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Biomedical subjects

H Shibasaki

Publications and source records attributed to H Shibasaki.

At least 271 records · Page 15Linked to original sources
PubMed1992

Multifocal demyelinating motor neuropathy: cranial nerve involvement and immunoglobulin therapy.

We report two patients with multifocal demyelinating motor neuropathy whose symptoms improved after immunoglobulin infusion. Clinical signs included atrophy of the tongue and limb muscles, closely resembling that of motor neuron disease. Nerve conduction studies revealed multiple sites of motor conduction block without sensory abnormalities, suggesting selective involvement of motor fibers. Careful documentation of conduction block is required to diagnose this entity, which may be treated with immunoglobulin therapy.

Action Potentials↗
PubMed1992

Somatosensory conduction delay in central and peripheral nervous system of diabetic patients.

Fifty-four diabetic patients with or without clinical evidence of neuropathy and with no clinical evidence of CNS dysfunction were studied by somatosensory-evoked potentials after electrical stimulation of the median nerve at the wrist and recorded from the scalp electrode against a noncephalic reference. Peripheral conduction index, calculated as the distance from the wrist to the C7 spinous process divided by the P9 latency, was significantly decreased (P less than 0.01) in diabetic patients (69.81 +/- 6.47 m/s) compared with 28 age-matched nondiabetic subjects (76.85 +/- 5.65 m/s). The P11-P13 interpeak latency, representative of the transit time from the dorsal column at the level of the sensory input into the cervical cord to the brain stem along the somatosensory pathways (CCT1), and the P13-N19 interpeak latency, representative of the transit time from the brain stem to the somatosensory cortex (CCT2), were significantly increased in diabetic patients (CCT1, 2.51 +/- 0.63 ms; CCT2, 5.76 +/- 0.92 ms) compared with nondiabetic subjects (CCT1, 2.28 +/- 0.36 ms, P less than 0.05; CCT2, 5.18 +/- 0.51 ms, P less than 0.01). We conclude that, in diabetic patients, neurophysiological abnormalities may be present in two distinct parts of the CNS and the peripheral nervous system.

Blood Pressure↗
PubMed1992

[Treatment of Guillain-Barré syndrome with "axonal" involvement by plasma exchange].

A 19-year-old man with Guillain-Barré syndrome (GBS), who had been bedridden, dramatically improved after plasma exchange despite electrophysiological evidence of severe axonal damage. We commenced the therapy at 24 days after the onset of illness. Each trial of plasma exchange improved the strength clinically and rapidly increased the amplitude of the compound muscle action potential. Four months later, muscle strength recovered to normal except for mild weakness of the distal limb muscles. The time course of such a prompt recovery precludes axonal regeneration as its underlying mechanism in our patient. We postulate that some humoral factor might have reversibly depressed the axonal excitability, causing clinical symptoms which mimic axonal degeneration. Plasma exchange is a choice of treatment even for patients with GBS showing electrophysiological findings suggestive of axonal involvement.

Adult↗
PubMed1992

Radiotherapy resolves leukemic involvement of the optic nerves.

A 40-year-old woman with acute lymphoblastic leukemia had a visual disturbance OD. The optic disc was slightly swollen in the right fundus, and blast cells in the cerebrospinal fluid were found. Radiotherapy to the brain and orbit resolved these findings. Five months later, visual acuity decreased OS. Radiotherapy also was effective in treating the leukemic involvement of the optic nerve.

Adult↗
PubMed1992

Ophthalmic complications in patients with malignant tumors of the nose and paranasal sinuses.

We examined 34 Japanese patients (16 men and 18 women) with malignant tumors of the nose and paranasal sinuses. Squamous cell carcinoma of the maxillary sinus was the most common tumor. During the patients' initial visits, several ophthalmic symptoms were noticed, including proptosis, epiphora, lid swelling, displacement of the globe, orbital mass, and sudden visual loss. In addition, several ocular and orbital symptoms and signs resulted from treatment with radiotherapy, chemotherapy, and surgery and from local recurrence of the tumor. Four patients underwent orbital exenteration, and one underwent evisceration. Five eyes had no light perception.

Adolescent↗
PubMed1992

[A case of multiple sclerosis with paroxysmal attacks of facial paresthesia, unilateral hand tremor, epigastric pain and urinary incontinence].

A Japanese woman, aged 42, was admitted because of paroxysmal attacks consisting of paresthesia of the left face, tremor in the right hand, epigastric pain and urinary incontinence. A year prior to the admission, she noticed some difficulty in writing, dysarthria and unsteadiness of walking. These symptoms had been persistent since then. At the end of March, 1991, these symptoms rapidly worsened, and she fell down frequently. She also experienced pain behind both eyes, numbness in her left fingers and toe, urinary frequency and the above-mentioned attacks. Neurological examination disclosed bilateral internuclear ophthalmoplegia and upbeating nystagmus on upward gaze, titubation in the head, scanning speech, dysmetria in all limbs, exaggerated reflexes in jaw and both legs, bilateral extensor plantar reflexes and ankle clonus. SEP showed delayed cortical response with stimulation of the median nerves bilaterally and of the right posterior tibial nerve. P40 was absent with the left posterior tibial nerve stimulation. VEP was normal. T2-weighted image of MRI showed multiple high intensity areas located around the third ventricle, crus cerebri and the right upper part of the pons. The diagnosis of multiple sclerosis was made. Each paroxysmal attack started with numbness in the left face and burning sensation in the neck. Almost simultaneously tremor in the right hand began. The surface EMG showed the rhythmic contractions in the dorsal hand muscles and wrist extensors at a frequency of 6-7 Hz, and sometimes it revealed synchronized contractions of finger flexors and the dorsal hand muscles. A few seconds later she felt painful sensation in the epigastric region, and the tremor gradually increased in its intensity.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Pain↗
PubMed1991

Amino acid sequence determination of the novel forms of Go alpha purified from bovine brain membranes.

Previously we have reported that there are at least four different forms of Go alpha in bovine brain membranes which can be distinguished by their elution profiles from Mono Q column and their immunological reactivities. The four alpha-subunits are referred to as alpha o1, alpha o2, alpha o3 and alpha o4 in their elution orders from the column. Partial amino acid sequences of the purified alpha o1 and alpha o2 were determined and compared with the predicted sequences of two classes of Go alpha cDNAs, termed Go alpha-1 and Go alpha-2. There were at least two unique fragments corresponding with the predicted amino acid sequence of the Go alpha-2 cDNA but different from that of the Go alpha-1 cDNA upon tryptic digestion of alpha o1- or alpha o2-subunit. The alpha o3- and alpha o4-subunits, but not alpha o1-and alpha o2-subunits, were recognized by an antibody raised against a unique amino acid sequence predicted from Go alpha-1 cDNA. These results suggest that alpha o1,2 subunits and alpha o3,4 subunits are encoded by Go alpha-2 cDNA and Go alpha-1 cDNA, respectively.

Amino Acid Sequence↗
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

A case of adult onset pure pallidal degeneration. I. Clinical manifestations and neuropathological observations.

We present a case of adult onset progressive neurodegenerative disease with a selective involvement in the globus pallidus (GP). The main symptom was extreme slowness in motion without rigidity, which was distinct from akinesia of parkinsonism. Dystonic posture developed in neck and fingers and mild rigidospasticity appeared in a later stage. Neuropathological examination shows a selective neuronal loss with gliosis in GP and degeneration of the efferent fibers. Although the subthalamic nucleus is slightly atrophic with minimal gliosis, there is no neuronal loss in the nucleus. The rest of the structures are pathologically insignificant. Because the pathological change is confined to GP neurons and their efferent fibers, we think that the marked slowness in motion and dystonic posture are ascribable to the selective GP lesion. A degenerative neurological disorder preferentially involved in GP was reported as pure pallidal degeneration (PPD). The onset of the PPD was in the first or second decades and the main symptoms were choreoathetosis, torsion dystonia and progressive rigidity. These distinct clinical features seemed to distinguish the present case from the previously described PPD. Therefore, we would like to call our case "adult onset" PPD. Clinicopathological correlation is discussed.

Adult↗
PubMed1991

A case of adult onset pure pallidal degeneration. II. Analysis of neurotransmitter markers, with special reference to the termination of pallidothalamic tract in human brain.

We analyzed neurotransmitter markers in a brain of a very rare case of pathologically confirmed adult-onset pure pallidal degeneration (PPD) as compared with 16 controls. Neurotransmitter concentrations are significantly altered in the globus pallidus (GP), subthalamic nucleus (ST) and the thalamic nuclei. Concentrations of gamma-aminobutyric acid (GABA) in the external segment (GPe) and internal segment (GPi) of GP and ST are decreased to 62, 45 and 55% of the control mean, respectively. Concentrations of glutamic acid are increased in GPi (144%) and ST (134%). Choline acetyltransferase (ChAT) activities are increased in GPe (232%), GPi (218%), ST (161%), and ventroanterior (VA, 210%) and ventrolateral nucleus (VL, 193%) of the thalamus. Noradrenaline (NA) concentrations in GPe and GPi are 56 and 43% of the control mean, respectively. Dopaminergic and serotonergic systems show no remarkable change. The grid microdissection analysis demonstrates a patchy GABA distribution in the thalamus of 3 controls, whereas a small GABA-rich area in the ventro-oral nucleus (VO) according to the atlas of Hopf disappears in adult onset PPD. These results strongly suggest that (1) GP GABAergic neurons are selectively degenerated and striatopallidal GABAergic nerve terminals are hypoactive; (2) ChAT activities in GP, ST, VA and VL are increased; (3) the subthalamopallidal glutamatergic system is not hypoactive; (4) activity of the noradrenergic system in GP is decreased; and that (5) VO in the thalamus specifically receives GABAergic nerve terminals from GP in human brain.

Adult↗
PubMed1991

Method for predicting an EEG waveform as an aid to the accurate recording of evoked potentials.

Evoked potentials are the brain's responses to incoming stimuli and are usually recorded under noisy circumstances. To improve the signal-to-noise ratio, signal averaging has been widely applied to the recorded data, but an improved method is required. A method of EEG waveform prediction for the accurate recording of evoked potentials is proposed, and an electroencephalographic waveform predicted by using an EEG model and a nonlinear exponentially weighted least squares method, subtracting the predicted EEG waveform from the raw data and extracting the evoked waveform. By the use of this method, we have successfully predicted the EEG waveform and detected the evoked potential with only a small number of averages.

Adult↗
PubMed1991

Scalp topography of giant SEP and pre-myoclonus spike in cortical reflex myoclonus.

Scalp topography of the giant SEP and the pre-myoclonus spike demonstrated by jerk-locked back averaging was studied by using a computer-assisted evoked potential mapping technique in 5 patients with cortical reflex myoclonus. The initial positive peak of giant SEP was localized to the postcentral region contralateral to the stimulus and was associated with a negative potential field of the same latency at the frontal region in all cases. The main positive peak of pre-myoclonus spike was localized to the postcentral region contralateral to the myoclonus in 4 cases, and maximal at the midline postcentral region extending contralaterally with respect to the myoclonus in 1 case. The postcentral positive peak was associated with a frontal negativity in 2 of the 5 cases. In those 2 cases, the main components of giant SEP and the pre-myoclonus spike showed a similar scalp distribution with respect to the hand which was stimulated or myoclonic jerks were recorded from, although the latter was much smaller and less sharp than the former. These findings support our previous hypothesis that those 2 activities might be generated, at least in part, by common physiological mechanisms. In 3 other cases, however, the postcentral positive peak of the pre-myoclonus spike was not associated with a frontal negativity.

Action Potentials↗
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

Changes in motoneuron excitability during postnatal life in the mouse.

H-reflex recovery, H-amplitude and H/M ratio were recorded in 54 mice aged 3-12 weeks to study the motoneuron excitability and changes in it during various stages of development. The H-reflex recovery curve at 12 wk showed 3 phases: an early, relative facilitation (before 10 ms), an almost total inhibition at 10 ms and a rapid recovery thereafter. At 3 wk, however, there was only slow recovery after 10 ms and the H-reflex recovery was significantly low during the 40-100 ms period as compared to those in the other age groups, indicating that between 3 and 6 wk, there was a significant increase in the motoneuron excitability. The H-reflex amplitude also showed a significant increase during the 3-6 wk period. However, the H/M ratio did not show any significant increase either during the 3-6 wk period or thereafter. It is concluded that the H-reflex recovery at 3 wk suggests hypoexcitability of the motoneurons, possibly due to immaturity. Since there was a significant increase in the H-reflex recovery during the 3-6 wk period without any parallel increase in the H/M ratio, it is concluded that presynaptic and polysynaptic mechanisms acting on the motoneurons develop during this period. The increase in the H-reflex amplitude is possibly due to the increase in the muscle mass. The H-reflex recovery pattern at 12 wk, without the phase of late inhibition observed in man, is suggestive of less supra-spinal control mechanisms acting upon the motoneurons.

Animals↗