Surgical interventions in the treatment of Parkinson's disease (PD) and essential tremor (ET): medial pallidotomy in PD and chronic deep brain stimulation (DBS) in PD and ET.

Surgical treatments for PD and ET are promising. Medial Pallidotomy, the surgical lesioning of the pallidum, often improves symptoms of long-standing PD. We enrolled twenty-seven late stage PD patients for unilateral medial pallidotomy who were then assessed by the Core Assessment Program for Intracranial Transplantation (CAPIT) protocol. One year after surgery persistent improvement was seen contralateral to the lesion in the following features: drug-induced dyskinesias (92%), akinesia (38%), rigidity (51%), and tremor (42%). Complications included transient dysarthria (7 patients), facial weakness (9 patients), limb weakness (1 patient), swallowing problems (4 patients) and intracerebral haemorrhage (1 patient). Thalamic DBS may improve tremor in PD and ET patients. Therefore, we enrolled fifteen patients (9 PD and 6 ET patients) with disabling tremor, unresponsive to medication. They were assessed by the United Parkinson's Disease Rating Scale (UPDRS) and the Tremor Rating Scale (for PD and ET patients, respectively). Three months after surgery, limb tremor contralateral to stimulation improved by 71% in PD patients and 76% in ET patients. Complications included transient paresthesias (all), confusional state (1 patient) and intracerebral bleed (1 patient). Unilateral medial pallidotomy safely improves some Parkinsonian symptoms contralateral to the lesion. Thalamic DBS may effectively and safely improve contralateral limb tremor in PD and ET.