SEARCH · Search PubMed

Results for “Subthalamic Nucleus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,027 records · Page 57Linked to original sources

PubMed1997

Dopamine/glutamate interactions in Parkinson's disease.

In Parkinson's disease, the tonic inhibition by basal ganglia output structures may be exacerbated by the action of the subthalamic nucleus. As expected, the reduction of excitatory impact from this structure has been shown to reduce akinesia in monkeys with experimental parkinsonism. The findings of receptor binding studies supporting an increased neuronal activity of efferents of the subthalamic nucleus in patients with Parkinson's disease, suggest that subthalamic nucleotomy or pallidotomy may be effective lesions in the neurosurgical treatment of Parkinson's disease. Systemic administration of glutamate antagonists has been shown to have anti-akinetic effects in animal models of Parkinson's disease. Other observations in monkeys indicate that excitatory amino acids such as glutamate are involved in the pathophysiological cascade of MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine)-induced neuronal cell death. The neuroprotective effects of competitive and non-competitive NMDA (N-methyl-D-aspartate) receptor antagonists against MPTP toxicity support the hypothesis that NMDA receptor-mediated events are involved in the neurotoxicity of MPTP. Glutamate antagonists may therefore be able to retard the progression and to improve the symptomatology of Parkinson's disease. Several compounds with anti-parkinsonian effects such as amantadine, memantine, budipine and orphenadrine have been shown to be non-competitive NMDA receptor antagonists and are candidates for clinical trials on the neuroprotective efficacy of NMDA receptor antagonism. Furthermore, glutamate antagonists are useful in the treatment of the akinetic parkinsonian crisis, a severe form of clinical deterioration in patients with Parkinson's disease.

Animals↗

PubMed1985

Common neural mechanisms in experimental chorea and hemiballismus in the monkey. Evidence from 2-deoxyglucose autoradiography.

The autoradiographic 2-deoxyglucose uptake technique was used to visualise local cerebral metabolic activity in the monkey in recently developed models of chorea and hemiballismus. Unilateral dyskinesia was induced by injection of a gamma-aminobutyric acid antagonist into the corpus striatum (in the case of chorea) or subthalamic nucleus (in the case of hemiballismus). Patterns of 2-deoxyglucose uptake suggest that during both forms of experimental dyskinesia the subthalamic nucleus and its projection to the globus pallidus are abnormally hypoactive.

Animals↗

PubMed1998

Hemiballism-hemichorea from marked hypotension during spinal anesthesia.

Hemiballism and hemichorea following anesthesia-induced hypotension has rarely been described, but a recent case suggests an association. After experiencing marked hypotension during spinal anesthesia, a 70-year-old woman developed hemiballism and hemichorea. Involuntary ballistic movements with writhing, consisting of repetitive rotation and flexion-extension without apparent muscle weakness, affected her left limbs proximally. Low-amplitude, involuntary, choreiform movements involved the distal portions of these limbs. Magnetic resonance imaging demonstrated an area of high signal intensity in the contralateral subthalamic nucleus, suggestive of a focal ischemic lesion. Although such occurrences are rare, anesthesiologists should be aware of the risk of subthalamic nucleus ischemia following marked hypotension.

Aged↗

PubMed1997

The efferent projections of the dorsal and ventral pallidal parts of the pigeon basal ganglia, studied with biotinylated dextran amine.

In the present study we have investigated the efferent projections of both the dorsal and the ventral pallidum of the pigeon basal ganglia, using the sensitive anterograde tracer biotinylated dextran amine [Veenman C. L. et al. (1992) J. Neurosci. Meth. 41, 239-254]. Injections of biotinylated dextran amine in the pigeon dorsal pallidum produced numerous fibers and terminals in specific nuclei of the thalamus, hypothalamus, pretectum and midbrain tegmentum. In the thalamus, labeled fibers and terminals were observed in the avian thalamic reticular nucleus, the proposed motor part of the avian ventral tier (ventrointermediate area), the avian parafascicular nucleus (nucleus dorsointermedius posterior), as well as in the avian nucleus subrotundus (which may be comparable to the posterior intralaminar nuclei of mammals). Labeled fibers and terminals were also observed in the avian subthalamic nucleus (anterior nucleus of the ansa lenticularis), in the pretectum (nucleus spiriformis lateralis) and in the avian substantia nigra pars reticulata. Injections of biotinylated dextran amine in the pigeon ventral pallidum produced fibers and terminals in specific centers of the telencephalon, hypothalamus, thalamus, epithalamus, and midbrain and isthmic tegmentum. Labeled fibers and terminals were also observed in the avian subthalamic nucleus and the inmediately adjacent lateral hypothalamus, the avian thalamic reticular nucleus, the avian medidorsal nucleusaand posterior intralaminar nuclei, and the lateral habenula. Finally, labeled fibers and terminals were found in the ventral tegmental area, the avian substantia nigra pars compacta and the midbrain/isthmic tegmentum, which includes the pedunculopontine tegmental nucleus. Our results indicate that both the dorsal and ventral pallida of birds have unique and specific projection patterns, which are very similar to those of their counterparts in mammals. Our study suggests that these avian basal ganglia regions may be related mainly to somatomotor and limbic functions, respectively.

Anatomy, Artistic↗

PubMed2005

Tuft-shaped astrocytes in Lewy body disease.

We investigated the occurrence and distribution of tuft-shaped astrocytes (TuSAs) in 60 brains from patients with Lewy body disease (LBD), which were clinically diagnosed as Parkinson's disease (PD) or dementia with Lewy bodies (DLB), and 85 brains from control subjects. TuSAs have been documented as a neuropathological hallmark of progressive supranuclear palsy (PSP). We found phosphorylated tau (p-tau)-positive and alpha-synuclein-negative TuSAs in 10 of 60 patients with LBD and 3 of 85 control cases. TuSAs were mainly located within the precentral and premotor gyri of the frontal lobe cortex. There were only few TuSAs, but the distribution pattern and morphological and immunohistological features were similar to that in PSP. Furthermore, other p-tau positive structures, including aggregates in neurons, coiled-like glial cells and threads showed a similar distribution to those in PSP; mainly in the hippocampus, striatum, subthalamic nucleus, precentral and premotor gyri, brainstem nucleus, and dentate nucleus. In these cases, however, neuronal loss and gliosis were not seen in the regions involved in PSP, such as the subthalamic nucleus, pallidum, inferior olivary, cerebellar dentate nuclei, and periaqueductal gray matter. Clinical features were indistinguishable between the LBD with and without TuSAs. The appearance of TuSAs was not related to the frequency of Lewy bodies, neurofibrillary tangles, and senile plaques, but was significantly more pronounced with advancing age in both LBD and controls. These findings suggest that in a subgroup of elderly individual cases, especially associated with LB pathology, the glial and neuronal p-tau accumulation is increased and has a distributional pattern similar to PSP.

Aged↗

PubMed1993

Hemiballism-hemichorea induced by subcortical ischemia.

Four patients presented with hemiballism-hemichorea as a clinical manifestation of white matter ischemia. These patients illustrate "positive" motor phenomena rather than limb weakness as a consequence of cerebral ischemia. In each patient, the involuntary movements disappeared following worsening of paresis. Subcortical white matter infarction in three patients and hemodynamic hypo-perfusion in the cerebral hemisphere contralateral to dyskinetic movements were possible causes. Neuroradiologically, none had pathological changes in the vicinity of the subthalamic nucleus. We presume from these observations that ischemia of the subcortical white matter, without involvement of the basal ganglia or the subthalamic nucleus, may cause hemiballism-hemichorea.

Aged↗

PubMed1982

Crossed connections of the substantia nigra in the rat.

The existence of crossed multisynaptic pathways that allow for the interdependent control of activity in one substantia nigra and its contralateral counterpart has been inferred from a number of recent biochemical and neurophysiological investigations. This prompted a reexamination of the connections of the substantia nigra with an emphasis on crossed inputs to and crossed projections from that nucleus. Male albino rats received 20-50-nl pressure injections of a 1% wheat germ agglutinin-conjugated horse-radish peroxidase (WGA-HRP) solution into the substantia nigra or into surrounding areas as controls. Following a 24-hour survival period the animals were processed according to the tetramethylbenzidine protocol for the visualization of HRP. The pattern of anterograde transport of WGA-HRP after substantia nigra injections, confirming for the most part previous reports, demonstrated ipsilateral nigral efferent projections to the striatum; globus pallidus; subthalamic nucleus; the lateral dorsal, paralamellar mediodorsal, ventromedial, and parafascicular thalamic nuclei; central gray, midbrain reticular formation; superior colliculus; and peribrachial area, including the pedunculopontine nucleus. Additionally, the nigral projections to the paralamellar mediodorsal and ventromedial thalamic nuclei and to the superior colliculus were demonstrated to be bilateral. Most of these connections were confirmed by the complementary retrograde experiment. In accordance with previous reports, intranigral WGA-HRP injections retrogradely labeled neurons located in the ipsilateral prefontal cortex, motor cortex, striatum, globus pallidus, central nucleus of the amygdala, anterior hypothalamic area, subthalamic nucleus, and dorsal raphe. Additionally, labeled perikarya were observed in the ipsilateral parafascicular thalamic nucleus, in the contralateral posterior lateral hypothalamic area, and in the ipsilateral and contralateral peribrachial-pedunculopontine area. These latter nigral afferents were confirmed with complementary WGA-HRP injections into each of the regions of origin. While bilateral peribrachial-pedunculopontine innervation of the substantia nigra has been reported in the cat there has been no previous demonstration of a crossed nigral afferent system from the contralateral posterior lateral hypothalamic area. The results are discussed with reference to the pathways that may mediate the interdependent control of the activity of neurons in the left and right substantia nigra. Additionally, the association of the substantia nigra with a variety of neuronal circuits, including the cerebellofugal, tectothalamic, thalamocortical, thalamostriatal, and basal ganglia pathways, are discussed.

Animals↗

PubMed2006

Functional role of the basal ganglia in the planning and execution of actions.

OBJECTIVE: Recent studies of functional brain imaging have shown the involvement of the basal ganglia in executive processes such as planning and set-shifting. However, the specific contributions of the striatum in those processes remain unknown. This study aimed to test the hypothesis that the caudate nucleus is primarily involved in the preparation of a novel action and not in set-shifting per se. METHODS: In the present event-related functional magnetic resonance imaging (fMRI) study, a new task was developed that permitted, for the first time, to distinguish between shifts in classification when the rule is implicitly given by the task from shifts that require cognitive comparison and planning. RESULTS: Significantly increased activity in the caudate nucleus and the putamen was observed only in conditions in which cognitive planning was required to perform a set-shift, whereas significant activation was seen in the subthalamic nucleus (another region of the basal ganglia) in all shifting conditions whether or not planning was required. INTERPRETATION: We suggest that the caudate nucleus and the putamen are particularly important, respectively, in the planning and the execution of a self-generated novel action, whereas the subthalamic nucleus may be required when a new motor program is solicited independently of the choice of strategy.

Adolescent↗

PubMed1988

Distribution of central omega 1 (benzodiazepine1) and omega 2 (benzodiazepine2) receptor subtypes in the monkey and human brain. An autoradiographic study with [3H]flunitrazepam and the omega 1 selective ligand [3H]zolpidem.

The distribution of the central omega 1 (benzodiazepine1; BZD1) and omega 2 (BZD2) receptor subtypes has been studied autoradiographically in monkey and human brain sections using [3H]flunitrazepam (which binds indiscriminately to omega 1 and omega 2 subtypes) and [3H]zolpidem (which recognizes selectively the omega 1 subtype). Both ligands labeled an homogeneous population of binding sites (Kd values approximately equal to 1.5 nM and approximately equal to 5 nM, respectively) whose pharmacological characteristics were similar to those of central omega (BZD) receptors. Regional displacement studies in monkey brain showed that zolpidem was a more effective displacer of [3H]flunitrazepam from omega 1-than from omega 2-enriched areas. For example, it was 73-fold more potent in the cerebellum (omega 1-enriched) than in the dentate gyrus (omega 2-enriched). Zolpidem thus selectively recognizes omega 1 sites in primate brain. The autoradiographic distribution of [3H]flunitrazepam (omega 1 + omega 2) binding sites in primate brain was highly heterogeneous. Very high densities were observed in lamina IV of the neocortex (with higher densities in the occipital than in the frontal pole), the substantia innominata and molecular layer of the dentate gyrus. Intermediate densities were found in other neocortical laminae, cerebellum (molecular layer), claustrum, globus pallidus, caudate-putamen, nucleus accumbens, dentate gyrus (granular layer) and the majority of thalamic nuclei. Structures displaying low binding densities included the substantia nigra and the subthalamic nucleus. The regional distribution pattern of [3H]zolpidem binding sites was qualitatively similar to that of [3H]flunitrazepam but the relative density of the 3H-ligands differed in several brain regions. The relative density of omega 1 and omega 2 subtypes in each particular primate brain region was evaluated by measuring 1) the ratio of [3H]zolpidem to [3H]flunitrazepam binding; 2) [3H]flunitrazepam binding in the presence and in the absence of 100 nM zolpidem. With both approaches, a preferential enrichment in omega 1 sites was observed in lamina IV of sensorimotor cortical regions and in the extrapyramidal motor system (globus pallidus, ventral thalamic complex, subthalamic nucleus, substantia nigra and cerebellum). In contrast, omega 2 sites predominated in limbic areas (e.g., the dentate gyrus, amygdala, nucleus accumbens, cingulate and parahippocampal gyri) and in the anterior thalamic nucleus and caudate nucleus.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1998

Blockade of subthalamic dopamine D1 receptors elicits akinesia in rats.

The role of dopamine in the subthalamic nucleus to control motor behaviour was investigated in rats using bilateral microinfusions of the dopamine D1 receptor antagonist SCH23390 and the dopamine D2 receptor antagonist S(-)-sulpiride. Selective blockade of subthalamic D1 receptors, but not of D2 receptors, produced catalepsy. These findings suggest that dopamine D1 receptors within the subthalamic nucleus play a prominent role in the regulation of motor functions. Furthermore, the data point to the possibility that a reduced dopaminergic tone at subthalamic dopamine D1 receptors might contribute to akinesia in Parkinson's disease.

Animals↗

PubMedDate not supplied

Hemiballismus: CT and MR findings.

OBJECTIVE: Our aim was to determine the frequency with which a lesion responsible for hemiballismus was detectable on CT and MR examinations. MATERIALS AND METHODS: The CT and MR examinations of six patients with hemiballismus were reviewed. Three patients underwent MRI alone, two CT alone, and one underwent both CT and MRI. Sites considered as possible locations for a lesion causing hemiballismus included the subthalamic nucleus on the side contralateral to the movements, contralateral putamen, caudate nucleus, thalamus, corpus striatum, lenticular nucleus, substantia nigra, and the premotor and motor cortex. RESULTS: A lesion likely to account for hemiballismus was found in five patients (contralateral subthalamic nucleus in four patients, contralateral putamen in one patient). Causes of hemiballismus included infarction (one patient), hemorrhage (two patients), trauma (one patient), and an abscess (one patient). A responsible lesion was detected in all five patients who underwent MRI. In one patient who underwent CT alone, a responsible lesion was not identified. CONCLUSION: A lesion responsible for hemiballistic movements can generally be found on cross-sectional imaging examinations. Because the multiplanar imaging capability of MR appears to allow for sensitive detection of even small lesions in sites likely to cause hemiballismus, MRI offers the best means of imaging these patients.

Aged↗

PubMed2003

Modulation of tremor amplitude during deep brain stimulation at different frequencies.

Rest tremor was quantified in the index finger tip of 16 patients with Parkinson's disease (PD) receiving deep brain stimulation (DBS) of the ventro-intermediate nucleus (Vim) of the thalamus, the subthalamic nucleus (STN), or the internal part of the globus pallidus (GPi) while being off L-dopa for 12h. Clinically, without DBS, tremor amplitude varied from absent to high. Tremor was recorded continuously for about 5 min under three conditions of DBS repeated twice, namely, effective frequency (E), ineffective frequency (I), and no DBS (O). No changes in tremor were observed across conditions in subjects with little or no tremor. However, in subjects with moderate to large amplitude tremor, DBS decreased tremor amplitude to near normal values within a few seconds. Generally, transitions were progressive and occurred with a varying time delay. Occasionally, tremor escaped from control regardless of the stimulation condition considered. In some cases tremor amplitude in one condition appeared to depend on the preceding condition. Finally, the results were reproducible on two consecutive days. We conclude that tremor control with DBS follows specific dynamical rules, which must be compatible with the hypotheses proposed regarding the underlying mechanisms of DBS.

Aged↗

PubMed1997

Re-evaluation of the functional anatomy of the basal ganglia in normal and Parkinsonian states.

In the late 1980s, a functional and anatomical model of basal ganglia organization was proposed in order to explain the clinical syndrome of Parkinson's disease. According to this model, the pathological overactivity observed in the subthalamic nucleus and the output station of the basal ganglia plays a crucial role in the pathophysiology of the motor signs of Parkinson's disease. The hyperactivity of subthalamic neurons in Parkinsonism is viewed as a direct consequence of a pathological hypoactivity of the external segment of the pallidum. This article reviews recent data from different experimental approaches that challenge the established model of basal ganglia organization by reinterpreting the functional interaction between the external segment of the pallidum and the subthalamic nucleus in both the normal and pathological state. Indeed, recent neurobiochemical studies have rather unexpectedly shown that the GABAergic and metabolic activities of the external pallidum are not decreased in human and non-human primates with Parkinsonism. This absence of any decrease in activity might be explained by the functionally antagonistic influences of the striatal and subthalamic afferences within the external pallidum, as suggested by several anatomical studies. In addition, there are clues from electrophysiological studies to suggest that the hyperactivity found in the subthalamic neurons in Parkinsonism may not depend solely on the level of activity in the external pallidum. In such a framework, the hyperactivity of the subthalamic neurons would have to be explained, at least in part, by other sources of excitation or disinhibition. However, any explanation for the origin of the subthalamic overactivity in Parkinsonism remains speculative.

Animals↗

PubMed1989

Dopaminergic innervation of the basal ganglia in the squirrel monkey as revealed by tyrosine hydroxylase immunohistochemistry.

The organization of the dopaminergic mesostriatal fibers and their patterns of innervation of the basal ganglia in the squirrel monkey (Saimiri sciureus) were studied immunohistochemically with an antiserum raised against tyrosine hydroxylase (TH). Numerous fibers arose from midbrain TH-positive cell bodies of the substantia nigra pars compacta (group A9), the retrorubral area (group A8), and the lateral portion of the ventral tegmental area (group A10). These fibers accumulated dorsomedially to the rostral pole of the substantia nigra where they formed a massive bundle that coursed through the prerubral field and ascended along the laterodorsal aspect of the medial fore-brain bundle in the lateral hypothalamus. Some ventrally located fibers ran throughout the rostrocaudal extent of the lateral preopticohypothalamic area and could be followed up to the olfactory tubercle, whereas other fibers turned laterodorsally to invade the head of the caudate nucleus. At more dorsal levels in the lateral hypothalamus, many fiber fascicles detached themselves from the main bundle and swept laterally to reach the globus pallidus, the putamen, and the amygdala. Several TH-positive fibers coursed along the dorsal surface of the subthalamic nucleus, and some invaded the dorsomedial third of this structure. The remaining portion of the subthalamic nucleus contained relatively few TH-positive elements. In contrast, the globus pallidus received a dense dopaminergic innervation deriving mostly from two fascicles that coursed backward along the two major output pathways of the pallidum: the lenticular fasciculus caudodorsally and the ansa lenticularis rostroventrally. At the pallidal level, the labeled fibres merged within the medullary laminae and arborized profusely in the internal pallidal segment and less abundantly in the external pallidal segment. However, the caudoventral portion of the external pallidum displayed a dense field of TH-positive axonal varicosities. Other fibers ran through the dorsal two-thirds of the external pallidum en route to the putamen. The striatum contained a multitude of thin axonal varicosities among which a few long and varicosed fibers were scattered. These immunoreactive neuronal profiles were rather uniformly distributed along the rostrocaudal extent of the striatum but appeared slightly more numerous in the ventral striatum than in the dorsal striatum. The pattern of distribution of the TH-positive axonal varicosities in the dorsal striatum was markedly heterogeneous: it consisted of typical zones of poor TH immunoreactivity lying within a matrix of dense terminal labeling.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1992

[A case of thalamo-subthalamic hemorrhage presenting monoballism in the contralateral lower extremity].

We report a 62-year-old man with ballism confined to the right leg, so-called monoballism. He was admitted to our hospital complaining of gait disturbance due to violent involuntary movements in the right lower extremity which had developed seven days before. He had a ten-years' history of hypertension and at age 57 had been diagnosed as having asymptomatic multiple cerebral infarcts. Until admission, he was taking antiplatelet drugs for the purpose of preventing thrombotic stroke. On neurological examination, he showed mild impairment of higher brain function, Horner's sign in the left eye, and typical ballism in the right lower extremity. Involuntary movements were never observed in the face and the other extremities. Surface electromyography also showed reciprocal burst discharges at about 1 Hz related to the ballistic movements in the right lower extremity. CT scan revealed a high density lesion surrounded by a low density in the left subthalamic area. MRI examination demonstrated a dumbbell shaped hemorrhage extending from the left subthalamic nucleus to the dorsomedial nucleus of the ipsilateral thalamus. Adding to the hemorrhage, many ischemic lesions were observed in the bilateral basal ganglia and thalamus including the left pallidum. The causal end of the hemorrhage apparently located in the anterior dorsomedial portion of the subthalamic nucleus. There were few reports concerning monoballism, especially monoballism limited to the lower extremity. Recent researches indicate that a subthalamic lesion reduces the excitatory control from the subthalamus to the internal segment of the globus pallidus, which leads to a disinhibition of the thalamus and gives rise to ballism.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Hemorrhage↗

PubMed2000

Electrophysiological localization of the substantia nigra in the parkinsonian nonhuman primate.

During ablative surgery and implantation of deep-brain stimulators for the treatment of movement disorders, electrophysiological techniques are often used for localization of subcortical targets. New restorative therapies for Parkinson disease, aimed at delivering drugs or cells to the substantia nigra (SN), are becoming available. Therefore, precise surgical approaches to the dopaminergic cell-containing region of the SN are required to avoid damage to nearby structures such as the corticospinal tract and subthalamic nucleus. In a study conducted in nonhuman primates, the authors evaluated the utility and accuracy of electrophysiological techniques in localizing the SN. Three adult rhesus monkeys were used as hosts for intranigral cell transplants. The monkeys were rendered hemiparkinsonian by intracarotid injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. With the aid of stereotactic guidance, chronic recording chambers were placed on the skull of each monkey and directed at the SN. In each monkey, 20 to 40 trajectories were explored with a microelectrode. Spontaneous and movement-related single-unit activities were recorded in the SN, pars reticulata, subthalamic nucleus, globus pallidus, striatum, thalamus, and red nucleus. Motor and ocular responses to microstimulation in the subthalamic area were noted. Using the electrophysiological and stereotactic information that was obtained, three-dimensional maps of the nigral complex were constructed to infer the location of the SN pars compacta. The maps were subsequently used to guide intranigral placement of fetal dopaminergic cells. Accurate delivery was verified by histological analysis. Based on the characteristic electrophysiological properties of the SN and surrounding structures in the parkinsonian state, microelectrode recording techniques may be used to ensure accurate placement of cell transplantation in the intranigral region.

Animals↗

PubMed1987

Analysis of the brain regions involved in myoclonus produced by intracerebral picrotoxin.

Picrotoxin caused myoclonic jerking of the opposite forelimb when applied to the striatum and the cortical surface of rat brain. Intrastriatal picrotoxin increased [3H]2-deoxyglucose uptake by the ipsilateral frontal cortex, thalamus and subthalamic nucleus. Electrolyte and ibotenic acid lesions made in the globus pallidus prevented striatally evoked myoclonus without affecting the movements elicited from the cortex. Electrolytic lesions in the subthalamic nucleus and thalamus affected striatally evoked myoclonus more than the cortically elicited response. It is concluded that striato-pallidal-thalamic-cortical circuitry is responsible for striatally evoked myoclonus.

Animals↗

PubMed1992

Contralateral disappearance of parkinsonian signs after subthalamic hematoma.

A man with Parkinson's disease (PD) suddenly developed a left hemiballismus, and the CT showed a hematoma of the right subthalamic nucleus. After the ballistic movements had disappeared, akinesia and the other parkinsonian signs did not reappear on the left. This clinical case confirms the involvement of the subthalamic nucleus in the akinesia of PD, as suggested by recent experimental data.

Aged↗