure of the components.
Package or component damage. Do not implant a device if the sterile package or components show signs of damage, if the sterile seal is ruptured, or if contamination is suspected for any reason. Return any suspect components to St. Jude Medical for evaluation.
Electrosurgery devices. Electrosurgery devices should not be used in close proximity to an implanted neurostimulation system. Contact between an active electrode and an implanted IPG, lead, or extension can cause severe injury to the patient. If use of an electrocautery device is necessary, first turn off the neurostimulation system.
System testing. To ensure correct operation, the system should always be tested after implantation and before the patient leaves the surgery suite.
Device modification. The equipment is not serviceable by the customer. To prevent injury or damage to the system, do not modify the equipment. If needed, return the equipment to St. Jude Medical for service.
Hospital and Medical Environments
Electrical medical treatment. In the case that a medical treatment is administered where an electrical current is passed through the body from an external source, first deactivate the IPG by setting all electrodes to off, turning stimulation off, and setting amplitude to zero. Regardless if the device is deactivated, take care to monitor the device for proper function during and after treatment.
High-output ultrasonics and lithotripsy. The use of high-output devices, such as an electrohydraulic lithotriptor, may cause damage to the electronic circuitry of an implanted IPG. If lithotripsy must be used, do not focus the energy near the IPG.
Ultrasonic scanning equipment. The use of ultrasonic scanning equipment may cause mechanical damage to an implanted neurostimulation system if used directly over the implanted system.
External defibrillators. The safety of discharge of an external defibrillator on patients with implanted neurostimulation systems has not been established.
Therapeutic radiation. Therapeutic radiation may damage the electronic circuitry of an implanted neurostimulation system, although no testing has been done and no definite information on radiation effects is available. Sources of therapeutic radiation include therapeutic X rays, cobalt machines, and linear accelerators. If radiation therapy is required, the area over the implanted IPG should be shielded with lead. Damage to the system may not beimmediately detectable.
Psychotherapeutic procedures. The safety of psychotherapeutic procedures, such as electroshock therapy and transcranial magnetic stimulation, which use equipment that generates electromagnetic interference, has not been established.
Electrocardiograms. Neurostimulation pulses may be detected by electrocardiograms.
Home and Occupational Environments
Patient activities and environmental precautions. Patients should take reasonable care to avoid devices that generate strong EMI, which may cause the neurostimulation system to unintentionally turn on or off. Patients should also avoid any activities thatwould be potentially unsafe if their symptoms were to return unexpectedly.
Mobile phones. The effect of mobile phones on deep brain stimulation is unknown. Patients should be advised to avoid carrying mobile phones in their shirt pocket or otherwise placing them directly over the deep brain stimulation system components. If interference occurs, try holding the phone to the other ear or turning off the phone.
Household appliances. Household appliances that contain magnets (e.g., refrigerators, freezers, inductive cooktops, stereo speakers, mobile telephones, cordless telephones, standard wired telephones, AM/FM radios, and some power tools) may unintentionally cause the neurostimulation system to turn on or turn off.
Therapeutic magnets. Patients should be advised to not use therapeutic magnets. Therapeutic magnets (e.g., magnets used in pillows, mattress pads, back belts, knee braces, wrist bands, and insoles) may unintentionally cause the neurostimulation system to turn on or off.
Radiofrequency sources. Devices that contain permanent magnets (e.g., mobile telephones, cordless telephones, standard wired telephones, and AM/FM radios) may unintentionally cause the IPG to turn on or off.
Deep brain stimulation potentially has the following adverse effects:
Possible surgical complications. Surgical complications include, but are not limited to, the following: intracranial hemorrhage (which can lead to stroke, paralysis, or death); subcutaneous hemorrhage or seroma; hematoma; cerebrospinal fluid leakage or cerebrospinal fluid abnormality; brain contusion; infection or inflammation; antibiotic anaphylaxis; skin disorder; edema; persistent pain at surgery site or IPG site; erosion; brachial plexus injury (nerves to chest, shoulder and arm); postoperative pain, stress, or discomfort; neuropathy (nerve degeneration); hemiparesis (muscular weakness or partial paralysis on one side of body); ballism or hemiballism (uncontrollable movements on both or only one side of the body); confusion—transient, nocturnal or ongoing; cognitive impairment, including delirium, dementia, disorientation, psychosis and speech difficulties; aphasia; deep vein thrombosis; complications from anesthesia; phlebitis (vein inflammation); pulmonary embolism (sudden blood vessel obstruction); aborted procedures (air embolism, unable to find target, surgical complication, etc.); complications from unusual physiological variations in patients, including foreign body rejection phenomena; pneumonia, seizure or convulsions; paralysis (loss of motor function, inability to move); stroke and death.