Randomised Crossover Trial of DBS of Differential PSA Regions in Parkinson's Disease and Tremor

Randomised Crossover Trial of Deep Brain Stimulation of Differential Posterior Subthalamic Area Regions in Parkinson's Disease and Tremor

The posterior subthalamic area holds promise as a target region for deep brain stimulation in tremor and Parkinson's disease. Using the magnetic resonance-directed implantable guide tube surgical technique, subregions of the posterior subthalamic area can be individually targetted on a single electrode lead trajectory. The hypothesis is that the caudal zona incerta may provide improved control of movement disorder symptoms than the more commonly stimulated dorsal zona incerta.

Randomisation between two treatment locations each programmed up to 3 milliamps in amplitude for 3 months: (1) caudal zona incerta and (2) dorsal zona incerta. This 6-month-long randomised phase is followed by 6 months of unblinded individualised empirically optimised settings programmed by a neurologist. Each of the three treatment periods ends with a full clinical, functional and quality of life assessment.

Inclusion Criteria:

• Medication-refractory tremor and/or Parkinson's disease as defined by UK Brain Bank criteria with either inadequate control of motor fluctuations or dyskinesia despite optimised medical therapy

Exclusion Criteria:

• Significant cognitive, psychiatric and medical co-morbidities
• Dementia with mini mental state examination score of less than 25/30
• Limited life expectancy due to a co-morbid condition