ABSTRACT
BACKGROUND: Tardive dyskinesia and dystonia (TDD) are severe side effects of dopamine-blocking agents, particularly antipsychotics. While deep brain stimulation (DBS) has proven effective in the treatment of TDD, little is known about the possible psychiatric complications of DBS in psychiatric patients. OBJECTIVE: To assess the efficacy and safety, specifically the psychiatric side effects, of DBS in patients with medication-induced TDD. DATA SOURCES: PubMed and EMBASE databases were searched systematically on May 25, 2011, for articles written in English, using the search terms deep brain stimulation AND tardive. STUDY SELECTION: Of the 88 original articles retrieved, 17 studies involving 50 patients with TDD who underwent DBS were included in the review. DATA EXTRACTION: Data on the severity of the movement disorders before and after DBS, as rated on the Burke-Fahn-Marsden Dystonia Rating Scale or similar scales, were extracted. Data on psychiatric symptoms before and after DBS were used to calculate the percent improvement per patient per rating scale. Overall improvement and confidence intervals were calculated using a 1-sample, 2-sided Student t test. RESULTS: The mean improvement of TDD of the combined patients 3 to 76 months after implantation was 77.5% (95% CI, 71.4%-83.3%; P < .000) on the Burke-Fahn-Marsden Dystonia Rating Scale. Of the 50 patients, 1 experienced an exacerbation of depression, and 1 experienced an exacerbation of psychosis. CONCLUSIONS: DBS seems to be effective and relatively safe for patients with treatment-resistant TDD; however, the results should be interpreted with caution, as most of the data are from case reports and small trials.
Subject(s)
Deep Brain Stimulation , Dyskinesia, Drug-Induced/therapy , Dystonic Disorders/chemically induced , Dystonic Disorders/therapy , Antiemetics/adverse effects , Antiemetics/therapeutic use , Deep Brain Stimulation/adverse effects , Deep Brain Stimulation/methods , Deep Brain Stimulation/psychology , Dyskinesia, Drug-Induced/diagnosis , Dyskinesia, Drug-Induced/physiopathology , Dyskinesia, Drug-Induced/psychology , Dystonic Disorders/diagnosis , Dystonic Disorders/physiopathology , Dystonic Disorders/psychology , Globus Pallidus/physiopathology , Humans , Neurologic Examination/drug effects , Psychiatric Status Rating Scales , Psychotropic Drugs/adverse effects , Psychotropic Drugs/therapeutic use , Treatment OutcomeABSTRACT
Deep brain stimulation (DBS) for Parkinson's disease often alleviates the motor symptoms, but causes cognitive and emotional side effects in a substantial number of cases. Identification of the motor part of the subthalamic nucleus (STN) as part of the presurgical workup could minimize these adverse effects. In this study, we assessed the STN's connectivity to motor, associative, and limbic brain areas, based on structural and functional connectivity analysis of volunteer data. For the structural connectivity, we used streamline counts derived from HARDI fiber tracking. The resulting tracks supported the existence of the so-called "hyperdirect" pathway in humans. Furthermore, we determined the connectivity of each STN voxel with the motor cortical areas. Functional connectivity was calculated based on functional MRI, as the correlation of the signal within a given brain voxel with the signal in the STN. Also, the signal per STN voxel was explained in terms of the correlation with motor or limbic brain seed ROI areas. Both right and left STN ROIs appeared to be structurally and functionally connected to brain areas that are part of the motor, associative, and limbic circuit. Furthermore, this study enabled us to assess the level of segregation of the STN motor part, which is relevant for the planning of STN DBS procedures.