1/45. From off-period dystonia to peak-dose chorea. The clinical spectrum of varying subthalamic nucleus activity.The effect of chronic bilateral high-frequency stimulation of the subthalamic nucleus (STN) on levodopa-induced dyskinaesias was investigated in eight patients with fluctuating Parkinson's disease complicated by functionally disabling off-period dystonia. All of the patients also had severe diphasic and peak-dose chorea, so that it was possible to study the effect of high-frequency stimulation on the different types of levodopa-induced dyskinaesias. Off-period fixed dystonia was reduced by 90% and off-period pain by 66%. After acute levodopa challenge, high-frequency stimulation of the STN reduced diphasic mobile dystonia by 50% and peak-dose choreic dyskinaesias by 30%. The effect of bilateral high-frequency stimulation of the STN on the Unified Parkinson's Disease Rating Scale motor score had the same magnitude as the preoperative effect of levodopa. This allowed the levodopa dose to be reduced by 47%. The combination of reduced medication and continuous high-frequency stimulation of the STN reduced the duration of on-period diphasic and peak-dose dyskinaesias by 52% and the intensity by 68%. Acute high-frequency stimulation of the STN mimics an acute levodopa challenge, concerning both parkinsonism and dyskinaesias, and suppresses off-period dystonia. Increasing the voltage can induce repetitive dystonic dyskinaesias, mimicking diphasic levodopa-induced dyskinaesias. A further increase in voltage leads to a shift from a diphasic-pattern dystonia to a peak-dose pattern choreodystonia. Chronic high-frequency stimulation of the STN also mimics the benefit of levodopa on parkinsonism and improves all kinds of levodopa-induced dyskinaesias to varying degrees. Off-period dystonia, associated with neuronal hyperactivity in the STN is directly affected by stimulation and disappears immediately. The effect of chronic high-frequency stimulation of the STN on diphasic and peak-dose dyskinaesias is more complex and is related directly to the functional inhibition of the STN and indirectly to the replacement of the pulsatile dopaminergic stimulation by continuous functional inhibition of the STN. Chronic high-frequency stimulation of the STN allows a very gradual increase in stimulation parameters with increasing beneficial effect on parkinsonism while reducing the threshold for the elicitation of stimulation-induced dyskinaesias. In parallel with improvement of parkinsonism, the levodopa dose can be gradually decreased. As diphasic dystonic dyskinaesias are improved to a greater degree than peak-dose dyskinaesias, both direct and indirect mechanisms may be involved. Peak-dose choreatic dyskinaesias, associated with little evidence of parkinsonism and thus with low neuronal activity in the STN, are improved, mostly indirectly. Fixed off-period dystonia, mobile diphasic dystonia and peak-dose choreodystonia seem to represent a continuous clinical spectrum reflecting a continuous spectrum of underlying activity patterns of STN neurons.- - - - - - - - - - ranking = 1keywords = subthalamic nucleus, subthalamic, nucleus (Clic here for more details about this article) |
2/45. Dopaminergic dysfunction in midbrain dystonia: anatomoclinical study using 3-dimensional magnetic resonance imaging and fluorodopa F 18 positron emission tomography.OBJECTIVE: To determine the role of damage to neuronal systems, especially the dopaminergic system, in patients with symptomatic dystonia and mesencephalic lesions. DESIGN: Stereotaxic magnetic resonance imaging analysis and positron emission tomography after the administration of fluorodopa F 18. patients: Of a group of 48 patients with unilateral dystonia following a stroke, 7 patients with a well-defined midbrain lesion were selected. RESULTS: All patients had unilateral dystonic posture of an upper extremity and cerebellar dysmetria or hypotonia. Cerebellar tremor was present in 1 patient. Two patients had resting and postural tremor, which showed a marked improvement with treatment with levodopa. In patients with dystonia only, dopaminergic lesions were mostly confined to the ventromesial mesencephalon and red nucleus area, including the substantia nigra and nigrostriatal and cerebellothalamic fibers. dystonia was severe and did not resolve with time in patients with lesions involving the nigrostriatal pathway, and the degree of dopaminergic denervation revealed by positron emission tomography was correlated with the severity of dystonia. In patients with resting and postural tremor, lesions of the dopaminergic structures were larger and located more laterally and dorsally in the pars compacta, the perirubral and retrorubral areas, and extending to the central tegmental tract. CONCLUSIONS: Dopaminergic dysfunction plays a role in the occurrence and severity of midbrain dystonia, and additional lesions to dopaminergic neurons in the perirubral and retrorubral areas result in tremor that responds to levodopa treatment.- - - - - - - - - - ranking = 0.0011090778737567keywords = nucleus (Clic here for more details about this article) |
3/45. globus pallidus deep brain stimulation for generalized dystonia: clinical and PET investigation.Bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) in a patient with severe idiopathic generalized dystonia resulted in immediate improvement of all aspects of dystonia. During joystick movement, GPi DBS reduced PET activation bilaterally in the primary motor, lateral premotor, supplementary motor, anterior cingulate, and prefrontal areas and ipsilaterally in the lentiform nucleus. Altering basal ganglia function with GPi DBS reverses the overactivity of certain motor cortical areas present in dystonia.- - - - - - - - - - ranking = 0.0011090778737567keywords = nucleus (Clic here for more details about this article) |
4/45. Symptomatic paroxysmal hemidystonia due to a demyelinating subthalamic lesion.We present a case of paroxysmal hemidystonia in a patient with an isolated demyelinating lesion in the subthalamic region, involving the posterior arm of the internal capsule and extending to the subthalamic nucleus and mesencephalon, possibly due to multiple sclerosis. Compared with similar reports in the literature, in our case there was a paucity of lesions, permitting a more direct clinico-anatomical correlation. The role of the subthalamic region and basal ganglia circuitry in the genesis of symptomatic dystonia is discussed.- - - - - - - - - - ranking = 0.52557554648251keywords = subthalamic nucleus, subthalamic, nucleus (Clic here for more details about this article) |
5/45. A CLN2 gene nonsense mutation is associated with severe caudate atrophy and dystonia in LINCL.Clinical features and results of the blood dna analysis are reported of a child affected with a distinct phenotype of the late infantile form of neuronal ceroid-lipofuscinosis (LINCL). He was affected by microcephaly and hypotonia since the fourth month of life; acquisition of motor and language abilities was severely impaired, and a disorder of communication with stereotyped movements followed. By age four, he developed signs and symptoms of progressive myoclonic encephalopathy along with motor and cognitive deterioration. Extrapyramidal signs were associated with neuroradiological findings of marked atrophy of the caudate nucleus. Specific curvilinear bodies were observed in blood lymphocytes and skin biopsy. Homozygous, nonsense mutation in the CLN2 gene was found giving origin to an Arg208stop, which produces an early transcription termination with loss of translation of about 50% of the gene product. Any relationship between the severe clinical features of our patient and the homozygous mutation here reported must be investigated on a larger number of LINCL patients bearing the same mutation.- - - - - - - - - - ranking = 0.0011090778737567keywords = nucleus (Clic here for more details about this article) |
6/45. Delayed onset of hemidystonia and hemiballismus following head injury: a clinicopathological correlation. Case report.The authors report the case of a young man who suffered multiple injuries in a motor vehicle accident, the most significant of which arose in the brain, creating an unusual clinical syndrome. After experiencing an initial coma for several days, the patient was found to have a right-sided homonymous hemianopsia and a right hemiparesis, which was more marked at the shoulder and was accompanied by preservation of finger movement. Dystonic movements appeared 2 months later and progressed, along with increased spasticity on volition, to severe uncontrolled arm movements at 2 years postinjury. This motor disorder continued to worsen during the following 6 years prior to the patient's death. At autopsy, the left side of the brain was observed to have marked atrophy of the optic tract, a partial lesion of the posterior portion of the medial segment of the globus pallidus (GP), and a reduction in the size of the internal capsule at the level of the GP, suggesting impaired circulation to these areas at the time of injury. The isolated lesion of the internal segment of the GP was the presumed cause of the dystonia, acting through an alteration in thalamic inhibition. The atrophic subthalamic nucleus was the probable cause of the hemiballismus. The authors speculate that this and other delayed and progressive features of this case were the result of an active, but disordered, adaptive process that failed to compensate and, instead, caused even greater problems than the original injury.- - - - - - - - - - ranking = 0.2keywords = subthalamic nucleus, subthalamic, nucleus (Clic here for more details about this article) |
7/45. Pallidal and thalamic neurostimulation in severe tardive dystonia.A 70 year old woman presented with a 6 year history of medically refractory severe tardive dystonia. After informed consent, a bilateral stereotactic electrode placement targeting the ventral intermediate thalamic nucleus (VIM) and the globus pallidus internus (GPi) was performed. After bilateral stimulation of the GPi, the patient showed a clear and stable improvement of the painful dystonic syndrome within hours. Stimulation of the VIM did not improve the hyperkinetic movements and simultaneous stimulation of both the GPi and the VIM did not result in any additional benefit. The possible pathophysiological mechanisms are discussed.- - - - - - - - - - ranking = 0.0011090778737567keywords = nucleus (Clic here for more details about this article) |
8/45. Neurofibromatosis type 1 presenting with hand dystonia.Neurofibromatosis type 1 is frequently associated with increased intensity T2-weighted magnetic resonance imaging (MRI) brain abnormalities, called "unidentified bright objects." Unidentified bright objects are generally held to be benign and tend to decrease in size during adulthood. We describe a case of neurofibromatosis type 1 with a similar thalamic and subthalamic MRI abnormality associated with contralateral hand dystonia. Over a 2-year follow-up, the lesions showed a reduction in size apparently correlated with a reduction in symptoms.- - - - - - - - - - ranking = 0.054262591080418keywords = subthalamic (Clic here for more details about this article) |
9/45. Cytochrome c oxidase partial deficiency-associated leigh disease presenting as an extrapyramidal syndrome.leigh disease is a subacute neurodegenerative disorder characterized by symmetric necrotic lesions in the basal ganglia, cerebellum, thalamus, brain stem, and optical nerves and caused by altered oxidative phosphorylation. We describe the clinical, biochemical, neuroimaging, and molecular studies of a 19-year-old boy with early-onset leigh disease manifesting as severe extrapyramidal disorder with generalized dystonia and choreoathetosis. He was born of healthy parents after an uneventful pregnancy and delivery. At the age of 2 1/2 years, after a minor respiratory infection, he developed unstable, broad-based gait and tremor of the hands. These symptoms persisted for the next several years, when ataxia became more prominent. Difficulty in swallowing, dysarthria, trunk dystonia, and marked dyskinesia of the arms and hands gradually developed. Nystagmus, transient ptosis, and strabismus also appeared. Abnormal laboratory findings included elevated plasma and cerebrospinal fluid lactate and pyruvate, with an abnormal lactate/pyruvate ratio. Cranial computed tomography and magnetic resonance imaging demonstrated signs of cerebellar atrophy, bilateral and symmetric hypodensities in the lentiform nucleus and thalamus, and transient hyperintensities of cerebral peduncles in T2-weighted sequences suggestive of leigh disease. Muscle biopsy revealed isolated fiber atrophy, necrotic fibers undergoing phagocytosis, and no ragged-red fibers. The measured catalytic activity of cytochrome c oxidase in skeletal muscle homogenates demonstrated a partial cytochrome c oxidase deficiency No abnormalities in the mitochondrial genome and in the SURF-1 gene were found. The boy is currently receiving levodopa therapy, creatine monohydrate, and a high dosage of thiamine and lipoic acid, his condition is stabilized, and extrapyramidal symptoms are less pronounced.- - - - - - - - - - ranking = 0.0011090778737567keywords = nucleus (Clic here for more details about this article) |
10/45. deep brain stimulation in the treatment of severe dystonia.A retrospective study of a consecutive series of 19 patients with medically intractable dystonia treated with uni- or bilateral deep brain stimulation (DBS) is reported. A minimal follow-up of 6 months was available, up to eleven years in one patient. The first twelve consecutive patients (4 with primary and 8 with secondary dystonia) were treated with chronic stimulation of the posterior part of the ventrolateral thalamic nucleus (VLp). In this group global functional outcome was improved in 8 patients, although dystonia movement and disability scale scores did not show significant improvement. Of the 12 patients treated first by VLp DBS, three (1 primary and 2 secondary dystonia) underwent pallidal (GPi) DBS after the VLp DBS failed to improve their symptoms. The last seven consecutive patients (5 primary and 2 secondary dystonia) were treated directly with GPi DBS. Extracranial infection prevented chronic GPi DBS in one patient. In another GPi patient, preliminary negative tests with the electrodes discouraged implantation of the stimulators, and the patient was not treated with chronic DBS. In the remaining group of eight patients including those previously treated with VLp DBS, chronic GPi DBS resulted in a significant improvement in the dystonia movement scale and disability scores. Although this is a retrospective study dealing with dystonia of heterogeneous etiology, the results strongly suggest that GPi DBS has a better outcome than VLp DBS.- - - - - - - - - - ranking = 0.0011090778737567keywords = nucleus (Clic here for more details about this article) |
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