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Clinical Neuroscience

NOVEMBER 20, 2015

[Hyperglycaemic hemiballismus: implications from connectivity analysis for cognitive impairments]

KINCSES Tamás Zsigmond, VADÁSZ Dávid, NÉMETH Dezsõ, JANACSEK Karolina, SZABÓ Nikoletta, DÉZSI Lívia, BABOS Magor, VÖRÖS Erika, VÉCSEI László

[Hyperglycaemia induced movement disorders, such as hemiballism are rare disorders. The syndrome is characterised by the triad of hemiballism, contralateral T1-hyperintense striatal lesion and non-ketotic hyperglycaemia. Here we report a patient with untreated diabetes presenting with acute onset of hemiballism. MRI revealed T1 hyperintensity of the head of the caudate nucleus and the anterior putamen. The patient also had acantocytosis. Based on the detailed examination of the neuroradiological results and earlier findings we will imply on the pathomechanism. Based on previous findings microhemorrhages, extensive mineralisation, gemistocytic astrocytosis might play role in the development of the imaging signs. The connectivity pattern of the striatal lesion showed extensive connections to the frontal cortex. In coexistence with that the most severe impairment was found on the phonemic verbal fluency task measuring frontal executive functions. ]

Clinical Neuroscience

JANUARY 30, 2016

Facial virus inoculations infect vestibular and auditory neurons in rats

HELFFERICH Frigyes, LOURMET Guillaume, SZABÓ Rebeka Éva, BOLDOGKŐI Zsolt, PALKOVITS Miklós

Background and purpose – There is growing evidence for the viral origin of the Bell’s facial palsy, vestibular neuritis and sudden sensorineural hearing loss, however their exact pathophysiology is still unknown. We investigated the possibility of brainstem infections following peripheral viral inoculations in rats. Methods – Pseudorabies virus, a commonly used neurotropic viral retrograde tracer was injected into the nasolabial region of rats. Five and 6 days after injections, infected brainstem nuclei were demonstrated by immunohistochemical techniques. Results – Infected neurons were found in the motor facial, the medial vestibular, and the sensory trigeminal nuclei, as well as in the medial nucleus of the trapezoid body. Conclusion – Pseudorabies virus infects auditory and vestibular sensory neurons in the brainstem through facial inoculation. The possible routes of infections: 1. trans-synaptic spread constituted by facio-vestibular anastomoses: primarily infected motor facial neuron infects neurons in the medial vestibular nucleus, 2. via trigeminal sensory nerves: the sensory trigeminal complex innervated by GABAergic medial vestibular neurons, and 3. one bisynaptical route: infected facial motoneurons may receive indirect input from the medial vestibular nucleus and the trapezoid body via connecting neurons in the sensory trigeminal complex. We may assume that latent infections of these areas may precede the infections of the peripheral organs and the reactivation of the virus exerts the symptoms.

Clinical Neuroscience

NOVEMBER 30, 2018

[Comparison of subthalamic nucleus planning coordinates in 1Tesla and 3Tesla MRI for deep brain stimulation targeting ]

JUHÁSZ Annamária, KOVÁCS Norbert, PERLAKI Gábor, BÜKI András, KOMOLY Sámuel, KÖVÉR Ferenc, BALÁS István

[Backgroud - Deep brain stimulation (DBS) involves placing electrodes within specific deep brain nuclei. For movement disorders the most common indications are tremors, Parkinsons disease and dystonias. Surgeons mostly employ MR imaging for preoperative target selection. MR field geometrical distortion may contribute to target-selection error in the MR scan which can contribute to error in electrode placement. Methods - In this paper we compared the STN target planning coordinates in six parkinsonian DBS patients. Each patient underwent target planning in 1T and 3T MRI. We statistically compared and analysed the target-, and the fiducial coordinates in two different magnetic fileds. Results - The target coordinates showed no significant differences (Mann-Whitney test, p > 0.05), however we found significant difference in fiducial coordinates (p < 0.01), in 3T MRI it was more pronounced (mean ± SD: 0.8 ± 0.3 mm) comparing to 1T (mean ± SD: 0.4 ± 0.2 mm). Conclusion - Preliminary results showed no significant differences in planning of target coordinates comparing 1T to 3T magnetic fields.]

Clinical Neuroscience

SEPTEMBER 23, 2011

[Role of deep brain stimulation in epilepsy]

JANSZKY József, BALÁS István, KOVÁCS Norbert

[The deep brain stimulation (DBS) is an emerging treatment option in brain disorders in which randomized multicenter trials proved its efficacy leading to licensing different DBS methods in various brain diseases. More recently more and more brain structures have become candidates for being “target” in a possible DBS treatment of epilepsy. At present, only the DBS of the anterior nucleus of the thalamus (ANT) can be considered as a proved method for epilepsy treatment. Other potential targets for DBS treatment in epilepsy are the subthalamic nuclei, and the amygdala- hippocampus complex. There are some ongoing randomized studies to investigating their therapeutical role. The therapeutical outcome of ANT-DBS treatment in drug-resistant epilepsy seems to be better than the new antiepileptic drugs, but much worse than the results of a potential epilepsy surgery. At about 10% of patients may become seizure-free and 50% of patients may have a significant improvement. Nowadays ANT-DBS should be considered as an “ultima ratio” in those adult drug-resistant epilepsy patients with normal intelligence in which neither new antiepileptic drugs nor resective epilepsy surgery are a reasonable therapeutical options.]

Clinical Neuroscience

MARCH 30, 2008

[Evidence for the expression of parathyroid hormone 2 receptor in the human brainstem (in English language)]

BAGÓ G. Attila, PALKOVITS Miklós, USDIN B. Ted, SERESS László, DOBOLYI Árpád

[Background and purpose - The parathyroid hormone 2 receptor (PTH2R) is a G protein coupled receptor. Pharmacological and anatomical evidence suggests that the recently identified tuberoinfundibular peptide of 39 residues is, and parathyroid hormone and parathyroid hormone-related peptide are not, its endogenous ligand. Initial functional studies suggest that the PTH2R is involved in the regulation of viscerosensory information processing. As a first step towards clinical applications, herein we describe the presence of the PTH2R in the human brainstem. Material and methods - Total RNA was isolated from postmortem human cortical and brainstem samples for RT-PCR. Good quality RNA, as assessed on formaldehyde gel, was reverse transcribed. The combined cDNA products were used as template in PCR reactions with primer pairs specific for the human PTH2R. In addition, PTH2R immunolabelling was performed on free floating sections of the human medulla oblongata using fluorescent amplification immunochemistry. Results - Specific bands in the RT-PCR experiments and sequencing of PCR products demonstrated the expression of PTH2R mRNA in the human brainstem. A high density of PTH2R-immunoreactive fibers was found in brain regions of the medulla oblongata including the nucleus of the solitary tract, the spinal trigeminal nucleus, and the dorsal reticular nucleus of the medulla. Conclusion - Independent demonstration of the presence of PTH2R mRNA and immunoreactivity supports the specific expression of the PTH2R in the human brainstem. The distribution of PTH2R-immunoreactive fibers in viscerosensory brain regions is similar to that reported in mouse and rat suggesting a similar role of the PTH2R in human as in rodents. This finding will have important implications when experimental data obtained on the function of the TIP39-PTH2R neuromodulator system in rodents are to be utilized in human.]

Clinical Neuroscience

NOVEMBER 30, 2006

[THE MODULATORY EFFECT OF ESTROGEN ON THE CAUDAL TRIGEMINAL NUCLEUS OF THE RAT IN AN ANIMAL MODEL OF MIGRAINE]

VARGA Hedvig, PÁRDUTZ Árpád, TAJTI János, VÉCSEI László, JEAN Schoenen

[Migraine is one of the most common neurological disorder affecting up to 14% of the population. The disease shows sexual dimorphism, thus gonadal steroids may play an important role in its patophysiology. One model of migraine headache is the systemic administration of nitric oxide (NO) donor nitroglycerin (NTG), which triggers a delayed attack without aura in many migraine patients but not in healthy volunteers. NTG is also able to activate the neurons of the caudal trigeminal nucleus in the rat. In our review we summarise the effect of NTG on the expression of some molecules, in the superficial laminae of the spinal portion of trigeminal nucleus caudalis, which play an important role in the pathomechanism of headaches, and the modulatory effect of chronic estradiol treatment. Our data show that NTG was able to modify all the examined substances in the caudal trigeminal nucleus, while chronic estradiol treatment abolished this effect. These data may help to understand the mechanisms by which estrogens influence trigeminal nociception and how nitric oxide triggers migraine attacks.]

Clinical Neuroscience

MARCH 20, 2007

[FINE STRUCTURE OF THE AREA SUBPOSTREMA IN RAT. OPEN GATE FOR THE MEDULLARY AUTONOMIC CENTERS]

FODOR Mariann, PALKOVITS Miklós, GALLATZ Katalin

[The area subpostrema (ASP) is a V-shaped area, ventral and ventrolateral to the area postrema. It constitutes the upper border zone of the commissural portion of the nucleus of the solitary tract. The ASP is considered as a morphological and functional key area for the medullary autonomic center. The capillaries here, in contrast to the capillaries of the area postrema are not fenestrated but establish a specific staining for acetylcholinaestherase (AChE). The ASP contains a high density of fibers and terminals of several neuropeptides which are known to affect on NTS activity. Receptors of different neuropeptids and cathecholamines and a dense network of GFAP positive glial processes are found also here. The neurons and the glial cells of the ASP are connected with the AP and a bidirectional connection exists between the ASP and NTS.]

Clinical Neuroscience

MARCH 30, 2008

[Emotion-related brain regions (in English language)]

SZILY Erika, KÉRI Szabolcs

[Converging data from human functional imaging in healthy subjects, neuropsychological studies of brain-damaged patients, and non-human neurophysiology indicate that emotional processing is linked to anatomically distinct and well-defined brain regions. A main characteristic of emotion-related brain regions (orbitofrontal cortex, anterior cingulated cortex, amygdala, insula) is their reciprocal anatomical connectivity with each other as well as with neuromodulatory systems (e.g., serotonergic dorsal raphe, cholinergic nucleus basalis of Meynert, and dopaminergic ventral tegmentum) and with other brain areas involved in sensory, motor, and cognitive functions. These structures mediate the representation of stimulus values, the affectleaden enhancement of sensory processing, and the predictions of values associated with actions in order to bias decision-making in uncertain situations. In this review, we discuss new results from the functional neuroanatomy of these brain circuits and outline their significance in the emergence of various psychopathological phenomena.]

Clinical Neuroscience

MARCH 30, 2006

[PLASTICITY OF NOCICEPTION: RECENT ADVANCES IN FUNCTION-ORIENTED STRUCTURAL PAIN RESEARCH]

KNYIHÁR Erzsébet, CSILLIK Bertalan

[Traditional concept holds that the pain unit consists of three neurons. The first of these, the primary nociceptive neuron, starts with the nociceptors and terminates in the dorsal spinal cord. The second one, called spinothalamic neuron, crosses over in front of the central canal and connects the dorsal horn with the thalamus. The third one, called thalamo- cortical neuron, terminates in the “pain centres” of the cerebral cortex. While this simplistic scheme is useful for didactic purposes, the actual situation is more complex. First, in the periphery it is only nociception that occurs, while pain is restricted to the levels of thalamus and the cortex. Second, pain results from interactions of excitation and inhibition, from divergence and convergence and from attention and distraction, in a diffuse and plastic system, characteristic for all levels of organization. This study describes the major cytochemical markers of primary nociceptive neurons followed by the presentation of recent data on the functional anatomy of nociception and pain, with special focus on the intrinsic antinociceptive system and the role of nitrogen oxide, opiate receptors, nociceptin and nocistatin. In addition to the classic intrinsic antinociceptive centres such as the periaqueductal gray matter and the raphe nuclei, roles of several recently discovered members of the antinociceptive system are discussed, such as the pretectal nucleus, the reticular formation, the nucleus accumbens, the nucleus tractus solitarii, the amygdala and the reticular thalamic nucleus, this latter being a coincidence detector and a centre for attention and distraction. The localisation of cortical centres involved in the generation of pain are presented based on the results of studies using imaging techniques, and the structural basis of corticospinal modulation is also outlined. Seven levels of nociception and pain are highlighted where pharmacological intervention may be successful, 1. the peripheral nociceptor, 2. the spinal ganglion, 3. the multisynaptic system of the dorsal horn, 4. the modulatory system of the brain stem, 5. the antinociceptive system, 6. the multisynaptic system of the thalamus, and 7. the cortical evaluating and localisation system that is also responsible for descending (inhibiting) control. The many levels of nociception and pain opens new ways both for pharmacological research and the general practitioner aiming to alleviate pain.]

Clinical Neuroscience

MARCH 20, 2007

[THE SUPRASPINAL INNERVATION OF THE LEFT ADRENAL IS MORE INTENSE THAN THAT OF THE RIGHT ONE]

GERENDAI Ida, WIESEL Ory, BOLDOGKŐI Zsolt, TÓTH E. Ida

[Background and purpose - Previous studies using the viral transneuronal tracing technique demonstrated that central autonomic circuits are involved in the innervation of the adrenal gland. Since increasing number of data indicate laterality in the neuroendocrine system, we aimed to investigate whether the supraspinal innervation of the adrenal gland exhibits asymmetry or not. Methods - The central circuitry involved in the innervation of the left and the right adrenal gland was studied in individual rats by dual transneuronal tracing using isogenic recombinant strains (BDG and BDL) of Bartha strain of pseudorabies virus. Results - Viral infection of brain nuclei (dorsal vagal nucleus, nucleus of the solitary tract, caudal raphe nuclei, A5 cell group, hypothalamic paraventricular nucleus) from the left adrenal was more severe than that from the right organ. Dual-infected neurons from the two adrenals were also detected both in the brain stem and in the hypothalamus. Conclusion - The results indicate a predominance in the supraspinal innervation of the left adrenal gland. Data further suggest that each adrenal gland is innervated both by side-specific neurons and by neurons which project to both organs.]