Background: Deep brain stimulation (DBS) for alleviation of motor symptoms in advanced Parkinson's disease (PD) is well established. However, autonomic effects of DBS are less clear.
Aim: To review published data on autonomic dysfunctions in DBS-treated patients with PD.
Methods: Medline bibliographic search was performed with the selected relevant keywords, through June 10th, 2010. Thirty three original papers meeting the criteria were identified.
Results: Effect of DBS on autonomic dysfunctions observed in PD differs depending on the underlying etiology. DBS of the subthalamic nucleus has no direct effects on cardiovascular functions. Relative improvement results from reduced levodopa intake. Majority of gastrointestinal and urinary tract disorders improve with neurostimulation. However, prolonged body weight gain is observed. Furthermore, urinary tract functions normalize, and in male patients with Parkinson's disease sexual satisfaction increases. Sweating disorders are markedly reduced. On the contrary, chronic stimulation in the area of STN may induce autonomic adverse effects including sialorrhea and urinary retention. In exceptional cases withdrawal of medication before planned DBS surgery may result in life-threatening parkinsonism-hyperpyrexia syndrome. Thus discontinuation of levodopa should be an inpatient procedure.
Conclusions: Selection of patients who undergo DBS should weigh potential benefits and risks resulting from multidirectional effects of neurostimulation on autonomic nervous system.