Stereotactic and functional neurosurgery
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Stereotact Funct Neurosurg · Jan 2008
Comparative StudyEffects of bilateral deep brain stimulation of the subthalamic nucleus on olfactory function in Parkinson's disease patients.
The goal of the present study was to evaluate the effects of bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) on olfaction in patients with Parkinson's disease (PD). ⋯ STN DBS can significantly improve olfactory cognitive function in PD patients. The possible mechanisms include an improvement in striatal metabolism and neuronal activity in the orbitofrontal cortex mediated by STN DBS, as well as increased glucose metabolism in the striatum, midbrain, cingulate gyrus, and motor and higher-order somatosensory association cortices.
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Stereotact Funct Neurosurg · Jan 2008
Comparative StudyModeling parkinsonian circuitry and the DBS electrode. II. Evaluation of a computer simulation model of the basal ganglia with and without subthalamic nucleus stimulation.
Treatment with deep brain stimulation (DBS) for Parkinson's disease (PD) has become routine over the past decade, particularly using the subthalamic nucleus (STN) as a target and utilizing microelectrode recordings to ensure accurate placement of the stimulating electrodes. The clinical changes seen with DBS in the STN for PD are consistently beneficial, but there continues to be only marginal understanding of the mechanisms by which DBS achieves these results. Using an analytical model of the typical DBS 4-contact electrode and software developed to simulate individual neurons and neural circuitry of the basal ganglia we compare the results of the model to those of data obtained during DBS surgery of the STN. Firing rate, interspike intervals and regularity analyses were performed on the simulated data and compared to results in the literature.
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Stereotact Funct Neurosurg · Jan 2008
Case ReportsSuccessful bilateral subthalamic nucleus stimulation for segmental dystonia after unilateral pallidotomy.
Several subcortical structures have been targeted for surgical treatment of dystonia, including motor thalamus, internal segment of globus pallidus (GPi), and more recently, the subthalamic nucleus (STN). Deep brain stimulation of GPi is currently the preferred surgical treatment, but it is unclear if targeting other structures would yield better results. Patients who have already had a pallidotomy yet continue to experience dystonic symptoms may be limited in further treatment options. ⋯ This result supports the efficacy of STN deep brain stimulation in dystonia patients, even those with prior pallidotomy.
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Stereotact Funct Neurosurg · Jan 2008
Comparative StudyBrain shift during deep brain stimulation surgery for Parkinson's disease.
Brain shift may occur during deep brain stimulation (DBS) surgery, which may affect the position of subcortical structures, compromising target localization. ⋯ Subcortical structures shift during DBS surgery. This shift appears to be gravity-dependent since structures only shifted posteriorly, and patients were primarily in the supine position. Posterior shift of RN may indicate STN displacement. Such positional change may compromise target localization, requiring multiple microelectrode adjustments. This may provide indirect justification for the necessity of microelectrode recordings during DBS surgery.
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Stereotact Funct Neurosurg · Jan 2008
Comparative StudyStereotactic MRI in DYT1 dystonia: focal signal abnormalities in the basal ganglia do not contraindicate deep brain stimulation.
To study stereotactic magnetic resonance imaging (MRI) features of the basal ganglia in DYT1 primary dystonia. ⋯ T(1)-hypointense/T(2)-hyperintense signal abnormalities are common findings in the putamen and globus pallidus of DYT1 patients but do not contraindicate DBS. However, their presence within the GPi may reduce the efficacy of DBS treatment.