Biomedical subjects

R Neshige

Publications and source records attributed to R Neshige.

At least 19 recordsLinked to original sources

PubMed1992

Automatic EEG interpretation: a new computer-assisted system for the automatic integrative interpretation of awake background EEG.

A new computer-assisted system for automatic interpretation of the awake electroencephalogram (EEG) was developed. First, all the items necessary for EEG interpretation were determined in accordance with the procedure that a qualified electroencephalographer (EEGer) goes through for the visual inspection of the background EEG activity, and then each item was defined quantitatively. For the automatic interpretation, specific EEG parameters were determined for each item so that they could fit the graded judgement of the item by the qualified EEGer as closely as possible. These specific EEG parameters were actually calculated from periodograms obtained from the time series of EEG records of 14 patients with various neurological diseases. The automatic EEG interpretation system thus established was applied to the EEG data of these 14 subjects and to 3 additional EEGs, and the results were compared with those obtained through the visual interpretation by the EEGer. This automatic EEG interpretation was found to be in good agreement with the visual interpretation by the EEGer in most EEG records. In contrast with the previous automatic analyses of EEG which were focussed on certain aspects of EEG such as the dominant rhythm, the present system is unique in its capability of providing an integrative interpretation of the spontaneous awake EEG by taking into account all its features except for paroxysmal abnormalities.

Adult↗

PubMed1992

Physiological study of the spinothalamic tract conduction in multiple sclerosis.

This is the first paper to study the physiological function of the spinothalamic tract in multiple sclerosis (MS) using pain-related somatosensory evoked potentials (pain SEPs) following CO2 laser stimulation. Among 12 patients with MS, hand- and foot-stimulated pain SEPs were significantly delayed or absent in 3 and 7, respectively. These results were totally consistent with clinical impairment of pain-temperature sensation. In contrast, the results of conventional electrically-stimulated SEPs were compatible with impairment of vibration sensation. Therefore, the examination of both pain and electric SEPs is very useful to evaluate the physiological function of the ascending spinal tract in patients with MS.

Adult↗

PubMed1992

Recording of event-related potentials (P300) from human cortex.

Auditory event-related potentials were recorded simultaneously from chronically implanted subdural electrodes and from scalp electrodes in three patients who were being evaluated for surgical treatment of epilepsy. These three cases showed clearly defined scalp-P300 and scalp-N300. A cortex-P300 was recorded from the midtemporal area, and a cortex-N300 was recorded from the inferior frontal area with some reflection at the basal temporal region. There were no potentials from an interhemispheric region. We could not observe any component from the cortex studied corresponding to scalp-recorded N200. Therefore, while the activity generated from the mesial temporal lobe may only make minor contributions to scalp-P300, that generated from the midtemporal area might make a major contribution to the scalp-P300. Additionally, generators of N200, P300, and N300 are different from each other. These findings, together with previous reports regarding the generator source of P300, also suggest that P300 is a complex arising from multifactorial generator sources, including the midtemporal and inferior frontal area.

Acoustic Stimulation↗

PubMed1992

Pain-related somatosensory evoked potentials following CO2 laser stimulation in peripheral neuropathies.

Pain-related somatosensory evoked potentials (pain SEPs) following CO2 laser stimulation were examined in 30 patients with peripheral neuropathies, and the results were compared with clinical sensory findings. Pain SEP findings showed a significant correlation with the clinical impairment of pain sensation, but not with the impairment of deep sensations. In contrast, conventional electrically-stimulated SEPs (electric SEPs) showed a significant correlation with deep sensations, but not with the impairment of pain sensation. Examinations of both pain SEPs and electric SEPs, therefore, are considered to be very useful to evaluate physiological functions of sensory nerves in patients with peripheral neuropathies.

Adult↗

PubMed1992

Systemic interferon-alpha in the treatment of HTLV-I-associated myelopathy.

Treatment with interferon-alpha (IFN-alpha) was undertaken in 16 patients with human T-lymphotropic virus type I-associated myelopathy (HAM). All patients had progressive spastic paraparesis before treatment. Twelve patients were enrolled in an open therapeutic trial with a dose of 3.0 x 10(6) IU/day of IFN-alpha and 4 in a randomized, double-blind, multidose (3.0 x 10(6), 1.0 x 10(6) or 0.3 x 10(6) IU/day) trial. IFN-alpha was injected intramuscularly for 28 days. Eight of 12 patients enrolled in an open trial and 2 patients receiving a dose of 3.0 x 10(6) IU/day of IFN-alpha in a randomized trial showed clinical improvements during and after the treatment. The results showed that, although not for all patients, systemic IFN-alpha with a dose of 3.0 x 10(6) IU/day is effective in the treatment of HAM.

Adult↗

PubMed1992

Accelerated aging of the brain in Werner's syndrome.

We report the electrophysiologic examination of a 55-year-old woman with Werner's syndrome. Needle EMG and peripheral conduction studies were normal. In contrast, EEG was moderately abnormal, the N20 and P25 potentials of SEPs were delayed and enlarged, and the event-related potential, P300, was delayed. These characteristic findings indicated accelerated aging of the brain, as in the other organs, in Werner's syndrome.

Brain↗

PubMed1991

CO2 laser-induced pain-related somatosensory evoked potentials in peripheral neuropathies: correlation between electrophysiological and histopathological findings.

Pain-related somatosensory evoked potentials (pain SEPs) following CO2 laser stimulation as well as conventional electrically stimulated SEPs (electric SEPs) were examined in 10 patients with peripheral neuropathies in whom the histopathological examination of the sural nerve was done. Results of pain SEPs showed a positive relationship with clinical impairment of pain sensation and densities of small myelinated fibers of the sural nerve. In contrast, results of electric SEPs showed a positive relationship with clinical impairment of deep and tactile sensations and with densities of large myelinated fibers of the sural nerve. Therefore, pain SEPs are considered to be generated by ascending signals mediated through nociceptive receptors and A delta fibers. The pain SEP is only one noninvasive and objective method currently available to investigate a physiological condition of the sensory pathway responsible for pain sense, and is especially useful when combined with the conventional electric SEPs.

Adolescent↗

PubMed1991

Estimation of conduction velocity of A delta fibers in humans.

Conduction velocity of A delta fibers of the human peripheral nerves was measured by using pain-related somatosensory evoked potentials following CO2 laser stimulation. It was found to be approximately 9 m/s in the forearm as well as in the lower leg. Because conventional conduction study using electric stimulation reflects only functions of large myelinated fibers related to deep proprioceptive and tactile sensations, the present noninvasive and simple, novel method is the only laboratory examination currently available to investigate physiological functions of the small diameter fibers mediating pain-temperature sensations.

Adult↗

PubMed1991

Treatment of HTLV-I-associated myelopathy with high-dose intravenous gammaglobulin.

Fourteen patients with HTLV-1-associated myelopathy were treated with high-dose intravenous gammaglobulin (IVGG). Ten received 10 g/day of IVGG and 4 received 400 mg/kg of body-weight/day of IVGG for 5 consecutive days. Improvement of spastic paraparesis was observed in 10 within 7 days of the commencement of IVGG. The therapeutic effects were sustained for more than 3 weeks in some patients. There were no side effects. Analysis of factors of relevance to the clinical improvement with IVGG showed that the beneficial response was preferentially found in patients having a high CSF titre of anti-HTLV-I antibodies, a high CSF IgG level and a marked brain MRI abnormality.

Adult↗

PubMed1991

Event-related brain potentials as indicators of visual recognition and detection of criminals by their use.

An event-related potential (ERP) was recorded, using photographs as stimuli, in 12 subjects for attended, 9 subjects for non-attended conditions and 14 subjects for a simulated criminal investigation. An ERP was detected only when a subject recognized a familiar image (target) mixed with other, unfamiliar images (non-target), regardless of whether he was asked to attend to or neglect the target image. ERPs in the subject who watched each picture but tried to ignore the relevant picture (non-attended) were more activated at the parietal region than at the central region, in contrast with ERPs in the subjects who paid attention to each picture without trying to ignore the relevant picture (attended). In the simulated criminal investigation, only a simulated thief, but not a simulated innocent subject elicited ERP only after the picture of a criminal site or thing was intermingled with pictures bearing no relationship to the crime. These findings indicate that the ERP using photographs as stimuli is useful as an objective indicator of crime-relevance.

Adult↗

PubMed1991

Pain-related somatosensory evoked potentials in syringomyelia.

Pain-related somatosensory evoked potentials following CO2 laser stimulation (pain SEPs) and conventional electrically-stimulated SEPs (electric SEPs) were examined in 8 patients with syringomyelia who showed various forms of dissociated sensory loss. Unlike clinical examination using a pin or needle, pain SEP is considered to be an objective and quantitative test to investigate functions of peripheral and central sensory pathways responsible for pain-temperature sensation (A delta fibres and the spinothalamic tract). Pain SEPs were abnormal in all patients. The results were generally compatible with the degree of a clinical impairment of pain-temperature sensation. Subclinical abnormality was detected in 3 patients. Electric median nerve SEPs using the scalp reference (Fz) were normal in 6 out of 8 patients. However, anterior and posterior cervical responses using a noncephalic reference were absent or small in 7 patients. Electric SEPs following tibial nerve stimulation were normal in 7 patients. These findings suggest that the function of the ascending fibres through the dorsal columns is intact in most patients, whereas the dorsal horn, where a fixed cervical potential is generated, is impaired. Pain SEPs combined with electric SEPs therefore appear to be extremely useful for investigating physiological function in the sensory pathways in patients who show 'dissociated sensory loss' such as in syringomyelia.

Adult↗

PubMed1991

Neuroepithelial cyst presenting as recurrent aseptic meningitis.

A 41-year-old man had three episodes of acute aseptic meningitis from the age of thirty-six. With each episode he had severe occipital headache associated with a mononuclear pleocytosis and an increase in CSF protein. He had a neuroepithelial cyst originating from the choroid plexus of the right cerebellomedullary cistern. Spontaneous ruptures of the cyst probably caused recurrent chemical meningitis. A neuroepithelial cyst must be considered in the differential diagnosis of intracranial cystic tumors presenting with aseptic meningitis.

Adult↗

PubMed1991

Numb chin syndrome secondary to Burkitt's cell acute leukemia.

We describe a case of Burkitt's cell acute lymphoblastic leukemia presenting with the bilateral numb chin syndrome as the initial symptom of the disease. Postmortem study of the trigeminal nerve showed heavy infiltrations of leukemic cells and destruction of axon and myelin by leukemic cells in the mandibular nerve.

Burkitt Lymphoma↗

PubMed1991

[A case of upper brainstem infarction developing symptomatic narcolepsy after the administration of anti-convulsant drugs].

A 52-year-old woman, who had ischemic infarction in the ventral upper brainstem due to subarachnoid hemorrhage in October 1986, had recurrent sleep and cataplexy attacks from May 1987. She was receiving valproate and phenytoin daily since 1986. The diagnosis of narcolepsy was made based on the clinical symptoms and EEG findings showing REM sleep during a sleep attack. Both sleep and cataplexy attack increased in parallel with an increase of the dose of anti-convulsant drugs and disappeared immediately after the discontinuation of the treatment. The findings that suggest that the administration of anti-convulsant drug as well as the brainstem vascular lesion was deeply involved in the development of narcolepsy in this case.

Brain Stem↗

PubMed1990

A method for real-time processing to study recovery functions of evoked potentials.

A new method for evaluating the recovery function of evoked potential (EP) in real time was reported. To record the test response of paired stimulation, the responses to alternate presentation of unpaired stimulus and several kinds of paired stimuli with various interstimulus intervals were averaged respectively and subtraction was made in real time. The EP's to the test stimulus obtained by the proposed method were proved to be accurate even under the changing recording conditions. A formula for computing the recovery correlation factor was derived as a measure of the recovery function of the recorded EP, and the recovery curves for three subjects were obtained.

Adult↗

PubMed1990

Pain-related somatosensory evoked potentials in cortical reflex myoclonus.

To elucidate the sensitivity to pain stimuli in patients with cortical reflex myoclonus, pain-related somatosensory evoked potentials (pain SEPs) following CO2 laser stimulation and conventional electrically-stimulated SEPs (electric SEPs) were compared in four patients with cortical reflex myoclonus. The P25 peak of electric SEPs was considerably enhanced but the P320 potential of pain SEPs was of normal amplitude in all patients. After medication, myoclonus was reduced and the amplitude of P25 was decreased, but P320 showed no change. In our previous study of the scalp distribution in normal subjects, a subcortical site, probably the thalamus, was considered to be the generator source of P320. Because most pain stimuli do not reach the cortex, patients with cortical reflex myoclonus are not sensitive to pain stimuli and P320 in pain SEPs is not enhanced.

Adolescent↗

PubMed1990

Cortical tremor: a variant of cortical reflex myoclonus.

Two patients with action tremor that was thought to originate in the cerebral cortex showed fine shivering-like finger twitching provoked mainly by action and posture. Surface EMG showed relatively rhythmic discharge at a rate of about 9 Hz, which resembled essential tremor. However, electrophysiologic studies revealed giant somatosensory evoked potentials (SEPs) with enhanced long-loop reflex and premovement cortical spike by the jerk-locked averaging method. Treatment with beta-blocker showed no effect, but anticonvulsants such as clonazepam, valproate, and primidone were effective to suppress the tremor and the amplitude of SEPs. We call this involuntary movement "cortical tremor," which is in fact a variant of cortical reflex myoclonus.

Aged↗

PubMed1990

[Treatment of HTLV-I-associated myelopathy with alpha-interferon and high-dose of gamma-globulin].

We administered alpha-interferon (alpha-IFN) and gamma-globulin (gamma-gl) to patients with HTLV-I-associated myelopathy (HAM). Patients selected for this study fulfilled the diagnostic criteria of HAM by Osame et al. As for alpha-IFN, 12 patients were injected intramuscularly with a dose of 3 X 10(6) IU/day of alpha-IFN for 28 days. As for gamma-gl, 10 patients were injected intravenously with a dose of 10 g/day of human gamma-gl for 5 days. alpha-IFN exerted therapeutic effects in 7 of 12 patients and gamma-gl in 6 of 10. The therapeutic effects were shown by the improvement in time for a 20-meter walk, muscle power of lower limbs and urinary frequency. All patients having a history of improvement by corticosteroid therapy showed beneficial responses to both treatments with alpha-IFN and gamma-gl. Contrarily, patients who had not improved by corticosteroid therapy did not show any improvement after gamma-gl and alpha-IFN administration. The therapeutic effects of gamma-gl and alpha-IFN were observed predominantly in cases with shorter duration of illness, more marked abnormality in cerebral MRI findings and higher CSF antibody titers to HTLV-I. There was no correlation between the therapeutic efficacy and clinical severity or serum antibody titers to HTLV-I. We conclude that therapies with alpha-IFN and gamma-gl were safe and effective for the treatment of HAM.

Adult↗