A parallel distributed neural network model of basal ganglia based on the neuroanatomy, neuropharmacology and neurophysiology is described. Despite recent advances in the understanding of the pathophysiology of movement disorders, little is known about the precise function the banal ganglia play in the control of movement. This article reviews an approach to studying the function of neural systems that is based on the use of a class of a computer models as parallel distributed processors (PDPs) and indicate its potential range of applications to the study of movement disorders. On this model, nigro-striatal dopaminergic system is considered as a threshold on the cortico-striatal glutamatergic fibers. So this dopaminergic system can control the striatal output to the globus pallidus and the striatal net model is consistent with clinical effect of Parkinson's disease that shows loss of dopaminergic function on the striatal medium spiny neurons due to nigral degeneration. The pallidal net is more complicated due to the probable reciprocal effects of dopaminergic function on the direct and indirect pathways of striato-pallidal connections which is not well known at present. But the neural network modal of PDPs would be a important field of neuroscience in a near future.
Basal Ganglia* ; Computer Simulation ; Ganglia ; Globus Pallidus ; Movement Disorders ; Neural Networks (Computer)* ; Neuroanatomy ; Neurons ; Neuropharmacology ; Neurophysiology ; Neurosciences ; Parkinson Disease

BACKGROUNDS: Headache is one of the common symptoms complained by patients at the emergency department. Postural headache is the characteristic symptom that is aggravated at upright position and relieved at recumbent position. This postural headache is associated with low cerebrospinal fluid (CSF) pressure. Spontaneous intracranial hypotension(SIH) is an unusual syndrome of postural headache and low CSF pressure without a precipitating event. The diagnosis of SIH is confirmed by 60mmH2O or less CSF opening pressure on lumbar puncture. However, the cases of SIH with normal CSF opening pressure have been reported. so it is needed to complement the diagnostic criteria of SIH. METHODS: A retrospective descriptive study with reviewing medical records of 10 patients who had been admitted at Asan Medical Center from Apr. 1995 to Jul. 1999 was done. Analyses were done on 22 variables of age, sex, clinical symptoms, spinal analysis findings, radiologic findings and therapeutic modality. Fisher's exact test and Mann-Whitney test were applied for statistical analysis (p-value < 0.05). RESULTS: 1. The male to female ratio was 3 : 7, and the mean age was 37.30+/-5.96 years. 2. Postural headache was characteristic symptom & complained by all patients. 3. The mean CSF pressure was 22.8+/-30.8 mmH2O. 4. Brain MRI demonstrated the pachymeningeal enhancement in all patients. 5. Radioisotope cisternography demonstrated slow ascent of tracer to the cerebral convexity in 88.9% patients, early soft tissue uptake suggestive of CSF leakage & rapid urinary accumulation of tracer in 66.7% patients, respectively. 6. 90.0% of all patients were recovered with autologous epidural blood patches, and 10.0% were recovered with conservative management. CONCLUSION: The SIH is an unusual syndrome. but we can diagnose the SIH in the patient, complains of a postural headache, if any following two or more criteria are present. 1. 60mmH2O or less CSF opening pressure on lumbar puncture. 2. Brain MRI finding : the pachymeningeal enhancement. 3. Cisternography findings : slow ascent of tracer to the cerebral convexity, early soft tissue uptake suggestive of CSF leakage & rapid urinary accumulation of tracer.
Blood Patch, Epidural ; Brain ; Cerebrospinal Fluid ; Chungcheongnam-do ; Complement System Proteins ; Diagnosis ; Emergency Service, Hospital ; Female ; Headache ; Humans ; Intracranial Hypotension* ; Magnetic Resonance Imaging ; Male ; Medical Records ; Retrospective Studies ; Spinal Puncture

BACKGROUND: Recently, the quantitative analysis of biological signals has been possible due to the development of digital machines, new mathematical theories including the nonlinear time series, chaotic and dynamic theories, and convenient statistical tools. The characteristics of biological signals however, can not analyzed solely through visual interpretation or judgement. The author statistically analyzed the EEG data of normal adults by using spectral analysis. METHODS: Quantitative EEG analysis was performed in 5 normal adults in order to analyze differences between the left and right hemispheres and interelectrode differences of the power spectrum of variable frequency bands. The results were statistically analyzed using SPSS. RESULTS: The spectral powers of the left frontal delta, the right parietal theta and left frontal alpha were significantly higher than the opposite sides. In the analysis of interelectrode difference, the tem-poral beta band power was significantly higher than the frontal areas. There were no significant interelectrode differ-ences in other frequency bands. CONCLUSIONS: The results of this study show that there are differences between the visually perceived EEG patterns and the frequency domain analysis. These findings suggest that EEG waves on record-ing papers are the results of interference among variable frequency bands. The continued analysis of EEG by using nonlinear parameters will be beneficial as a powerful tool in understanding the neural network dynamic in the brain.
Adult* ; Brain ; Electroencephalography* ; Humans ; Rabeprazole

The pathway and mechanism of convergence movement of eyes are not exactly confirmed at now. But, according to the recent neurophysiologic studies, the convergence cells was found in an area of the mesencephalic reticular formation just dorsal and lateral to the oculomotor nucleus and rostral to the superior colliculus. I experienced four patients, who complained diplopia due to unilateral convergence palsy. These cases of unilateral convergence palsy suggests that the Rt. Convergence cells and the Lt. Convergence cells in the mesencephalic reticular formation has independent pathway to ipsialteral medial rectus motoneuron nucleus.
Diplopia ; Humans ; Paralysis* ; Reticular Formation ; Superior Colliculi

Herbal medicines have been used for thousands of years, and herb preparations are commercially available for the folk remedies or for the promotion of health. In contrast to chemical drugs, herbs are regarded to be non-toxic and safe, because of their natural origin. But accumulating clinical data claim the toxicity of herbal medicine. They can cause adverse effects through (1) toxicity of the herb itself or bioactivation of its metabolites, (2) interaction with prescribed drugs, and (3) heavy metals contaminated in the herbal products. Recent studies have disclosed various neurologic side effects of herbal medicine, including cerebrovascular accident, convulsion, encephalopathy, hallunication, and psychosis. In addition to, some herbs interact with the neurologic therapeutic drugs, such as anticoagulants and antiepileptic drugs, leading to failure to control the patients' diseases. Also, there is growing evidence that herbal medicine products contain potentially harmful levels of lead, mercury and arsenic, all of which have neurotoxicity. Systematic validation of the potency and toxicity of herbal medicines as well as screening of toxic heavy metal content should be warranted.
Anticoagulants ; Anticonvulsants ; Arsenic ; Drug Interactions ; Health Promotion ; Herbal Medicine* ; Mass Screening ; Medicine, Traditional ; Metals, Heavy ; Psychotic Disorders ; Seizures ; Stroke

No abstract available.
Aged* ; Dementia ; Headache ; Humans ; Parkinson Disease ; Stroke ; Vertigo

BACKGROUND: Although anticardiolipin antibody(aCL)-related stroke is far more frequently identified in younger populations, the role of aCL in the pathogenesis of cerebral infarction may be important also in the old, stroke-prone population. We studied the clinical profiles of aCL- related stroke in elderly patient to look at its role on the pathogenesis of ischemic stroke. METHODS: We analyzed unselected patients with acute ischemic stroke and age matched controls for the presence of aCL, prospectively. Also, we studied the characteristics of these patients based on the conventional risk factors and other clinical, laboratory and radiological features in them. RESULTS: aCL was positive 30 (14.7%) of 203 stroke patients, but 11 (6.1%) in 193 control patients. The proportion of patients having more than one of the risk factors was significantly greater in aCL-positive (24/30, 80.0%) than in aCL-negative patients (100/173, 57.8%). The incidence of aCL positivity was significantly greater in patients having one or more risk factors (24/124, 19.3%) than in patients not having any of the risks (6/79, 7.6%). Two of the patients had prolonged aPTT, and only one had a lupus anticoagulant. A positive ANA and false-positive VDRL were not found in our patients. Radiological findings confer subcortical infarction. CONCLUSION: The elevated aCL are a risk marker for stroke also in the elderly population. Our aCL-positive patients generally had multiple risk factors for stroke and are associated with subcortical infarctions, contrary to previous studies. The role of aCL as a disease marker for ischemic stroke in elderly patients warrants further investigations.
Aged* ; Antibodies, Anticardiolipin* ; Cerebral Infarction ; Humans ; Incidence ; Lupus Coagulation Inhibitor ; Prospective Studies ; Risk Factors ; Stroke*

In this study the quantitative changes of the SP (senile plaque) and NFT (neurofibrillary tangle) in the subnucleus of amygdaloid nucleus were analyzed. All patients (83 cases) were diagnosed clinically and confirmed pathologically as Alzheimer disease. The results were: 1) The SP was most prominenentlv observed in the basomedial sub'nucleus region but NFT was in the lateral subnuclei. 2) There were positive Rank Correlation of pathologic degree between the amygdaloidal subnuclei and neocortex except accessory basal subnuclei. 3)Lateral subnucleus had no Rank Correlation between its SP & NFT.
Alzheimer Disease ; Amygdala* ; Humans ; Neocortex

No abstract available in English.
Neoplasm Metastasis* ; Stomach* ; Ureter*

In this study the quantitative changes of the SP (senile plaque) and NFT (neurofibrillary tangle) in the intrinsic hippocampal neural circuit were analyzed. All patients (86 case) were diagnosed clinically and confirmed pathologically as Alzheimer disease. The results were: 1) The NET and SP were most prominenetly observed in the C/A1 region, but they were not so many in the CA2 and CA3 regions. 2) There were quantitative correlation between the NFT and the SP except in the presubiculum and the dentate fascia. 3) There were no significant rank correlation between the perikaryonic NFT and the terminal SP in the dentate fascia and the CA3 area. 4) There were significant statistic difference of the quantity of the NFT and the SP between each neighboring areas in the intrinsic hippocampal neural circuit. I think there could be some influences of cholinergic fiber that they were from the medial septal nuclei and the nuclei of the diagonal band to the dentate fascia and the CA3 area.
Alzheimer Disease* ; Cholinergic Fibers ; Dentate Gyrus ; Humans ; Neural Pathways* ; Septal Nuclei