Clinical Improvements From DBS Mostly Meet Parkinson’s Patients’ Expectations, Study Shows

Deep brain stimulation can effectively reduce physical impairment caused by Parkinson’s disease and meets most patients’ expectations for improvements in several domains, a study reports.

However, researchers found that the procedure did fall short of meeting most patients’ expectations concerning the reduction of non-motor symptoms.

The study, “Does the degree of improvement after deep brain stimulation surgery for Parkinson’s disease (PD) meet the patient’s expectations?” was presented at the recent 2018 International Congress of Parkinson’s Disease and Movement Disorders in Hong Kong.

Deep brain stimulation (DBS) is a technique that uses electric stimulus applied to specific areas of the brain to treat people with advanced Parkinson’s disease whose motor symptoms, such as tremors, are not reduced with standard medication.

Thin wires are surgically implanted in the brain to deliver electric pulses to the subthalamic nucleus (STN) or the globus pallidus interna (GPi), areas of the brain involved in motor function.

Several studies have shown that DBS can effectively reduce motor symptoms and the necessary daily dose of medication, improving overall quality of life, in patients with advanced Parkinson’s as well as in patients with early-stage disease.

In this exploratory study, researchers identified which symptoms patients expected to improve with DBS and whether the anticipated levels of improvement were met after they had the procedure.

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The team assessed expectations prior to surgery and at six months to two years after DBS in 28 patients with advanced Parkinson’s disease, 20 of whom underwent STN-DBS and eight of whom had GPi-DBS. All patients completed a visual analogue scale (VAS) questionnaire — used to measure subjective characteristics or attitudes believed to range across a continuum of values and cannot easily be directly measured.

Significant clinical improvements regarding physical impairment, mobility, ability to perform activities of daily living, and stigma after DBS were observed. In addition, a significant reduction in total levodopa equivalent daily doses (mg/day) of 50.45% was observed in patients treated with STN-DBS.

These objectively determined outcome improvements were in accordance with patients’ self-reported changes after the treatment.

In general, pre-DBS patients’ expectations and the positive changes in Parkinson’s symptoms noted were not significantly different.

“There was no significant difference … between the pre-DBS expectations of general improvement in PD [Parkinson’s disease] symptoms and the perceived general improvement 6 months to 2 years after surgery confirming that general expectations of improvement were met after DBS,” the researchers wrote.

Most patients reported that expectations of improvement after DBS were met, namely 64% for motor symptoms, 71% for quality of life, and 83% for reductions in daily medication dose.

However, only 25% of the expected levels of improvement were met for non-motor symptoms and social domain.

The motivations for DBS were also met after surgery. In the GPi-DBS group, all patients (100%) were satisfied with the final reduction on uncontrolled movements (dyskinesia), 83.3% for motor symptoms, and 66.7% for quality of life.

In the STN-DBS treated group, 84.2% were satisfied with medication reduction, 78.9% with amelioration of motor symptoms, and 73.7% with their quality of life.

These findings demonstrate that DBS clinical outcomes meet the expectations of most patients. However, pre-DBS expectations for improvement of non-motor symptoms and social domain were not met after surgery.

“Overall, both STN-DBS and GPi-DBS patients were satisfied that DBS had met their expectations of surgery,” the researchers concluded.