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Germ cell tumors in the basal ganglia are very rare in females. The authors report the case of a 12-year-old girl with such a tumor in the left basal ganglia. The tumor was subtotally removed and responded well to irradiation.
Three cases of histologically proven cryptic arteriovenous (AV) malformation of the basal ganglia are reported. Seventeen cases of patients showing putaminal hemorrhage in the CT scan underwent craniotomy for evacuation of a hematoma between January 1986 and December 1988. The preoperative diagnosis was hypertensive putaminal hemorrhage. In all three cases a network of abnormal vessels around the internal capsule was detected at surgery. Case 1: A 62-year-old male was admitted to our hospital with consciousness disturbance (JCS 20), total aphasia and right hemiparesis. The CT scan showed left putaminal hemorrhage. The volume of the hematoma was 45 ml by CT criteria. Left carotid angiography did not demonstrate any abnormal findings. Case 2: 69-year-old male was admitted with consciousness disturbance (JCS 10) and right hemiparesis. Left putaminal hemorrhage (volume 25 ml) was recognized on the CT scan. Two hours after admission, the consciousness level suddenly deteriorated (JCS 100). At that moment, the volume of the putaminal hematoma had increased to 100 ml. AV malformation was not detected by left carotid angiography. Case 3: A 50-year-old male was admitted with consciousness disturbance (JCS 20), total aphasia and right hemiparesis. The CT scan showed left putaminal hemorrhage of 73 ml. Pathohistological examination proved AV malformation in each case. The three cases described here suggest the following; 1) The incidence of the basal ganglia cryptic AV malformation has been considered low, but meticulous examination shows that among the cases diagnosed as hypertensive hemorrhage, AV malformation is not infrequently the hidden cause.(ABSTRACT TRUNCATED AT 250 WORDS)
Glucose metabolic rate in the basal ganglia, thalamus, and somatosensory cortex was examined in eight patients with schizophrenia before and after receiving neuroleptic medication. Basal ganglia metabolic rates were increased with medication: more on the right than on the left and more in putamen than caudate. The cortical anteroposterior ratio, an index of relative hypofrontality, was not affected by neuroleptics. The brain areas that were found to be altered by neuroleptics were selected for comparison between off-medication schizophrenics and controls. Metabolic rates in the basal ganglia tended to be low in patients with schizophrenia in comparison to 24 age- and sex-matched controls.
Using diffusion tensor (DT) MRI and histogram analysis, we measured mean diffusivity ((-)D) of basal ganglia grey matter (GM) from eight patients with acute disseminated encephalomyelitis (ADEM), 10 patients with multiple sclerosis (MS), and 10 healthy controls. Patients with ADEM had higher average (-)D (p=0.02) and lower (-)D histogram peak height (p=0.008) of the basal ganglia GM than patients with MS. Microscopic tissue damage occurs in the basal ganglia of ADEM patients, but not in MS patients with a similar burden of MRI-visible brain lesions.
The basal ganglia system has been proposed as a possible neural substrate for action selection in the vertebrate brain. We describe a robotic implementation of a model of the basal ganglia and demonstrate the capacity of this system to generate adaptive switching between several acts when embedded in a robot that has to "survive" in a laboratory environment. A comparison between this brain-inspired selection mechanism and classical "winner-takes-all" selection highlights some adaptive properties specific to the model, such as avoidance of dithering and energy-saving. These properties derive, in part, from the capacity of simulated basal ganglia-thalamo-cortical loops to generate appropriate "behavioral persistence".
We describe a case of germinoma of the left basal ganglia. An 11-year-old boy, who demonstrated calcification of the left basal ganglia on CT scan following a head injury at the age of 3 years, presented with a weakness of the right upper extremity for 2 months. MRI demonstrated high intensity in the left basal ganglia on a T1-weighted image without enhancement as well as high intensity on a T2-weighted image. Ipsilateral hemiatrophy of the hemisphere and midbrain was also noted. In addition, high intensity in the left internal capsule and cerebral peduncle was demonstrated on T2-weighted image. Surgical specimens obtained by stereotactic biopsy showed germinoma with a two-cell pattern. The patient had remained asymptomatic for 8 years after abnormal calcification was initially detected on CT scan. Ipsilateral hemiatrophy of the hemisphere and midbrain was demonstrated before the onset of weakness.
We present two patients with hereditary hemorrhagic telangiectasia (HHT) accompanied by multiple hepatic arteriovenous malformations (AVMs) whose cranial MRI demonstrated high signal intensity in the basal ganglia on T1-weighted images. Manganese levels in peripheral blood were very high in both patients. These two cases indicate that there may be a significant relationship between high intensity basal ganglia and multiple hepatic AVMs. While the precise mechanism of the signal alternation in the basal ganglia is unproven, high blood levels of manganese in these patients suggest that abnormal intensity in the basal ganglia may be due to deposition of manganese.
GABA and glutamate, the main transmitters in the basal ganglia, exert their effects through ionotropic and metabotropic receptors. The dynamic activation of these receptors in response to released neurotransmitter depends, among other factors, on their precise localization in relation to corresponding synapses. The use of high resolution quantitative electron microscope immunocytochemical techniques has provided in-depth description of the subcellular and subsynaptic localization of these receptors in the CNS. In this article, we review recent findings on the ultrastructural localization of GABA and glutamate receptors and transporters in monkey and rat basal ganglia, at synaptic, extrasynaptic and presynaptic sites. The anatomical evidence supports numerous potential locations for receptor-neurotransmitter interactions, and raises important questions regarding mechanisms of activation and function of synaptic versus extrasynaptic receptors in the basal ganglia.
In recent years, a number of new molecules, particularly peptides, have been identified as putative neurotransmitters. The basal ganglia, is especially rich in a number of classical transmitter molecules, amino acids and neuropeptides considered to function in neurotransmission. These include: the well-described terminal fields in the striatum which originate from the brain stem and contain the monoamines, dopamine and serotonin; amino acid containing axons projecting from the cortex and thalamus; striatal cholinergic and peptide-positive interneurons; and amino acid and peptide containing projection neurons to the globus pallidus and substantia nigra. Two amino acids, glutamate and aspartate, are considered to provide excitatory input to the striatum while gamma aminobutyric acid is thought to mediate inhibitory output. Neuropeptides which are richly concentrated in the basal ganglia include, enkephalin, dynorphin, substance P, somatostatin, neuropeptide Y and cholincystokinease. Changes in many of these peptide levels have recently been associated with a number of basal ganglia disorders.
The aim of this study was to examine basal ganglia volumes and regional cerebral blood flow in asymptomatic subjects at-risk for Huntington's disease who had undergone genetic testing. We determined which measures were the best 'markers' for the presence of the mutation and for the onset of symptoms. Twenty subjects who were Huntington's disease gene mutation-positive and 24 Huntington's disease gene mutation-negative participants, all of whom had a parent with genetically confirmed Huntington's disease, and were therefore 50% at-risk for inheriting the Huntington's disease gene mutation, were included in the study. To evaluate basal ganglia structure and function, MRI and single photon emission computed tomography (SPECT) were used. Quantitative measures of regional volumes and relative measures of regional perfusion were calculated. SPECT and MRI scans were co-registered so that MRI anatomy could be used accurately to place SPECT regions. Estimated years-to-onset in the mutation-positive subjects was calculated based on a regression formula that included gene (CAG)(n) repeat length and parental age of onset. Changes in imaging measures in relation to estimated years-to-onset were assessed. The imaging measure that was most affected in mutation-positive subjects was putamen volume. This was also the measure that correlated most strongly with approaching onset. In subjects >/=7 years from estimated onset age, the putamen volume measures were similar to those of the mutation-negative subjects. However, in subjects </=6 years from estimated onset age, there were dramatic reductions in putamen volume, resulting in >90% discrimination from both the far-from-onset and the mutation-negative subjects. Caudate volume and bicaudate ratio also showed a significant decline in the close-to-onset subjects, although to a lesser degree than putamen volume reductions. Furthermore, SPECT basal ganglia perfusion deficits were observed in mutation-positive subjects. Imaging markers of neuropathological decline preceding clinical onset are important for assessing the effects of treatments aimed at slowing the course of Huntington's disease. The current study suggests that quantitative assessment of basal ganglia may provide a means to track early signs of decline in individuals with the Huntington's disease gene mutation prior to clinical onset.
We herein describe a 12-year-old male patient with a germinoma of the basal ganglia who presented with progressive hemiparesis. MR imaging showed ipsilateral cerebral hemiatrophy predominantly in the left basal ganglia, whereas no mass or enhancement was depicted. Single photon emission CT revealed no significant uptake of thallium, whereas (11)C-methionine positron emission tomography showed clearly discernible uptake in the left putamen. Stereotactic biopsy, referencing the results of (11)C-methionine positron emission tomography, was performed, allowing histologic verification of germinoma to be established. (11)C-methionine positron emission tomography was the only technique that indicated the precise localization of the tumor in our patient and enabled biopsy-based final diagnosis of the basal ganglia germinoma without any overt mass formation.
Recent neuroanatomical data obtained with single-axon or single-cell labeling procedures in both rodents and primates have revealed the presence of various types of projection neurons with profusely collateralized axons within each of the major components of the basal ganglia. Such findings call for a reappraisal of current concepts of the anatomical and functional organization of the basal ganglia,which play such a crucial role in the control of motor behavior. The basal ganglia now stand as a widely distributed neuronal network, whose elements are endowed with a highly patterned set of axon collaterals. The elucidation of this finely tuned network is needed to understand the complex spatiotemporal sequence of neural events that ensures the flow of cortical information through the basal ganglia.
A case of basal ganglia calcification (diagnosed in vivo) and schizophreniform psychosis occurring in a young adult with Down's syndrome is reported. A stress-vulnerability model is suggested. Because of the relatively high prevalence of basal ganglia calcification to Down's syndrome, this population appears well suited for systematic study of the neuropsychiatric aspects associated with this neurological condition.
Topographical distribution of the propagation of seizure activity in the basal ganglia was studied during focal motor seizures from the focus in the face-hand area of Area 4 in the monkey, using the [14C]deoxyglucose autoradiography method. The focal seizures were induced by injecting potassium penicillin G into the face-hand area in the right motor cortex. The propagation of seizure activity in the basal ganglia was localized in the ventral and caudal parts of the ipsilateral putamen and globus pallidus lateral and medial segments, and in part of the reticular portion of substantia nigra. These areas in the basal ganglia seem to be functionally linked to the face-hand area of the motor cortex.
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Song learning in oscine birds relies on a circuit known as the "anterior forebrain pathway," which includes a specialized region of the avian basal ganglia. This region, area X, is embedded within a telencephalic structure considered homologous to the striatum, the input structure of the mammalian basal ganglia. Area X has many features in common with the mammalian striatum, yet has distinctive traits, including largely aspiny projection neurons that directly innervate the thalamus and a cell type that physiologically resembles neurons recorded in the mammalian globus pallidus. We have proposed that area X is a mixture of striatum and globus pallidus and has the same functional organization as circuits in the mammalian basal ganglia. Using electrophysiological and anatomical approaches, we found that area X contains a functional analog of the "direct" striatopallidothalamic pathway of mammals: axons of the striatal spiny neurons make close contacts on the somata and dendrites of pallidal cells. A subset of pallidal neurons project directly to the thalamus. Surprisingly, we found evidence that many pallidal cells may not project to the thalamus, but rather participate in a functional analog of the mammalian "indirect" pathway, which may oppose the effects of the direct pathway. Our results deepen our understanding of how information flows through area X and provide more support for the notion that song learning in oscines employs physiological mechanisms similar to basal ganglia-dependent forms of motor learning in mammals.
Hemolytic-uremic syndrome is a microangiopathy often associated with neurologic symptoms. Several patients with persistent lesions in cerebrum and basal ganglia have been reported. We present two children with bilateral basal ganglia and additional unilateral cerebellar lesions in magnetic resonance imaging. These resolved completely in one child. In the other child there were still residuals after 11 weeks. The neurologic symptoms of both improved after several therapeutic plasma exchanges and disappeared after months.
Expression of dopamine receptors (DA-Rs) in astrocytes was examined in vitro and in vivo using primary cultured astrocytes and brain slices from rat basal ganglia. Astrocytes from basal ganglia expressed DA D1-, D3-, D4- and D5-receptors and D4-mediated signal transduction in response to DA, suggesting possible involvement of astrocytes in the pharmacological action of atypical antipsychotic drugs and in DA response in some neurological diseases.