What Is Deep Brain Stimulation?
Deep brain stimulation (DBS) is frequently referred to as a brain pacemaker. It functions similarly to a pacemaker, except instead of providing electrical signals to the heart, it sends them to the brain. Deep brain stimulation is currently being used to treat a growing number of neurological and mental illnesses, particularly therapy-resistant Parkinson's disease. Patients with Parkinson's disease, essential tremor, or dystonia who are unable to control their symptoms with medication are candidates for deep brain stimulation.
It is crucial to remember that deep brain stimulation is not a cure for the disease but rather a technique to manage it better. It has a variety of advantages, including the ability to take fewer medications and thus endure few side effects of the drug. There are four parts of the deep brain stimulation system:
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Leads are thin cables that are insulated and terminated in electrodes placed in the brain. It is inserted into the brain and connected to an extension wire through a tiny hole in the skull.
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A pulse generator or a neurostimulator is like a small pacemaker-type device that generates electrical pulses. It is concealed beneath the skin of the chest, just below the collarbone, or in the belly.
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Extension leads connect to the leads implanted in the brain and carry electrical pulses from the device. It travels from the scalp to the behind of the ear, going down the neck and the chest, and is hidden beneath the skin.
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A hand-held programmer can alter the device's signals as well as turn it on and off.
When the pulse generator is on, it sends constant electrical pulses to the brain's target locations, altering the abnormal activity that is causing symptoms. Deep brain stimulation works in a very similar manner to a pacemaker that works for the heart.
Who Is a Suitable Candidate for Deep Brain Stimulation?
The patient should be evaluated by a multidisciplinary team of specialists that includes a neurologist, neurosurgeon, neuropsychologist, and psychiatrist. Deep brain stimulation is not suggested if patients are well treated with medicines. Patients who match the following characteristics are usually candidates for deep brain stimulation:
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Despite taking the proper drug dosage, symptoms are not properly controlled.
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The quality of life for a patient is considerably reduced by symptoms.
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Current drugs have too many side effects to be tolerated.
What Happens Before a Deep Brain Stimulation Surgery?
Tests for memory, reasoning, and mood will be required. Magnetic resonance imaging (MRI) and computerized tomography (CT) scans aid in determining which portion of the brain has to be treated. Because the patient will most likely be awake during the brain operation, knowing how to relax can help. Consider deep breathing and meditation as options. The patient will sign consent documents and fill out paperwork at the doctor's office to tell the surgeon about their medical history, including allergies, medications, anesthetic responses, and past procedures. Several days before surgery, presurgical testing, for example, a blood test, electrocardiogram (ECG), and chest X-ray may be required. Consult the primary care physician about quitting certain drugs and obtaining surgical clearance. If the patient has a history of heart problems, they may additionally require approval from their cardiologist. Seven days before the surgery, discontinuation of all nonsteroidal anti-inflammatory drugs (NSAIDs) and blood thinners should be done. In order to avoid bleeding and healing issues, quit smoking and alcohol one week prior to the surgery and two weeks after that.
Before surgery, the patient may be requested to use Hibiclens (CHG) or dial soap to cleanse their skin and hair. Bacteria are killed, and surgery site infections are reduced. After midnight before the surgery, the patient may not eat or drink anything, including their Parkinson's medicines. They are advised to sleep well. The deep brain stimulation procedure consists of several steps. It lasts the majority of the day, during which they may be awake and not taking any medications. On the day of the surgery:
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Use antibacterial soap in the shower. Wear loose-fitting, freshly washed clothing.
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Wear closed-back flat-heeled shoes.
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Suppose patients have been told to take their regular medication on the morning of surgery. In that case, they are advised to do it slowly.
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Make-up, hairpins, contacts, body piercings, nail polish, and other accessories should be removed.
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A list of the medications with the dosages and when the patient generally takes them as well as a list of drug or food allergies.
What Happens During a Deep Brain Stimulation Surgery?
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The surgeon may insert both the lead and the neurostimulator in certain circumstances; in others, the two procedures may be done independently, with the neurostimulator implanted days or weeks after the lead is inserted.
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A frame stabilizes the head and offers coordinates to assist the doctors in guiding the lead to the correct region in the brain throughout the procedure. The patient is given local anesthesia as well as a light sedative to assist them in resting throughout the procedure. The head frame or halo is screwed to the skull and stays in place during the treatment to keep the head in the correct posture. The patient usually sleeps under general anesthesia during image-guided deep brain stimulation surgery, such as with an interventional MRI (iMRI) or computerized tomography (CT) scan, while the surgeon utilizes pictures of the brain to direct the lead to its target.
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The neurosurgeon will puncture a small hole in the patient's skull to place the lead. To ensure correct lead placement, the team records the process as the lead passes through the brain tissue. During the recording, the person may be instructed to move their face, arm, or leg at specific periods. Microelectrode recording (MER) uses a high-frequency electrical current to pinpoint the surgical location for the installation of the deep brain stimulator. The information gained through microelectrode recording (MER) provides an accurate target for ultimate deep brain stimulator installation because the structure of each person's brain varies.
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The doctor may suggest an image-guided treatment for toddlers, patients with severe symptoms, very worried or afraid patients, or those whose leads are connected to specific areas of the brain. Any clothing, jewelry, and other things that could interfere with the operation are removed. The lead is then connected to an external neurostimulator after it is in place.
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The doctors use electrical stimulation delivered through the lead for a brief period to see if symptoms improve or side effects (such as muscular contractions or visual abnormalities) emerge. The lead is connected to the neurostimulator through an extension wire put beneath the scalp. This treatment is performed while the patient is under general anesthesia.
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The neurostimulator is inserted beneath the outer layers of skin, generally just beneath the collarbone but also in the chest and belly. The neurostimulator is connected to the extension wire from the lead. A plastic cap and stitches are used to close the gap in the skull.
What Happens After a Deep Brain Stimulation Surgery?
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The pulse generator in the chest is turned on in the doctor's office a few weeks following surgery. Using a sophisticated remote control, the doctor can easily program the pulse generator from outside the patient's body.
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The level of stimulation is tailored to the needs of the patient, and it could take up to six months to establish the right balance. The stimulation may be uninterrupted for 24 hours of the day, or the doctor may advise patients to turn off their pulse generator at night and switch it on in the morning, depending on their condition.
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One can turn stimulation on and off with a special remote control that they take home. The doctor may set the pulse generator so that the patient can make minor adjustments at home at any time. The life of the battery of the generator varies depending upon its use and the settings, and whenever the battery needs to be replaced, the generator will be replaced by the surgeon in an outpatient operation.
What Are the Advantages of Deep Brain Stimulation Surgery?
The benefits of deep brain stimulation are:
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Deep brain stimulation does not cause lasting damage to any portion of the brain, unlike some of the other surgical alternatives.
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As the person's sickness progresses or their response to drugs varies, the electrical stimulation can be adjusted and reversed.
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If deep brain stimulation is creating significant adverse effects, the stimulator can be turned off at any moment with no long-term consequences.
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Since deep brain stimulation is reversible and does not cause permanent brain damage, it may be possible to use the new, not-yet-available therapy methods.
What Are the Risks and Limitations of Deep Brain Stimulation Surgery?
There are risks and hazards with any surgical treatment. Surgery issues, hardware (device and cable) complications, and stimulation-related difficulties are the three types of deep brain stimulation complications.
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Brain bleeding, brain infection, incorrect placement of the leads, and less-than-ideal placement of the leads are all surgical problems.
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Lead failure or failure of any other part of the deep brain stimulation system, lead movement, battery failure, pain over the pulse generator device, infection around the device, and the breaking of the device through the skin are all examples of hardware complications.
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During the period of the programming of the device, all patients have stimulation-related problems. Unintentional movements (dyskinesia), feet seeming frozen to the floor, loss of balance, speech impairment, involuntary muscular contractions, double vision, and numbness and tingling (paresthesia) are some of the most common side effects, which can be reversed if the device is adjusted right.
Conclusion:
Deep brain stimulation has been shown to be an effective and safe treatment for the disorders for which it has been approved in adequately selected individuals. Although symptoms may not entirely disappear, most people see a significant improvement. In the settings that are still being investigated, positive outcomes have been seen. All surgical procedures have advantages and benefits, as well as risks and consequences. To establish if deep brain stimulation is right for a patient, the patient and their doctor will talk about it and other available therapy options.
