Alliance Team visits Huntington Memorial Hospital DBS Team

Huntington Memorial Hospital’s Movement Disorders Program Pasadena, California

In February, 2010, The Parkinson Alliance was invited by the Movement Disorder’s team at Huntington Memorial Hospital (HMH) in Pasadena, California to become more familiar with their program.  We spent the day with the multi-disciplinary treatment team and observed a Deep Brain Stimulation (DBS) surgical intervention in one of their patients.

We thought it would be interesting for our readers to get a glimpse into how this Movement Disorders Program approaches DBS procedures as a treatment for their Parkinson’s disease (PD) patients. We have included the information about their program in a question and answer format. The following topics were discussed:

 

DISCLAIMER:  The approach to DBS described below is specific to the Huntington Memorial Hospital’s Movement Disorders Program. There are likely some commonalities as well as some differences between this program’s approach to the DBS procedure and the approach used with other Movement Disorder Programs. Thus, the information below should not be generalized.


Who is part of your interdisciplinary team?


How does the movement disorders team maximize the interdisciplinary model to optimize the DBS therapy outcome?


The program at HMH has a comprehensive approach in the care of patients with PD and their families.   Communication between team members is facilitated by the proximity of their offices as well as a monthly case review conference. Their operating room team, including a neurosurgeon, a neurologist, a specially-trained nurse practitioner, an anesthesiologist, a neurophysiologist, and OR nursing staff has been working together on deep brain stimulator implants for nearly 8 years and have performed over 250 DBS procedures. They emphasize a close working relationship between team members to help facilitate optimal surgical outcomes and to help ensure the patients’ comfort in the operating room.

The Movement Disorder’s Program at HMH also sponsors a monthly patient support group and biweekly exercise program. They include a separate support group specifically for caregivers (i.e., family members, friends, and other caregivers) of patients with Parkinson’s disease. They believe that taking care of the “whole” individual and collaborating in the care with his or her caregivers is crucial to obtaining the best possible outcome for each patient.
   
How does your team identify a good candidate for Deep Brain Stimulation to treat PD?

The best candidates for deep brain stimulation are patients with Parkinson’s disease who had responded well to medical therapy early in the course of their disease and then begin to experience difficulty with movement or unwanted movements despite taking their medications. Some good candidates may also be those who are intolerant of medications used to treat Parkinson’s disease because of medication side effects or declining effects of medication despite maximal medication treatment. When a patient fits the above profile, their general health status (usually with the help of their primary care doctor) as well as their memory and other thinking skills (conducted by a neuropsychologist) are assessed before making the final decision of whether DBS surgery is an appropriate treatment option for them.

What can a patient expect before surgery?

 
A patient is initially screened by the neurosurgeon and nurse practitioner (and movement disorder doctor, dependent on the institution) to determine if he or she may benefit from treatment with deep brain stimulation (DBS). The patient and their family are counseled with regards to the nature of the intended operation, its expected benefits and outcomes, and risks of surgery.

A patient may be asked to visit his or her primary care doctor to obtain further input regarding the health of the patient and to ensure he or she will be able to tolerate the surgery. Some patients may also visit a cardiologist, pulmonologist, or other physician specialist. Also, routine pre-operative tests such as blood and urine laboratory tests, heart tests such as an EKG/ECG, and a chest x-ray are performed.
 
Each patient is evaluated by a neuropsychologist. The primary responsibility of the neuropsychologist during the pre-surgical phase of DBS is to conduct an evaluation to determine whether or not a patient is a good candidate for DBS treatment.  Specifically, the neuropsychologist will assess both thinking skills and psychological factors such as emotional well-being to assist in determining candidacy for the procedure.

Standardized testing using the Unified Parkinson’s Disease Rating Scale (UPDRS) is also performed. This assessment involves stopping Parkinson’s medications for 12 hours, performing a series of tests, and then repeating these tests while the patient is back on Parkinson’s medications.

Finally, a pre-operative Magnetic Resonance Image (MRI) of the brain is the key to the success of this operation. It serves as a roadmap which can be followed during surgery by our neurophysiologist and the surgeon to ensure proper electrode placement.

Do patients who are going to have bilateral DBS (DBS on both sides of the brain) at Huntington Memorial Hospital undergo the surgery [on both sides of the brain] on the same day or on two different dates?

The neurosurgeon at Huntington Memorial Hospital prefers to conduct the surgery on two different dates for two main reasons. First, the movement disorder team has found that individuals who undergo surgery on one side at a time tend to experience a quicker recovery. Second, if one conducts surgery on both sides of the brain on the same day, the brain may swell or shift during the first procedure, which may then slightly alter the location of the “target” on the second side. Specifically, during any brain surgery, including a burr hole for placement of DBS, the brain usually shifts by a small amount because of pressure equalization and introduction of intracranial air. So, after the first DBS implant is performed, the target for the second side, in some patients, may have shifted by a millimeter or two. This small shift may affect the targeting and thus the effectiveness of DBS on the second side. This shift is one of the main arguments to use intra-operative MRI that helps optimize the outcome of the procedure if bilateral DBS surgery is performed on the same day. However, simply waiting a couple of weeks between the procedure allows the brain to return to its normal position and eliminates this problem.

What can a patient expect on the day of surgery?


A patient will be asked not to eat or drink anything after midnight of the day prior to surgery so that the anesthesiologist can safely treat the patient during surgery. A patient will also be asked not to take his or her usual Parkinson’s medications, so that all his or her usual symptoms can be evaluated in the operating room. This will help with placing the DBS at the best spot in the brain.

A patient and his or her family can expect to arrive 2 hours before surgery so that the patient can register with the hospital and nurses can prepare the patient for surgery.

Before surgery, and with deep sedation, a special “stereotactic” frame is placed by the neurosurgeon. This means the patient is fully asleep during this part of the procedure. Our team then escorts the patient to radiology for a CT scan of the head. This CT scan is fused to (or superimposed on) the MRI scan that was previously obtained. Using the MRI and CT scans, the surgeon then uses the computer in the operating room to choose the location in the brain for the DBS implant.

The patient returns to the operating room where he or she is in a semi-seated position; the stereotactic frame is attached to both the head and the gurney (mobile bed).

During surgery, the patient is asleep. In this type of surgery, however, it is important that the team be able to determine the optimal placement of the electrodes, which requires that the patient be awakened so that the effects of the stimulator can be tested. The patient is asked to perform some basic movements while the stimulator is “on” so positioning can be fine tuned. The severity of the patient’s tremor and/or rigidity is also assessed. The patient will not feel any pain during this part of the procedure. Remarkably, the brain itself has no pain sensors!

Once the stimulator placement is optimized, the patient is again sedated so the operation can be completed.

Why is a patient awake during parts of the procedure? For how long is a patient awake?

It is important to highlight the role of the anesthesiologist. This clinician has the critical role of helping to sedate the patient at specific points during the DBS procedure, which helps to maximize patient comfort. In fact, the patient is asleep for approximately two-thirds of the procedure at Huntington Memorial Hospital. The anesthesiologist uses his or her skills to bring the patient in and out of a sedated state to assist in maximizing comfort and to assist the other members of the movement disorder’s team in identifying optimal lead placement. 

The patient is awake during about one-third of the procedure for assessment of their movement, rigidity, and tremor. The team tries to reduce or even eliminate tremor or rigidity associated with Parkinson’s disease while ensuring that no other improper movement or sensations are created. Simple adjustments of the electrodes based on patient testing and the report of his or her sensations ensures side effects are eliminated/minimized and optimal placement is obtained.

What happens after surgery? How long is a patient in the hospital after surgery?

A patient typically stays at the hospital for one night after surgery and is discharged home the next day. His or her stimulator will be functioning at a low level and the patient can expect to continue some of their Parkinson’s medications as well. It is when the patient returns for a follow-up visit in the outpatient setting that the actual programming occurs to help maximize the effects of DBS.

Prior to discharge, the patient is seen again by his or her surgeon and/or nurse practitioner. The patient can also expect an evaluation by a neurologist as well as a physical therapist. A specialist in physical medicine and rehabilitation, called a physiatrist, may also assess whether or not the patient requires additional rehabilitation and may recommend several days of acute rehabilitation before discharge home. This allows the team the opportunity to optimize the deep brain stimulator programming and medication treatment in conjunction with therapy services by physical, occupational, and speech therapists.

How many days after discharge do patients typically return to your office?

The patient returns for a follow-up appointment with his or her neurologist, neurosurgeon and nurse practitioner approximately 1 week after surgery. The incision will be checked and if appropriate, sutures or skin staples will be removed. Most importantly, it is time for further programming of their deep brain stimulator and for more medication adjustment.

Could you describe the programming process?

Patients leave the hospital with low-level stimulator settings.

As part of the DBS placement operation, a small electrical stimulation generator, similar to a pacemaker, is placed in the upper chest area. This generator houses the computer and battery that power the DBS equipment in the brain, connected by a small wire that travels in the neck and the scalp, through the skull to the brain electrodes.

A small radio receiver connected to a computer is placed over the generator so the doctor or nurse practitioner can “talk” to the generator and change settings. The patient’s symptoms are checked as settings are changed. This process takes place at several sessions over the course of several different visits until the combination of settings and medications sufficiently decreases or eliminates the symptoms of PD (e.g., the motor symptoms that improve with Levodopa (dopamine) are generally the individual symptoms that will improve with surgery).

It is very important to remember that programming is not a “one-time” occurrence. It is up to the patient and his or her doctor or nurse practitioner to work together over the course of several visits to optimize treatment with both DBS programming and medication changes [as needed].

In first few days after surgery, some individuals can experience changes in their symptoms due to the low-level settings that have been established.  There may also be a “microlesion effect,” caused by the actual electrode placement in the brain and the brain’s reaction to this placement. Some patients have additional but short-lived improvements of their symptoms and are concerned when the effects decrease. This slight decrease in initial improvement does not mean that the stimulator is not working. It just means it is time to begin proper programming.

What follow-up appointments [and with whom] can the patient expect to have?

The patient is usually followed by his or her neurologist for medication and DBS management. The patient will also be seen by his or her movement disorder’s team for additional DBS programming and to manage the surgical incisions.

If a patient is in need of bilateral DBS, does he or she undergo surgery for both sides on the same day? If not, approximately how long is the duration between surgical visits? 

Implantation of the DBS electrodes is typically done on one side of the brain at a time. The HMH team typically recommends several weeks between operations to allow for resolution of brain swelling.

Does every patient receive rehabilitation services?

The patient is typically seen by Physical Therapist (PT) and Occupational Therapist (OT), and he or she may also have an evaluation by Speech Therapist (ST). If a patient is thought to benefit from acute inpatient rehabilitation, there will be a request for a consultation by a Physical Medicine and Rehabilitation physician (physiatrist).
 
What makes a DBS patient an inappropriate or appropriate candidate for rehabilitation services?


Many patients can benefit from PT/OT/ST on an outpatient basis, but the decision for acute inpatient rehabilitation is more involved. The patient's diagnosis of PD is a rehabilitation diagnosis. Some factors that are taken into consideration when determining the appropriateness for a referral for acute inpatient rehabilitation include: a decline in function post-operatively, medical necessity, and a reasonable expectation that the patient will improve functionally in a reasonable time period.

Is the decision to engage in rehabilitation based solely on the physiatrist’s evaluation, and what is the general perspective about rehabilitation following DBS?

The physiatrist uses the data gathered from PT/OT/ST in conjunction with the patient's other medical problems to determine medical necessity for acute inpatient rehabilitation.  The physiatrist uses the data to conceptualize whether a patient will 1. be able to make a reasonable return towards their prior level of function, and 2. demonstrate a reasonable improvement from his or her current level of function in a reasonable amount of time while requiring 24 hour rehabilitation nursing and physician treatment and supervision.  
 
Patients in an acute rehabilitation facility are followed closely by the rehabilitation physician and frequently by the Movement Disorder’s team, which allows for better coordination of therapies and adjustments to DBS settings and closer medication management. Patients in the acute rehab setting receive more intensive therapy daily than a patient would get in the outpatient setting. To participate in acute inpatient rehabilitation a patient must be able to participate in 3 hours of multidisciplinary therapy daily (PT, OT, and ST), typically at least 5 days per week, often 6.

We want to extend a special thank you to Dr. Igor Fineman and Jen Birch, NP for the invitation to spend time with their team and for the educational experience.