Beyond nine years of continuous subthalamic nucleus deep brain stimulation in Parkinson's disease

Abstract

Deep brain stimulation of the subthalamic nucleus is an effective treatment for advanced Parkinson's disease. The benefits of bilateral subthalamic stimulation are well documented, and some studies reported outcomes with a follow-up of 5 to 6 years; nevertheless, few data are available beyond 5 years. We report a long-term prospective evaluation of 14 consecutive parkinsonian patients, treated by bilateral subthalamic stimulation for at least 9 years. Motor symptoms, activity of daily living, and motor complications were evaluated by means of the Unified Parkinson's Disease Rating Scale, while cognition and mood were assessed with a specific neuropsychological test battery; medication intake, stimulation parameters, comorbidity, and adverse events were also recorded. Patients were evaluated before surgery and at 1, 5, and ≥ 9 years after surgery. At last follow-up, deep brain stimulation significantly improved the motor score by 42% compared to baseline, whereas activities of daily living were no longer improved; there was a 39% reduction in the dosage of dopaminergic drugs and a 59% improvement of L-dopa-related motor complications. The neuropsychological assessment showed that 4 patients (29%) developed a significant cognitive decline over the follow-up period. These results indicate a persistent effect of deep brain stimulation of the subthalamic nucleus on the cardinal motor symptoms in advanced Parkinson's disease patients in the long-term; however, a worsening of patients' disability, mainly due to disease progression, was observed.

Long-term outcome of subthalamic nucleus DBS in Parkinson's disease: From the advanced phase towards the late stage of the disease?

“…Our findings agree with what observed in other studies [6], [7] and [8], and could be chiefly explained by the progression of the disease over time [16]. While the cardinal PD symptoms keep on improving with stimulation, there is a progressive emerging of poorly levodopa-responsive symptoms, mainly axial symptoms, speech problems and postural instability.…”

“…STN-DBS efficacy on PD motor symptoms is well documented in the short-and medium-term, up to 5-6 years [4] and [5], while a few papers with a small number of examined patients addressed the long-term efficacy of this procedure [6], [7] and [8].…”

“…Recently, three series have further expanded the time-length of the follow-up, showing that the effect of STN-DBS on motor symptoms persists after 8-10 years of continuous stimulation [6], [7] and [8]; however, the patients showed a progressive decline in activities of daily living (ADL), consistent with the progression of disease.…”

l‐Dopa/carbidopa intestinal gel and subthalamic nucleus stimulation: Effects on cognition and behavior

“…Longer series suggested that STN‐DBS cognitive effects do not influence quality of life (Contarino et al., 2007) or daily living activities (Zangaglia et al., 2012). Long‐term studies have shown that the proportion of STN‐DBS patients who converted to dementia was not different compared to those receiving medication at 2 years follow‐up (Zibetti et al., 2011). Overall, STN‐DBS does not seem to modify the cognitive evolution along the course of the disease (Rodriguez‐Oroz, Obeso, & Lang, 2005; Merola et al, 2011).…”

Non-motor signs in Parkinson’s disease: a review

“…From a different perspective, a study that evaluated the main limiting factors of activities of daily living (ADL) in patients undergoing stereotactic surgery with deep brain stimulation for the treatment of PD, showed that after nine years since the intervention, non-axial signs, including tremor, rigidity and bradykinesia, remained relatively stable. However, axial signs (postural instability and gait disorder) and NMS began to exert a growing negative effect, reflecting levels of functionality that were similar or worse than those observed before surgery 9 .…”