Tanya Simuni, Jurg L. Jaggi, Heather Mulholland, Howard I. Hurtig, Amy Colcher, Andrew D. Siderowf, Bernard Ravina, Brett E. Skolnick, Reid Goldstein, Matthew B. Stern and Gordon H. Baltuch
Object. Palliative neurosurgery has reemerged as a valid therapy for patients with advanced Parkinson disease (PD) that is complicated by severe motor fluctuations. Despite great enthusiasm for long-term deep brain stimulation (DBS) of the subthalamic nucleus (STN), existing reports on this treatment are limited. The present study was designed to investigate the safety and efficacy of bilateral stimulation of the STN for the treatment of PD.
Methods. In 12 patients with severe PD, electrodes were stereotactically implanted into the STN with the assistance of electrophysiological conformation of the target location. All patients were evaluated preoperatively during both medication-off and -on conditions, as well as postoperatively at 3, 6, and 12 months during medication-on and -off states and stimulation-on and -off conditions. Tests included assessments based on the Unified Parkinson's Disease Rating Scale (UPDRS) and timed motor tests.
The stimulation effect was significant in patients who were in the medication-off state, resulting in a 47% improvement in the UPDRS Part III (Motor Examination) score at 12 months, compared with preoperative status. The benefit was stable for the duration of the follow-up period. Stimulation produced no additional benefit during the medication-on state, however, when compared with patient preoperative status. Significant improvements were made in reducing dyskinesias, fluctuations, and duration of off periods.
Conclusions. This study demonstrates that DBS of the STN is an effective treatment for patients with advanced, medication-refractory PD. Deep brain stimulation of the STN produced robust improvements in motor performance in these severely disabled patients while they were in the medication-off state. Serious adverse events were common in this cohort; however, only two patients suffered permanent sequelae.
Atsushi Umemura, Jurg L. Jaggi, Howard I. Hurtig, Andrew D. Siderowf, Amy Colcher, Matthew B. Stern and Gordon H. Baltuch
Object. Deep brain stimulation (DBS) has been advocated as a more highly effective and less morbidity-producing alternative to ablative stereotactic surgery in the treatment of medically intractable movement disorders. Nevertheless, the exact incidence of morbidity and mortality associated with the procedure is not well known. In this study the authors reviewed the surgical morbidity and mortality rates in a large series of DBS operations.
Methods. The authors retrospectively analyzed surgical complications in their consecutive series of 179 DBS implantations in 109 patients performed by a single surgical team at one center between July 1998 and April 2002. The mean follow-up period was 20 months.
There were 16 serious adverse events related to surgery in 14 patients (12.8%). There were two perioperative deaths (1.8%), one caused by pulmonary embolism and the second due to aspiration pneumonia. The other adverse events were two pulmonary embolisms, two subcortical hemorrhages, two chronic subdural hematomas, one venous infarction, one seizure, four infections, one cerebrospinal fluid leak, and one skin erosion. The incidence of permanent sequelae was 4.6% (five of 109 patients). The incidence of device-related complications, such as infection or skin erosion, was also 4.6% (five of 109 patients).
Conclusions. There is a significant incidence of adverse events associated with the DBS procedure. Nevertheless, DBS is clinically effective in well-selected patients and should be seriously considered as a treatment option for patients with medically refractory movement disorders.
Atsushi Umemura, Jurg L. Jaggi, Carol A. Dolinskas, Matthew B. Stern and Gordon H. Baltuch
✓ Generalized dystonia is one of the most disabling movement disorders. Ablative stereotactic surgery such as pallidotomy has been performed for medically refractory dystonia. Recently, deep brain stimulation (DBS) has appeared as an alternative to ablative procedures. Nevertheless, there have been few published reports detailing improvement in dystonia with DBS.
This 36-year-old man with Hallervorden—Spatz syndrome suffered from intractable primary generalized dystonia for 28 years. He was completely dependent for activities of daily living and wheelchair bound because of continuous severe dystonic movements in the face, tongue, neck, trunk, and upper and lower extremities while at rest. The Burke-Fahn-Marsden (BFM) Dystonia Rating Scale score was 112 (maximum 120 points). Bilateral DBS of the globus pallidus internus was performed and resulted in marked improvement in motor functioning and dystonic symptoms with a significant reduction in disability. The BFM score improved to 22.5 points (80% improvement) at 3 months postsurgery and the patient's dystonia was still well suppressed 1 year after surgery.
Bilateral pallidal stimulation is an effective and safe treatment for intractable generalized dystonia in Hallervorden—Spatz syndrome, even if the disability is severe and longstanding.
Galit Kleiner-Fisman, Grace S. Lin Liang, Paul J. Moberg, Anthony C. Ruocco, Howard I. Hurtig, Gordon H. Baltuch, Jurg L. Jaggi and Matthew B. Stern
Medically refractory dystonia has recently been treated using deep brain stimulation (DBS) targeting the globus pallidus internus (GPI). Outcomes have varied depending on the features of the dystonia. There has been limited literature regarding outcomes for refractory dystonia following DBS of the subthalamic nucleus (STN).
Four patients with medically refractory, predominantly cervical dystonia underwent STN DBS. Intraoperative assessments with the patients in a state of general anesthesia were performed to determine the extent of fixed deformities that might predict outcome. Patients were rated using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) preoperatively and 3 and 12 months following surgery by a rater blinded to the study. Mean changes and standard errors of the mean in scores were calculated for each subscore of the two scales. Scores were also analyzed using analysis of variance and probability values were generated. Neuropsychological assessments and quality of life ratings using the 36-Item Short Form Health Survey (SF-36) were evaluated longitudinally.
Significant improvements were seen in motor (p = 0.04), disability (p = 0.02), and total TWSTRS scores (p = 0.03). Better outcomes were seen in those patients who did not have fixed deformities. There was marked improvement in the mental component score of the SF-36. Neuropsychological function was not definitively impacted as a result of the surgery.
Deep brain stimulation of the STN is a novel target for dystonia and may be an alternative to GPI DBS. Further studies need to be performed to confirm these conclusions and to determine optimal candidates and stimulation parameters.