Deep Brain Stimulation (DBS) Components and its Adverse Side Effects

Description

Deep Brain Stimulation (DBS) is a neurosurgical procedure in which a neurostimulator is implanted. This device sends electrical impulses to specific targets in the brain (the brain nucleus) through implanted electrodes in order to treat movement disorders like Parkinson's disease, essential tremor, and dystonia as well as other conditions like Obsessive-Compulsive Disorder (OCD) and epilepsy. DBS directly modifies brain activity in a regulated way, despite the fact that its basic principles and mechanisms are not fully understood.DBS is used to treat some Parkinson's disease symptoms that are ineffectively managed by therapy.To simulate the clinical consequences of lesioning, high-frequency (>100 Hz) stimulation is used to treat Parkinson's Disease (PD) in three target structures: the Subthalamic Nucleus (STN), Internal pallidum, and Ventrolateral thalamus. As long as they do not have serious neuropsychiatric issues, it is advised for those with Parkinson's Disease (PD) who have motor fluctuations and tremor that medication cannot properly manage or for those who are drug intolerant. Neural stimulators have been used to treat four brain regions in PD. The thalamus, globus pallidus internus, subthalamic nucleus, and pedunculopontine nucleus are among them. However, in everyday practice, the majority of DBS procedures target either the globus pallidus internus or the subthalamic nucleus.

In general, DBS is linked to improvements in motor score evaluations of 30% to 60%. However, DBS is continually administered with set parameters, and it only partially controls the motor fluctuations that are a hallmark of Parkinson's disease. The idea of Adaptive Deep Brain Stimulation (ADBS), a sort of DBS that automatically changes stimulation parameters to parkinsonian symptom, was therefore developed in recent years. ADBS devices are now being researched for use in therapeutic settings.

With DBS, there is a risk of neuropsychiatric side effects such euphoria, apathy, hallucinations, hyper sexuality, cognitive impairment, and depression. These side effects, however, may be transient and related to appropriate electrode placement, open-loop vs closed loop stimulation, which refers to a continuous stimulation or an A.I. monitoring delivery system, and stimulator calibration, making them theoretically reversible.

The Implanted Pulse Generator (IPG), the lead, and the extension make up the DBS system. The IPG is a battery-operated neurostimulator that emits electrical pulses into the brain that disrupt neuronal activity at the target region. It is housed in a titanium housing. The lead is a coil of polyurethane-insulated wire with four platinum-iridium electrodes that is inserted into one or more distinct brain nuclei. An extension, or insulated wire, connects the lead to the IPG, which is positioned subcutaneously below the clavicle. The extension travels from the head, down the side of the neck, behind the ear, and to the IPG. A doctor, nurse, or other healthcare provider can calibrate the IPG.

In the brain, DBS leads are positioned in accordance with the kinds of symptoms that need to be treated. The lead is inserted in the zona incerta or ventrointermediate nucleus of the thalamus to treat non-Parkinsonian essential tremor; The lead may be inserted in the globus pallidus internus or the subthalamic nucleus for the treatment of dystonia and PD symptoms (rigidity, bradykinesia/akinesia, and tremor), the nucleus accumbens for OCD and depression, the posterior thalamic region or periaqueductal grey for chronic pain, and the anterior thalamic nucleus for the treatment of epilepsy.

During surgery, the brain can move somewhat, causing the electrodes to move or become loose from their original position. Although electrode misplacement is generally simple to detect using a CT scan, it may result in more serious issues like personality changes. Moreover, problems from surgery including brain bleeding are possible. Swelling of the brain tissue, moderate confusion, and tiredness are common side effects following surgery. A follow-up visit is performed to take out the sutures, activate the neurostimulator, and programme it after 2-4 weeks.