Deep brain stimulation for Parkinson's disease and tremor:: Prague experience 1998-2003

We present our clinical procedures and own observations of the effects of deep brain stimulation (DBS). From 1998 to 2003, 33 patients were implanted, including 8 cases of disabling tremor of various origin where DBS of the ventral intermedius (VIM) nucleus of the thalamus was performed. and 225 pats. with bilateral DBS of the subthalamic nucleus (STN) for complicated Parkinson's disease (PD). VIM DBS significantly reduced tremor however the effects of stimulation were limited in some cases by additional symptoms of the underlying disease. STN DBS effectively modified main symptoms of PD. markedly reduced or suppressed motor fluctuations and dyskinesias, and improved functional performance and self sufficiency of the patients. The doses of dopaminergic drugs were reduced by 55% on average and medication could be stopped completely in 4 pats. Subcutaneous tissue reactions were the most, frequent complications of the surgery in 4 pats. Body weight gain was the most common side-effect, of DBS STN in 23 out of 25 pats., by 9.4 kg on average, range 2-23 kg. In 6 pats., intermittent dystonia of lower limb was elicited by STN DBS. Disorders of gait (in 10 pats.), dysartria and hypophonia (8 pats.), and depression (6 pats.) were the most frequent PD symptoms that persisted or deteriorated after STN DBS, Accidental switching off by external magnetic field was the most usual technical cause of stimulator failure. In conclusion, DBS is a symptomatic treatment method for selected patients with PD or intractable tremor who are insufficiently compensated by pharmacotherapy and whose impairment features and general biologic condition promise long-term improvement. Adequate patient selection according to the indication criteria, implantation procedure, and post-operative follow-up performed in a specialized center are prerequisites of success of DBS. Excellent functional effects of DBS in correctly indicated cases, improved quality of patients' life, and savings of medication, health- and social care expenses compensate for expensiveness of DBS.