Obsessive-Compulsive Disorder (OCD) is a mental health condition in which people have unwanted and constant thoughts, feelings or ideas that make them anxious or uncomfortable, and perform compulsive behaviors or rituals to reduce the distress caused by the obsessions. OCD affects about 1-2% of adults and children around the world. The condition can be debilitating, interfering with daily activities and relationships, leading to depression and anxiety, and affecting the quality of life.

Treatment of OCD

The treatment of OCD involves psychotherapy, medications, or a combination of both.

Cognitive-behavioral therapy (CBT) is an effective form of psychotherapy that focuses on identifying and changing negative thoughts and beliefs that cause anxiety and behavioral responses. CBT can be delivered in individual or group settings.

Medications that are commonly used to treat OCD are selective serotonin reuptake inhibitors (SSRIs), which are antidepressants that can also help reduce the repetitive thoughts and behaviors associated with OCD.

However, some people do not respond to medications or have side effects that limit their use.

Deep Brain Stimulation for OCD

A new treatment option for severe and treatment-resistant OCD is Deep Brain Stimulation (DBS).

DBS is a neurosurgical procedure that involves implanting electrodes into specific regions of the brain, and connecting them to a pacemaker-like device that delivers electrical impulses to modulate the activity of the brain circuits involved in OCD.

DBS has been used successfully for over two decades to treat movement disorders such as Parkinson’s disease and Essential Tremor.

More recently, DBS has shown promise in treating psychiatric disorders such as depression, bipolar disorder, and OCD that are refractory to other treatments.

How DBS Works

The exact mechanisms by which DBS works for OCD are not fully understood. However, it is believed that DBS stimulates the cortical-striatal-thalamo-cortical (CSTC) circuits that are involved in the control of repetitive thoughts and behaviors.

These circuits involve the anterior cingulate cortex (ACC), the orbitofrontal cortex (OFC), the striatum, and the thalamus.

Abnormalities in these circuits have been implicated in the pathophysiology of OCD, where the ACC is hyperactive and the OFC is hypoactive, leading to the inability to suppress intrusive thoughts and the urge to perform compulsive behaviors.

DBS modulates the activity of these circuits, leading to the improvement of OCD symptoms.

How DBS is Done

The DBS procedure involves several steps:.

1. Pre-operative evaluation:

The patient is evaluated by a neurosurgeon, a neuropsychologist, and a psychiatrist to determine if they are suitable for DBS and to identify the target brain regions for electrode placement.

2. Stereotactic surgery:

The patient is placed under general anesthesia, and a stereotactic frame is attached to their head to provide a stable reference for brain imaging. The patient undergoes a brain MRI or CT scan to localize the target regions for electrode placement.

3. Electrode placement:

The neurosurgeon uses the stereotactic frame and brain imaging to place the electrodes precisely into the target regions of the brain.

The patient is awake during this part of the procedure to provide feedback to the surgical team and to ensure that the electrodes are in the correct place without causing side effects.

4. Internal pulse generator (IPG) placement:

The IPG is a small device that is implanted under the skin, usually in the chest, and connected to the electrodes in the brain through wires that are passed under the skin.

The IPG generates the electrical impulses that stimulate the brain circuits that are targeted for OCD treatment.

DBS Studies for OCD

There have been several studies of DBS for OCD that have shown promising results.

1. Greenberg et al. (2006)

Greenberg et al. implanted DBS electrodes in the ventral capsule/ventral striatum (VC/VS) of 10 patients with treatment-resistant OCD. They found a significant improvement in OCD symptoms in all patients at 12 months after surgery.

The patients reported a reduction in intrusive thoughts and compulsive behaviors, and improved mood and quality of life.

2. Denys et al. (2010)

Denys et al. implanted DBS electrodes in the subthalamic nucleus (STN) of 16 patients with treatment-resistant OCD. They found a significant improvement in OCD symptoms in all patients at 12 months after surgery.

The patients reported a reduction in intrusive thoughts and compulsive behaviors, and improved mood and quality of life.

3. Figee et al. (2013)

Figee et al. implanted DBS electrodes in the VC/VS of 16 patients with treatment-resistant OCD. They found a significant improvement in OCD symptoms in all patients at 12 months after surgery.

The patients reported a reduction in intrusive thoughts and compulsive behaviors, and improved mood and quality of life.

Side Effects of DBS

Although DBS is generally safe and well-tolerated, there are potential risks and side effects that must be considered.

Physical side effects:

DBS can cause temporary or permanent physical side effects such as infection, bleeding, headache, nausea, vomiting, and dizziness. These side effects can usually be managed with medication or adjustments to the electrical stimulation parameters.

Psychological side effects:

DBS can cause temporary or permanent psychological side effects such as mood changes, anxiety, irritability, and impulsivity. These side effects can usually be managed with medication or adjustments to the electrical stimulation parameters.

In rare cases, DBS can exacerbate or trigger psychiatric symptoms, and careful patient selection and screening are crucial to minimize these risks.

Conclusion

DBS is a promising and effective treatment option for severe and treatment-resistant OCD.

The procedure involves implanting electrodes into specific regions of the brain and providing electrical stimulation to modulate the activity of the brain circuits involved in OCD. Several studies have shown significant improvements in OCD symptoms and quality of life in patients who underwent DBS.

However, DBS is not without risks, and careful patient selection, screening, and monitoring are necessary to ensure optimal outcomes and minimize potential side effects.