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PubMed2006

Involvement of human basal ganglia in offline feedback control of voluntary movement.

Practice makes perfect, but the neural substrates of trial-to-trial learning in motor tasks remain unclear. There is some evidence that the basal ganglia process feedback-related information to modify learning in essentially cognitive tasks , but the evidence that these key motor structures are involved in offline feedback-related improvement of performance in motor tasks is paradoxically limited. Lesion studies in adult zebra finches suggest that the avian basal ganglia are involved in the transmission or production of an error signal during song . However, patients with Huntington's disease, in which there is prominent basal ganglia dysfunction, are not impaired in error-dependent modulation of future trial performance . By directly recording from the subthalamic nucleus in patients with Parkinson's disease, we demonstrate that this nucleus processes error in trial performance at short latency. Local evoked activity is greatest in response to smallest errors and influences the programming of subsequent movements. Accordingly, motor parameters are least likely to change after the greatest evoked responses so that accurately performed trials tend to precede other accurate trials. This relationship is disrupted by electrical stimulation of the nucleus at high frequency. Thus, the human subthalamic nucleus is involved in feedback-based learning.

Aged↗
PubMed2001

Action monitoring, error detection, and the basal ganglia: an ERP study.

The error negativity (Ne or ERN) is an event-related brain potential component, which is assumed to reflect error detection. Recently it has been hypothesized that the basal ganglia are assumed to play a crucial role in error detection. In the present study we ask whether the Ne is altered in patients with Parkinson's disease (PD), who have an impaired function of the basal ganglia. We recorded the Ne in patients and in matched controls, while they performed different tasks that require a relatively high cognitive control, which is supposed to pose particular problems on PD. The Ne was in fact smaller in the patients than in the controls in all tasks. Our results suggest an impairment of error detection in PD for different types of demanding tasks. This supports the hypothesis that the basal ganglia do play an important role for error detection in action monitoring.

Aged↗
PubMed1994

New pattern of hyperechogenicity in thalamus and basal ganglia studied by color Doppler flow imaging.

Thirty-seven infants whose cerebral real-time B-mode ultrasound (CUS) documented hyperechogenic areas in the thalamus and basal ganglia (HTBG) either of linear or fine punctate pattern, were studied prospectively by color Doppler imaging (CDI). This study aimed to establish a relationship between these areas and the regional vasculature, to analyze associated disorders to establish pathogenesis, and to determine clinical significance. HTBG were diagnosed in the first 4 days of life in all but 7 infants. Different patterns of HTBG were observed: punctate in 11 infants, linear in 12, and mixed in 14. The basal ganglia were affected in all patients, 9 also had involvement of the thalamus. CDI confirmed that HTBG were allocated along the gangliothalamic vessels. Blood flow velocity waves were obtained at this level in all patients. Real-time spectral analyses were performed in 35 patients and compared with a control group of 20 healthy neonates. Differences were not significant. Computed tomography and magnetic resonance imaging failed to indicate this abnormality. Necropsy revealed basophilic deposits in the walls of involved arteries. Congenital infections manifested in 5 patients, chromosomal abnormality in 1, dysmorphic syndromes in 9 (3 unidentified), isolated congenital defects in 5, and diverse congenital disorders in 3. In the remaining 14, no congenital disorders nor infections were found. This CDI study demonstrates the vascular location of these HTBG. Supported by early CUS diagnosis, it is speculated that vascular injury in that region has a prenatal origin. This abnormality does not appear to alter regional blood flow. HTBG are associated with very heterogeneous disorders and in most patients the etiology and pathogenesis remain unclear.

Arteries↗
PubMed2001

Neuroimaging in basal ganglia disorders: perspectives for transcranial ultrasound.

Transcranial sonography is a new diagnostic tool, allowing not only the evaluation of cerebral arteries but also the two-dimensional display of the brain parenchyma. In this review we will summarize basics of the application, the ultrasound anatomy of the brain and sonographic findings in some movement disorders. While in normal adults basal ganglia nuclei are hypoechogenic, they are hyperechogenic in certain basal ganglia disorders. In Parkinson's disease, for example, the substantia nigra can be depicted as a distinctly echogenic area. An elevated echogenicity of the lentiform nuclei was noticed in patients with primary adult-onset dystonia. In both disorders the altered echogenicity may arise from higher heavy metal tissue content (i.e. iron in Parkinson's disease and copper in primary dystonia). Our findings converge to the hypothesis that transcranial ultrasound sensitively detects pathological metal accumulation not identified by other neuroimaging techniques (CT and MRI) and therefore provides new insights in the diagnosis of basal ganglia disorders. The implications of these findings for the understanding of the pathogenesis and its usefulness for the early diagnosis of movement disorders are outlined.

Basal Ganglia Diseases↗
PubMedDate not supplied

[Metabolism of acetylcholine and gamma-aminobutyric acid in the basal ganglia and limbic cortex of rats at different stages in the development of alcohol dependence].

An increase in content of acetylcholine (AC) as well as stimulation of choline acetyltransferase and acetylcholinesterase were observed in basal ganglia of rat brain during development of alcohol dependency, thus indicating the activation of the AC structures. Less distinct activation of the AC structures occurred in limbic (frontal) cortex. At the step of complete alcohol dependency the patterns of AC metabolism were considerably normalized in the both brain structures; at the same time, activity of the gamma-aminobutyric acid (GABA) system was decreased, which occurred due to inhibition of the GABA synthesis. At the III step of experimental alcoholism with "physical" dependency on ethanol synthesis and release of the AC were lowered, especially distinct in basal ganglia. These phase alterations in the activity of the AC structures in basal ganglia were accompanied by the similar alterations in content of glutamate: an increase of glutamate at the I step of alcoholism and a decrease--at the III step. Possible mechanisms and pathogenetic role of the phase alterations observed in metabolism of the brain neurotransmitters and in activity of AC- and GABA-structures during development of alcohol dependency are discussed. The data obtained suggest that the specific steps of alcoholism should be taken into consideration in the differential treatment using neurotransmitter drugs.

Acetylcholine↗
PubMed1995

Multimodality treatment of deep arteriovenous malformations: thalamus, basal ganglia, and brain stem.

THE THERAPEUTIC APPROACH toward arteriovenous malformations (AVMs) located in the basal ganglia, thalamus, and brain stem has evolved from microsurgical resection as the predominant therapy to a combination of microsurgery, embolization, and radiosurgery. This multimodality treatment was used in the management of 32 patients with deep AVMs of all sizes. Twenty-two patients with surgically accessible AVMs (i.e., typically located in the brain stem and thalamus) underwent microsurgical resection. The AVMs of half of these patients were devascularized preoperatively with transfemoral embolization. Five patients with residual AVMs were then treated with radiosurgery. Ten patients had AVMs, typically located in the basal ganglia, that were surgically inaccessible. These patients underwent embolization to reduce the AVM size, and the postembolization nidus was then treated with radiosurgery. For patients treated early in the series with a predominantly surgical approach, the complete resection rate was 43%. For patients treated later in the series after radiosurgery was incorporated into the management scheme, the complete elimination rate was 72%. Overall, there were no deaths in this series, and the permanent treatment-associated morbidity rate was 9%. These results indicate that an individualized, multimodality approach can be used to eliminate both large and small deep AVMs with an acceptably low morbidity and mortality rate.

Adolescent↗
PubMed1992

Effects of reversible blockade of basal ganglia on a voluntary arm movement.

1. The effects of a reversible blockade of basal ganglia were examined in two monkeys trained to perform a visually guided, step-tracking arm movement around the elbow joint. To block glutamatergic excitation, kynurenate (a glutamate antagonist) was locally injected into the putamen and the external segment (GPe) and the internal segment (GPi) of the globus pallidus contralateral to the arm tested. Muscimol [a gamma-aminobutyric acid (GABA) agonist] was also used to suppress neuronal activity in these structures. The drugs were injected in the arm area of the putamen, which was identified by microstimulation or by recording neural activity. For the GPe and GPi, injections were made into the area medioventral to the arm area of the putamen. 2. The blockade of the putamen caused abnormal braking of the arm movements. The first step of the movement became hypometric, and multiple steps were necessary to reach the target. The electromyographic (EMG) analysis revealed an increase of burst activity in the antagonist muscles and a decrease of that in the agonist muscles at the fast movements. The tonic activity increased in the extensor muscles during a holding period. 3. The blockade of the GPi caused dysmetric movements. Amplitude and peak velocity of the first step of movement largely fluctuated among trials. It became difficult for the animal to brake and adjust its arm onto the target. 4. The blockade of the GPe caused a flexion posture at the elbow joint of the contralateral arm. The tonic activity of the flexor muscles increased. Cocontraction of the agonist and antagonist muscles was also observed. 5. These results suggest that the putaminopallidal system of the basal ganglia contributes to both of two motor functions: 1) static control to maintain the posture with tonic muscle activity, and 2) dynamic control to enable fast movements.

Animals↗
PubMed2001

Proton magnetic resonance spectroscopy (1H-MRS) of motor cortex and basal ganglia in de novo Parkinson's disease patients.

Proton MR spectroscopy (1H-MRS) has been previously performed in Parkinson's disease (PD) and parkinsonian syndromes to evaluate in vivo concentrations of basal ganglia and cerebral cortex metabolites such as N-acetylaspartate (NAA), choline (Cho), and creatine (Cr). However, this technique has never been used to evaluate motor cortex in untreated PD patients. In this study, single-voxel 1H-MRS of basal ganglia and motor cortex was carried out in 10 de novo patients with PD and 10 age-matched healthy controls. A significant reduction in the NAA/Cr ratio was observed in the motor cortex of PD patients compared with controls (p)<(0.01). Basal ganglia spectra did not allow any evaluation due to the presence of artefacts related to inorganic paramagnetic substances. The motor cortex reduction of the NAA/Cr ratio in de novo PD patients may reflect an altered neuronal functioning due to a loss of thalamocortical excitatory inputs and may represent an in vivo marker for the diagnosis of PD.

Aged↗
PubMed1992

Preprotachykinin gene expression in the human basal ganglia: characterization of mRNAs and pre-mRNAs produced by alternate RNA splicing.

The nature and distribution of preprotachykinin (PPT, i.e. substance P/neurokinin A-encoding) gene expression in human basal ganglia was determined. Northern blot analysis visualized a single band of approximately 1300 bases, confirming the postmortem stability of PPT mRNA. Gross anatomical analysis indicated that PPT gene expression was relatively evenly distributed throughout the human caudate and putamen, but absent in the globus pallidus and substantia nigra. Nuclease protection analysis of these tissues established that human PPT mRNA consisted of approximately 80-85% beta-PPT (exon 1-7 derived) mRNA and 15-20% gamma-PPT (minus exon 4), with no alpha-PPT (minus exon 6) mRNA detected; these data contrast with the proportions of PPT mRNAs seen in non-human species. The incompletely spliced PPT RNA species detected in basal ganglia accounted for approximately 8% of total human PPT RNA and suggested a fixed order of exon splicing. Since various PPT mRNAs encode different combinations of tachykinin peptides with distinct biological activities, the markedly different proportions of PPT mRNAs seen in human basal ganglia compared to non-human tissues may be of physiological significance.

Animals↗
PubMed1980

Basal ganglia calcification on CT scanning in children with acute lymphocytic leukemia.

Calcification occurring in the basal ganglia in children with acute lymphocyte leukemia following therapy is uncommon and to the best of our knowledge has not been reported prior to therapy. Eleven cases of bilateral symmetrical calcification in the basal ganglia were noted in 2350 CT scans, two being in children with acute lymphocytic leukemia. In one of the two cases, calcification was present prior to therapy.

Basal Ganglia Diseases↗
PubMed1987

Physiology of the basal ganglia and pathophysiology of Parkinson's disease.

This paper reviews current concepts concerning the anatomical organization and functions of the basal ganglia focusing mainly on the role of the basal ganglia in control of movement. Results of several studies which have been carried out on patients with Parkinson's disease are also reviewed and discussed as examples of altered normal physiological mechanisms.

Action Potentials↗
PubMed2001

Movement-related potentials in the basal ganglia: a SEEG readiness potential study.

OBJECTIVES: The brain potentials preceding and accompanying self-paced acral limb movements (Bereitschaftspotential/readiness potential (RP) paradigm) were studied in 12 patients. METHODS: Intracranial electrodes were implanted in order to explore intractable epilepsy. The electrodes were introduced into sites corresponding to the electroclinical characteristics of each patient's epileptic seizures. In 7 patients, several depth electrodes were implanted orthogonally, in the temporal, fronto-orbital and prefrontal cortex. In 4 patients, subdural strip electrodes were used for the exploration of the fronto-temporal convexity. There were no RPs recorded in these areas. No contacts were placed in the central region known to generate cortical RP. In all the patients, one or two diagonal electrodes passed through or touched the basal ganglia to reach the amygdala and the hippocampus. The putamen was explored in 11 patients (in 3 of them bilaterally); the caudate head was explored in two patients, and the pallidum was explored in two patients. RESULTS: RP with a clear amplitude gradient was present in all explored structures, however a phase reversal was never observed. RP was observed in the caudate in all recordings, and in the pallidum in one patient. It was recorded in the putamen in 8 out of the 11 explored patients. RPs were displayed contralaterally to the movement 9 times in 13 explorations, and ipsilaterally 4 times in 9 explorations. The shape of RP resembled the RP shape in the cortex and on the scalp. Movement accompanying potentials (MAPs) were also present in all 3 explored structures. The electrophysiological characteristics of MAP differed from RP, indicating separate generators. In the basal ganglia, RPs preceded the onset of movement by 500-1500 ms, at an average of 1080 (+/-330) ms. It seems that the RP in the basal ganglia starts slightly later than the RP in the motor cortices. That should be definitely demonstrated in patients with simultaneous recordings from cortical and subcortical structures. RP and MAP were displayed synchronously in the cortex and in the basal ganglia during most of the premovement period, as well as during the execution of movement. RP generators were reported by several authors in other deeply located structures, i.e. in the thalamus and in the brain-stem. CONCLUSIONS: Based on all these recordings, we presume that the RPs recorded on the scalp are generated simultaneously in several cortical as well as subcortical structures.

Adult↗
PubMed1999

Immunohistochemical localization of subtype 4a metabotropic glutamate receptors in the rat and mouse basal ganglia.

Recent studies suggest that metabotropic glutamate receptors (mGluRs) may play a significant role in regulating basal ganglia functions. In this study, we investigated the localization of mGluR4a protein in the mouse and rat basal ganglia. Polyclonal antibodies that specifically react with the metabotropic glutamate receptor subtype mGluR4a were produced and characterized by Western blot analysis. These antibodies recognized a native protein in wild-type mouse brain with a molecular weight similar to the molecular weight of the band from a mGluR4a-transfected cell line. The immunoreactivity was absent in brains of knockout mice deficient in mGluR4. mGluR4a immunoreactivity was most intense in the molecular layer of the cerebellum. We also found a striking mGluR4a immunoreactivity in globus pallidus, and moderate staining in substantia nigra pars reticulata and entopeduncular nucleus. Moderate to low mGluR4a immunoreactivity was present in striatum and other brain regions, including hippocampus, neocortex, and thalamus. Double labeling with mGluR4a antibodies and antibodies to either a dendritic marker or a marker of presynaptic terminals suggest a localization of mGluR4a on presynaptic terminals. Immunocytochemistry at electron microscopy level confirmed these results, revealing that in the globus pallidus, mGluR4a is mainly localized in presynaptic sites in axonal elements. Finally, quinolinic acid lesion of striatal projection neurons decreased mGluR4a immunoreactivity in globus pallidus, suggesting a localization of mGluR4a on striatopallidal terminals. These data support the hypothesis that mGluR4a serves as a presynaptic heteroreceptor in the globus pallidus, where it may play an important role in regulating g-amino-n-butyric acid (GABA) release from striatopallidal terminals.

Animals↗
PubMed1987

Basal ganglia influences on the cerebellum of the cat.

The changes in firing rate of intracerebellar nuclear neurons following electrical stimulation of the contralateral basal ganglia were investigated in adult cats, in which antidromic activation of cortico-pontine and/or cortico-olivar fibers arising in the area 6 had been excluded by chronic ablation of the motor cortex. Activation of putamen and caudate nucleus induced discharge changes in a low percentage (below 12.5%) of both medial and lateral cerebellar nuclei neurons, while stimulation of globus pallidus and especially of entopeduncular nucleus modified the spontaneous discharge of a greater percent of cells (up to 29%), mainly in the most lateral cerebellar portions. The basal ganglia-induced effects were abolished upon section of the brachium pontis but not of the restiform body. Latency values of the responses, which were predominantly excitatory in nature, suggest the involvement of structures interposed between basal ganglia and precerebellar systems. We postulated that impulses issued by the basal ganglia could reach the cerebellum through a pathway that involves the pedunculopontine nucleus and the nucleus reticularis tegmenti pontis.

Animals↗
PubMed1982

GABA-transaminase in the basal ganglia: a pharmacohistochemical study.

A pharmacohistochemical procedure to demonstrate histochemically those cells with the ability to synthesize the GABA-metabolizing enzyme GABA-transaminase has been applied to determine the localization of this enzyme in the basal ganglia. In normal, pharmacologically unmanipulated animals, strong GABA-transaminase activity is present throughout the neuropil in many nuclei of the basal ganglia. The striatum, globus pallidus, entopeduncular nucleus, subthalamic nucleus and substantia nigra are all heavily stained. White matter such as the corpus callosum and internal capsule are unstained. Pretreatment of rats with the irreversible GABA-transaminase inhibitor ethanolamine-O-sulfate resulted in a marked reduction in the general neuropil staining. At a suitable post-injection survival time, cells which had synthesized new GABa-transaminase molecules could be detected. Small, positive neurons were present in the striatum and entopeduncular nucleus, while the globus pallidus, substantia nigra zona reticulata, and the ventral pallidal region contained many large, intensely GABA-transaminase-positive neurons. The results indicate that much of the GABA-transaminase in the basal ganglia is neuronal in origin. The relationship of GABA-transaminase to GABA neurons is discussed.

4-Aminobutyrate Transaminase↗
PubMed2005

Partial seizures triggering infantile spasms in the presence of a basal ganglia glioma.

Infantile spasms associated with brain tumors have been reported. A focal cortical lesion can induce infantile spasms by triggering the brainstem and basal ganglia in this vulnerable age group. We report the case of a female infant with a low-grade glioma in the right basal ganglia, spreading to the cortical area. She presented at the age of five months with left hemiparesis and partial seizures. She developed infantile spasms at the age of 12 months. This is the first video clip report of partial seizures triggering symmetrical spasms in series, secondary to a basal ganglia glioma extending to the cortex. [Published with video sequences].

Anticonvulsants↗
PubMed2005

Neurologic spectrum of chronic liver failure and basal ganglia T1 hyperintensity on magnetic resonance imaging: probable manganese neurotoxicity.

BACKGROUND: An atypical form of parkinsonism has been described in patients with chronic liver disease, associated with increased T1 signal in the basal ganglia on magnetic resonance imaging. The magnetic resonance imaging signal changes are characteristic of manganese accumulation, which has been neuropathologically confirmed. Manganese neurotoxicity may result in additional neurologic findings besides parkinsonism. OBJECTIVE: To fully characterize patients with chronic central nervous system symptoms and chronic liver failure associated with basal ganglia T1 hyperintensity. DESIGN: Prospective and retrospective case study. SETTING: Mayo Clinic, Rochester, Minn. PARTICIPANTS: Eight patients referred for neurologic evaluation and studied prospectively, and 7 additional retrospectively identified patients who had been examined by Mayo Clinic neurologists. MAIN OUTCOME MEASURES: Neurologic syndromes identified. RESULTS: Three syndromes were recognized in these 15 patients with liver failure and basal ganglia T1 hyperintensity on magnetic resonance imaging: (1) isolated parkinsonism, (2) gait ataxia plus other neurologic findings (ataxia-plus), and (3) cognitive impairment with psychiatric features. All but 1 patient had elevated blood manganese levels. Ammonia levels were normal in most, and the neurologic syndromes did not appear to reflect the well-known toxic-metabolic encephalopathy of liver disease. CONCLUSIONS: Chronic liver failure may result in heterogeneous neurologic syndromes that cut across a variety of liver diseases. We selected cases on the basis of evidence of brain manganese accumulation, and this may be a crucial component of these syndromes. Further studies are necessary to explore this issue.

Adult↗
PubMed1995

Basal ganglia T2 relaxation times in schizophrenia: a quantitative magnetic resonance imaging study in relation to tardive dyskinesia.

Transverse, or spin-spin, relaxation times (T2) from magnetic resonance images of basal ganglia structures were compared between control subjects and patients with schizophrenia, who were subdivided on the basis of the presence or absence of tardive dyskinesia. As a group, schizophrenic patients showed evidence of somewhat more prolonged T2 relaxation times in the right putamen and globus pallidus than did control subjects; there were no significant correlations between hemispheric T2 values and corresponding volumes of the lateral ventricles. Overall, there was little difference in T2 values between patients with and without tardive dyskinesia. These data extend the range of evidence for basal ganglia dysfunction in schizophrenia, but they do not support earlier reports of prominent T2 changes associated with tardive dyskinesia.

Adult↗