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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↗
PubMed2005

[Evoked potentials of the somatic cortex, thalamus, and electromyographic reactions of the cat shoulder muscles elicited by elbow joint straightening in norm and after injection of neurotoxin].

EMG activity from the elbow joint muscles and evoked potentials (ep) from the somatic cortex (fields 4, 6) and thalamic nuclei (vl, vpl) elicited by passive extension were recorded in the unanesthetized cats before and after MPTP injection (total dose 10 mg/kg). It was shown, that after MPTP injection changes of the EMG response in cats are similar to that observed in parkinsonian patients: The increase of amplitude and duration of the stretch-related m2-3 -components of EMG, as well as excitation increase in thalamus and cortex was shown after MPTP. Perturbation of an external extensor loading applied to the forearm with different fixed force moments elicited m. biceps brachii EMG reactions which amplitude in norm correlated with a muscle stretch size. The MPTP injection influenced this dependence. Contrary to EMG responses n26-60 amplitude of the thalamic and cortical EP did not depend on the level of muscle stretch neither in norm nor after MPTP injection. Hence it supposed that an afferent excitation, which was responsible for this EP, did not take part in a generation of the m2-components of the stretch reflex. Late (n100) component's amplitude of the thalamic nuclei EP depended on the muscle stretch level. After MPTP injection this relation disappeared just as in the EMG responses. Since m2 components aroused in the spinal cord motor neurons earlier than n100 components in thalamus it is supposed that excitation of shoulder muscle receptors and spinal neurons, which provided with origin of m2 components consisting of EMG responses, were responsible for generation of the EP late components of thalamic nuclei VL and VPL.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1992

The thalamus and insomnia.

The thalamus has been shown to play a primary role in the organization of the wake-sleep rhythm. This was confirmed by experimental findings in which athalamic cats displayed severe and persistent insomnia, and by clinical observations that thalamic degeneration, with selective or prevalent involvement of the anterior or dorsomedial nuclei, virtually abolishes the ability to generate electroencephalographic sleep patterns. Loss of sleep has been associated with autonomic (tachycardia, hyperthermia, tachypnea) and endocrine (increased plasma cortisol and catecholamine levels) activation. The clinical and experimental evidence suggests that degeneration of the anterior and dorsomedial thalamic nuclei (so-called "visceral thalamus") leads to permanent loss of autonomic and endocrine homeostasis and restorative body processes by relieving the hypothalamus of cortical inhibitory control.

Adult↗
PubMed2005

Proton magnetic resonance spectroscopy of the anterior cingulate gyrus, insular cortex and thalamus in schizophrenia associated with idiopathic unconjugated hyperbilirubinemia (Gilbert's syndrome).

OBJECTIVE: To examine whether patients with schizophrenia associated with idiopathic unconjugated hyperbilirubinemia (Gilbert's syndrome [GS]) have specific changes in brain metabolism. METHODS: We applied proton magnetic resonance spectroscopy (H-MRS) to the anterior cingulate gyrus, insular cortex and thalamus of patients with schizophrenia and GS (n = 15) or without GS (n = 15), all diagnosed with schizophrenia according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), and healthy subjects (n = 20). RESULTS: In the anterior cingulate gyrus, patients with schizophrenia and GS showed significant decreases in N-acetyl aspartate/creatine-phosphocreatinine (NAA/Cr), choline/creatine-phosphocreatinine (Cho/Cr) and myoinositol/creatine-phosphocreatinine (ml/Cr) ratios compared with healthy subjects and compared with patients with schizophrenia without GS. Patients with schizophrenia without GS also showed significant decreases in NAA/Cr, Cho/Cr and ml/Cr compared with healthy subjects. In the insular cortex, patients with schizophrenia and GS showed significant decreases in NAA/Cr, Cho/Cr and ml/Cr compared with healthy subjects and compared with patients with schizophrenia without GS. Patients with schizophrenia without GS also showed significant decreases in NAA/Cr, Cho/Cr and ml/Cr compared with healthy subjects. In the thalamus, patients with schizophrenia and GS showed significant decreases in NAA/Cr, Cho/Cr and ml/Cr compared with healthy subjects, whereas patients with schizophrenia without GS only showed a significant decrease in ml/Cr compared with healthy subjects. CONCLUSIONS: Our findings suggest that brain metabolism is more severely compromised in the subtype of schizophrenia with GS.

Adult↗
PubMed1991

Differential gene expression for glutamic acid decarboxylase and type II calcium-calmodulin-dependent protein kinase in basal ganglia, thalamus, and hypothalamus of the monkey.

In situ hybridization histochemistry, using cRNA probes, revealed a complementarity in the distributions of cells in the basal ganglia, basal nucleus of Meynert, thalamus, hypothalamus, and rostral part of the midbrain that showed gene expression for glutamic acid decarboxylase (GAD) or the alpha-subunit of type II calcium-calmodulin-dependent protein kinase (CAM II kinase-alpha). Cells in certain nuclei such as the thalamic reticular nucleus, globus pallidus, and pars reticulata of the substantia nigra show GAD gene expression only; others in nuclei such as the basal nucleus of Meynert, medial mamillary nuclei, and ventromedial hypothalamic nuclei show CAM II kinase-alpha gene expression only. A few nuclei, for example, the pars compacta of the substantia nigra and the greater part of the subthalamic nucleus, display gene expression for neither GAD nor CAM II kinase-alpha. In other nuclei, notably those of the dorsal thalamus, and possibly in the striatum, GAD- and CAM II kinase-expressing cells appear to form two separate populations that, in most thalamic nuclei, together account for the total cell population. In situ hybridization reveals large amounts of CAM II kinase-alpha mRNA in the neuropil of most nuclei containing CAM II kinase-alpha-positive cells, suggesting its association with dendritic polyribosomes. The message may thus be translated at those sites, close to the synapses with which the protein is associated. The in situ hybridization results, coupled with those from immunocytochemical staining for CAM II kinase-alpha protein, indicate that CAM II kinase-alpha is commonly found in certain non-GABAergic afferent fiber systems but is not necessarily present in the postsynaptic cells on which they terminate. It appears to be absent from most GABAergic fiber systems but can be present in the cells on which they terminate. This suggests that the kinase may be differentially engaged in pre- and postsynaptic functions at certain synapses.

Animals↗
PubMed2006

[Comparison of right thalamus and temporal cortex metabolite levels of drug-naive first-episode psychotic and chronic schizophrenia in patients].

OBJECTIVE: The aim of this study was to use Magnetic Resonance Spectroscopy (MRS) to investigate whether patients with chronic schizophrenia have different brain metabolite levels in the temporal cortex and thalamus than drug-naive first-episode patients. METHOD: We compared right-handed male first-episode patients (n=13) and chronic schizophrenic cases (n=15) with gender- and handedness-matched controls (n=10). Right temporal and right thalamic N-Acetylaspartate (NAA)/Creatine (Cre), NAA/Choline (Cho), and Cho/Cre ratios were obtained with MRS. RESULTS: Right temporal NAA/Cre, NAA/Cho, and right thalamus NAA/Cre ratios were significantly lower both in the chronic and first-episode patient groups when compared to normal controls (p<. 001), suggesting decreased neuronal integrity in both patient groups. There were no significant correlations between symptom severity and functional status with MRS variables (p=.027). These results suggested that both patient groups had neural integrity problems. Duration of illness (days) in the first-episode patients was significantly correlated with right temporal NAA/Cre and NAA/Cho. CONCLUSIONS: These results suggested that first-episode and chronic patients had significantly impaired neural integrity, particularly in the temporal cortex. It seems that in the acute phase of the first-episode, neural integrity impairment increased along with days elapsed without treatment.

Aspartic Acid↗
PubMed1991

Patterns of unit activity in the rostral thalamus of cats related to short-latency discrimination between different auditory stimuli.

Short-latency auditory-responsive units were found in the rostral thalamus of cats during performance of conditioned eyeblink responses (CRs) elicited discriminatively by a forward-paired, 70-dB-click conditioned stimulus (CS) as opposed to a backward-paired, 70-dB-hiss discriminative stimulus (DS). Discharges in response to the CS or DS were found in 57% of 138 units tested. Forty-one percent of units responding to the CS did so at latencies of less than 40 msec. After conditioning a discriminative CR to click CS, an increase in the ratio of CS-evoked activity to baseline activity was found relative to that before conditioning. This increase was attributable, in part, to a decrease in baseline activity and, in part, to an increase in the magnitude of response to the CS. These responses preceded early components of the electromyographically measured motor responses with latencies sufficient to contribute to initiation of the movement. After acquisition of the CR, the proportion of CS responsive units also increased. We conclude that this area of the thalamus, a region thought to support thalamocortical reverberatory activity, also functions to transmit short-latency auditory signals. Our evidence further suggests that this region may participate in the elicitation of conditioned responses by specific auditory stimuli and in discrimination between auditory stimuli of different significance.

Acoustic Stimulation↗
PubMed1991

[The distribution of senile plaques and acetylcholinesterase staining in the thalamus in dementia of Alzheimer type].

Recent development of histochemical techniques has demonstrated a significant cholinergic projection from the basal forebrain to the mediodorsal and reticular thalamic nuclei. To determine whether the regional distribution of senile plaques is related to the pattern of cholinergic innervation, we studied the distribution of plaques and changes in acetylcholinesterase (AChE) reactivity in the thalamus of patients with dementia of Alzheimer type (DAT). Brains from 2 age-matched patients without neurologic or psychiatric diseases were used as controls. Eight patients with DAT could be divided to 3 groups according to the distributional pattern of plaques; scarcely distributed, localized and diffusely distributed groups. In general, plaques were preferentially distributed in such subnuclei closely related to the cerebral cortex as anterior, intralaminar, mediodorsal nuclei and posterolateral-pulvinar nuclear complex, rather than in the region that receives projections from the basal forebrain. In addition, the majority of plaques exhibited AChE reactivity, while plaques were less common in the region showing the most prominent AChE reactivity in the thalamus of control cases. The present results provide an evidence against the cholinergic hypothesis of plaque formation and indicate an active involvement of AChE in plaque formation.

Acetylcholinesterase↗
PubMed1991

Distribution of parvalbumin-immunoreactivity in the rat thalamus using a monoclonal antibody.

1. The distribution of parvalbumin cell bodies and fibers in the thalamus of the rat was studied using a monoclonal antibody and the avidin-biotin-peroxidase method. The densest clusters of immunoreactive perikarya were observed in the nuclei ventralis posterior, reticularis, ventralis anterior and zona incerta, whereas the nuclei habenularis lateralis, lateralis posterior, lateralis, centralis lateralis and ventralis lateralis had the lowest density. In the nucleus geniculatum laterale ventralis, the density of parvalbumin cell bodies was intermediate. In all these thalamic nuclei, small, round or fusiform immunoreactive cells with short immunolabeled dendritic processes were observed. 2. The densest network of immunoreactive fibers was observed in the nuclei geniculatum laterale ventralis, reticularis and zona incerta. The nuclei geniculatum laterale dorsalis, ventralis posterior, medialis ventralis, ventralis anterior, anterior ventralis, anterior dorsalis and rhomboidens contained a moderate number of parvalbumin fibers, whereas the nuclei lateralis posterior, habenularis lateralis, parataenialis, centrum medianum, lateralis, centralis lateralis, ventralis lateralis, medialis dorsalis, anterior medialis, ventralis medialis and lateralis anterior had the lowest density of immunoreactive fibers. In addition, a large number of immunoreactive fibers was found in the lemniscus medialis and a scarce number in the stria medullaris. 3. No immunoreactive structure was observed in the nuclei habenularis medialis, paraventricularis, reuniens and geniculatum mediale. 4. Thus, perikarya and fibers containing parvalbumin are widely distributed throughout the thalamus of the rat, suggesting that parvalbumin might play a role, directly or indirectly, in limbic, visual and somatosensory mechanisms.

Animals↗
PubMed1990

[Chemical neuro-anatomy of the thalamus: an example of the co-expression of 2 neuropeptides, cholecystokinin and intestinal vasoactive peptide].

Recent studies using hybridization histochemistry have demonstrated the presence of cholecystokinin (CCK) gene expression in thalamocortical and thalamo-striatal neurons. To further understand the chemical anatomy of the thalamus, we used the same method to study the coexpression of CCK and vasoactive intestinal peptide (VIP) genes in the same neurons. Most of the neurons expressing the VIP gene in the rat dorsal thalamus (found especially in the ventrolateral nucleus) also expressed the CCK gene, as demonstrated by autoradiography on emulsion-coated adjacent sections studied with probes recognizing either mRNA. Some further neurons, located in the reticular nucleus, had VIP mRNA at lower levels of expression but did not appear to contain CCK mRNA.

Animals↗
PubMed1988

[Effect of electric stimulation or lesion of the thalamus on cerebral circulation].

Local cerebral blood flow (lCBF) in the thalamus and cerebral cortex was determined in 16 alert rabbits after electric stimulation of thalamic nuclei, and in 22 anesthetized dogs after thermocoagulation of posterior part of the thalamus. The cerebrovascular dilatory effect and increase in the lCBF were observed. Rheoelectroencephalographic investigations in 13 patients with parkinsonism subjected to stereotaxic lesion of thalamic ventrolateral nuclei also showed a diffuse reduction of arterial tone and cerebrovascular resistance. The data obtained seem to explain the reactive hyperemia which may develop primarily as a neurogenic reaction and then be maintained by metabolic changes.

Animals↗
PubMedDate not supplied

[Dynamics of local cerebral blood flow after thermodestruction of the thalamus in the dog].

The dynamics of changes in local cerebral blood flow (LCBF) after stereotaxic thermodestruction of the right thalamus was studied by the method of hydrogen clearance. The experiments were conducted on 22 mongrel dogs. On the 10-12th day after implantation of platinum electrodes the initial values of LCBF were determined symmetrically in the thalami and frontal cortex of dogs who were awake. The animals were anesthetized, the initial values of LCBF were again determined, and destruction of the right thalamus was performed. Reactive hyperemia developed close to the focus of thermodestruction and persisted 90 minutes. In the remaining sites the reactive hyperemia was less manifest and was seen 10-15 minutes.

Anesthesia, General↗
PubMed1977

[Arteries of the thalamus in man. Choroidal arteries. III. Absence of the constituted thalamic territory of the anterior choroidal artery. IV. Arteries and thalamic territories of the choroidal and postero-median thalamic arterial system. V. Arteries and thalamic territories of the choroidal and postero-lateral thalamic arterial system].

The anterior chor oideal artery cannot be considered as an arterial source for thalamic vascularization. Its territory is primarily pallidocapsular and reaches the thalamus only irregularly and superfically. 2. The posteromedian choroideal and thalamic system, in its infrathalamic portion, gives off lateral mesencephalosubthalamic, inferocentral (for the tips of the arcuate nucleus and the inferolateral part of the centre median nucleus), brachiopulvinarian and posterocentral arteries. In its suprathalamic portion it gives off medial pulvinarian and superomedian thalamic arteries. These arteries irriguate the major part of nucleus medialis and the nucleus anterior. 3. The posterolateral choroideal and thalamic system gives off lateral genicular arteries (for the lateral geniculate body), inferolateral pulvinarian and superolateral thalamic arteries. These arteries irriguate the dorsal part of the interal region of the thalamus.

Arteries↗
PubMed1982

[Multiple opiate receptor sites in the rabbit thalamus and cerebellum: preliminary characterization (author's transl)].

Inhibition of 3H-etorphine binding by D-Ala2, D-Leu5-enkephalin, a delta agonist and by morphiceptin, a mu agonist, reveals the existence of at least two classes of binding sites for the tritiated oviparine in membranes from the Rabbit thalamus and cerebellum. In the thalamus, approximately 50% of these sites appear to be mu receptor sites whereas the other half is neither of the mu nor of the delta subtype. In the cerebellum, at least 80% of the 3H-etorphine binding sites would belong to the mu subtype. This result may be related to the fact that the rabbit cerebellum contains appreciable quantities of methionine-enkephalin but little if any leucine-enkephalin.

Animals↗
PubMed1984

Quantitative studies of the evolution of the thalamus in primates.

A quantitative study of the thalamus and metathalamus has been carried out on brains of six different primate species. The allometric formula devised by Stephan, Bauchot and Andy (1970) has been slightly modified as two steps have been utilized in order to attain the required magnification of the final photomicrograph (a positive print, as opposed to Stephan et al's negative print). The thalamic and metathalamic structures are divided on the basis of their developmental stages into two groups--paleothalamus and neothalamus, so that their proportions to each other in primate phylogeny can be estimated. The results show that the neothalamus extends the paleothalamus by two-thirds (2/3rds) in Tupaia and by more than three-quarters (3/4ths) in Cercopithecus. Of all the thalamic groups, the dorsolateral thalamic nuclear group is most dominant in all primate species, except Tupaia, where the ventrolateral thalamic nuclei are larger than all other nuclei. The pulvinar is the most dominant nucleus in all species except Tupaia. These quantitative results conform, in most places, with the observations of other researchers, while they do not agree much with the qualitative observations of the thalamus in the same species (Simmons 1974). How this study has a bearing on the phylogenetic positions of the Tupaioidea and the Tarsioidea in the Primate Order, is briefly discussed.

Animals↗
PubMed1984

[A case report of infarction of the bilateral thalamus and the midbrain].

A 63 years old man was admitted because of coma of 24 hours duration. He had a history of infarction of the medulla oblongata 7 months earlier. On admission he was unconscious and had right oculomotor nerve palsy. To a painful stimulus, he responded with only a slight body movement. On the CT scan, low density areas were seen in the bilateral thalamus and the midbrain. In the next day he recovered from coma and abnormal behaviors appeared such as wondering in the ward, touching other patient's face and manipulating his stool. Verbal expression was extremely poor. Chlorpromazine was needed to suppress abnormal behaviors. Thereafter, abnormal behaviors gradually subsided and by the 23 hospital day he became bedridden even when chlorpromazine was withdrawn. At that time, he said only "yes" or "no" in response to questions and only few spontaneous movements were observed. From the 40 hospital day he suffered from pneumonia and gradually sank into the state of akinetic mutism. He died on the 50 hospital day. Pathologically, infarctions destroyed the n. parafascicularis, n. centromedianus and the intralaminar nuclei in the left thalamus, n. parafascicularis and a part of n. centromedianus in the right. In the medulla oblongata, right n. ambiguous and reticular formation were destroyed. Both thalamic lesions extended posteriorly to unite with the midbrain lesion.(ABSTRACT TRUNCATED AT 250 WORDS)

Akinetic Mutism↗
PubMed1978

An atlas of the dorsal thalamus of the marsupial brush-tailed possum, Trichosurus vulpecula.

In several respects the dorsal thalamus of Trichosurus presents a level of organizational complexity considerably in advance of that seen in Didelphis. In particular, such features as the lamination of the dorsal lateral geniculate, the distinct subdivisions of the ventroposterior and lateroposterior complexes, and the more pronounced separation of the ventroanterior from the ventrolateral nucleus, are similar to conditions found in many eutherians. On the other hand, some features which Trichosurus shares with Didelphis, such as the lack of a median central nucleus, and the well developed midline nuclei, are usually said to be indicative of a more 'primitive' level of neural organization. In most instances the thalamic nuclei in Trichosurus are easily homologized with those of Didelphis and other mammals. The difficult areas are the lateral and posterior groups of nuclei, regions which have generally been troublesome in most mammals thus far examined. What does become apparent after this examination of the Trichosurus thalamus is that this representative of the diprotodontid radiation has produced some neurological features which strikingly parallel those of certain advanced eutherians while retaining other features generally considered to be generalized and primitive. Within the metatheria Trichosurus represents a considerable advance over Didelphis. However, as will be seen in later papers in this series, there are other features, particularly those of thalamocortical fibre distribution, which serve to set Trichosurus quite markedly apart from both Didelphis and at least certain eutherian mammals (Haight & Neylon, 1977b, c, 1978).

Animals↗
PubMed1981

[Restoration of disrupted functions in patients who have sustained hemorrhages into the optic thalamus].

Using computerized tomography of the brain the authors diagnosed hemorrhages to the thalamus in 8 patients out of 74 with hemispheral hemorrhages. Peculiarities of the restoration of the disturbed functions in this group of the patients are analyzed. A dissociation between the marked restoration of elementary motor functions and a poorer restoration of motor habits was revealed. This dissociation was due to a considerable degree to the presence of a pronounced asthenodepressive syndrome in these patients. The clinical syndrome characteristic of hemorrhage to the thalamus is described.

Adult↗