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[Radiological diagnosis and differential diagnosis of calcifications of the basal ganglia (author's transl)].

The radiological appearance and main features of calcifications of the basal ganglia in metabolic, toxic and hypoxemic disorders, degenerative and systemic diseases, tumors as well as infectious and parasitic lesions are described and demonstrated by typical radiographs. The roentgenological differential diagnosis and etiological classification are debated on occurence, incidence, localization, and topography with regard to individual structures of the basal ganglia, distribution pattern and according to the dimension, shape, margin and density pattern of these calcifications.

Basal Ganglia↗

Preliminary findings of antistreptococcal antibody titers and basal ganglia volumes in tic, obsessive-compulsive, and attention deficit/hyperactivity disorders.

BACKGROUND: Previous studies have provided preliminary serological evidence supporting the theory that symptoms of tic disorders or obsessive-compulsive disorder (OCD) may be sequelae of prior streptococcal infection. It is unclear, however, whether previously reported associations with streptococcal infection were obscured by the presence of diagnostic comorbidities. It is also unknown whether streptococcal infection is associated in vivo with anatomical alterations of the brain structures that have been implicated in the pathophysiology of these disorders. METHODS: Antistreptococcal antibody titers were measured in 105 people diagnosed as having CTD, OCD, or attention-deficit/hyperactivity disorder (ADHD) and in 37 community controls without a disorder. Subjects were unselected with regard to their history of streptococcal exposure. Basal ganglia volumes were measured in 113 of these subjects (79 patients and 34 controls). RESULTS: A DSM-IV diagnosis of ADHD was associated significantly with titers of 2 distinct antistreptococcal antibodies, antistreptolysin O and anti-deoxyribonuclease B. These associations remained significant after controlling for the effects of CTD and OCD comorbidity. No significant association was seen between antibody titers and a diagnosis of either CTD or OCD. When basal ganglia volumes were included in these analyses, the relationships between antibody titers and basal ganglia volumes were significantly different in OCD and ADHD subjects compared with other diagnostic groups. Higher antibody titers in these subjects were associated with larger volumes of the putamen and globus pallidus nuclei. CONCLUSIONS: These findings suggest that the prior reports of an association between antistreptococcal antibodies and either CTD or OCD may have been confounded by the presence of ADHD. They also support the hypothesis that in susceptible persons who have ADHD or OCD, chronic or recurrent streptococcal infections are associated with structural alterations in basal ganglia nuclei.

Adult↗

Network models of the basal ganglia.

Over the past year, a number of conceptual and mathematical models of the basal ganglia and their interactions with other areas of the brain have appeared in the literature. Even though the models each differ in significant ways, several computational principles, such as convergence, recurrence and competition, appear to have emerged as common themes of information processing in the basal ganglia. Simulation studies of these models have provoked new types of questions at the many levels of inquiry linking biophysics to behavior.

Animals↗

Effect of a functional impairment of corticostriatal transmission on cortically evoked expression of c-Fos and zif 268 in the rat basal ganglia.

The activity-dependent induction of immediate-early genes is commonly used to map activated neuronal networks. In a previous analysis of the cortico-basal ganglia circuits, we have shown that a cortical stimulation produces Fos protein expression in the striatum and the subthalamic nucleus, with a pattern which conforms to the anatomical organization of cortical projections [Sgambato V. et al. (1996) Neuroscience 81, 93-112]. In the present study, we examined the effects of a unilateral blockade of the corticostriatal transmission on c-fos and zif 268 messenger RNA expression evoked in the substantia nigra pars reticulata and the subthalamic nucleus following stimulation of the ipsilateral motor cortex. The blockade of the corticostriatal pathway was performed either by an excitotoxic striatal lesion or by an application of the AMPA/kainate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione within the striatum. After application of the glutamate receptor antagonist, which prevented the cortical stimulation activating the GABAergic striatonigral pathway, the induction of both c-fos and zif 268 messenger RNAs was facilitated in the ipsilateral substantia nigra pars reticulata. In the subthalamic nucleus ipsilateral to the application of 6-cyano7-nitroquinoxaline-2,3-dione, the cellular discharges evoked by stimulation of the cortex were considerably shortened as a result of the blockade of the disinhibitory striato-pallido-subthalamic circuit. However, a strong expression of immediate-early genes was still induced by the cortical stimulation. By contrast, after unilateral kainate lesion of the striatum, the cortical stimulation was no longer able to induce c-fos and zif 268 messenger RNA expression in the ipsilateral subthalamic nucleus and in the substantia nigra pars reticulata bilaterally. The lack of immediate-early gene induction strongly contrasted with the neuronal discharges evoked in these nuclei by the cortical stimulation. Comparison between the cortically evoked neuronal activities and the pattern of immediate-early gene expression suggests that the induction of immediate-early genes in the basal ganglia mainly reflects the level of synaptic activity rather than the frequency of discharge of the postsynaptic neurons. Moreover, the results stress that modifications of immediate-early gene expression observed in the basal ganglia after an acute or a chronic interruption of the corticostriatal transmission are not superimposable.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

[Hemichorea-hemiballism associated to basal ganglia hemorrhage in uncontrolled diabetes mellitus: report of two cases].

Two cases of acute onset hemichorea-hemiballism in female patients with complicated diabetes mellitus are described. Computerized tomography showed diffuse basal ganglia hemorrhage contralateral to the abnormal movements. Occurrence of such a presentation in a teenager with insulin-dependent diabetes mellitus is unique. The relationship between non-ketotic hyperglycemia, structural damage in the basal ganglia and movement disorders are reviewed.

Adolescent↗

Cortex, white matter, and basal ganglia in schizophrenia: a volumetric postmortem study.

Postmortem volumetry of cortex, white matter, and basal ganglia was performed in 23 brains of schizophrenic patients and 23 brains of controls closely matched for gender, age, and hemisphere. Stereological methods were applied to serial coronal sections of complete hemispheres. We found no significant volume changes of cortex and white matter in schizophrenics. Striatal volume of schizophrenics was increased bilaterally reaching a significant level on the left side. Volumes of the globus pallidus were increased in both hemispheres reaching a significant level on the right side. After psychopathological differentiation, basal ganglia volume increase was also found in the subgroup of paranoid-hallucinatory schizophrenics.

Basal Ganglia↗

Basal ganglia high-energy phosphate metabolism in neuroleptic-naive patients with schizophrenia: a 31-phosphorus magnetic resonance spectroscopic study.

OBJECTIVE: This study used 31-phosphorus magnetic resonance spectroscopy ((31)P MRS) to investigate basal ganglia abnormalities in neuroleptic-naive patients with schizophrenia. METHOD: Nineteen schizophrenia patients and 31 age- and sex-matched healthy comparison subjects underwent (31)P MRS. RESULTS: The phosphocreatine/total phosphorus and phosphocreatine/total ATP ratios in both basal ganglia were significantly lower in patients. CONCLUSIONS: Schizophrenia patients showed features of increased metabolism in the basal ganglia consistent with impaired activity of the frontostriatal pathways.

Adenosine Triphosphate↗

Subthalamic neurons coordinate basal ganglia function through differential neural pathways.

The subthalamic nucleus (STN) is a key component of basal ganglia circuitry that mediates a variety of motor functions. The STN neurons send glutamatergic projections to the output structures of basal ganglia, including the substantia nigra pars reticulata (SNr) and the entopeduncular nucleus, and also innervate the globus pallidus (GP). However, the mechanism by which the STN regulates motor functions in the neural circuitry is not fully understood. Here we performed conditional ablation of the STN neurons by using immunotoxin-mediated cell targeting. We then analyzed dopamine (DA)-mediated motor behavior and firing activity of the SNr and GP neurons. Ablation of the STN neurons increased spontaneous movement and reduced hyperactivity in response to DA stimulation. Ablation of these neurons modulated the pattern and rate of spontaneous firing of the SNr neurons, although it did not substantially affect spontaneous firing of the GP neurons. The ablation attenuated DA-induced suppression of the firing rate of the SNr neurons and inhibited DA-induced elevation of the rate of the GP neurons. In addition, pharmacological blockade of GP activation in response to DA stimulation inhibited the suppression of SNr activity and the resultant motor activation. These results suggest that the STN neurons suppress spontaneous behavior through their direct projection to the output neurons and that, in response to DA, they contribute to expression of behavior by acting on the output neurons mainly through the GP-mediated pathways. We conclude that the STN coordinates motor behavior through differential neural pathways depending on the state of DA transmission.

Action Potentials↗

Portal-systemic encephalopathy: presence of basal ganglia lesions with high signal intensity on MR images.

Sixteen patients with cirrhosis of the liver underwent cranial magnetic resonance (MR) imaging and transarterial portography to evaluate the relationship between basal ganglia lesions and portal-systemic collateral vessels. No neuropsychiatric disturbance was observed in any of the patients at the time of the MR examination, but four patients with portal-systemic encephalopathy were included in the study. Basal ganglia lesions, characterized by increased signal intensity on T1-weighted MR images, were observed in nine of the 16 patients, including the four with portal-systemic encephalopathy. These nine patients had large portal-systemic collateral vessels that were more than 10 mm in diameter. These collateral vessels were receiving blood from the superior mesenteric vein (SMV) in all nine patients. The lesions involved the globus pallidus and portions of internal capsules in a bilateral and symmetric fashion and did not exhibit mass effect. The authors conclude that there may be a significant relationship between high-intensity basal ganglia lesions and large portal-systemic collateral vessels receiving blood from the SMV.

Aged↗

Respiratory responses to electrical stimulation of the basal ganglia in cats.

The aim of the present study was to investigate the involvement of basal ganglia in altering respiration. The experiments were carried out on cats using the electrical stimulation techniques. The electrical stimulation of the basal ganglia caused locus-dependent changes both in the tidal volume and the rate of respiration. The most frequent effect of stimulation was hyperpnea and decrease in the tidal volume in awake, freely moving cats. An increase in the tidal volume appeared only as rebound-like aftereffect. The stimulation that caused hyperpnea in awake cats elicited smaller changes under chloralose or ketamine-induced anaesthesia, and, in certain cases, the stimulation produced apnea. After locally applied neurotoxic damage, the electrical stimulation failed to induce significant respiratory changes. It is suggested that the fast, small amplitude ventilation is, probably, produced by high excitation that shifts the respiratory rhythm generator towards the upper limits of its regulatory range. The slowing of ventilation might be produced by an inhibitory mechanism, which is able to cause even apnea under anaesthesia.

Anesthesia↗

Perfusion-weighted dynamic susceptibility (DSC) MRI: basal ganglia hemodynamic changes after apomorphine in Parkinson's disease.

Relative regional blood flow of basal ganglia was studied by means of perfusion-weighted dynamic susceptibility (DSC) MRI. Parkinson's disease (PD) patients showed a significant inter-hemispheric asymmetry due to a higher perfusion in the more affected side, while normal subjects did not. PD exhibited an abnormal "asymmetry index" in the measured nuclei. A second DSC-MRI examination performed after subcutaneous apomorphine administration did not show any significant asymmetry in PD patients. DSC-MRI of basal ganglia confirms the asymmetry observed in PET studies of PD patients, suggesting that this method is a promising and low-cost technique in neurodegenerative diseases.

Antiparkinson Agents↗

Anti-basal ganglia antibodies: a possible diagnostic utility in idiopathic movement disorders?

BACKGROUND: The spectrum of post-streptococcal brain disorders includes chorea, tics, and dystonia. The proposed mediators of disease are anti-basal ganglia (neuronal) antibodies (ABGA). AIM: To evaluate ABGA as a potential diagnostic marker in a cohort of UK post-streptococcal movement disorders. METHODS: Forty UK children presenting with movement disorders associated with streptococcal infection were recruited. ABGA was measured using ELISA and Western immunoblotting. To determine ABGA specificity and sensitivity, children with neurological diseases (n = 100), children with uncomplicated streptococcal infection (n = 40), and children with autoimmune disease (n = 50) were enrolled as controls. RESULTS: The mean ELISA result was increased in the post-streptococcal movement disorder group compared to all controls and derived a sensitivity of 82.4% and specificity of 79%. The Western immunoblotting method to detect ABGA derived a sensitivity and specificity of 92.5% and 94.7% respectively. There was common binding to basal ganglia antigens of 40, 45, and 60 kDa. Immunofluorescence localised the antibody binding to basal ganglia neurones. CONCLUSION: ABGA appears to be a potentially useful diagnostic marker in post-streptococcal neurological disorders. Western immunoblotting appears to be the preferred method due to good sensitivity and specificity and the ability to test several samples at once.

Adolescent↗

Parkinsonism and rest tremor secondary to supratentorial tumours sparing the basal ganglia.

Intracranial neoplasms are an uncommon cause of symptomatic Parkinsonism and rest tremor. We found an incidence of 0.3% in a prospective evaluation of 907 patients with supratentorial tumours. Eight patients with Parkinsonism and rest tremor secondary to supratentorial tumours sparing the basal ganglia are reported. Neuro-imaging revealed compression and distortion of the basal ganglia by large tumours which were identified histopathologically as meningiomas in four patients and as an epidermoid, a fibrillary astrocytoma, an anaplastic oligodendroglioma and a glioblastoma. Six patients underwent tumour removal by craniotomy, in two the histopathology was obtained by stereotactic biopsy. Four patients were free of Parkinsonian symptoms and signs on long-term follow-up. The possible pathophysiological mechanisms involved are discussed. Since some of these patients closely resemble cases of idiopathic Parkinson's disease, and the movement disorder can precede other symptoms and signs or will remain isolated in the further course, the diagnosis of an intracranial neoplasm was generally delayed in these patients. Increased awareness of this rare entity may lead to an earlier diagnosis. Early computed tomography in patients with Parkinsonism might help to detect these patients with a potentially curable cause of their condition.

Adult↗

Involvement of sensorimotor, limbic, and associative basal ganglia domains in L-3,4-dihydroxyphenylalanine-induced dyskinesia.

Dyskinesia represents a debilitating complication of L-3,4-dihydroxyphenylalanine (L-dopa) therapy for Parkinson's disease. Such motor manifestations are attributed to pathological activity in the motor parts of basal ganglia. However, because consistent funneling of information takes place between the sensorimotor, limbic, and associative basal ganglia domains, we hypothesized that nonmotor domains play a role in these manifestations. Here we report the changes in 2-deoxyglucose (2-DG) accumulation in the sensorimotor, limbic, and associative domains of basal ganglia and thalamic nuclei of four groups of nonhuman primates: normal, parkinsonian, parkinsonian chronically treated with L-dopa without exhibiting dyskinesia, and parkinsonian chronically treated with L-dopa and exhibiting overt dyskinesia. Although nondyskinetic animals display a rather normalized metabolic activity, dyskinetic animals are distinguished by significant changes in 2-DG accumulation in limbic- and associative-related structures and not simply in sensorimotor-related ones, suggesting that dyskinesia is linked to a pathological processing of limbic and cognitive information. We propose that these metabolic changes reflect the underlying neural mechanisms of not simply motor dyskinesias but also affective, motivational, and cognitive disorders associated with long-term exposure to L-dopa.

Animals↗

Gait function in high-functioning autism and Asperger's disorder : evidence for basal-ganglia and cerebellar involvement?

Gait abnormalities have been widely reported in individuals with autism and Asperger's disorder. There is controversy as to whether the cerebellum or the basal-ganglia frontostriatal regions underpin these abnormalities. This is the first direct comparison of gait and upper-body postural features in autism and Asperger's disorder. Clinical and control groups were matched according to age, height, weight, performance, and full scale IQ. Consistent with Hallet's (1993) cerebellar-gait hypothesis, the autistic group showed significantly increased stride-length variability in their gait in comparison to control and Asperger's disorder participants. No quantitative gait deficits were found for the Asperger's disorder group. In support of Damasio and Maurer's (1982) basal-ganglia frontostriatal-gait hypothesis, both clinical groups were rated as showing abnormal arm posturing, however, only the Asperger's group were rated as significantly different from controls in terms of head and trunk posturing. While DSM-IV-TR suggests that Asperger's disorder, but not autism, is associated with motoric clumsiness, our data suggest that both clinical groups are uncoordinated and lacking in motor smoothness. Gait differences in autism and Asperger's disorder were suggested to reflect differential involvement of the cerebellum, with commonalities reflecting similar involvement of the basal-ganglia frontostriatal region.

Asperger Syndrome↗

Neurotransmitters in basal ganglia and cortex of Alzheimer's disease with and without Lewy bodies.

We measured the concentrations of the monoamines, their precursors, and their metabolites, and the activity of choline acetyltransferase (ChAT) in basal ganglia and cortical regions of postmortem brains from cases with histologically verified pure Alzheimer's disease (AD), AD with diffusely distributed Lewy bodies (Lewy body variant [LBV]), and normal controls. Dopamine and homovanillic acid (HVA) were severely depleted in basal ganglia of the LBV cases but were not significantly altered in pure AD cases; tyrosine hydroxylase levels in putamen were also significantly reduced in LBV but not AD cases. These reductions in basal ganglia dopamine and HVA suggest that LBV cases have a level of dopamine depletion similar to Parkinson's disease (PD). Additionally, ChAT activity in caudate and norepinephrine concentration in putamen were significantly reduced in the LBV group, which may have contributed to the absence of resting tremor and the milder presentation of parkinsonian features in this group compared with classic PD. In frontal, parietal, and temporal cortex, activity of ChAT in the LBV group was significantly reduced compared with controls and lower than in pure AD.

3,4-Dihydroxyphenylacetic Acid↗

Pattern of expression of the serotonin2C receptor messenger RNA in the basal ganglia of adult rats.

The distribution of the serotonin (5-HT) receptor 5-HT2C mRNA was examined at the single-cell level with in situ hybridization histochemistry and emulsion autoradiography in the basal ganglia and mesolimbic system of adult rats, with focus on the pallidum and the substantia nigra, which receive striatal inputs and play a critical role in basal ganglia function. 5-HT2C receptor mRNA expression was always restricted to a subpopulation of neurons in the regions examined. In the neostriatum, labeled neurons were more numerous in the rostral nucleus accumbens than in the caudal nucleus accumbens and were more numerous in the ventral and ventrolateral caudate-putamen than in the dorsal caudate-putamen, where labeled neurons were restricted to isolated clusters. In striatal target areas, dense labeling in the entopeduncular nucleus (internal pallidum, direct striatal output pathway) contrasted with an absence of labeling in the globus pallidus (external pallidum, indirect striatal output pathway). Double-label in situ hybridization in the substantia nigra revealed coexpression of 5-HT2C receptor mRNA with glutamic acid decarboxylase but not with tyrosine hydroxylase mRNA, indicating that it was restricted to gamma-aminobutyric acid (GABA)ergic neurons. In this region, dense labeling for 5-HT2C mRNA was found in half of the neurons at middle and caudal levels of both the pars compacta and the pars reticulata, with little labeling rostrally. The data suggest that drugs acting on the 5-HT2C receptor could selectively affect discrete neuronal populations in the basal ganglia and mesolimbic systems and indicate a new level of neurochemical heterogeneity among GABAergic neurons of the substantia nigra.

Animals↗