Psychologists develop new roles with Parkinsonís patients
By Paula Hartman-Stein, Ph.D.
High tech surgical therapy used to treat advanced Parkinsonís disease is creating new opportunities in health psychology and neuropsychology. Specialty medical centers that offer Deep Brain Stimulation (DBS), or the implanting of electrodes that provide bilateral continuous high frequency stimulation of the subthalamic nucleus (STN), are increasingly requesting input from psychologists in the screening of appropriate patients for the procedure and follow up interventions for the patient and family.
According to Rochelle Winnett, Ph.D. from THE Virginia Mason Main Clinic in Seattle, Wash., "The good news is that the neurologist and neurosurgeon involved with these procedures value our input and have been open to including us in the assessment, post-treatment and rehabilitation phase of care with patients who are considered for DBS. In fact, this is about to be launched as a treatment protocol at our medical center."
DBS is considered an alternative treatment when pharmacological therapy fails to provide a satisfactory improvement of the quality of the patientís life. DBS has been shown to improve many Parkinson symptoms of tremor, rigidity, motor fluctuations, and permits a 40 percent to 80 percent reduction in the doses of antiparkinsonian medication.
However, the surgery is not without its risk to cognition, behavior, and mood. "There are data showing that patients with significant dementia have poor outcomes from DBS," explained William Stiers, Ph.D. Chief of Rehabilitation Psychology and Neuropsychology at the University of Kansas Medical Center.
Stiersí program has two components, a pre-operative neuropsychological assessment and post-op evaluation to assess patient anxiety and work with the family to improve coping skills. "We sometimes do in-vivo exposure for patients who are anxious about surgery. Post operatively we see folks for adjustment issues and management of depression and anxiety," Stiers said. In addition, Stiers and his staff work with patients not accepted for DBS because "they often experience significant hopelessness."
In one European study that analyzed reasons for excluding patients, about 30% were not considered suitable for surgery. The most frequent cause of exclusion was the finding of neuropsychological deficits or psychiatric disorders.
Rates of exclusion vary from center to center. According to Angela Haffenden, Ph.D., Clinical Neuropsychologist at the Calgary Health Region, Calgary, "Debates about patients who are borderline-suitable often end with a compromise rather than no surgery at all, starting with a unilateral stimulation procedure, waiting a number of months before trying the other side of the brain."
To assist in the selection of appropriate patients, Haffenden follows recommendations from the Toronto research team of Saint-Cyr and Trepanier that a borderline level of performance in a cognitive area indicates risk of post-surgical decline in that skill following DBS surgery. The research was reported in a 2000 issue of Movement Disorders.
"The specific skills at risk are weighed against the benefits of surgery. For example, decreased visual memory in isolation can be worked around and would likely have less of an impact on functioning than decreased verbal memory and executive function difficulties," according to Haffenden. Age, social support, and pre-existing psychiatric disorders are also factors she considers before she recommends a candidate for surgery.
Psychological and behavioral red flags include disturbance of mood, anxiety, and gambling. "Anyone with gambling issues is screened out unless the issue has been addressed and stable for a long time. We have seen gambling re-emerge as a problem after surgery," she said.
"By far the worse outcomes I have seen are people with bleeds during surgery who end up with significant executive dysfunction," according to Haffenden. "These people are extremely difficult for their families to handle and have little or no insight into the behaviors. Sometimes they themselves are quite happy as the surgery may have improved their motor function, though their spouses are at their breaking point."
There is little in the way of large scale, well-controlled studies of mood and behavioral disturbance post DBS surgery, but there are case reports of depression and manic behavior including hypersexuality following the procedure. Also Haffenden noted disturbing newly emerging data of a link between STN Deep Brain Stimulation and suicide. "There are much higher rates of suicide than in non-surgical Parkinsonís populations, though the reason is not clear. These suicides do not appear linked to surgical outcome and occur a few years after surgery," she explained.
Jeff Shaw, Ph.D., neuropsychologist from the Booth Gardner Parkinsonís Care Center in Seattle, Washington, noted that important tasks for psychologists on the treatment team include evaluating the patientís and familyís expectations for cognitive and functional outcomes and educating about potential side effects such as personality and emotional changes. "Possibly the most important role is to provide enough information to establish adequately informed consent," according to Shaw.
As in any new service, psychologists need to figure out appropriate coding and billing procedures. Many psychologists use the standard neuropsychology clinical assessment codes when billing for pre and post surgical cognitive evaluations. However, psychosocial education and preparation for surgery as well as interventions geared toward coping with sequelae of the procedure fit well within the newer Health and Behavior codes available to psychologists. These are billed in 15 minute increments of face to face time with the patient and do not require a psychiatric diagnosis. The medical disorder is the appropriate diagnosis to note on the claim form.
According to Antonio Puente, Ph.D., APA representative to the American Medical Associationís Clinical Procedure Code Committee, "The H and B codes were explicitly developed for the application of psychological principles to the assessment and rehabilitation of medical disorders." Interventions with DBS patients fit that description well.
National Psychologist, Vol. 13, No. 4, pp 4-5
Paula Hartman-Stein, Ph. D. is a consultant at the Center for Healthy Aging in Kent, Ohio, current President of APAís section of Clinical Geropsychology, and Director of Geriatric Psychology at Summa Health System in Akron. She can be reached through her website,www.centerforhealthyaging.com.