Biomedical subjects

K Kaga

Publications and source records attributed to K Kaga.

At least 127 records · Page 7Linked to original sources

PubMed1994

Temporary latency shifts in auditory evoked potentials by injection of lidocaine in the rat.

Temporary latency shifts in auditory evoked potentials by intravenous injection of lidocaine were investigated in albino rats. Auditory brainstem responses (ABR) were recorded with 4000Hz short tone bursts. There was no significant difference of latencies in wave Pl of the ABR between drug-administered group (6 mg/kg body weight of lidocaine) and control group (0.6 ml/kg of 0.9% saline). As for waves P2. P3 and P4 of ABR, the latencies of the waves were significantly prolonged after the lidocaine injection (p < 0.05. U-test). The prolongation of latency of wave P4 was the most prominent in the fast waves and dependent on the dose of lidocaine. The latencies of the slow positive wave of the evoked potentials on the inferior colliculus (wave S) with clicks and the slow positive wave (wave P) and the negative wave following ABR (wave NA) with 4000Hz short tone bursts were also studied. The latencies of waves S. P and NA showed significant temporal prolongation (p < 0.05, U-test) after lidocaine injection. The present study revealed that a relatively small dose of lidocaine can cause temporary prolongation of latencies of auditory evoked potentials not only in the fast components but also in the slow components including wave NA which is a large slow negative wave following the ABR. The effects are considered to be caused by the action of lidocaine which reduces the excitabilities on the auditory nervous system.

Acoustic Stimulation↗

PubMed1994

Chronological changes of auditory brainstem responses in Cockayne's syndrome.

Cockayne's syndrome (CS) is a rare autosomal recessive premature-aging disorder which is clinically characterized by physical and mental retardation, retinal pigmentation, sensorineural deafness and other neurological abnormalities. Auditory brainstem responses (ABRs) and behavioral audiometry were studied in 4 cases of confirmed CS chronologically. In one case, ABRs were normal at first but became abnormal. Initially, ABRs revealed only wave I with prolonged latency and thereafter no response. In another case, ABRs revealed the absence of all waves beyond wave III and then revealed the disappearance of all waves. In 2 other cases, ABRs were absent from the first testing. Behavioral levels were elevated in all 4 cases. In 2 cases, behavioral levels did not change in spite of partial disappearance of ABR waves, but they had elevated severely since all waves including wave I disappeared. Our findings suggest that the disease spreads from the upper brainstem to the cochlear nerve and that the site of the lesion causing hearing loss in CS is in the brainstem lesion as well as the peripheral one.

Adolescent↗

PubMed1994

Temporal bone pathology of leukemia and malignant lymphoma with middle ear effusion.

This report describes the histopathological findings of the middle ear in patients with leukemia and malignant lymphoma whose middle ear effusion (MEE) was observed from temporal bone specimens. There were 19 patients (35 ears) with leukemia and 8 patients (16 ears) with malignant lymphoma. MEE was observed in 8 of 35 ears with leukemia, and 5 of 16 ears with malignant lymphoma. In 8 ears with leukemia with MEE, pathological changes included effusion containing floating tumor cells in 4 and tumor infiltration around the Eustachian tube in 3. In 1 of 5 ears with malignant lymphoma with MEE, MEE was accompanied by tumor infiltration. Infection was present in 13 ears of patients with leukemia and malignant lymphoma. It is suggested that there are various causes, including infection, obstruction of the Eustachian tube with tumor infiltration and a tendency to bleed, of MEE in leukemia and malignant lymphoma.

Adolescent↗

PubMed1994

Analysis of auditory brain stem response with lidocaine injection into the cerebrospinal fluid in rats.

Auditory brain stem response (ABR) was recorded in 10 rats with total spinal anesthesia induced by injection of 2% lidocaine hydrochloride into the subarachnoid space through the skull. The ABR disappeared immediately (within 4 minutes) after the injection of 13.3 to 40.0 mg/kg lidocaine. The disappearance started with the later waves of the ABR. After cessation of the injection, the ABR reappeared and recovered progressively from wave I to wave IV. The effect of lidocaine on the ABR was reversible and extended in the acoustic nerve to the midbrain.

Animals↗

PubMed1994

Temporal bone pathology in patients without caloric response.

Pathologies of serial sections of 9 temporal bones from 6 patients without caloric response were studied. The patients died of epipharyngeal cancer, middle ear cancer, chronic renal failure with DIC, pancreatic cancer with DIC, multiple brain metastasis of pancreatic cancer, and leukemia. Under light microscopy, 8 ears showed pathologies in the vestibular end organs and the nerves. Possible causes of the lack of caloric responses in the 8 ears were endolymphatic hemorrhage, labyrinthitis, leukemic infiltration in the labyrinth, degeneration or disappearance of the vestibular sensory cells, reduction in the number of vestibular nerve fibers, and/or brainstem lesions. The remaining one ear did not show abnormal findings in the vestibular end organs or the nerves, but the patient had brainstem lesions. Four types of temporal bone pathologies were observed according to the lesion site responsible for the lack of caloric response; i) sensory type, ii) neural type, iii) mixed type and iv) central type.

Adult↗

PubMed1994

[Combined CDDP-THP-PEP chemotherapy (PTP therapy) for head and neck squamous cell carcinoma--a group study].

A group study of chemotherapy for head and neck squamous cell carcinoma, using CDDP, THP and PEP, was carried out on 32 cases at the department of Otolaryngology, University of Tokyo, and 7 affiliated hospitals. The combined chemotherapy, which we call "PTP therapy", consisted of 30 mg/m2 of THP on day 1, 70 mg/m2 of CDDP on day 2, and 5 mg/body/day of PEP on 4 successive days. The overall response rate was 78.1% (CR: 15.6%; PR: 62.5%). No major side effect was observed in any case. PTP therapy is useful in neoadjuvant chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1994

Bronchoscopy findings and early treatment of patients with blunt tracheo-bronchial trauma.

Five of 238 patients who suffered blunt chest trauna required surgery to repair a tracheobronchial injury. All patients were injured in a motor vehicle accident. The site of the injury was within 2.5 cm of the carina in four patients and 5.5 cm proximal to the carina in one. Pre-, intra-, and post-operative respiratory management was facilitated by the insertion of a Univent tube, an endotracheal tube with movable blocker capable of excluding one lung. The Univent tube prevented aspiration of blood by the healthy lung and the development of acute respiratory failure. Improved control over ventilation has the secondary benefit of allowing the surgeon to assess other injuries under less duress in patients with multiple trauma.

Accidents, Traffic↗

PubMed1993

Effects of primary auditory cortex lesions on middle latency responses in awake cats.

In order to clarify the role of the primary auditory cortex (AI) on middle latency responses (MLRs), we recorded the auditory evoked potentials (AEPs) from the vertex and the right and left AI areas of the skull simultaneously before and after creating serial lesions of the AIs contralateral and ipsilateral to the stimulated ear in 7 awake cats. The auditory brainstem responses (ABRs) and MLRs recorded from the vertex in normal awake cats revealed the presence of peaks 1-8, NA and PA within the analysis time of 50 msec. After there were serial AI lesions, (1) all the peaks remained at nearly the same latencies, (2) the amplitude of the NA was decreased significantly, that of the PA was slightly decreased and those of peaks 6, 7 and 8 were variable, and (3) the difference between the effects of the first operation (contralateral AI) and the second operation (ipsilateral AI) was not statistically significant. These findings indicated that the main, prominent effect of bilateral AI lesions on MLRs in the awake cat is a significant decrease in the NA amplitude.

Anesthesia, General↗

PubMed1993

Auditory and vestibular pathology in brainstem death revealed by auditory brainstem response.

Auditory brainstem response (ABR) before and after the cessation of brainstem activity and postmortem histological findings in the temporal bone and auditory and vestibular pathways of two cases of brainstem death are reported. A brainstem death state of at least 48 h in Case 1 and of at least 24 h for the left side and several hours for the right side in Case 2 was demonstrated by neurological examination, flat EEG, and persistent absence of ABR. Postmortem examination was performed 3 h after death in Case 1, and 1 h after death in Case 2. Pathological studies of the entire length of the auditory and vestibular pathway revealed total autolysis of the organ of Corti and vestibular endorgans and swollen cochlear and vestibular ganglia in Case 1, and, in Case 2, on the right side, preservation of the organ of Corti and vestibular endorgans and mildly swollen cochlear and vestibular ganglia, but on the left side, destruction of the organ of Corti and vestibular endorgan and markedly swollen cochlear and vestibular ganglia. We believe that distinct pathological changes in auditory and vestibular endorgans, and other changes of the cochlear and vestibular ganglia as observed in these two cases, may develop if the duration of absent ABR is prolonged.

Adult↗

PubMed1993

Vestibular pathology of totally deaf ears.

The temporal bone vestibular pathologies of 23 totally deaf ears (16 patients) were studied. Abnormal findings in the saccule were seen more often than in the other vestibular sensory organs. Abnormal findings in the vestibular ganglion cells were found in 7 ears. There were fewer ears with main damage in the hair cells than with main damage in the nerves.

Adolescent↗

PubMed1993

Slow blood flow of the vertebrobasilar system in patients with dizziness and vertigo.

We evaluated 102 patients with dizziness or vertigo who were 50 years of age and over, using magnetic resonance imaging (MRI). Slow blood flow (SBF) in the vertebrobasilar system was detected in 36 patients (35%). The patients with SBF experienced dizziness or vertigo for a longer period than those without SBF. The apogeotrophic type of direction-changing nystagmus was observed in 10 of 36 patients with SBF. No significant differences were found between patients with and without SBF with other neurotological tests. Because MRI can detect both infarcts in the hind-brain and SBF in the vertebral and basilar arteries it is recommended for evaluation of vascular disorders in older patients with vestibular symptoms.

Aged↗

PubMed1993

Three-staged graft replacement for multifocal aortic aneurysms in the Marfan syndrome.

A three-staged operation for multifocal aortic aneurysms was conducted over a period of 8 months in a 52-year-old woman with the Marfan syndrome. The aortic valve and ascending aorta, the abdominal aorta and the upper half of the descending thoracic aorta were replaced. As of 9 months after the third operation, the patient's course has been uneventful, but continuous follow-up will be needed in view of the character of this disease.

Angiography↗

PubMed1993

Surgical treatment of non-penetrating injury to the aorta.

During a 17-year period, eight cases of blunt traumatic injury to the aorta were surgically treated at our hospital. The locations of the lesions were the descending thoracic aorta in four cases, abdominal aorta in two cases, and traumatic DeBakey type IIIb dissection in two cases. Surgical repairs were carried out during the acute or subacute period in four cases and others were electively treated during the chronic period. One patient suffering from acute traumatic dissection of the aorta died of acute renal failure following acute ischemia in the lower extremities 10 days after surgery. Accordingly, the overall mortality rate was 12.5% in this series. We believe that elective operations should be carefully considered if they are possible.

Adolescent↗

PubMed1992

Delayed motor function and results of vestibular function tests in children with inner ear anomalies.

The relation between the results of vestibular function tests and gross motor development was examined in 4 children with inner ear anomalies. CT scans demonstrated the absence of lateral semicircular canals in both ears in all 4 cases. None responded to caloric stimulation using 40 ml of icewater. In contrast, the damped rotation test elicited per-rotatory nystagmus in all cases. Per-rotatory nystagmus was provoked in only two cases by the Bárány rotation test. Development of gross motor function, especially independent walking, was more delayed in the two children in whom the Bárány rotation test failed to elicit per-rotatory nystagmus.

Child↗

PubMed1992

Cat 'P300' and cholinergic septohippocampal neurons: depth recordings, lesions, and choline acetyltransferase immunohistochemistry.

The role of septohippocampal circuits in the generation of the P300 response in cats (n = 12) was explored in a series of depth recording, tract-tracing and lesion experiments. Systematic mapping of the hippocampus in 1-mm increments from rostral to caudal extent revealed large positive potentials, greater in amplitude to rare than to frequent stimuli, within the 200-500 ms range. Each map revealed maximal amplitude responses at diverse, widely distributed hippocampus loci. Furthermore, these electrical responses displayed polarity inversion within the hippocampus that was generally localized to the pyramidal cell layer; polarity inversion was also observed in the adjacent entorhinal cortex and amygdala. Injections of propidium iodide, a tract-tracing agent, into these inversion sites resulted in retrograde labeling of small clusters of choline acetyltransferase (ChAT)-positive neurons in the medial septal nucleus and vertical limb of the diagonal band. Aspiration lesions that bilaterally destroyed large amounts of caudal hippocampus from stereotaxic levels A4 to A1 resulted in a decreased number of cells expressing ChAT in the rostral basal nuclear complex. In only 2 cats was the preoperative presence of a significant vertex P300 absent postoperatively. In the majority of cases (5 of 8 animals), hippocampal aspiration produced an enhancement of the preoperative P300 potential. We conclude that cholinergic mechanisms are importantly, albeit not exclusively, involved in the mediation of P300 potentials in cats. Neurons mediating P300 responses appear to be organized in diverse clusters of septal and diagonal band cells. These septal cells may facilitate, and in turn be facilitated or inhibited as a function of hippocampal, or other, allocortical feedback loops.

Animals↗

PubMed1992

Pure word deafness due to left hemisphere damage.

We report the case of a 55 year-old right-handed man who presented with a long lasting pure word deafness following left thalamic bleeding. There was no sign of aphasia. The auditory deficit was specific for language, while recognition of music and environmental sounds was normal. CT, MRI and PET examinations showed that the lesion was anatomically and functionally confined to the left cerebral hemisphere, mainly the white matter of the temporal and parietal lobes. Wernicke's area was largely preserved. It is proposed that pure word deafness was consequent to the isolation of Wernicke's area from incoming auditory information due to the interruption both of the association fibers from the right auditory area traveling across the corpus callosum and of the left auditory radiations.

Brain Injuries↗

PubMed1992

Temporal bone findings in keratitis, ichthyosis, and deafness syndrome. Case report.

In 1981, the term KID syndrome was suggested for patients with congenital ichthyosis associated with deafness and keratitis. We had a chance to examine the temporal bone of an infant with this syndrome. This patient showed no auditory brain stem response in either ear. Temporal bone studies revealed cochleosaccular abnormality. These findings are offered as a possible explanation for the patient's deafness. The pathologic inner ear findings of congenital deafness syndromes associated with ichthyosis have been heretofore reported in Refsum's syndrome and in a case with universal alopecia. In these cases, the temporal bone pathologic findings were a result of cochleosaccular abnormality. From our case and previous reports, it is suggested that the deafness associated with congenital ichthyosis might be the result of cochleosaccular abnormality.

Cochlea↗

PubMed1992

[Clinical study of paragangliomas in the thorax].

Four cases of paraganglioma in the thorax, consisted of 3 cases originating from the mediastinum and a case of pulmonary metastasis from the posterior peritoneum, were clinically investigated. Three were malignant and one was benign with noradrenaline secretion. On surgical excision, preoperative arterial embolization was assumed to be useful for reducing hemorrhage during procedure. Pre and intra-operative circulatory management was also mandatory in case of functioning paraganglioma. Of the 3 malignant cases, 2 survived for more than 10 years with radiotherapy alone or surgical resection of multiple metastatic nodules in the bilateral lungs. The other one, though inoperable due to extensive invasion to right and left atria, showed highly sensitivity to intra-arterial infusion chemotherapy of CDDP. These results suggested that long term survival might be expected even in metastatic or inoperable cases. There were no reliable histologic features distinguishing malignant from benign tumors, however 2 malignant cases with local invasion showed aneuploid patterns in the DNA histograms, which might offer a adjunct possibility in the assessment of malignancy.

Adult↗