NINE

Taking Care of Your DBS System and Other Precautions

Once you have your DBS implanted and programmed, you will be involved in keeping it working properly and preventing it from being damaged or causing harm. There are medical tests and procedures that could turn off your stimulator, cause your stimulator to malfunction, or even lead to stroke or death. Falls or accidents may result in damage to your DBS. We recommend that you and your family or friends become familiar with the precautions that need to be taken to prevent harmful interactions with your DBS.

WHAT IF I FALL OR GET INTO AN ACCIDENT?

While a large component of this chapter will be spent describing the consequences of exposing your DBS to electromagnetic or magnetic fields generated by machines and medical equipment, the most common risk to your DBS is experienced by taking a fall or being involved in an accident. Falling, being involved in a motor vehicle accident, and experiencing some other type of accident are the most frequent causes of device failure. Sudden pulling or jarring that occurs from falling or being involved in an accident can break the small wires in your stimulator lead or extension. The wires can break anywhere along the system, but it usually occurs at one of the connections along the route near the stimulator or the lead. Remember that there are four small wires wrapped within the extension wire that go from the four contacts at the tip of the lead to your stimulator in your chest. It is hoped that, if you experience a break, it will only occur in one of these wires, and the device can be reprogrammed to work around the broken wire using a different wire or contact. Unfortunately, that is not always possible. Broken wires most often require another surgery to fix the DBS.

While you can probably do most of your regular activities after DBS placement, certain activities are just bad ideas. For example, contact sports such as football or rugby should be avoided. Scuba diving may also be dangerous because water pressure could damage the system. When riding in cars, wear your seat belt. If you like to ride bicycles or rollerblade, please wear a helmet to protect your head. The purpose of DBS is to improve your quality of life, and if you find yourself being able to try more activities, we encourage it. However, we would recommend using your common sense to prevent injury.

WHAT ABOUT MAGNETS?

It is possible that your DBS can be turned off by common electromagnetic or magnetic fields. An electromagnetic field is the electric and magnetic force that is detectable around a magnet or an electric current. Electromagnetic or magnetic fields can be generated from a wide variety of sources. Medical equipment, machines, car engines, radios, wireless telephones, handheld power tools, refrigerator doors, and stereo speakers are some of the common sources that can turn off your DBS. Security devices at airports, store entrances, and court buildings could also potentially turn off your device. While your DBS will not be harmed, you may find having your stimulator accidently turned off to be an inconvenience.

You will be given a handheld device when your DBS system is implanted. This handheld device allows you to turn your DBS system on and off, and can also allow you to check whether the system is on or off. Depending on the model of your stimulator, you may also be able to adjust the stimulation settings for your DBS or switch between different settings that the neurologist sets for you. We always suggest that people check every night if their stimulator is on or off before going to bed. The reason for this is that if the stimulator happens to be turned off, you only have to review what happened in the past 24 hours to figure out what could have turned the stimulator off, as the stimulator was on the night before. When you do not check whether the stimulator is on or off each night, and one night you happen to check it because your symptoms are worse, it could have been turned off that day or a couple of days before.

It is also best to use the handheld programmer to check your DBS after having any medical procedure or test or if you have been near a potential electromagnetic field. The airport is a special situation. Remember that going through the metal detectors or even having the wands run over you could potentially turn off the stimulator. When you approach a security entrance at the airport or other secure environment where metal detectors are used, let them know you have a pacemaker and ask to have your security check done by hand. There is no need to say you have DBS or a stimulator because they likely will not know what that is. However, if you use the word “pacemaker,” you will be placed in a special line to be hand searched. They may ask you for your ID card that shows you have a pacemaker device, although we have heard from individuals that they rarely have to show it. Some people also carry a letter written by their physicians, just in case.

Whenever you notice your symptoms have suddenly worsened, we recommend that you use your handheld programmer to check your DBS to determine if it was accidentally turned off. See Chapter 10 for instructions on how to do this. You can easily use the programmer to turn it back on.

CAN I GET OTHER MEDICAL PROCEDURES DONE WITH THE DBS SYSTEM?

There are guidelines and certain precautions that need to be applied to those with DBS. The following paragraphs describe the most common guidelines. Further information about the interaction of your DBS with other devices, equipment, or procedures can be provided by the implanting physician or device manufacturer.

Diathermy

The precaution that has the most serious consequences is also the least frequently encountered. People with DBS cannot have diathermy performed anywhere on their body. What is diathermy? Diathermy is a medical treatment that delivers energy and heat within body tissues using high-frequency electrical currents. This energy can be transferred through the DBS system to the brain, causing tissue and nerve damage in the brain, resulting in serious injury or even death. This could happen regardless of where the diathermy treatment is applied on the body. There are no circumstances in which diathermy can be performed on an individual with DBS. Diathermy may be called shortwave diathermy, microwave diathermy, therapeutic ultrasound diathermy, and deep heat therapy. It is most commonly used by physical therapists to treat sore achy muscles or by dentists following a painful dental procedure. Diathermy should not be confused with diagnostic ultrasound that is commonly used to obtain images for diagnostic purposes or visualize internal structures in the body.

X-rays or Fluoroscopy

Routine X-rays will not affect your stimulator. However, because you may be exposed to a large electromagnetic field in the X-ray suite, you should check your stimulator to make sure it is still on.

CT and PET (Positron Emission Tomography) Scans

These diagnostic scans will not harm your stimulator and are safe for those with DBS. After the scan, be sure to check your stimulator to make sure it is still on.

Magnetic Resonance Imaging

There is concern for those with DBS when undergoing MRI. Because MRI uses a large magnet and radio waves to create images, MRI is not safe in most circumstances. It can heat the DBS system. This heat may be transmitted through the wires and out the contacts at the tip of the lead, which may burn the surrounding brain tissue. Although it is possible for an individual with DBS to have an MRI, the scan should only be done at a center that is familiar with DBS because there are specific rules that must be followed. First, only a brain MRI can be performed with a DBS system in place. This brain MRI can only be performed using a head coil with the MRI strength being 1.5 Tesla or less. The head coil is the part of the machine that actually takes the pictures of the brain. It looks like a basket and slides over the person’s head during the MRI scan. To get MRI pictures of other parts of the body, other types of coils are used. An individual with DBS should never have a total body or full body radio frequency coil MRI that extends over the chest. This means that spine, body, shoulder, knee, or other MRIs of the body cannot be done.

Before undergoing a brain MRI, the stimulator should be programmed to 0 V and then turned off. This is because the MRI will switch the DBS system on and off multiple times throughout the entire scan. If your DBS stimulator settings are set at their normal voltage, this frequent on/off toggling could be uncomfortable, causing tingling sensations or temporary shocks. The handheld programmer does not have the capability to turn the stimulator down to 0 V, so someone from the DBS team (or someone familiar with DBS if you are not getting the MRI at your DBS center) will need to turn the stimulator down to 0 V. Although there does not seem to be any problems with MRIs as long as the above guidelines are followed, many academic medical centers have radiology departments that will not perform MRIs in anyone with a DBS system in place, not even brain MRIs.

We recommend that, just in case, MRI be avoided if possible for people with DBS. If you are scheduled to undergo an MRI, you should inform your physician or the MRI department of these precautions.

Electrocautery

Electrocautery is commonly used during surgical procedures. It utilizes an electrical current to stop bleeding vessels or tissues. It should be used with caution in those with DBS. Monopolar or unipolar electrocautery should not be used. If electrocautery is necessary, a bipolar device may be used as long as the DBS is set at 0 V and turned off. The difference between monopolar and bipolar electrocautery is somewhat similar to the difference between monopolar and bipolar settings in DBS (reviewed in Chapter 8). In monopolar electrocautery, the electrical current flows from the cautery pen through the subject’s body. In bipolar cautery, the electrical current flows only from one tip of the cauterizer to the other, and a limited amount of tissue is affected in between. Because of the difference in the mechanism, the power setting required for bipolar cautery devices is lower than with monopolar electrocautery.

If you have DBS and are undergoing a surgical procedure, your surgeon should be aware that you have a DBS device and that only bipolar electrocautery should be used. Furthermore, the surgeon should know that the ground lead needs to be placed as far away as possible from your DBS such as on the leg.

Cardiac Pacemakers

There is a small risk that the DBS will cross talk or interfere with a cardiac pacemaker. However, if the pacemaker is placed at least 10 inches from the DBS, and there is intraoperative testing to check for interference, those with DBS can safely have a cardiac pacemaker.

Emergency Cardio Pulmonary Resuscitation (CPR)

We are often asked about the precautions that should be used if an individual with DBS suffers a cardiac arrest and needs emergency CPR and defibrillation (electric shock to the heart). Clearly, those who suffer a life-threatening emergency that requires resuscitation should be defibrillated if necessary. However, it is likely that the DBS will be damaged. If possible, place the defibrillator pads at least 2 inches from the stimulator and use the lowest defibrillation settings possible.

Electrocardiogram (EKG) or Electroencephalogram (EEG)

An EKG monitors the electrical activity of your heart and reveals your heart rhythm and heart rate. It is done by applying 12 sticky pads to your chest, arm, and leg. An EEG is similar, except that it monitors the electrical activity of your brain. These tests are safe for those with DBS. However, the DBS is likely to produce interference or artifact that will make it difficult to interpret the EKG or EEG. The DBS can be temporarily turned off with your handheld programmer while the EKG or EEG is being done. However, if someone requires continuous monitoring, like in an intensive care unit, it may be difficult to leave the DBS off continuously.

Ultrasound

Ultrasound is also called sonography. This is a medical procedure that uses high-frequency sound waves to produce images of organs, tissues, or blood flow inside the body. The sound waves come out of a device called a transducer. Diagnostic ultrasound is safe for those with DBS. To eliminate artifact from the DBS, however, it is recommended that the DBS be set at 0 V and then turned off using the physician programmer. The transducer should be kept at least 6 in. away from the stimulator.

Lithotripsy

Lithotripsy is a treatment that uses shock waves to break up kidney stones. It can damage the DBS system. However, if it is necessary to perform lithotripsy in someone with DBS, then the DBS should be shielded, and the stimulator should be programmed to 0 V and turned off with the physician programmer.

Dental Work

In general, dental procedures are safe for those with implanted DBS systems, except for diathermy (mentioned earlier in this chapter). However, electric dental equipment such as drills or X-ray machines should be kept far away from the DBS generator and wires in the neck and scalp. For extensive dental work, or for suspected tooth abscess (infection), we recommend that those with DBS be treated with antibiotics prior to having the work done.

Radiation Therapy

In the event an individual with DBS needs to undergo radiation therapy to treat cancer, this can be accomplished safely. We recommend that the radiation beams be kept as far away from the DBS system (including stimulator and wires) as much as possible and apply a protective shield over the DBS stimulator.

Mammogram (Breast X-ray)

Mammograms can be performed safely in those with DBS. Care should be taken to avoid compressing the DBS. Make sure you tell the technician about your DBS so that undue pressure is not applied on the DBS or connector.

Industrial Equipment

Industrial plants or environments with large electrical equipment should be avoided as they may affect your DBS. Examples of equipment to avoid include arc welding equipment, power lines, and electric generators.

Household Appliances

Small household appliances and equipment should not affect the DBS. However, if power tools or equipment are held close enough to the DBS generator, they can turn it off. Microwave ovens can be safely used by those with DBS.

Taking care of your DBS is essential to keep it working properly and to prevent it from being damaged or causing harm. Certain medical procedures or tests are contraindicated for those with DBS. However, most medical equipment and procedures are compatible so that your DBS should not interfere with any necessary medical care. DBS failure is more commonly the result of falls or accidents rather than medical equipment or procedures. We recommend that you and your family or friends become familiar with the precautions that were identified in this chapter and refer to this anytime you have questions about the compatibility of your DBS. If more information is needed, or if a procedure is proposed that was not included in this chapter, contact the device manufacturer or the implanting physician before undergoing the procedure.