Effects of subthalamic nucleus stimulation and levodopa on the autonomic nervous system in Parkinson's disease

Abstract

Dysfunctions of the autonomic nervous system (ANS) are common in Parkinson's disease (PD). Regarding motor disability, deep brain stimulation of the subthalamic nucleus (STN) is an effective treatment option in long lasting PD. The aims of this study were to examine whether STN stimulation has an influence on functions of the ANS and to compare these effects to those induced by levodopa. Blood pressure (BP) and heart rate (HR) during rest and orthostatic conditions, HR variability (HRV) and breathing-induced cutaneous sympathetic vasoconstriction (CVC) were tested in 14 PD patients treated with STN stimulation during "ON" and "OFF" condition of the stimulator. The effects of a single dose of levodopa on ANS were tested in 15 PD patients without DBS. STN stimulation had no influence on cardiovascular ANS functions, whereas CVC was significantly increased. In contrast, levodopa significantly lowered BP and HR at rest and enhanced orthostatic hypotension. Further, HRV, skin perfusion and temperature increased after administration of levodopa. Our results suggest that in contrast to levodopa, STN stimulation has only minor effects on autonomic functions. Since less pharmacotherapy is needed after STN stimulation, reduced levodopa intake results in relative improvement of autonomic function in deep brain stimulated PD patients.

Differentiated Baroreflex Modulation of Sympathetic Nerve Activity During Deep Brain Stimulation in Humans

“…Levodopa treatment has been shown to induce several negative effects on autonomic function by lowering BP and HR and therefore worsen orthostatic hypotension. A reduction in levodopa intake attributable to STN stimulation therefore improves autonomic function in patients with Parkinson disease 49 as well as enhances the effect of STN-DBS on cognitive function. 50 Although differences in dopaminergic medication state could have influenced our results, this is unlikely given that the entire experiment took <1 hour, during which time variance of dopaminergic state would be only modest.…”

Nonmotor outcomes in Parkinson’s disease: is deep brain stimulation better than dopamine replacement therapy?

“…Thus a small significant impact of STN-DBS may have been missed. Ludwig and colleagues compared the effect of levodopa with that of STN-DBS [Ludwig et al 2007]. This was an immediate effect of a single dose of levodopa and the effect of STN-DBS compared with when it was switched off.…”

“…The cardiovascular autonomic dysfunction in PD may be a combination of central and peripheral autonomic changes and the lack of effect of STN-DBS may stem from its inability to correct the peripheral component. An overall improvement in autonomic functions may be gained by the reduction of dopaminergic drugs after STN-DBS [Ludwig et al 2007]. Larger randomized, controlled studies are needed to confirm the role of STN-DBS in orthostatic hypotension.…”

Deep Brain Stimulation Improves Performance of Complex Instrumental Paradigms

“…Therefore some trials also investigated the effects of STN DBS within a study design with the stimulator first being switched off and then on or vice versa. At least partially, the investigators compared their results with the effects found following acute levodopa administration in PD patients [6,7,8,9]. Changes of motor behavior and cognitive function and the interaction between the two may also be studied with various instrumental tasks in a standardized fashion in order to demonstrate the effects of antiparkinsonian drugs [10, 11].…”