Deep brain stimulation (DBS) is a well-established treatment for Parkinson’s Disease. Minimally invasive, the procedure involves implantation of electrodes in the brain, with input from the patient who is awake throughout the surgery. Now, with an advanced neuro-intervention system, patient input is no longer required. So the patient can ‘sleep’ through the entire procedure.
The system is ClearPoint, and it’s currently available at only a handful of hospitals across the nation. Recently, Akron General Medical Center became the first between Cleveland and Columbus to offer DBS when it installed this new technology.
ClearPoint is an integrated system of software and hardware used for the planning, targeting and delivery of DBS. Specifically, the ClearPoint system utilizes intra-operative magnetic resonance imaging (iMRI) to provide stereotactic guidance for the placement and operation of instruments and devices.
Mark R. Hoeprich, MD, is the neurosurgeon who performs DBS at Akron General’s Neuroscience Institute. Dr. Hoeprich joined Akron General after completing fellowship training in epilepsy-function neurosurgery at the Montreal Neurological Institute and Hospital last year.
“The ClearPoint is new and exciting technology,” he says. “Coupled with our 3T iMRI that’s built right into our neurosurgery suite, it offers real-time image-guidance, so intra-operative participation of the patient is no longer required. Instead, the patient can undergo DBS while under general anesthesia.”
DBS Then and Now
Introduced in 1987, DBS has been refined as technology has evolved. The ClearPoint system, however, has revolutionized the procedure – making it safer, much faster (90–120 minutes), more comfortable and less stressful for the patient, according to Dr. Hoeprich.
“Patients have far less anxiety than when undergoing brain surgery awake,” Dr. Hoeprich explains. “Also patients with severe head tremor, who cannot be safely placed in a headframe while awake, can now undergo DBS. The frame goes on after they’re sedated and comes off prior to the patient awaking.”
And, with this technology, Dr. Hoeprich is able to perform bilateral placement of the electrodes – instead of placing them on one side at a time. This reduces total time of the procedure and time under anesthesia for the safety and convenience of the patient.
“It’s exciting. This system is totally state-of-the-art and just makes the procedure so much better,” he says.
The ClearPoint system utilizes iMRI to provide stereotactic guidance for the placement and operation of instruments and devices during DBS procedures.
Once sedated and placed in the frame, the patient is positioned inside the gantry of the iMRI where high-res anatomical images are taken before and during the procedure. This aids Dr. Hoeprich in seeing, selecting and reaching the neurological target.
ClearPoint software assists him in planning the optimal trajectory path from the surface of the skull down to the target and guides the location of the entry point in the patient’s skull. As the electrode is advanced, he observes real-time images to ensure that no undesirable events have taken place, such as hemorrhage, and to confirm that the desired target has been reached
“The power of this unit allows very good visualization of the electrode. We can see extremely well while placing it,” says Dr. Hoeprich. “And with the ClearPoint software and controller we can control the pitch and roll and direction of the electrode as it’s advanced.”
Once the electrode is docked, it is secured with fasteners, and the wires are tunneled under the skin to the chest wall below the clavicle. Generally, the patient stays in the hospital overnight and goes home the next day.
After a one- to two-week healing period, the unit is activated and programmed. The neurologist adjusts frequencies and on-off duration until the most effective stimulation is achieved. If there are side effects, the current can be adjusted or stopped entirely.
“Because Parkinson’s is progressive, patients should expect re-programming of the DBS system. And that’s the beauty of the procedure; it’s adaptable to the progression of the disease,” Dr. Hoeprich explains. “We can change the programming parameters as needed. Or we can turn it off or remove it, if needed. Unlike the old DBS procedure, this one is not ablative – it’s nondestructive – so it’s totally reversible.”
Patient Selection and Applications
Optimal results are generally achieved in patients ages 75 and under. “Selected patients ages 75–80 may be considered for the procedure, but there is potentially less benefit,” Dr. Hoeprich explains. “Beyond 80, the disease has probably progressed significantly enough that the patient does not receive much benefit from the stimulation.”
No special testing is required before referring a patient for DBS. However, the diagnosis of Parkinson’s should be confirmed with a trial of appropriate medications.
“If patients have a good response to Parkinson’s medications, they will likely have good response to DBS,” says Dr. Hoeprich.
DBS has also proven to be an effective option for patients with essential tremor, particularly when the dominant hand is affected severely enough to interfere with the activities of daily living and the tremor is not well controlled with medication. It’s also an option for select patients with obsessive-compulsive disorder.
While most patients, and even many physicians, consider surgery as a last resort, Dr. Hoeprich advises otherwise for patients with Parkinson’s.
“As soon as patients start having side effects from medication or they’re not getting good symptom control, they should be referred,” he says. “The reality is DBS with real-time imaging is a very safe procedure. The complication rates are very low. And it works best earlier on.”
He points out, however, that DBS is not a cure. It is an adjunct to medication and reduces medication doses.
“DBS reverses symptoms to the point they become more manageable, giving patients better control over movement and tremor and a better quality of life,” he says. “Rigid muscles loosen, and because a lower dose of medication controls tremor, dyskinesias subside.”
For more information about DBS at Akron General Medical Center, visit akrongeneral.org/neuro. To refer a patient to Dr. Mark Hoeprich, call 330-344-3100.