Relationship of clinical efficacy to postmortem-determined anatomic subthalamic stimulation in Parkinson syndrome.

OBJECTIVE/BACKGROUND: Patients with medically refractory Parkinson's disease (PD) obtain significant clinical benefit from subthalamic nucleus (STN) stimulation. The degree to which a successful outcome relates to the anatomic location of the stimulating electrode has not yet been clearly established. Many studies have attempted to correlate the clinical result with the electrode location using postoperative magnetic resonance imaging (MRI) and there have been a few that used autopsy-determined locations. In this report, we describe long-term clinical follow-up in a patient with autopsy-determined electrode tip anatomic location. METHODS: A 67-year-old patient with a 27-year history of idiopathic PD complicated by disabling motor fluctuations and dopaminergic dyskinesias underwent bilateral STN deep brain stimulation (DBS). He was prospectively followed in a long-term clinical protocol until his death 40 months after electrode placement. Postoperative magnetic resonance (MR) imaging and postmortem studies of this patient's brain were performed to localize DBS tip locations. RESULTS: STN stimulation produced improvement of the patient's motor fluctuations, dyskinesias and clinical motor performance, especially appendicular tremors, rigidity and bradykinesia. MRI showed the electrode tips to be within 2 mm of the intended target. Postmortem brain analysis identified the right DBS tip location at the dorsomedial edge of the STN, with the left electrode in the vicinity (but not within) the STN. Chronic DBS elicited minor reactive changes were confined to the immediate vicinity of the electrode tracks. The pathological analysis demonstrated numerous cortical Lewy bodies and degenerative encephalopathy, establishing the diagnosis of transitional type diffuse Lewy body disease (DLBD) rather than simple PD. CONCLUSION: This patient obtained clinical benefit from STN stimulation typical of that seen for most PD patients. Both the MR analysis and the autopsy demonstrated electrode placement at or outside the boundaries of the STN, suggesting that that clinical efficacy may not depend on electrode location within the central region of the STN.

Operative techniques and morbidity with subthalamic nucleus deep brain stimulation in 100 consecutive patients with advanced Parkinson's disease.

OBJECTIVE: Subthalamic nucleus (STN) stimulation for patients with medically refractory Parkinson disease (PD) is expanding. Reported experience has provided some indication of techniques, efficacy, and morbidity, but few centres have reported more than 50 patients. To expand this knowledge, we reviewed our experience with a large series of consecutive patients. METHODS: From March 1999 to September 2003, 191 subthalamic stimulator devices (19 unilateral) were implanted in 100 patients with PD at New York Presbyterian Hospital/Columbia University Medical Center. Sixteen patients had undergone a prior surgery for PD (pallidotomy, thalamotomy, or fetal transplant). Microelectrode guided implantations were performed using techniques similar to those described previously. Electrode implantation occurred 1-2 weeks before outpatient pulse generator implantation. RESULTS: Reductions of dyskinesias and off severity/duration were similar to prior published reports. Morbidity included: 7 device infections (3.7%), 1 cerebral infarct, 1 intracerebral haematoma, 1 subdural haematoma, 1 air embolism, 2 wound haematomas requiring drainage (1.0%), 2 skin erosions over implanted hardware (1.0%), 3 periprocedural seizures (1.6%), 6 brain electrode revisions (3.1%), postoperative confusion in 13 patients (6.8%), and 16 battery failures (8.4%). Of the 100 patients, there were no surgical deaths or permanent new neurological deficits. The average hospital stay for all 100 patients was 3.1 days. CONCLUSION: Subthalamic stimulator implantation in a large consecutive series of patients with PD produced significant clinical improvement without mortality or major neurological morbidity. Morbidity primarily involved device infections and hardware/wound revisions.