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The amplitude of compound sensory nerve action potentials (compound SNAP) increases with decreasing nerve temperature. This effect is much more pronounced in antidromic sensory nerve conduction studies compared to orthodromic recordings. It has been suggested, that the increase is mainly caused by increased duration and amplitude of the generating nerve fiber action potentials. In order to study these...
It is not well known which trigger points are suitable for obtaining movement-related cortical potentials (MRCPs) steadily upon forward stepping, because this paradigm consists of various movements. To make this issue clear, we recorded MRCPs in 10 healthy subjects when they stepped the right leg forward volitionally every 15 second from the standing position, and investigated the changes of MRCPs...
There are no specific diagnostic markers for amyotrophic lateral sclerosis (ALS) but physiological testing is an integral to the diagnosis. Multilevel conductions are essential to detect motoneuronopathy with conduction block. It is often important to stimulate very proximally (root level) since often the major site of block is proximal. Needle EMG has useful prognostic features and gives evidence...
In light of recent advances in applying theory of chaos to the analysis of brain function, a new method is presented that combines nonlinear dynamics theory, signal processing and information theory for the analysis of electric and magnetic activity of the human brain. Of particular interest is the application of this method for the analysis of event related desynchronization of EEG activity, imaging...
Multiple sclerosis (MS) patients may report temporary neurological deterioration with elevated body or ambient temperatures, probably by conduction block in partially demyelinated axons. Our purpose was to determine whether body cooling could reverse the conduction block clinically and electrophysiologically. Ten stable, temperature-sensitive, clinically definite MS patients (mean age 39 [plusmn]...
A loss of motor units is an essential part of most neurogenic disorders of the anterior horn cell, plexus, and peripheral nerve. Standard nerve conduction study amplitudes provide a coarse, but quantitative estimate of the loss of motor units in neurogenic disease. Needle electromyography (EMG) provides a more reliable, but entirely subjective measure of the loss of motor units. In recent years a...
A case of gelastic seizure during nocturnal sleep is reported. A 46-year-old female developed laughing fits during sleep in the night. She could not recall these episodes afterward. Neurologic examination revealed no abnormal signs, and cranial CT, MRI and SPECT detected no focal lesions. EEGs during drowsy state showed sharp waves predominantly in the left temporal region as well as in the frontal...
We applied magnetic stimulation to neck for evaluating autonomic function in 78 normal subjects and 60 patients with neurological disorders. Magnetic stimulation of neck is highly reproducible method of inducing sympathetic skin responses (SSRs) and sudomotor potentials (SPs), because this technique could produce strong afferent sensory inputs proximally. SSRs and SPs were recorded from electrodes...
Traditionally Koreans enjoy drinking alcohol when they have social or private meeting. In 1981 it was estimated that they consumed 5.4 liters of pure alcohol per one person, which ranked one of the highest among all the countries in the world. In Korea the life time prevalence rate of alcoholism was approximately 22% by the epidemiological studies in urban and rural areas, much higher than those in...
The purpose of this study was to examine whether an odorant stimulus that deviate from a semantic context can elicit the N400 component of event-related brain potentials (ERPs) as a word. ERPs were recorded while 14 students judged the veracity of a simple statement (e.g., lemon/is not/coffee) presented with the order of subject (S), object (O), and verb (V), which is normal in Japanese grammar with...
Current rapid progress in medical technology has made automatic analysis of MUP (motor unit action potential) possible by using a microcomputer. Recent commercially-based EMG machines have provided with programs for MUP analysis. We compared results of the computerized MUP analysis with the analysis by the experienced electromyographer to show the clinical value of the MUP analysis program. Materials...
Quantitative pharmaco-EEG (QPEEG) was developed based on the findings that any drug which affects human behavior (psychotropics) also produce significant changes in quantitative electroencephalogram (QEEG) or computer-analyzed EEG (CEEG) (Itil, 1974). The statistically significant central nervous system (CNS) effective single doses of psychotropics, as established by changes in CEEG measurements seem...
To determine the effects of severe cerebral damage on brainstem functions in early development, we examined magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), auditory brainstem response (ABR), short-latency somatosensory evoked potential (SSEP) and blink reflex (BR) in three children with hydranencephaly, and three patients with diffuse cerebral lesions caused by...
Dipole source estimation (DSE) was performed, using a multiple spatio-temporal dipole approach, to define the epileptic spikes generator(s) in four patients undergoing presurgical evaluation; the results were correlated with stereo-electroencephalographic (SEEG) findings. Scalp EEG showed: fronto-temporal spikes (four patients) associated with ipsilateral independent temporo-parieto-occipital spikes...
The tonic activity of spinal motoneurones (MNs) can be influenced by transcranial magnetic stimuli. The pattern of modulation is best appreciated by constructing a peri-stimulus time histogram in which counts of the times of motor unit (MU) discharge are accumulated over many stimulus trials. Hand muscle MNs show a short duration (4-5 ms) increase in firing probability about 25 ms after the stimulus...
Latency and amplitude changes of P300 activity have been widely used for investigating the cognitive functioning. In this study we attempted to evaluate the topography of P300 abnormalities in Alzheimer Disease (AD) and Parkinson's Disease (PD) groups. We prospectively studied 23 probable AD, 13 PD patients, and 15 healthy controls. P300 activity was elicited by standard auditory oddball paradigm...
During submaximal fatiguing handgrip, intraneural recordings have shown a MSA increase. Aim of this study was to determine, by means of an accelerometer detecting the muscle surface oscillation (mechanomyogram, MNG) the influence of an increased MSA on the mechanical properties of the non-fatiguing muscle. In five healthy subjects (age range 20-40) an accelerometer was placed 2 cm distally the tibialis...
The spinal mechanisms underlying spasticity are still vastly unknown. We have therefore investigated three different spinal control mechanisms in a population of spastic multiple sclerosis patients and in a population of healthy control subjects.i) Disynaptic reciprocal Ia inhibition was measured as the short-latency (cond.-test interval 2-3 ms) depression of the soleus H-reflex following stimulation...
A double motor unit potential has two identical or similar components which are separated by not more than 20 ms. Double motor unit potentials appear usually in acute neurogenic processes such as amyotrophic lateral sclerosis, but may appear also in other neuromuscular disorders as well as in normal muscles at the beginning and at the end of movement.The double potentials differ one from another in...
To determine the value of somatosensory evoked potentials (SEP) testing in evaluating sensory deficit in stroke patients, we analyzed the relationship of their findings in 100 patients. SEP waveforms were obtained over the spine and scalp in response to tibial nerve stimulation at the ankle. Interside differences of latencies (P35, N42, P53), interside amplitude ratios (N42, P53) and the correlation...
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