Deep brain stimulation may sound intimidating, but if it means helping patients with Parkinson’s disease or essential tremor, this advanced surgery with a technological solution can help.
Dr. Andre Machado, chairman of the Neurological Institute at the Cleveland Clinic, answers some questions about deep brain stimulation, including what it means, how it works and the long-term effects.
HealthScene Ohio: What exactly is deep brain stimulation (DBS)? And could you describe the surgical procedure behind it?
Dr. Andre Machado: Deep brain stimulation is a neurostimulation system – that is, an electrical system similar to a pacemaker that sends controlled and adjustable electrical pulses to areas of the brain that are targeted by the surgeon. Common areas of the brain targeted in the treatment of Parkinson’s disease or essential tremor are the globus pallidus, subthalamic nucleus and thalamus. DBS leads are inserted in the brain with stereotactic techniques guided by either physiology (i.e., brain mapping) or by images obtained during the procedure, such as intraoperative MRI or intraoperative CT.
HSO: Readings state the three components of DBS: the implanted pulse generator, the lead and an extension. Can you describe these and their significance?
AM: The pulse generator is the power source and computer that controls the whole DBS system. It generates the sequence of controlled electrical pulses that are delivered to the brain. The extension wire transmits the electrical pulses from the generator – typically implanted in the chest – to the brain lead. The brain lead is implanted in the target area(s) in the depth of the brain and delivers the electrical pulses to the area the surgeon targets.
HSO: What are the side effects and/or complications of DBS?
AM: The side effects of DBS can be categorized as related to the procedure, the device or the stimulation.
- Related to the procedure: The most dreaded side effect of the surgical procedure is hemorrhage in the brain, which amounts to a stroke. This is fortunately quite uncommon. Other complications include infection, suboptimal placement of the lead requiring revision surgery and wound breakdown.
- Related to the device: Medical devices can malfunction or break, requiring surgery to replace them. They can also break through the skin, becoming exposed. That usually requires removal of the hardware and reimplantation.
- Related to stimulation: When adjusting the device, patients will always feel some side effect from stimulation, such as tingling on one side of the body or muscle pulling. These are temporary and reversible. We program around these side effects to produce the desired effects with as few side effects as possible. Long-term stimulation can cause cognitive side effects in some patients, and we do a thorough assessment preoperatively to mitigate this risk (see below).
HSO: Does DBS have a role to play in the treatment of stroke victims?
AM: DBS is not common for stroke victims. We are now studying how DBS can help stroke victims in a first-in-man clinical trial at Cleveland Clinic. We are enrolling patients who have had a stroke in the last 12-36 months and remain with significant weakness on one side of the body as a sequela. Stroke patients who want to participate in our clinical trial can contact our research coordinator, Alexandria Wyant, at wyanta@ccf.org, or call 216-444-1179.
HSO: What other ailments might be relieved through DBS?
AM: DBS is commonly performed – a standard of care – in patients with Parkinson’s disease and essential tremor as well as some forms of dystonia. DBS is FDA-approved for these conditions and reimbursed by Medicare, Medicaid and commercial insurance. DBS provides excellent relief of tremor, rigidity, bradykinesia, freezing of gait and dyskinesias. DBS consistently improves the quality of life and function in patients with advanced Parkinson’s disease and tremor.
HSO: How should patients prepare for a DBS procedure?
AM: Patients with Parkinson’s disease or essential tremor who have attempted medical management and cannot control their symptoms well with medications alone should contact a specialized center to book an appointment. In order to determine if the patient is a good candidate for the procedure, we conduct thorough testing including neurological assessments, video recordings on and off medications, and a cognitive assessment.
HSO: For those who undergo DBS, what is altered, fixed or changed within the brain?
AM: The effects of DBS are adjustable and reversible. The electrical pulses modulate the activity of the neural networks associated with the symptoms that we want to treat: tremor, rigidity, bradykinesia and dyskinesia. DBS does not change the gross anatomy of the brain and does not produce a lesion in the brain like procedures that were done in the past, such as thalamotomy and pallidotomy.
HSO: Does this procedure cure the disease or illness?
AM: No. DBS does not cure Parkinson’s disease or tremor. It significantly improves the symptoms, quality of life and function of patients with these disorders.
HSO: What are the short-term and long-term benefits of DBS?
AM: DBS provides short- and long-term improvements in quality of life and function by treating symptoms that interfere with daily life such as tremor. Patients who are having limitations in their quality of life or social life because of these motor symptoms have significant improvements after DBS. For example, patients who avoid going out in public or eating in public because of severe tremor note that their social lives and independence to perform activities of daily living improve after DBS. Also, patients who are losing the ability to perform their job or occupation because of slowness or tremor note significant improvements and can remain in their jobs.
HSO: What are some recent breakthroughs in DBS, both in terms of procedure process and in terms of effects from the surgery?
AM: Significant breakthroughs include improvements in how the surgery is done. We can now offer DBS as a faster and safer operation than in the past. We can also offer the operation to be done under general anesthesia, thanks to new technology and experience at Cleveland Clinic. In the past, all patients had to have their surgery done awake in order to test the effects of DBS. We can now perform the operation under general anesthesia using an intraoperative MRI to guide the placement of the leads, obviating the need for having the patient awake in some cases. Other breakthroughs are related to research on how DBS may be able to help patients with other disorders such as OCD, stroke and other disorders of movement.
Lydia Freudenberg is a contributing editor. Feedback welcome at feedback@cityscenemediagroup.com.
About the Expert
Dr. Andre Machado is the Chairman of the Neurological Institute and the Charles and Christine Carroll Family Endowed Chair in Functional Neurosurgery. Dr. Machado performs deep brain stimulation (DBS) surgery for patients with Parkinson’s disease, tremor, dystonia and obsessive-compulsive disorder, as well as surgical procedures for patients with trigeminal neuralgia, intractable pain syndromes and spasticity.
Dr. Machado received his medical degree from the University of Sao Paulo in 1997. He completed his residency in the same institution in 2003 and obtained his Ph.D. in 2004. He came to the Cleveland Clinic in 2004, completed his fellowship in Stereotactic and Functional Neurosurgery in 2006, and has been on the staff of the Cleveland Clinic since.
