LCIG, DBS show quality of life gains, symptom easing: Real-world study

No improvements seen with continuous subcutaneous apomorphine infusion

Patricia Inácio, PhD avatar

by Patricia Inácio, PhD |

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Parkinson’s disease patients’ quality of life significantly improved with Duopa, a formulation of levodopa and carbidopa infused directly into the intestines, and subthalamic deep brain stimulation (DBS), but not with a continuous subcutaneous apomorphine infusion, according to a real-world, single center study.

Apomorphine also didn’t show any major changes in patients’ nonmotor or motor symptoms. Those given Duopa showed significant motor symptoms gains, however, and patients who received STN-DBS saw improvements in both.

Because patients had different characteristics at the start of the study, such as symptom severity, however, “treatment centers should be aware of this potential confounder when assessing and offering device-assisted treatment options,” researchers wrote in “A single centre prospective study of three device-assisted therapies for Parkinson’s disease,” which was published in npj Parkinson’s Disease.

A feature of Parkinson’s disease is the progressive loss of the brain’s dopaminergic neurons, or nerve cells, that produce the neurotransmitter dopamine — a chemical messenger essential for muscle control.

Standard treatment includes levodopa and its derivatives, which provide cells more material to make dopamine. However, with prolonged treatment patients can develop off episodes when symptoms aren’t adequately controlled between doses. Involuntary, jerky movements, or dyskinesia, can also occur.

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Comparing device-assisted strategies for treating off episodes

Several device-assisted strategies have been developed to help ease off episodes and dyskinesia.

Among these are apomorphine (sold as Apokyn, among others) that mimics dopamine’s activity in the brain. Injected subcutaneously (under the skin) with a pen, it’s approved in the U.S. for managing off episodes. It can also be administered as a continuous infusion during the day.

Duopa, a levodopa/carbidopa intestinal gel (LCIG), has been shown to efficiently treat motor fluctuations. It’s administered with a portable pump into the duodenum or upper jejunum by a permanent tube that’s been surgically inserted.

Deep brain stimulation (DBS) is a nondestructive surgical approach that involves placing a device inside the brain to deliver electrical impulses to stimulate specific brain areas.

Despite the number of studies that have tested each strategy’s effectiveness, few have compared the three with respect to patient outcomes, leading researchers in Australia to compare nonmotor and motor fluctuations, and quality of life, with each strategy at six and 12 months in a real-world observational study.

A total of 66 patients (46 men, 20 women; median age at start of treatment, 62) followed at the Neurology Department, Westmead Hospital, Australia between 2014-2019 were analyzed. Among them, 13 were treated with apomorphine continuous infusion, 19 with LCIG, and 34 with STN-DBS.

At the start of the study, the patients in the STN-DBS group showed significantly less severe cognitive, nonmotor, and motor scores, while the LCIG group had a longer disease duration and higher nonmotor scores.

The median total levodopa equivalent daily dose (LEDD; a sum of all Parkinson’s medications taken) significantly increased in the LCIG group after six (median, 2,014.5 mg) and 12 months (median, 2,038 mg) over the beginning of the study (median, 1,358 mg). In contrast, those receiving STN-DBS saw a significant reduction in LEDD, decreasing from 1,125.7 mg at baseline to 475 mg after six months and 462.5 mg after 12 months. No changes were observed in LEDD in the apomorphine group.

Initially, all the apomorphine and LCIG patients began with a 16-hour infusion rate. Only one patient in the apomorphine group switched to a 24-hour infusion after 12 months. In the LCIG group, after six months, four patients transitioned to 24 hours. Changing to a 24-hour infusion was prompted by freezing of gait, a sudden and temporary inability to begin or continue walking.

During the 12 months of follow-up, the STN-DBS group had fewer clinical visits (median, 8). The apomorphine group had a median of 10 clinical visits and the LCIG group had 15.

Quality of life gains with LCIG, STN-DBS

Quality of life, as assessed using the Parkinson’s disease questionnaire (PDQ-39), significantly improved at both six and 12 months in the LCIG and STN-DBS groups. No improvements were seen in the apomorphine group.

Only STN-DBS patients saw an ease in nonmotor symptoms at both six and 12 months, as shown by a decrease in Unified Parkinson’s Disease Rating Scale (UPDRS) part I scores, from a median score of 13 to 10.5 after six months, and 8.5 after 12 months.

Patients in both the STN-DBS and LCIG group saw significant gains in motor parameters, but none were seen in the apomorphine group. The gains were in UPDRS-IV scores, which assesses treatment-related complications, and the Unified Dyskinesia Rating Scale (UDysRS), which measures dyskinesia.

The LCIG group saw a reduction in freezing of gait, which was measured using the New Freezing of Gait Questionnaire (FOG-Q). These improvements were observed up to 12 months.

At the six-month mark, there were no changes in caregiver burden for any group. However, at 12 months, only the STN-DBS group showed a reduced caregiver burden, as measured using in the Zarit Burden Interview and Caregiver Strain Index.

Side effects occurred in 59% of patients, but none were deemed severe or resulted in hospitalization or death.