Stereotactic and functional neurosurgery
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Stereotact Funct Neurosurg · Jan 2005
Case ReportsVenous air embolism during deep brain stimulation surgery in an awake supine patient.
Deep brain stimulation (DBS) of the subthalamic nucleus and globus pallidus is used to improve Parkinsonian symptoms and reduce levodopa-induced motor complications in Parkinson's disease (PD). This procedure is usually performed with minimal or no sedation to allow accurate feedback from patients during surgery. ⋯ We describe a case of intraoperative VAE in an awake, supine patient while undergoing DBS surgery for PD who presented with coughing, tachypnea and hypoxemia. The difference in clinical presentation between VAE in awake vs. anesthetized patients is discussed as are intraoperative monitoring techniques and management options.
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Stereotact Funct Neurosurg · Jan 2005
Effect of chronic deep brain stimulation of the subthalamic nucleus for frontal lobe epilepsy: subtraction SPECT analysis.
Experimental data and case reports of patients with intractable epilepsy treated with deep brain stimulation (DBS) of the subthalamic nucleus (STN) suggest a considerable anticonvulsant effect. However, no satisfactory mechanisms of action have yet been elucidated. We investigated the putative therapeutic mechanisms of DBS from cerebral perfusion changes as measured by subtracting the SPECT image of the pre-DBS period from that of the chronic post-DBS state. ⋯ We demonstrated that the cerebral perfusion increase in the irritative zones of epilepsy patients is associated with favorable seizure reduction after STN DBS in 2 cases of frontal lobe epilepsy. Although the exact mechanism remains unknown, our findings suggest that the perfusion changes after STN DBS in frontal lobe epilepsy patients are quite different from those in subjects with Parkinson's disease. Our preliminary data suggest the clinical relevance of subtraction SPECT imaging in assessing the postprocedural outcome as well as the characteristics of SPECT perfusion patterns in other epilepsy syndromes.
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Stereotact Funct Neurosurg · Jan 2005
Clinical TrialError analysis of MRI and leksell stereotactic frame target localization in deep brain stimulation surgery.
Stereotactic deep brain stimulation (DBS) is the surgical treatment of choice for medication-refractory patients with Parkinson's disease and essential tremor. The subthalamic nucleus and ventral intermediate nucleus of the thalamus appear to be effective targets for electrode placement. Because these targets are small and encased in fiber tracts, their localization can be exceedingly difficult. ⋯ The mean errors were 0.09 +/- 0.34 mm perpendicular, lateral to medial, 0.01 +/- 0.32 perpendicular, posterior to anterior, and -0.08 +/- 0.33 mm parallel to the electrode, superior to inferior. According to statistical analysis, the error was random and did not seem to move in any predictable fashion. Therefore, we conclude that preoperative MRI images can be safely used in DBS surgery, and they do not negatively affect its accuracy.
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Stereotact Funct Neurosurg · Jan 2005
Comparative StudyComparison of radiosurgery planning modalities for acoustic neuroma with regard to conformity and mean target dose.
To evaluate dose conformity and mean target dose in light of previous comparative studies and state-of-the-art radiosurgery delivery modalities. ⋯ Conformity of the prescription isodose to the target shape is of major importance in radiosurgery. The modalities compared represent commercially available and widely accepted systems. Gamma Knife plans derived using the 'wizard' option and finalized by hand yield the best conformity.