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Biomedical subjects

I Shimoyama

Publications and source records attributed to I Shimoyama.

At least 55 records · Page 3Linked to original sources
PubMed1989

[Significance of "on-off phonation test" to detect oral diadochokinesia in dysarthric patients].

Oral diadochokinetic abilities in 6 patients with ataxic dysarthria (ATAXICs), 6 with spastic dysarthria (SPASTICs), 3 with parkinsonism (PARKINs), and 6 normal subjects (NORMALs) were investigated using repetition of monosyllable /pa/ and "on-off phonation test" in which they had been requested to repeat interrupted vowel /a/ as fast as possible. Oscillographic as well as photographic records of the speech acoustic signal were obtained to analyse interval for a syllable, which consisted of voiced and unvoiced intervals, and peak-value of voiced interval. The results were as follows: 1) ATAXICs and SPASTICs showed prolonged interval for a syllable, yet that of PARKINs was within normal range, when tested either in /a/ or in /pa/. 2) Standard deviation and coefficient of variation for intervals of syllable and those of peak-values in voiced interval could not distinguish their characteristics among ATAXICs, SPASTICs, and PARKINs. 3) In "on-off phonation test", ATAXICs showed prolonged unvoiced intervals, while SPASTICs did prolonged voiced intervals. Results suggested that hypotonic laryngeal muscles in ATAXICs might result in prolongation of unvoiced interval, but that prolonged voiced interval related to biased hypertonus of laryngeal adductor. It is concluded that "on-off phonation test" could, with reasonable sensitivity, reflect the phonatory dynamics of laryngeal muscles in dysarthric patients.

Aged↗
PubMed1988

Thalamic, brainstem, and cerebellar glucose metabolism in the hemiplegic monkey.

Unilateral ablation of cerebral cortical areas 4 and 6 of Brodmann in the macaque monkey results in a contralateral hemiplegia that resolves partially with time. During the phase of dense hemiplegia, local cerebral metabolic rate for glucose (1CMRG1c) is decreased significantly in most of the thalamic nuclei ipsilateral to the ablation, and there are slight contralateral decreases. The lCMRGlc is reduced bilaterally in most of the brainstem nuclei and bilaterally in the deep cerebellar nuclei, but only in the contralateral cerebellar cortex. During the phase of partial motor recovery, lCMRGlc is incompletely restored in many of the thalamic nuclei ipsilateral to the ablation and completely restored in the contralateral nuclei. In the brainstem and deep cerebellar nuclei, poor to moderate recovery occurs bilaterally. Moderate recovery occurs in the contralateral cerebellar cortex. The findings demonstrate that a unilateral cerebral cortical lesion strongly affects lCMRGlc in the thalamus ipsilaterally and in the cerebellar cortex contralaterally, but in the brainstem bilaterally. Partial recovery of lCMRGlc accompanies the progressive motor recovery. The structures affected include those with direct, and also those with indirect, connections to the areas ablated.

Animals↗
PubMed1988

[Cerebral lateralization in two cases of crossed dextral aphasia with right-hemisphere arteriovenous malformation].

This paper reports two cases of crossed dextral aphasia. The first patient was a 60-year-old right-handed male with no family history of sinistrality. He experienced sudden onset of left hemiplegia and loss of consciousness. A CT scan showed high-density area in the right fronto-parietal region. An angiography revealed an arteriovenous malformation (AVM) in the right parietal lobe. It was fed by a branch of the middle cerebral artery and drained through a cortical vein. Neuropsychological examination one week after the surgery showed severe defects of all language moderalities. He was alert and cooperative, but completely mute. He recognized common words by auditory and visual stimuli, but could not perform simple command. He wrote some meaningless letters when asked to write his own name. Auditory and reading comprehension gradually improved thereafter, but Broca's type of aphasia with non-fluent hesitant and effortful output was still present four months after the surgery. The second patient was a 38-year-old right-handed male. All members of this family are right-handed except for one sister who is left-handed. He suddenly suffered left hemiparesis and loss of consciousness. A CT scan disclosed a right parietal intracerebral hematoma. And an AVM which was fed by the angular artery and drained through a cortical vein was angiographically demonstrated in the same area. Postoperatively the left hemiparesis rapidly disappeared, but left homonymous hemianopsia and anomic type of aphasia still persisted. His speech was fluent and daily communication was possible in spite of circumlocutory paraphasic output.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Clinical study of traumatic cerebellar contusion].

Numerous authors have reported cases of traumatic cerebellar contusion. A few authors have emphasized delayed deteriorations in patients with cerebellar contusion. Since CT scan was introduced into daily clinical practice, it has become obvious that cerebellar contusion were not necessarily associated with severe head injuries. Of 1176 head-injured cases admitted to our department in the past five years, eight (0.7%) were diagnosed by CT scans to have cerebellar contusion. Among eight cases, two of them were deeply comatose on admission because they had concomitant diffuse cerebral contusions and died soon after admission. Remaining six cases had predominantly cerebellar contusion on CT scans and showed minimal neurological deficits on admission. Most of them recovered without any significant disabilities. But two of them deteriorated several hours after injury, showing brain-stem compression for which emergency posterior fossa decompression were carried out without recovery. One of them underwent external decompression which resulted in intracerebellar massive hemorrhage and the other missed the timing of surgery. In conclusion, it is important to prepare for unexpectedly rapid deterioration, for which wide craniectomy and sufficient internal decompression would be required.

Adult↗
PubMed1984

Traumatic intracerebral haematomas of delayed onset.

25 cases of traumatic intracerebral haematomas of delayed onset were found among 775 cases of acute head injuries. All these 25 cases were analysed both clinically and with computed- tomographical studies. Their clinical features were different from those of classical " traumatische Spät- Apoplexie " originally described by Bollinger in 1891, in the following aspects; absence of the symptom-free interval and absence of apoplectic onset of symptoms after a relatively long lucid interval. These traumatic intracerebral haematomas of delayed onset were, on the other hand, characterized by the following; the patient was injured when the head was in motion, the injury was not necessarily severe, the onset of signs and symptoms were gradual and insidious, all 25 cases but 4, had cranial vault fractures and/or basal skull fractures, precipitating factors could not be identified, though hypotensive episodes were present in 60% of cases, intracerebral haematomas appeared within 72 hours following the head injury in most of cases, though more than 4 days later in a small number of cases, the appearance of such intracerebral haematomas suggested an unfavourable outcome, cerebral contusion might be a major contributory factor.

Adolescent↗
PubMed1984

Inhibitory effects of cerebellar cortical stimulation on sympathetic nerve activity in rabbits.

In anaesthetized and paralyzed rabbits, renal sympathetic nerve activity was observed by integrating and averaging impulse discharges. The activity was readily depressed by stimulation with a train of a few pulses of lobules I, II, III, VIIa, and VIIIa. The effective sites which caused the marked depression on the sympathetic nerve activity were distributed in the ipsilateral vermal cortex, predominantly in the medial part. The latency of depression was around 200 msec. Stimulation of these lobules caused a reduction of the systemic blood pressure, but this effect required stimulation by repetitive pulses, for a period of up to 10 sec.

Anesthesia↗
PubMed1978

Vestibular nucleus neurons relaying excitation from the anterior canal to the oculomotor nucleus.

A morphological approach was undertaken to determine which vestibular nucleus neurons relay excitation from the anterior canal to the IIIrd nucleus. In anesthetized rabbits HRP was iontophoresed into the IIIrd nucleus and cells filled with HRP reaction product (positive cells) searched for within the vestibular nuclear complex. By lesioning the MLF or brachium conjunctivum immediately after iontophoresis it was demonstrated that positive cells in the dorsum of the superior vestibular nucleus are backfilled via their axons which ascend in the brachium conjunctivum. By contrast positive cells in the center of the superior nucleus are backfilled via their axons in the MLF. In electrophysiological experiments in the presence of a severed MLF the anterior canal was selectively stimulated for orthodromic, and the 3rd nucleus stimulated for antidromic, activation of vestibular nucleus neurons. Recording extracellularly with glass microelectrodes filled with fast green FCF the only cells both ortho- and antidromically activated were localized to the dorsum of the superior vestibular nucleus. It is concluded that cells dorsally located in the superior nucleus relay the disynaptic excitatory vestibulo-ocular reflex from the anterior canal to the contralateral 3rd nucleus via their axons which ascend in the brachium conjunctivum.

Animals↗
PubMed1976

[Brain abscess secondary to pulmonary arteriovenous malformation, case report (author's transl)].

A case of brain abscess in the right parietal lobe secondary to pulmonary arteriovenous malformation of the right lung is presented. A 27-year-old man was admitted for headache and left homonymous hemianopsia. CAG, VAG and brain scan detected brain abscess of the right parietal lobe which was successfully removed surgically. He had been noted to have generalized cyanosis and club finger which corresponded to polycytemia and hypercapnia on examination. Subsequently pulmonary arteriovenous malformation was found in the right lower lobe of the lung which was also successfully excised by thoracic surgeons. Brain abscess was caused by peptostreptococcus anaerobius.

Adult↗