1/40. Idiopathic parkinsonism with superimposed manganese exposure: utility of positron emission tomography.It is difficult to distinguish manganism from idiopathic parkinsonism by clinical signs only. Case history and examination: A 48-year-old welder for over 10 years complained of masked face, right side (arm and leg) resting tremor, and bradykinesia for over one year. magnetic resonance imaging (MRI) findings showed symmetrical high signal intensities in the globus pallidus on T1 weighted image. These intensities disappeared almost completely six months after cessation of exposure. 18F-6-fluorodopa (18F-dopa) positron emission tomography (PET) findings showed reduced 18F-dopa uptake in the left putamen, findings which appear in idiopathic parkinsonism. A PET study is necessary to distinguish manganism from idiopathic parkinsonism, especially in a working environment with elevated Mn concentrations, such as welding.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
2/40. The behavioral complications of pallidal stimulation: a case report.We report a case of recurrent manic episodes associated with chronic deep brain stimulation (DBS) targeting globus pallidus (GP) in the treatment of Parkinson's disease (PD). Cardinal PD symptoms and dyskinesia improved with DBS, and neuropsychological testing found improvements in visuospatial measures associated with left DBS and in verbal memory with right DBS when compared to the patient's preoperative baseline. Under conditions of right, left, and bilateral DBS, the patient experienced bouts of mania and hypomania lasting several days at a time. Positron emission tomography (PET) with (15)O-labeled water was performed after his first manic episode under four conditions: no stimulation, right DBS, left DBS, and bilateral DBS. Although no manic switch occurred during the course of the PET study, all three DBS conditions were associated with decreases in regional flow in the left parahippocampus and hippocampus and right mid-cingulate gyrus. Increases in flow in left inferior frontal area, bilateral insula, dorsolateral prefrontal cortex, and cuneus were common to all DBS conditions. GP stimulation in PD may be associated with behavioral and cognitive effects. Distributed blood flow changes observed with pallidal DBS support a role for the pallidum in cognition and affective regulation.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
3/40. Apraxia of lid opening is alleviated by pallidal stimulation in a patient with Parkinson's disease.Apraxia of lid opening (ALO) is a syndrome characterized by a non-paralytic inability to open the eyes at will in the absence of visible contraction of the orbicularis oculi muscle. Here we report that globus pallidus internus deep brain stimulation on the right side markedly alleviates ALO as well as gait freezing in a patient with Parkinson's disease.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
4/40. Failure of long-term pallidal stimulation corrected by subthalamic stimulation in PD.Bilateral high-frequency continuous stimulation of the internal globus pallidus or subthalamic nucleus constitutes a new therapeutic approach for the treatment of patients with severe PD. The authors report two patients in whom stimulation of the globus pallidus failed to give long-term relief and was successfully replaced by bilateral subthalamic stimulation. The results emphasize the reversibility of deep brain stimulation therapy and suggest that the subthalamic target is preferable to the pallidal target.- - - - - - - - - - ranking = 2keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
5/40. A case of frontotemporal dementia and parkinsonism of early onset with progressive supranuclear palsy-like features.We report a patient with frontotemporal degeneration and parkinsonism with mental retardation. The patient was a 54-year-old man who had parkinsonism that resembled progressive supranuclear palsy, frontotemporal degeneration and myoclonus. His family included many affected members. Neuropathologically, there was degeneration of the frontal and temporal cortices, the basal ganglia, the brainstem and the cerebellum. Microscopically, neuronal loss was severe in the frontal and temporal cortex, the globus pallidus, substantia nigra, red nucleus and dentate nucleus. Fibrillary changes were found in neurons and glia that were immunostained for tau. Although we could not define the genetic abnormalities, we thought that this case might have involved frontotemporal dementia and parkinsonism linked to chromosome 17.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
6/40. Effects of anterodorsal pallidal stimulation on gait freezing (Kinesia paradoxa) in Parkinson's disease.The results of a double-blind evaluation of the effects of internal globus pallidus (GPi) stimulation in 7 patients with advanced Parkinson's disease are summarized. The evaluation was performed 6-8 months after surgery while the patients were on medication with an optimal dose and schedule. The stimulation was turned off for at least 12 h. It was turned on in the morning (or maintained turned off), and the best and worst scores during their daytime activity were recorded as the on-period and off-period scores, respectively. A significant reduction in the total score on part III of the Unified Parkinson's disease Rating Scale was induced by GPi stimulation at the off-period (-57%) as well as the on-period (-36%). Clinically important improvement was also achieved in severe gait freezing (kinesia paradoxa) in 2 patients when stimulation was applied to the anterodorsal portion of the GPi. Such an effect was observed during unilateral stimulation of the right side alone.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
7/40. Does stimulation of the GPi control dyskinesia by activating inhibitory axons?A 69-year-old woman with Parkinson's disease and levodopa-induced dyskinesias had a deep brain stimulation (DBS) electrode inserted into the right globus pallidus internus (GPi). During the operation, the GPi was mapped with dual microelectrode recordings. Stimulation through one microelectrode in GPi inhibited the firing of GPi neurons recorded with another microelectrode 600--1,000 microm distant. The inhibition could be obtained with pulse widths of 150 micros and intensities as low as 10 microA. Single stimuli inhibited GPi neurons for approximately 50 ms. Trains of 300 Hz stimuli inhibited GPi neuron firing almost completely. Postoperatively, stimulation through macroelectrode contacts located in the posterior ventral pallidum controlled the patient's dyskinesias. The effect could be obtained with pulse widths of 50 micros and frequencies as low as 70--80 Hz. We postulate stimulation of the ventral pallidum controls dyskinesias by activating large axons which inhibit GPi neurons.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
8/40. Lacunar infarct during pallidotomy: case report.A symptomatic lacunar infarct is an unusual complication which may develop during stereotactically guided pallidotomy using radiofrequency thermoablation. We describe a 54-year-old man with Parkinson's disease involving predominantly the right side, progressively deteriorating under medical management. He underwent stereotactically guided radiofrequency thermoablation of the posteroventral globus pallidus interna. Despite intraoperative microelectrode recording and stimulation, the patient developed right facial weakness and pronator drift during the procedure. MRI showed a small lacunar infarct in the left internal capsule, in addition to the appropriately placed ablative lesion. We discuss the potential mechanisms for this type of injury.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
9/40. Contraversive eye deviation during deep brain stimulation of the globus pallidus internus.Clinical signs help determine correct electrode positioning during stereotactic implantation for chronic high-frequency pallidal stimulation in Parkinson's diease (PD). The authors describe a patient who had marked, sustained, contraversive eye deviation caused by stimulation during pallidal surgery. The underlying mechanism is probably an excitation of fibers in the internal capsule by volume-conducted current spread. Such conjugate eye deviation is thus not necessarily an indication of incorrect electrode placement.- - - - - - - - - - ranking = 4keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
10/40. Subcortical brain mechanisms in speech and language.This paper reviews current research and contemporary theories of subcortical participation in the motor control of speech production and language processing. As a necessary precursor to the discussion of the functional roles of the basal ganglia and thalamus, the neuroanatomy of the basal ganglial-thalamocortical circuitry is described. Contemporary models of hypokinetic and hyperkinetic movement disorders based on recent neuroanatomical descriptions of the multi-segmented circuits that characterise basal ganglion anatomy are described. Reported effects of surgically induced lesions in the globus pallidus and thalamus on speech production are reviewed. In addition, contemporary models proposed to explain the possible contribution of various subcortical structures to language processing are described and discussed in the context of evidence gained from observation of the effects of circumscribed surgically induced lesions in the basal ganglia and thalamus on language function. The potential of studies based on examination of the speech/language outcomes of patients undergoing pallidotomy and thalamotomy to further inform the debate relating to the role of subcortical structures in speech motor control and language processing is highlighted.- - - - - - - - - - ranking = 1keywords = globus pallidus, pallidus, globus (Clic here for more details about this article) |
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