What is Neuromodulation Surgery for Psychiatric Disorders?
Despite advancements in medication for anxiety, obsessive-compulsive disorder, depression, and schizophrenia, some patients don’t respond to these treatments. That’s why doctors are starting to think about brain surgery as a final option for these hard-to-treat cases. This type of surgery, called neuromodulation surgery, involves placing a device within the brain to adjust the brain’s networks.
The idea to use surgery to treat mental health issues isn’t new. But in the past, it was often viewed negatively because it led to many complications and deaths, without noticeably improving the patients’ condition. Back in 1881, a Swiss psychiatrist named Gottlieb Burckhardt used surgery to treat aggression and hallucinations in six patients but was only partially successful. Several years later, more surgeries were performed to affect different parts of the brain, like the frontal lobe, with the hope to improve mental health conditions. However, these methods also underwent modifications due to their risks.
Frontal lobe surgery gained traction after a successful experiment with chimpanzees. This inspired Egas Moniz, a Portuguese neurologist, to introduce prefrontal leucotomy, a surgical procedure. He believed that problematic connections to the frontal lobe were the cause of some mental ill-health, and removing these connections would help. This technique was used widely and even earned Moniz a Nobel Prize.
Then came the era of transorbital leucotomy, a less invasive surgery performed by an American neurosurgeon, Walter Freeman. This quick procedure aimed to separate the frontal lobe from the thalamus by accessing the brain through the back of the eye using a sharp instrument. However, like earlier procedures, this method too had complications and didn’t always prove effective.
Psychiatric treatment took a significant turn in the late 1950s with the introduction of psychotropic drugs approved by the U.S. Food and Drug Administration. Meanwhile, surgical techniques were also evolving. The concept of stereotactic surgery, which allowed precise lesions in deep brain areas, was developed. This technique, along with the growing understanding of the brain’s structure and function, and the success of similar surgeries in treating movement disorders like Parkinson’s disease, led medical professionals to consider neuromodulation surgery again for treating psychiatric conditions. The ongoing discussion is about whether these techniques should be used only as a last resort, or for other purposes too, like altering the cognition of healthy individuals. Profession guidelines for these procedures were introduced, emphasizing the importance of ethics in healthcare.
What Causes Neuromodulation Surgery for Psychiatric Disorders?
Our understanding of the brain and how it functions has greatly improved over the years, thanks to new ways of studying it. But figuring out why some people develop mental health disorders is still quite challenging. Most doctors think that these disorders are likely caused by a combination of many factors. Two of the most significant factors are believed to be genetics (the traits and conditions we inherit from our parents) and environment (the world around us, including our experiences).
Let’s take schizophrenia as an example. While we don’t know the precise cause, it’s thought that genetics plays a role in about 80% of cases. There are also some significant childhood experiences and environmental elements that are believed to contribute, like exposure to infections while still in the womb, not getting enough nutrition early in life, and living in a city.
This multi-factor approach is also used to explain other disorders like obsessive-compulsive disorder, anxiety disorder, and depression. Anorexia nervosa, an eating disorder characterized by extreme weight loss due to self-starvation, is also highly influenced by genetic factors.
Risk Factors and Frequency for Neuromodulation Surgery for Psychiatric Disorders
Psychiatric disorders present a serious challenge both in the United States and globally. According to the American Psychiatric Association, about 1 in every 4 adults in the United States is diagnosed with a mental health disorder each year. These disorders not only cause disability, distress for the patients, but they also impose a heavy financial burden on the economy. For example, as per a 2002 report, the cost of treatments for schizophrenia alone was about $63 billion.
- It’s estimated that between 15-20% of adults will suffer from a serious depressive episode in their lifetime.
- About 2-3% of the population is affected by Obsessive-Compulsive Disorder (OCD).
- Between 10-25% of people with psychiatric disorders don’t see improvements from medication and behavioral therapy.
- About 20-30% of patients with schizophrenia don’t respond to antipsychotic medications and can’t lead a healthy life.
- Furthermore, Anorexia Nervosa (AN), a psychiatric disorder, is common in young women, affecting about 1% of them. Yet, it has the highest mortality among all psychiatric disorders.
Before medications for psychiatric disorders were introduced, about 10,000 leucotomies, a form of brain surgery, were done in the United States and the UK. Within a few years, this number significantly climbed, with over 60,000 procedures. However, with the introduction of a medication called chlorpromazine in 1954, things began to change. In its first year, about 2 million patients received this drug. Nowadays, fewer than 15 types of destructive brain procedures are performed each year in the United States.
Signs and Symptoms of Neuromodulation Surgery for Psychiatric Disorders
Psychiatric disorders are not diagnosed with tests or biological markers, according to the Diagnostic and Statistical Manual of Mental Disorders. Diagnosis is primarily done by identifying the patient’s symptoms, behaviors, personality traits, among other features. Certain diagnostic tests exist, but are usually used to rule out other possible health conditions.
The main tools for diagnosing and treating mental illnesses are taking a comprehensive medical history and physical examination of the patient. Understanding a patient’s past and present health condition, psychiatric history, substance abuse situation, family and social background, as well as medication details helps the doctor grasp the entire scenario. Information such as patient’s familial susceptibility to certain disorders and social difficulties can prove useful. Sometimes, a medication’s effectiveness on a family member might hint toward its likely success on the patient.
The physical examination starts with a simple visual assessment of the patient. This can provide information about the patient’s overall health and nutritional status. For instance, inappropriately dressed or untidy patients could be significant. Other areas of examination include the patient’s psychological activity levels, mood and emotions, and thought process and content. It’s important to observe for signs of reduced or overly frenetic movement, abnormal speech patterns, presence of hallucinations or delusional thoughts, or potential self-harm or harm to others.
The documented history of the patient can focus the physical examination on specific parts of the body. For instance, if a patient appears pale and dry, the doctor may suspect self-neglect or improper diet due to conditions like depression, schizophrenia, or anorexia nervosa. Symptoms such as scarring from self-harming are scrutinized in cases hinting towards borderline personality disorder, depression, or eating disorders. Any physical signs that stick out from the patient’s history are given further attention during the physical examination.
Testing for Neuromodulation Surgery for Psychiatric Disorders
There have been significant advancements made in how we evaluate brain function which helps us target treatments for mental health conditions. There are several diagnostic techniques that provide useful information about different areas of the brain and how they’re functioning.
One such technique is TMS— Transcranial Magnetic Stimulation. TMS is a noninvasive (doesn’t involve surgery), which means it can safely probe how different brain areas are functioning as it shouldn’t cause physical harm.
Other techniques include fMRI (Functional Magnetic Resonance Imaging) and PET (Positron Emission Tomography) scans. These are particularly good at giving insights about the deeper structures of the brain that are located beneath the outer layer or cortex.
Of course, it’s important that doctors eliminate other potential health conditions that might explain the appearance of symptoms typically associated with psychiatric disorders. So, laboratory tests could be done to ensure that the symptoms are not caused by other physical illnesses. Doctors might also use techniques like MRI (Magnetic Resonance Imaging) or CT (Computed Tomography) scans to get a detailed picture of specific parts of the body as necessary.
Treatment Options for Neuromodulation Surgery for Psychiatric Disorders
In treating psychiatric disorders, the main goal is to improve a patient’s ability to function within society. In the past, surgery on the brain (known as psychosurgery) was avoided due to the stigma attached to it. But now, as our knowledge about brain structure and function increases and microsurgical techniques evolve, it is being cautiously used as a form of treatment for psychiatric disorders.
Now, the preferred surgical method for psychiatric disorders is neuromodulatory surgery; specifically, a technique known as deep brain stimulation (DBS) is commonly used. DBS is less invasive and has reversible effects, unlike older procedures that permanently removed parts of the brain. This surgery involves placing electrodes deep within the brain to either stimulate or inhibit specific regions, helping to balance out brain activity and alleviate symptoms of conditions such as OCD, anxiety disorders, and major depression. The exact way in which DBS works remains unknown but it is thought to adjust the activity of neurons and the pathways between them.
DBS is a complex procedure and requires careful planning. It involves the use of neuroimaging studies and the attachment of a special frame to the patient’s head. The surgical path must avoid any vessels and walls within the brain, and the position of the electrodes is confirmed through postoperative brain imaging. Once implanted, the stimulation can be adjusted based on the individual’s needs, and regular psychiatric and neuropsychological assessments are needed to evaluate the effectiveness of the procedure.
The effectiveness of DBS largely depends on the targeted area in the brain. For depression and other major affective disorders, DBS has shown good results in about 50-70% of patients. For OCD, the positive response rate is between 40-90%.
Vagal nerve stimulation (VNS) is another surgical option for treating psychiatric disorders. It involves a device being surgically implanted to stimulate the left vagal nerve in the neck, which can help control certain neurological and mental health conditions. Originally developed as a treatment for epilepsy, VNS has also been found to be effective in managing depression and anxiety disorders. Its effectiveness was initially questioned, but recent studies have shown it to be successful in treating treatment-resistant depression.
Aside from surgical options, non-invasive procedures like transcranial magnetic stimulation (TMS) and electroconvulsive therapy (ECT) are also used to treat psychiatric disorders. ECT is known to be one of the most effective treatments for chronic major depression resistant to drug treatment, and TMS is often used for diagnostic purposes and has been used to treat conditions like major depressive disorder
Unfortunately, these less invasive methods are often underutilized due to their stigma. But research is ongoing, with new techniques being developed and tested.
What else can Neuromodulation Surgery for Psychiatric Disorders be?
When diagnosing mental health conditions that might be improved with neuromodulation treatments, it’s really important to get it right. A wrong diagnosis could mean patients end up getting treatments that aren’t suitable for them. There are several other health issues that may seem like mental health conditions at first because they share some symptoms, but they’re actually different problems. Once these other health issues are treated, the mental health symptoms can get better. These conditions include:
- Attention-deficit/hyperactivity disorder (ADHD)
- Autoimmune disorders, like rheumatoid arthritis and lupus
- Chronic fatigue syndrome
- Hypercortisolism, which involves having too much cortisol and is seen in conditions like Cushing’s disease or syndrome
- Diabetes
- Fibromyalgia – a long-term condition that causes pain all over the body
- Hypothyroidism – where the thyroid doesn’t produce enough hormones
- Lyme disease – an infection caused by tick bites
- Sleep disorders
What to expect with Neuromodulation Surgery for Psychiatric Disorders
Despite its initially negative reputation, modern cingulotomy – a type of brain surgery – has shown to bring about an improvement in nearly 70% of patients living with Obsessive Compulsive Disorder (OCD) and in about 75% of patients with major depression, five years after the treatment.
Another procedure, known as anterior capsulotomy with radiosurgery, has resulted in over 70% improvement in patients with severe, unmanageable OCD over a 5-year period. For those suffering from alcohol dependence and unmanageable Anorexia Nervosa (AN), a method called bilateral stereotactic radiofrequency ablation of the nucleus accumbens has offered remission rates (no recurrence of symptoms) of 64-82%.
The use of bilateral cingulotomy for heroin addiction has also seen a remission rate of 45%.
For another treatment called Deep Brain Stimulation (DBS), the success rate varies depending on the mental health disorder and where in the brain the treatment is targeted.
* For OCD, use of DBS in the internal capsule has shown a 55% improvement rate, while the anterior capsule/striatum has a 62% response rate and the inferior thalamic peduncle has a 100% response rate. The nucleus accumbens shows an improvement rate of 38% and the subthalamic nucleus, a 50% response rate.
* For Major Affective Disorder (a type of mood disorder), DBS in the anterior capsule/striatum has shown a 40% improvement rate with 25% going into remission, while the cingulate has a 58% improvement rate with 28% remission. The nucleus accumbens has shown 48% improvement and 5% remission.
* For Tourette Syndrome (TS), only individual case reports and small group studies have been conducted so far, showing a wide range of improvements from 46% to nearly 100%.
Possible Complications When Diagnosed with Neuromodulation Surgery for Psychiatric Disorders
Complications and Side Effects:
- Seizures
- Bleeding in the brain (Intracranial hemorrhage)
- Mild mood elevation (Hypomania)
- Extreme mood elevation (Mania)
- Deterioration of depression
- Increased risk of suicide
- Need for additional surgeries due to battery changes
- Issues with the medical device (Hardware malfunction)
- Infections
- Incorrect placement of the electrode (Electrode misplacement)
- Skin wearing off (Skin erosion)
- Weakness on one side of the body (Hemiparesis)
Preventing Neuromodulation Surgery for Psychiatric Disorders
Despite the advancements in medicine for treating mental health disorders like schizophrenia, anxiety disorders, obsessive-compulsive disorder (OCD), and depression, some patients don’t respond well to these treatments. Neuromodulation offers another option which often results in effective treatment for these patients.
Neuromodulation is a process that modifies or adjusts nerve activity by delivering electrical or pharmaceutical agents directly to a target area.
It is important for both doctors and patients to examine these new modulatory treatments carefully, especially when dealing with mental health disorders that have not responded to other treatments. Each treatment method should be given consideration based on scientific evidence rather than their past reputation. All these neuromodulatory treatments should be tested in blind trials and systematic randomized trials. This means patients in the study don’t know if they’re receiving the actual treatment or a placebo, which helps to eliminate bias and accurately measure the treatment’s effectiveness. Furthermore, finding the right patients to treat and the specific areas in their brain to target are necessary steps that need further exploration.
Deep brain stimulation (DBS), a type of neuromodulation, is often used for patients suffering from difficult to treat obsessive-compulsive disorder, major mood disorders, Gilles de la Tourette syndrome (which causes a person to make unintended sounds or movements), and anorexia nervosa. Occasionally, it is also used to treat drug addiction and certain forms of severe aggression or self-aggression.
