Clinical Neuroscience

[THE ROLE OF CHRONIC BRAIN HYPOPERFUSION IN THE PATHOGENESIS OF ALZHEIMER'S DISEASE - FACTS AND HYPOTHES]

ZÁDORI Dénes, DATKI Zsolt, PENKE Botond

NOVEMBER 30, 2007

Clinical Neuroscience - 2007;60(11-12)

[In Alzheimer’s disease, which belongs to the neurodegenerative disorders, the ethiopathogenetic role of several risk factors has been proved. A considerable number of them are mainly known as cardiovascular risk factors and can precipitate chronic brain hypoperfusion. Using functional imaging techniques, this hypoperfusion and the resulting hypometabolism become detectable in the watershed areas of the brain as early as in the stage of mild cognitive impairment. Hypoperfusion leads to the degeneration of capillaries in this area causing the deterioration of diffusion. The further reduction of nutrient and oxygen support of neurons is capable to initiate a neurodegenerative process which spreads along the glutamaterg system arising from the neurons of the association cortices. The neuropathological lesions of this neuronal system, such as the neurofibrillary tangles and the β-amyloid plaques, are known to be the characteristic markers of Alzheimer's disease. In our review we present the development of hypoperfusion and its consequences in the watershed areas of the brain and describe the neurodegenerative process of the neuronal system arising from the neurons of the association cortices in the early stage of Alzheimer's disease. Considering the previous hypotheses and the neuropathological lesions of Alzheimer's disease we give a new consensus model to characterize the pathomechanism of the disorder.]

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Clinical Neuroscience

[DIFFUSION TENSOR AND FUNCTIONAL MR IMAGING OF SEVERE TRAUMATIC BRAIN INJURY AT LOW MAGNETIC FIELD]

JANSZKY József, AUER Tibor, SCHWARCZ Attila, DÓCZI Tamás, EZER Erzsébet, CZEITER Endre, ARADI Mihály, HUDVÁGNER Sándor, BÜKI András

[Aim of the study - Presentation of diffusion tensor imaging (DTI) performed at low magnetic field (1 Tesla) in the algorithm of work-up of a patient suffering from severe traumatic brain injury (TBI). Method - DTI and functional MRI (fMRI) were applied at 1 Tesla for visualization of neural pathways and examination of sensory functions of a patient with severe TBI. DTI-measurement was also performed on a healthy patient for comparison. Results - DTI acquired at low magnetic field yielded appropriate visualization of neural pathways. DTI confirmed the results of the clinical and fMRI examinations in the patient suffering from severe TBI. Conclusion - An optimized DTI can be useful in the examination of patients with TBI, moreover, it may also help in the establishment of diagnoses of other central nervous system diseases affecting neuronal pathways. The presented results suggest that DTI of appropriate quality can be performed at low magnetic field.]

Clinical Neuroscience

[BILATERAL “OVER THE TOP” DECOMPRESSION THROUGH UNILATERAL LAMINOTOMY FOR LUMBAR AND THORACIC SPINAL CANAL STENOSIS]

BANCZEROWSKI Péter, VERES Róbert, LIPÓTH László

[Objective - The standard surgical procedures used in degenerative thoracic and lumbar spinal canal stenosis allows decompression of the neural structures by unroofing the spinal canal, often resulted in destruction or insufficiency of facet joints, sacrifice the interspinosus/supraspinosus ligament complexes and stripping of the paraspinal muscles altering an already pathologic biomechanical milieu causing segmental instability. Various less invasive techniques exists to save the integrity and prevent the instability of the spine and allow decompression of neural structures located in the spinal canal. The authors discusses the experiences with technique of unilateral laminotomy for bilateral decompression. Methods - The unilateral laminotomy for bilateral decompression technique was performed at 60 levels in 51 patients to decompress the symptomatic degenerative stenosis of the thoracic and lumbar spinal canal. The inclusion criteria were used as follows: symptoms of neurogenic claudication and/or radiculopathy, myelopathy, neuroimaging evidence of degenerative stenosis and absence of instability. Symptoms were considered refractory to nonsurgical conservative management or myelopathy was detected. Results - The distribution of mostly affected segments were the L 4-5 (45%) and L3-4 (28.4%). Neurogenic claudication and walking distance improved during the follow up period in all patients. Seven patients (13.73%) reported excellent, 32 (62.74%) good, 12 (23.53%) fair outcome and no patient a poor overall outcome. The low back pain was the major residual postoperative complaint. 25 (49%) patients were very satisfied with their outcome, 23 (45.1%) were fairly satisfied, 2 (3.9%) were not very satisfied and 1 (2%) patients was dissatisfied. Conclusion - The unilateral laminotomy for bilateral microdecompression technique minimizes resection of and injury to tissues not directly involved in the pathologic process, while affording a safe and through decompression of neural structures located in a degeneratively stenotic spinal canal.]

Clinical Neuroscience

[UNALTERED MRNA EXPRESSION OF CALCITONIN-LIKE RECEPTOR AND RECEPTOR ACTIVITY MODIFYING PROTEINS IN HUMAN ARTERIES IN STROKE AND MYOCARDIAL INFARCTION]

VÉCSEI László, KAREN Eskesen, TAJTI János, HORTOBÁGYI Tibor, SZOK Délia, LARS Edvinsson

[Calcitonin-like receptor (CL-R) is a functional CGRP1- receptor when complexed with RAMP1 or an adrenomedullin-receptor or when complexed with RAMP2 or RAMP3. This study was carried out 1. to set up a method to examine the relative quantity of mRNA of CL-R, RAMP1, RAMP2 and RAMP3 in human coronary (CA), pulmonary (PA) and middle cerebral arteries (MCA), and 2. to examine the level of mRNA expression in cerebro- and cardiovascular diseases. The method was validated with respect to the use of postmortem tissue and we compared β-actin and GAPDH as housekeeping genes. There was no time-dependent change in total RNA and level of mRNA for β-actin or GAPDH could be detected in vessels removed from 1 and 5 days post mortem. The expression of β-actin appears lower in coronary artery than in pulmonary artery and middle cerebral artery with no significant difference for GAPDH; both worked well. There were some differences in mRNA expression for CL-R (higher) and RAMP3 (lower) in middle cerebral artery compared to coronary artery and pulmonary artery. There was no significant difference in mRNA for RAMP1 and RAMP2 in the three types of arteries. We did not observe any difference in mRNA for CL-R and RAMPs in arteries from patients with hemorrhagic stroke, arteriosclerosis and acute myocardial infarction when compared to patients without these diagnoses. Thus the mRNA expression seems to be unaltered in these disorders.]

Clinical Neuroscience

[ONE-AND-A-HALF SYNDROME - TWO CASES]

SZIRMAI Imre, ILNICZKY Sándor, KAMONDI Anita, VÁRALLYAY György, GAAL Barbara, PALÁSTI Ágnes, GULYÁS Szilvia

[One-and-a-half syndrome is characterized by combination of the clinical features of unilateral horizontal gaze palsy and internuclear ophthalmoplegia. The common symptoms are double vision and oscillopsia. The lesion is located in the paramedian pontine reticular formation, involving the centre of horizontal gaze and medial longitudinal fasciculus. More extensive brainstem damage may result in additional neurological signs. The most frequent underlying diseases are vascular insults, multiple sclerosis, and brainstem tumor. We present two cases of one-and-a-half syndrome. Both patients had lacunar infarction in the paramedian pontine tegmentum, revealed by MRI. The first patient had isolated eye movement disorder, while the second had additional nuclear-type facial paresis. In the first case brainstem evoked potentials indicated brainstem damage, in the second patient it was normal. Ocular symptoms improved within some days in both patients.]

Clinical Neuroscience

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[Congress calendar 2007;60(11-12)]

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