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PubMed2006

Increased antistreptococcal antibody titers and anti-basal ganglia antibodies in patients with Tourette syndrome: controlled cross-sectional study.

The association between Tourette syndrome, attention-deficit hyperactivity disorder (ADHD), and obsessive-compulsive disorder following streptococcal infections has been documented, but with conflicting reports. We thus felt it was important to investigate this association in a group of Italian patients not previously documented. We took blood on 69 patients with Tourette syndrome and 72 age- and sex-matched tic-free controls. Laboratory staff were blind to the diagnostic status of the subjects. Evidence of recent streptococcal infection was defined using antistreptolysin titers. Anti-basal ganglia antibodies were determined using human basal ganglia sections. Statistical analysis was conducted using analysis of variance and chi-square tests. Raised antistreptolysin titers were found in 41 of 69 (59%) patients with Tourette syndrome and 14 of 72 (19%) controls (P = .000). Positive anti-basal ganglia antibodies were found in 22 of 69 (32%) subjects with Tourette syndrome compared with 7 of 72 (10%) controls, which was also significant (P = .002). Raised antistreptolysin titers were detected in 18 of 22 (82%) patients with Tourette syndrome with positive anti-basal ganglia antibodies and 22 of 47 (47%) patients with negative anti-basal ganglia antibodies (P = .01). These results support the reported association between streptococcal infection and anti-basal ganglia antibodies and some patients with Tourette syndrome.

Adolescent↗
PubMed1987

Changes in the content of dopamine and its metabolites in the basal ganglia following right middle cerebral artery occlusion and reflow in monkeys.

Focal ischaemia was produced experimentally in Macaca radiata monkeys by occlusion of middle cerebral artery (MCA). There was a lowering of the dopamine (DA) content of basal ganglia after 4 and 12 h of occlusion. DA content was restored to normal in basal ganglia after restoration of blood flow. With the progress of time the DA content was increased above that of sham controls. Changes were also observed in the non-occluded left basal ganglia. The homovanillic acid (HVA) content was decreased significantly at 12 h after occlusion. After the onset of reflow, the HVA content of the right basal ganglia was higher than that of sham controls. The 3,4 dihydroxyphenylacetic acid (DOPAC) content of right basal ganglia was significantly decreased after 12 h occlusion. Reflow restored the level of DOPAC to normal within 1 h after removal of clip. Discrete changes were also observed in the left basal ganglia at some of the time intervals.

3,4-Dihydroxyphenylacetic Acid↗
PubMed2006

The basal ganglia are hyperactive during the discrimination of tactile stimuli in writer's cramp.

Writer's cramp is a focal hand dystonia that specifically affects handwriting. Though writer's cramp has been attributed to a dysfunction of the basal ganglia, the role of the basal ganglia in the pathogenesis of writer's cramp remains to be determined. Seventeen patients with writer's cramp (nine females; age range: 24-71 years) and 17 healthy individuals (six females; age range: 27-68 years) underwent functional MRI (fMRI) while they discriminated the orientation of gratings delivered to the tip of the right index finger. Statistical parametric mapping was used to analyse the fMRI data. The significance level was set at a corrected P-value of 0.05. Relative to healthy controls, patients with writer's cramp showed a widespread bilateral increase in task-related activity in the putamen, caudate nucleus, internal globus pallidus and lateral thalamus. In these areas, hyperactivity was more pronounced in patients who had recently developed writer's cramp. The enhanced response of the basal ganglia to tactile input from the affected hand is compatible with the concept of impaired centre-surround inhibition within the basal ganglia-thalamic circuit and may lead to an excessive activation of sensorimotor cortical areas during skilled movements affected by dystonia. Outside the basal ganglia, dystonic patients showed task-related overactivity in visual cortical areas, left anterior insula and right intraparietal sulcus, but not in the primary or secondary sensory cortex. In addition, task-related activity in the cerebellar nuclei, posterior vermis, right paramedian cerebellar hemisphere and dorsal pons was inversely related with the severity of hand dystonia. Regional activity in these areas may reflect secondary adaptive reorganization at the systems level to compensate for the dysfunction in the basal ganglia-thalamic loop.

Adult↗
PubMed1996

Basal ganglia volume and proximity to onset in presymptomatic Huntington disease.

OBJECTIVE: To determine in presymptomatic individuals who carry the gene mutation for Huntington disease whether proximity to estimated age at onset is associated with volume of basal ganglia, as measured on magnetic resonance imaging scans. DESIGN: Survey study involving correlations between basal ganglia volume, measured blind to subject status, and estimation of subjects' age at onset. SETTING: Huntington's Disease Presymptomatic Testing Program at The Johns Hopkins University School of Medicine, Baltimore, Md. PATIENTS AND OTHER PARTICIPANTS: Subjects included 47 individuals at risk for Huntington disease (ie, off-spring of patients with Huntington disease). Twenty subjects tested positive for the gene mutation but were not symptomatic. Twenty-seven subjects tested negative. MAIN OUTCOME MEASURES: Estimated age at onset was calculated for each of 20 gene-positive individuals using an empirically derived formula based on the subject's trinucleotide repeat length and parental age at onset. Each subject's age at the time of the magnetic resonance imaging scan was subtracted from his or her estimated age at onset, yielding estimated years to onset. Volumes of caudate, putamen, and globus pallidus were measured on magnetic resonance imaging scans. RESULTS: After controlling for the subject's age at the time of the scan, significant correlations were found between volumes of all basal ganglia structures and years to onset. Gene-positive subjects who were far from onset had smaller basal ganglia volumes than gene-negative subjects for all structures except globus pallidus. Gene-positive subjects who were close to onset had smaller volumes than gene-negative subjects for all basal ganglia structures and had smaller volumes than subjects far from onset for all structures except caudate. CONCLUSIONS: The results suggest that atrophy of the basal ganglia occurs gradually, beginning years before symptom onset.

Adult↗
PubMedDate not supplied

[Role of the basal ganglia in the occurrence of paradoxical sleep dreams (hypothetical mechanism)].

A hypothetical mechanism of the basal ganglia involvement in the occurrence of paradoxical sleep dreams and rapid eye movements is proposed. According to this mechanism, paradoxical sleep is provided by facilitation of activation of cholinergic neurons in the pedunculopontine nucleus as a result of suppression of their inhibition from the output basal ganglia nuclei. This disinhibition is promoted by activation of dopaminergic cells by pedunculopontine neurons, subsequent rise in dopamine concentration in the input basal ganglia structure. striatum, and modulation of the efficacy of cortico-striatal inputs. In the absence of signals from retina, a disinhibition of neurons in the pedunculopontine nucleus and superior colliculus allows them to excite neurons in the lateral geniculate body and other thalamic nuclei projecting to the primary and higher visual cortical areas, prefrontal cortex and back into the striatum. Dreams as visual images and "motor hallucinations" are the result of an increase in activity of definitely selected groups of thalamic and neocortical neurons. This selection is caused by modifiable action of dopamine on long-term changes in the efficacy of synaptic transmission during circulation of signals in closed interconnected loops, each of which includes one of the visual cortical areas (motor cortex), one of the thalamic nuclei, limbic and one of the visual areas (motor area) of the basal ganglia. pedunculopontine nucleus, and superior colliculus. Simultaneous modification and modulation of synapses in diverse units of neuronal loops is provided by PGO waves. Disinhibition of superioir colliculus neurons and their excitation by pedunculopontine nucleus lead to an appearance of rapid eye movements during paradoxical sleep.

Basal Ganglia↗
PubMed1998

Acute movement disorders with bilateral basal ganglia lesions in uremia.

Acute and subacute extrapyramidal movement disorders are rarely reported in uremic patients. We report three such cases with basal ganglia lesions. All three had advanced renal failure with high serum creatinine levels. One of the patients had a history of ischemic heart disease and acute pulmonary edema with hypoxemia. Another patient had experienced arterial hypotension during previous hemodialysis. The third had prominent metabolic acidosis. One of the patients developed generalized dyskinesias, whereas the other two developed gait disturbances. Neuroimaging studies in all three cases showed bilateral changes in the basal ganglia. The natural history was self-limiting with gradual improvement. Diminution of the basal ganglia lesions was demonstrated on follow-up imaging in two of the three cases. We conclude that acute or subacute movement disorders with bilateral basal ganglia lesions may occur in uremia. Hypoperfusion with global brain ischemia and selective vulnerability of the basal ganglia to uremic toxins may account for these lesions.

Acute Disease↗
PubMed1999

What are the computations of the cerebellum, the basal ganglia and the cerebral cortex?

The classical notion that the cerebellum and the basal ganglia are dedicated to motor control is under dispute given increasing evidence of their involvement in non-motor functions. Is it then impossible to characterize the functions of the cerebellum, the basal ganglia and the cerebral cortex in a simplistic manner? This paper presents a novel view that their computational roles can be characterized not by asking what are the "goals" of their computation, such as motor or sensory, but by asking what are the "methods" of their computation, specifically, their learning algorithms. There is currently enough anatomical, physiological, and theoretical evidence to support the hypotheses that the cerebellum is a specialized organism for supervised learning, the basal ganglia are for reinforcement learning, and the cerebral cortex is for unsupervised learning.This paper investigates how the learning modules specialized for these three kinds of learning can be assembled into goal-oriented behaving systems. In general, supervised learning modules in the cerebellum can be utilized as "internal models" of the environment. Reinforcement learning modules in the basal ganglia enable action selection by an "evaluation" of environmental states. Unsupervised learning modules in the cerebral cortex can provide statistically efficient representation of the states of the environment and the behaving system. Two basic action selection architectures are shown, namely, reactive action selection and predictive action selection. They can be implemented within the anatomical constraint of the network linking these structures. Furthermore, the use of the cerebellar supervised learning modules for state estimation, behavioral simulation, and encapsulation of learned skill is considered. Finally, the usefulness of such theoretical frameworks in interpreting brain imaging data is demonstrated in the paradigm of procedural learning.

Journal Article↗
PubMed1980

Bilateral basal ganglia calcifications visualised on CT scan.

Thirty-eight cases of basal ganglia calcification imaged on computed axial tomography were reviewed. Most cases were felt to represent senescent calcification. The possibility of a vascular aetiology in this group is discussed. A less common group of patients was identified with calcification secondary to abnormalities in calcium metabolism or radiation therapy. Three cases of basal ganglia calcifications were detected in juvenile epileptic patients receiving chronic anticonvulsants. These cases may be related to abnormalities in calcium metabolism and alkaline phosphatase activity. Clinical evidence of basal ganglia abnormality was generally absent demonstrating the preservation of neuronal pathways in most cases.

Adolescent↗
PubMed2002

Distinct responses of basal ganglia substance P systems to low and high doses of methamphetamine.

Substance P (SP) is a neuropeptide closely associated with basal ganglia dopaminergic neurons. Because some neuropeptide systems in the basal ganglia (i.e. neurotensin and metenkephalin) are differentially affected by treatment with low or high doses of methamphetamine, we determined if basal ganglia SP pathways were also differentially influenced in a dose-dependent manner by this psychostimulant. Employing in vivo microdialysis, it was observed that the low dose (0.5 mg/kg) of methamphetamine increased the extracellular concentration of SP in the substantia nigra, but not in globus pallidus or striatum. In contrast, the high dose (10 mg/kg) of methamphetamine did not increase extracellular SP content in any of these structures. The effect of the low-dose methamphetamine treatment on nigral extracellular SP levels was blocked by pre-treatment with either a D1 or D2 antagonist. In addition, 12 h after similar methamphetamine treatments, a dose-dependent differential response in SP tissue levels occurred in some of the regions examined. When these changes occurred, the low dose of methamphetamine usually reduced, whereas the high dose increased, SP tissue content. This study demonstrated opposite responses of the basal ganglia SP system to low and high doses of methamphetamine and suggested that a combination of dopamine D1 and D2 receptor activity contributed to these effects.

Animals↗
PubMed2006

Serotonin involvement in the basal ganglia pathophysiology: could the 5-HT2C receptor be a new target for therapeutic strategies?

The basal ganglia are a highly interconnected group of subcortical nuclei in the vertebrate brain that play a critical role not only in the control of movements but also in some cognitive and behavioral functions. Several recent studies have emphasized that serotonergic pathways in the central nervous system (CNS) are intimately involved in the modulation of the basal ganglia and in the pathophysiology of human involuntary movement disorders. These observations are supported by anatomical evidence demonstrating large serotonergic innervation of the basal ganglia. In fact, serotonergic terminals have been reported to make synaptic contacts with dopamine (DA)-containing neurons and gamma-aminobutyric acid (GABA)-containing neurons in the striatum, globus pallidus, subthalamus and substantia nigra. These brain areas contain the highest concentration of serotonin (5-HT), with the substantia nigra pars reticulata receiving the greatest input. Furthermore, in these structures a high expression of 5-HT different receptor subtypes has been revealed. In this paper, evidence demonstrating the serotonergic control of basal ganglia functions will be reviewed, focusing on the role of the 5-HT2C receptor subtype. In addition, the involvement of 5-HT2C receptors in neurological disorders such as Parkinson's disease and other related motor disorders, and their management with drugs blocking the 5-HT2C receptor will be discussed.

Animals↗
PubMed2001

[A new history of basal ganglia and physiopathology of Parkinson's disease].

The author analyzes basic and clinical experimental works of the last forty years and reaches the following conclusions: The motor system is an indivisible entity in which the basal ganglia are a key part. An important link in the history of the basal ganglia is the description by Llamas and Reinoso-Suárez in 1965 of connections from the substantia nigra compacta to the globus pallidus medialis and lateralis, and striatum through extremely thin, diffusely distributed fibers. They also described connections from the ventral tegmental area to the basal forebrain and the cerebral cortex. These connections are still not accepted one decade later. Rather than as cortico-basal ganglia-cortical parallel loops, the basal ganglia are actually structured as a widely distributed neuronal network with a great biochemical and connective variety. Basal ganglia intrinsic circuits have an important influential role in this network. Very varied brain structures influence basal ganglia neuronal network, mainly the cerebral cortex and the thalamic nuclei, essentially those that receive output from the basal ganglia. This complex organization provides the foundations for and elucidates the difficulty of explaining the pathophysiology of the clinical manifestations of Parkinson's disease as well as illustrating the need for future multidisciplinary research on this topic.

Basal Ganglia↗
PubMed1991

Visual attentional disturbance with unilateral lesions in the basal ganglia and deep white matter.

To elucidate the role of the basal ganglia and deep white matter in the visual attention mechanism, a new visual attention task was carried out by 15 patients, 9 with left-side and 6 with right-side basal ganglia and/or deep white matter damage without visual field defects, and by 12 normal subjects. Their reaction times were recorded in response to a random visual stimulation by pushing a button with the hand ipsilateral to the side of the lesion. All the patients with damage to the right side of the brain had a longer reaction time in the left space than in the right or middle space. With conventional test, only one of them showed left unilateral spatial neglect. Seven of the 9 patients with a left lesion had a significantly longer reaction time in the right space than in the left. None had unilateral spatial neglect. Both the right and left brain-damaged groups showed longer reaction times in both spaces, compared to the normal groups. There was no significant difference in reaction time among the control subjects. These findings suggest that the basal ganglia and deep white matter in each hemisphere play some role in directing visual attentional factors into both spaces. Visual attentional disturbance was highly evident even with left-side brain damage, and this kind of disturbance is not usually revealed with the current tasks used for testing unilateral spatial neglect.

Adult↗
PubMed1983

Neuropsychiatric disturbances associated with idiopathic calcification of the basal ganglia.

A patient with idiopathic calcification of the basal ganglia (ICBG) manifested a schizophrenialike psychosis beginning at age 17 and later developed a complex movement disorder and mild dementia. Extensive calcification of the basal ganglia was demonstrated by computerized tomography. Review of reported cases of ICBG suggests that patients who become symptomatic early in adulthood are more likely to present with psychosis, whereas those presenting later in life typically manifest dementia and a motor system disorder. ICBG, like other conditions affecting subcortical structures, can produce schizophrenialike symptoms that may precede the onset of intellectual deterioration and extrapyramidal motor disturbances.

Basal Ganglia Diseases↗
PubMed2001

[Prevalence and clinical significance of computerized tomography verified idiopathic calcinosis of the basal ganglia].

With increasing CT examinations of the cerebrum, the discovery of basal ganglia calcification becomes more frequent. In order to correlate these calcifications to the symptoms believed to be accompanied with Fahr's disease 2318 cranial CT scans were examined. There was an overall incidence of basal ganglia calcification of 12.5%. The most frequent location was the globus pallidus (96.4%). In the examined population there was no correlation found between the calcifications and symptoms having been described with striopallidentate calcifications.

Aged↗
PubMed2002

Basal ganglia volumes in first-episode schizophrenia and healthy comparison subjects.

BACKGROUND: Previous studies suggest that dysfunction of cortico-striato-pallido-thalamic (CSPT) circuitry may be involved in the pathophysiology of schizophrenia but also show that basal ganglia structure is highly plastic and may be influenced by antipsychotic treatments. Controversy remains about whether basal ganglia pathology can be detected in vivo among treatment-naïve patients. We conducted a magnetic resonance imaging (MRI) study to examine basal ganglia structures and the limbic forebrain in first episode schizophrenia and healthy comparison subjects. METHODS: Fifty-one patients with first-episode schizophrenia and 28 healthy comparison subjects participated in the study. A high-resolution, special contrast (white matter nulling) MRI sequence was used to measure the caudate nucleus, nucleus accumbens, putamen, and subcommissural limbic forebrain. RESULTS: Volumes of the basal ganglia regions of interest (adjusted for total brain volume and age) did not differ significantly between the groups. Age correlated significantly with caudate and putamen volumes bilaterally in the healthy comparison group, but not among patients. CONCLUSIONS: The findings suggest that there are no volumetric abnormalities in basal ganglia before treatment in first-episode schizophrenia. The lack of a negative correlation between age and striatal volume among patients may implicate illness-associated factors that alter normal age-related changes in basal ganglia size.

Adult↗
PubMed1998

Neuropathological characteristics and alteration of the dopamine D2 receptor in hypoxic-ischemic basal ganglia necrosis.

The neuropathological characteristics and alteration of the dopamine D2 receptor (D2R) were investigated in 27 cases of hypoxic-ischemic basal ganglia necrosis (BGN) by means of neuropathological and immunohistochemical methods. Perinatal hypoxic-ischemic BGN manifested neuronal karyorrhexis as well as eosinophilia, karyorrhexis being more predominant in preterm infants and eosinophilia more predominant in full-term infants. Immunoreactivity to D2R was detected in the cytoplasm and dendrites of small and large neurons in the basal ganglia, and increased with neuronal maturation during the late gestational period in normal human basal ganglia. The number of D2R-positive neurons was smaller in all cases of acute BGN than that in controls, the areas of decreased D2R-positive neurons corresponding to the damaged regions observed on HE staining. Furthermore, neurons showed high expression of D2R in a few cases of remote BGN, suggesting some plasticity as to the recovery of D2R. Thus, the neuropathological characteristics of perinatal hypoxic-ischemic BGN may be related to neuronal maturation during different developmental stages in each region, and D2R development may play a role in the basal ganglia vulnerability to hypoxic-ischemia.

Basal Ganglia↗
PubMed1986

Motor functions of the basal ganglia.

This session dealt with the structure and function of the basal ganglia and their role in motor control. The key issues discussed in the first four presentations concerned the pathophysiology of movement performance in parkinsonian patients and in animal models of this disease. Three papers were presented on neurochemically specified subsystems of the basal ganglia. Therapeutic aspects (stereoencephalotomy and chronic electrical stimulation of neural tissue) were discussed in the last two papers. A brief account is given on the highlights of each of these reports.

Animals↗
PubMed1992

[Two cases of acute disseminated encephalomyelitis with lesions in the thalamus or basal ganglia on MRI].

Lesions in the thalamus or basal ganglia have rarely been reported in acute disseminated encephalomyelitis (ADEM). We experienced 2 cases of ADEM, in which MRI showed lesions in the thalamus or basal ganglia. Case 1, a 4-year-old boy, had gait disturbance, hyperesthesia and hyperreflexia. MRI (T2 weighted image) showed multiple high intensity areas in the right frontal lobe, bilateral parietal lobes and bilateral thalami. Case 2, a 4-year-old girl, complained of gait disturbance following a febrile episode, and displayed hyperreflexia. Several days later, she had visual disturbance of the left eye. MRI (T2 weighted image) revealed multiple high intensity areas in the dentate nucleus of left cerebellum, left occipital lobe, bilateral caudate nuclei, and the anterior part of bilateral lenticular nuclei. In both cases, CT could not demonstrate these lesions. Both of them were treated with corticosteroid and recovered rapidly. They had no recurrence. MRI is useful in diagnosis and follow-up of ADEM and may reveal lesions other than cerebral or cerebellar white matters.

Acute Disease↗