Overview of Deep Brain Stimulation
Since the late 19th century, when scientists first discovered that certain parts of the brain control movement, there has been a lot of interest in using electrical stimulation to understand and treat brain disorders. After the initial discovery, researchers were able to map out different functions of the brain’s surface. This led to them being able to identify deeper structures within the brain in the 1950s, by directly stimulating these areas during surgery.
In the following decade, scientists started to explore the idea of treating brain-related disorders using constant electrical stimulation. By the 1970s, they had proven that ongoing stimulation could help manage pain, control movement disorders and treat epileptic seizures.
Fast forward to the 1990s, scientists combined the technology used in implanted heart pacemakers with permanently implanted deep brain electrodes. This landmark integration led to the birth of what we now call deep brain stimulation (DBS). Essentially, DBS involves sending electrical impulses to specific parts of the brain to help manage certain neurological conditions.
Anatomy and Physiology of Deep Brain Stimulation
Deep brain stimulation, or DBS, is a treatment that involves inserting electrodes next to certain parts of the brain. These electrodes are connected to a machine similar to a pacemaker, called a pulse generator, which is placed under the skin of the chest. The pulse generator is controlled by a computer which sets the right levels of voltage, speed, and pulse duration. DBS is often used to stimulate parts of the brain like the subthalamic nucleus (STN), globus pallidus interna (GPi), and the ventral intermediate nucleus of the thalamus (VIM).
We’re still not entirely sure how DBS works to ease symptoms, but there are lots of theories. It is clear that stimulating deep parts of the brain can affect a wide range of brain functions. The benefits we see from DBS likely depend on many factors like the characteristics of the brain cells being stimulated, the size of the area being stimulated, the specific settings of the pulse generator, and the specifics of the patient’s condition. Current research suggests that DBS likely helps by increasing the activity of the specific brain cells being targeted.
Why do People Need Deep Brain Stimulation
Deep brain stimulation (DBS), a procedure recognized by the United States Food and Drug Administration (FDA), is used to treat various conditions like essential tremors, dystonia, Parkinson’s disease, and obsessive-compulsive disorder (OCD) that doesn’t respond to regular treatments.
DBS technology has been increasingly used over time. It started being used for treating essential tremors and the tremor of Parkinson’s disease. Research has shown that DBS, when used to stimulate a part of the brain called the ventral intermediate nucleus of the thalamus, can reduce tremors by over 80% on average. Stimulating another part of the brain, the globus pallidus internus, helps reduce many motor symptoms of Parkinson’s disease, including involuntary muscle movements caused by a medication called dopamine. It’s thought to work by normalizing the firing frequency of the dysfunctional globus pallidus internus. DBS has also improved walking, shaking, and slow movements in people with Parkinson’s disease by stimulating a part of the brain called the subthalamic nucleus. It’s been used to help control pain too, by stimulating sections of a brain region known as the thalamus.
In 1999, DBS began to be used for psychiatric purposes. Since then, many studies focusing on DBS for treatment-resistant psychiatric illnesses have been performed. More recently, DBS has been found to help people with Tourette Syndrome by stimulating certain parts of the brain like the centromedian-parafascicular complex of the thalamus, the globus pallidus internus, and the anterior limb of the internal capsule. The most notable use of DBS might be for OCD and depression that hasn’t responded to other treatments. DBS of a part of the brain called the subgenual cingulate white matter has demonstrated efficacy in the improvement of mood in those struggling with treatment-resistant depression. DBS of both anterior limbs of the internal capsules has shown a reduction of OCD-related symptoms. Stimulating either the ventral capsule, the ventral striatum, or the STN led to the FDA approving DBS for OCD that hasn’t responded to other treatments, in 2009. The first use of DBS for depression that hasn’t responded to other treatments was also in 2009.
Now, scientists are studying possible future uses of DBS for other psychiatric conditions like addiction, autism, anorexia nervosa, anxiety disorders, and schizophrenia.
When a Person Should Avoid Deep Brain Stimulation
Deep brain stimulation (DBS), a procedure that uses electrical currents to stimulate brain areas affecting movement and mood, is generally safe for most patients. However, these devices may not be suitable for people who are unable to use the brain-control device properly. Once a person has this device in their body, they should avoid certain medical procedures. These include whole-body MRI scans, which are detailed imaging tests, transcranial magnetic stimulation, a non-invasive procedure that uses magnetic fields to stimulate nerve cells in the brain, and diathermy, a treatment method that uses high-frequency electric current to generate heat. These procedures can interfere with the stimulator device, leading to improper functioning or complications.
Equipment used for Deep Brain Stimulation
The right tools for Deep Brain Stimulation (DBS), a type of brain surgery, include a few specific items. First, there’s a lead with electrodes – this is a sort of wire that is placed in the brain and sends electrical signals. Then, there is another wire to connect the lead to a pulse generator, which is the device that actually creates these signals. On top of this, there are also the usual tools that are used for brain surgery and for the implantation of the pulse generator into the chest wall.
Who is needed to perform Deep Brain Stimulation?
The procedure involves a team of medical experts. The central figure in this team is an experienced neurosurgeon, who conducts the surgery with their team. As the Deep Brain Stimulation (DBS) technique is mainly used for treating nerve disorders currently, the doctor that typically recommends you for the surgery is a neurologist, who specializes in the nervous system and its disorders.
However, in cases like hard-to-treat Obsessive-Compulsive Disorder (OCD), a psychiatrist (a doctor who specializes in mental disorders) may recommend you for the surgery, sometimes after discussing with a neurologist. The doctor who recommends the surgery and the neurosurgeon will talk about your case together. They will identify the key areas in your brain that the implanted device will stimulate to help manage your symptoms.
Preparing for Deep Brain Stimulation
Before the procedure can take place, the doctor needs to make sure that it’s safe and suitable for the patient to have surgery. This is called getting medically cleared. After the patient is cleared for surgery, they will have imaging tests done on their brain. These tests let the doctors see exactly where they need to put the electrodes in the brain.
How is Deep Brain Stimulation performed
Once the surgery starts, the medical team will secure a special frame on the patient’s head to keep it from moving. This frame is known as a stereotactic head frame. Usually, the patient is put to sleep for the surgery with general anesthesia, but sometimes local anesthesia, where only part of the body is numbed, can also be used. Interestingly, the brain itself doesn’t need to be numbed because it doesn’t have any pain-sensing cells.
In the next step, the surgeon places a thin wire, which has tiny electrodes at the end, into specific parts of the brain identified before the surgery. This wire is then linked to a cable that runs just under the skin, which eventually connects to a device called a pulse generator, which is placed inside the chest wall. The pulse generator sends electrical signals along the wire to the brain. Throughout the surgery, both the brain surgeon and a specialist in brain function check to make sure the electrodes are put in the right place.
Next, the team carries out a separate surgery to place the pulse generator device under the skin, near the collarbone. This part of the operation typically requires the patient to be put under general anesthesia. The pulse generator is then set up with a special remote control, which can adjust the electrical signals sent to the brain.
Possible Complications of Deep Brain Stimulation
Deep brain stimulation, a type of brain surgery, can have side effects that are different between patients and sometimes tricky to recognize. The obvious complications are usually related to the surgical process itself and can include bleeding, the need for hardware adjustments, and infections. However, some side effects related to mental and neurological health can be subtler.
Several factors explain why identifying these side effects can be tricky. Firstly, patients may not share all their symptoms with their doctors. Likewise, doctors may not ask the exact questions that reveal these side effects. In some cases, side effects may be ignored or not documented unless they are severe or troubling. It can also be challenging to differentiate pre-existing symptoms from new side effects caused by deep brain stimulation. Lastly, certain side effects may appear gradually over time. For example, some symptoms related to balance in Parkinson’s disease can slowly develop. As we understand our brains better through science, some effects considered improvements before are now seen as red flags. For instance, increased impulsivity in Parkinson’s patients was once seen as a positive outcome, but it is now recognized as a sign of impaired impulse control. Despite these complexities, current studies suggest deep brain stimulation is quite safe with only minor and possibly negligible side effects. However, some reported side effects from deep brain stimulation include mild issues with walking or talking, emotional instability, worsening depression, seizures, difficulty concentrating, confusion, and headaches.
What Else Should I Know About Deep Brain Stimulation?
Deep brain stimulation (DBS) – the process of sending electrical signals to the brain – is hailed as a life-changing treatment for people with Parkinson’s disease. This technique has already received approval from the Food and Drug Administration (FDA) for treating diseases such as essential tremor (uncontrollable shaking), dystonia (involuntary muscle contractions), Parkinson’s disease, and severe obsessive-compulsive disorder. Currently, there are ongoing studies exploring how DBS can be used in other conditions like addiction, autism, anorexia nervosa, anxiety disorders, and schizophrenia. This potentially opens up many new possibilities for using this technique to treat a wide range of mental health conditions.
