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Biomedical subjects

Y Handa

Publications and source records attributed to Y Handa.

At least 109 records · Page 6Linked to original sources
PubMed1991

Evaluation of extracranial-to-intracranial bypass surgery using iodine 123 iodoamphetamine single-photon emission computed tomography.

Eleven patients with occlusive cerebrovascular diseases were imaged with N-isopropyl-p-I-123 iodoamphetamine. Preoperative and postoperative single-photon emission computed tomography was performed in 10 patients undergoing extracranial-to-intracranial bypass procedures. New images were reconstructed from the two images obtained on the different days by superimposition and division in each pixel to get the ratio of cerebral perfusion change. All patients with bypass procedures had an increase in cerebral blood flow in the affected areas, and nine of 10 had an increase in cerebral blood flow in the contralateral cortex. There was no increase in cerebral blood flow in one case with no operation. Neither our procedure nor the results in this small series prove that recovery of function is due to an increase in blood flow, but we believe this is the case.

Adult↗
PubMed1991

Intermaxillary fixation using screws. Report of a technique.

A technique of intermaxillary fixation using screws anchored in the maxilla and mandible has been described. AO (Synthes) screws with a diameter of 3.5 mm and 12 mm to 16 mm in length were inserted at the antero-lateral surface of the maxilla and the buccal surface of the mandible. This technique is particularly suitable for mandibular fractures in denture wearing patients.

Aged↗
PubMed1991

Kabuki make-up syndrome (Niikawa-Kuroki syndrome) with cleft lip and palate.

Kabuki make-up syndrome (Niikawa-Kuroki syndrome), recognized in Japan in 1981, is characterized by mental and growth retardation with specific craniofacial malformation such as lower palpebral eversion and depressed nasal tip. In this paper we describe a case associated with cleft lip and palate. Attention should be paid by maxillofacial surgeons to this syndrome, since 41% of the cases have been associated with cleft lip and palate (Niikawa et al., 1988; Tonoki and Niikawa, 1988).

Cleft Lip↗
PubMed1991

Balloon occlusion of carotid-cavernous fistula via subtemporal transdural approach.

This is a report on a patient with traumatic carotid-cavernous sinus fistula (CCF). She gradually noticed noise in her head and suffered from partial ophthalmoplegia. Angiography demonstrated a left high flow CCF. She underwent a direct surgical treatment with a detachable balloon because an endovascular balloon embolisation for the CCF had been unsuccessful. Immediate disappearance of the bruits after surgery was noted and the patient recovered progressively her ophthalmoplegia. Follow angiograms 3 months after surgery revealed the disappearance of the fistula and an appearance of a false aneurysm. She is asymptomatic and periodically monitored in the outpatient clinic.

Arteriovenous Fistula↗
PubMed1991

EC-IC bypass for adult patients with moyamoya disease.

We have performed 10 bypass operations on 7 adult patients with moyamoya disease over the past 6 years. Four had haemorrhagic episodes and three had ischemic episodes. Three patients underwent superficial temporal artery-middle cerebral artery (STA-MCA) bypass on both sides and the other four had the procedure on one side. Six of 7 patients showed angiographical improvement after the bypass operation while one patient did not. This patient underwent the second severe stroke and became vegetative during the course of follow-up. Another patient died of myocardial infarction during the follow-up time. Five patients are capable of carrying out their original work. Considerations regarding the cause, operative methods and disease course in the patients are discussed.

Adult↗
PubMed1991

Plateau-wave phenomenon (I). Correlation between the appearance of plateau waves and CSF circulation in patients with intracranial hypertension.

Plateau waves, as described by Lundberg (1960), can often be observed in patients with increased intracranial pressure (ICP) resulting from brain tumours, benign intracranial hypertension and other causes. The clinical significance of the waves, however, is still debated. In this study, the ICP was recorded continuously, the size of the ventricular system was evaluated using computerized tomography (CT), the cerebrospinal fluid (CSF) flow was studied using isotope cisternography, and the absorptive capacity of the CSF was determined by measuring the conductance to CSF outflow, in 94 patients with increased ICP. All patients who received continuous ICP monitorings had a basic ICP level of more than 200 mmHg, and these patients were assigned to two groups on the basis of the presence or absence of the plateau waves in the ICP recordings: group I comprising 17 patients without plateau waves but with a high ICP resulting from subarachnoid haemorrhage or hypertensive intracerebral haemorrhage, within 5 days after the start of bleeding; and group II consisting of 77 patients with both plateau waves and a high ICP resulting from brain tumours, meningitis carcinomatosa, benign intracranial hypertension, superior sagittal sinus thrombosis and communicating hydrocephalus. The isotope cisternography and conductance to CSF outflow studies showed that there was neither a delay in CSF circulation nor an impairment of CSF absorption in the group 1 patients and these patients showed no ventricular dilatation on CT, whereas there was a marked sluggishness in the CSF flow and a severe defect in the CSF absorption capacities of the group II patients irrespective of the presence or absence of ventricular dilatation on CT. The present observations indicate that patients with a plateau-wave phenomenon have a marked impairment of CSF absorption and CSF flow. We suggest that the phenomenon is an important sign indicating an impairment of CSF absorption capacities.

Adult↗
PubMed1991

Plateau-wave phenomenon (II). Occurrence of brain herniation in patients with and without plateau waves.

From 1980 to 1989, during intracranial pressure (ICP) recording, brain herniation (central transtentorial herniation associated with uncal herniation) developed in 15 patients as a result of aneurysmal rebleeding, uncontrollable brain swelling and/or oedema in spite of attempts at treating increased ICP. The relationship between the ICP level at which herniation occurred and the ICP fluctuation patterns in continuous ICP recordings prior to the development of the herniation was studied retrospectively. As for the ICP fluctuation patterns, the patients were assigned to 2 groups on the basis of the presence or abscence of plateau waves of Lundberg: group I comprising 8 patients without plateau waves but with a high ICP, and group II comprising 7 patients with both plateau waves and a high ICP. In the group I patients the herniation occurred as a result of aneurysmal rebleeding or brain swelling after subarachnoid haemorrhage, and in the group II patients the herniation resulted from brain tumour, meningitis carcinomatosa and superior sagittal sinus thrombosis. In the group I patients the herniation developed at a mean ICP level of 70-98 mmHg, and in the group II patients it occurred at a mean ICP level of 120-150 mmHg, far higher than the ICP level causing herniation in the group I patients. It has been shown that patients with a plateau-wave phenomenon in continuous ICP recordings have a marked impairment of cerebrospinal fluid (CSF) absorption and a delayed CSF flow.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Impairment of cerebral autoregulation during the development of chronic cerebral vasospasm after subarachnoid hemorrhage in primates.

We studied the impairment of autoregulation of cerebral blood flow (CBF) and its effect on the electrical activity of the brain during the development of chronic cerebral vasospasm after subarachnoid hemorrhage, using a vasospasm model in primates. Fourteen animals were divided into two groups: a clot group (8) and a sham-operated group (6). To induce subarachnoid hemorrhage, all the animals underwent craniectomy, and in the clot group, the autologous blood clot was located around the arteries dissected free from the arachnoid membrane. Cerebral angiography was performed before subarachnoid hemorrhage and 7 days after (Day 7). On Day 7, regional CBF in the parietal lobe--measured by the hydrogen clearance method--and central conduction time were studied during either graded hypertension or hypotension. In the clot group, the mean vessel caliber of the cerebral arteries on the right side (clot side) of the circle of Willis showed significant (P less than 0.01) reduction (more than 40%) as compared with the values on the contralateral, non-clot side. The values for the bilateral parietal CBF in the sham-operated group and the left parietal CBF in the clot group were fairly constant when the mean arterial blood pressure (MABP) was in the range of 60 to 160 mm Hg. In the clot group, right parietal CBF was significantly (P less than 0.05) smaller than that on the left side at an MABP level of 40 to 100 mm Hg, and increased at an MABP level of 180 mm Hg. The right parietal CBF increased as the arterial blood pressure increased, showing impairment of autoregulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

The correlation between immunological reaction in the arterial wall and the time course of the development of cerebral vasospasm in a primate model.

To investigate the role of immunological reactions in the development of cerebral vasospasm after subarachnoid hemorrhage (SAH), the authors studied the correlation between immune/inflammatory reactions in the arterial wall and the time course of vasospasm in primates. Twenty monkeys were divided into four groups of 5 animals each: 1) a control group of sham-operated animals, 2) animals subjected to angiography 3 days after the induction of SAH (3-day SAH), 3) animals subjected to angiography 7 days after SAH (1-week SAH), and 4) animals subjected to angiography 7 and 14 days after SAH (2-week SAH). To induce SAH, the main cerebral arteries on the right were dissected free of the arachnoid, and an autologous blood clot was placed around the arteries. To evaluate vasospasm, all animals underwent a baseline angiogram before SAH; angiography was repeated at different intervals in each group, as outlined above. Histopathological changes and the deposition of the immunoglobulin IgG in the arterial wall were evaluated immunohistochemically in each group. The cerebral arteries on the side of the clot showed evidence of mild vasospasm (-24.6% reduction) on the angiogram performed on Day 3, severe vasospasm (-51.7%) on Day 7, and mild vasospasm (-12.8%) on Day 14. The infiltration of inflammatory cells was most marked in the spastic arterial wall in the 1-week SAH group. In the 2-week SAH group, severe myonecrosis and intimal disruption were observed, even in the vessels that showed only mild vasospasm, and the inflammatory reactions had almost abated.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Cerebral vasospasm and vasoconstriction caused by endothelin.

We investigated the histological changes between arteries constricted by endothelin for 7 days and vasospastic arteries induced by the double injection of autologous blood. Group 1 was a sham-operated group. Group 2 animals received a continuous cisternal injection of endothelin-1 (1.7 x 10(-9) mol/7 days) by a miniosmotic pump implanted in the neck musculature for 7 days. Group 3 received double injections of cisternal blood administered 48 hours apart. Angiography showed severe constriction of the basilar artery, 34.6% and 43% in Groups 2 and 3, respectively, on Day 7. Histological study showed marked constriction of the basilar artery in both Group 2 and Group 3. Degenerative changes in endothelial cells and smooth muscle cells were observed in both Group 2 and Group 3. Immunohistochemical study demonstrated endothelin-1 in the endothelial cells in Group 2, but not in Group 1 or in Group 3. It is suggested that endothelin-1 may play an important role in the pathogenesis of cerebral vasospasm.

Animals↗
PubMed1991

Changes in phosphorus-31 magnetic resonance spectra caused by epidural balloon in cats.

Changes in brain high energy phosphate metabolite and pH levels were studied using serial phosphorus (P)-31 magnetic resonance spectroscopy (MRS) in an epidural balloon cat model. The balloon was inflated with 1, 2, 3, or 4 ml of water at 1 ml/sec and deflated after obtaining a spectrum 4 minutes later. Serial spectra, intracranial pressure (ICP), physiological parameters, and the pupil sizes were observed for 1 hour. The mean ICP after balloon inflation increased to between 36 +/- 3 and 130 +/- 6 mmHg. Some animals showed oculomotor paralyses. Phosphocreatine, adenosine triphosphate, phosphodiester, and phosphomonoester levels suddenly decreased after inflation and gradually recovered after balloon deflation. Acidosis progressed with cerebral compression for 4 minutes and gradually recovered. All changes and recovery were volume related. This study demonstrates the potential of P-31 MRS for noninvasive, serial, in vivo measurements of critical high energy phosphate metabolites and intracellular pH after head injury.

Animals↗
PubMed1991

Functional anatomical studies of the elbow movements. I. Electromyographic (EMG) analysis.

Activities of the elbow flexors and extensors during the movement of the elbow flexion and extension were analyzed in six normal human volunteers by electromyography (EMG). In the flexors, the majority of the muscles showed EMG activities during both the flexion and extension phases, although patterns and amplitudes of EMG activities varied from individual to individual. The biceps brachii always became less active when the forearm was in pronation. In the extensors, increase of EMG activities was observed at the period of the maximum elbow extension in the majority of cases, while no EMG activity was shown throughout the movement in some cases. During the elbow movement except at the maximum extension, the triceps brachii was almost inactive and some of their three heads, in particular the long head, often showed no EMG activity. In contrast, the anconeus was usually active, sometimes showing strong EMG activity.

Adult↗
PubMed1991

Effect of chemical sympathectomy on cerebral blood flow in rats.

Thirty male Wistar rats, weighing 350 to 400 gm each, received stereotactic injections of 6-hydroxydopamine (300 micrograms/kg) into the left lateral ventricle. The same amount of saline was injected into a control group of 15 rats. Seven days after this procedure, cerebral blood flow (CBF) was measured by the hydrogen clearance method. A hypertensive condition at a mean arterial pressure of about 160 mm Hg was maintained for 1 hour by intravenous infusion of phenylephrine. In the 6-hydroxydopamine-treated group, CBF increased significantly after the elevation of systemic blood pressure compared with that in the control group, and cerebral autoregulation was impaired. After a 1-hour study, the specific gravity of the cerebral tissue in the treated group significantly decreased; electron microscopic studies at that time revealed brain edema. It is suggested that depletion of brain noradrenaline levels causes a disturbance in cerebral microvascular tone and renders the cerebral blood vessels more vulnerable to hypertension.

Animals↗
PubMed1991

[Influence of total body hyperthermia on normal brain tissue].

The influence of total body hyperthermia (TBHT) on normal brain tissue was studied in 40 dogs. The dogs were anesthetized with sodium thiopental (10 mg/kg/hr) intravenously, and were ventilated by artificial respirator. The TBHT was induced by extracorporeal circuit in cooperating a heat exchanger. Rectal temperature was raised to 41.5 degrees C and maintained at 41. 5 -42.0 degrees C for 2 hr (HT period) and was then fallen to normothermia by cooling, Regional cerebral blood flow (CBF) was measured by hydrogen clearance method before heating, during and after TBHT treatment. Brain temperature, rectal temperature, intracranial pressure (ICP), brain tissue pH and electroencephalography (EEG) were monitored continuously during TBHT. Histopathological changes of the brain tissue were studied in dogs killed just after TBHT and 2 weeks after TBHT. Autoregulation of the CBF during HT period was assessed by measuring the regional CBF and the ICP at a state of induced hypo- or hypertension. The brain temperature (at the depth of 5mm under the brain surface) was usually 0.6 degrees C lower than the rectal temperature during HT period. The regional CBF increased from 38.1 +/- 6.5 (mean +/- SD) to 49.1 +/- 9.8ml/100 g/min by raising rectal temperature, and it recovered to a normal value after cooling. The ICP increased from 10.3 +/- 4.2 to 16.8 +/- 3.4 mmHg by raising rectal temperature, and it returned to a normal value after cooling. Brain tissue pH decreased from 7.33 +/- 0.02 to 7.17 +/- 0.09 rapidly when the rectal temperature reached 41.0 degrees C, and then returned to a normal value gradually after the start of cooling.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Effects of antihypertensive drugs on intracranial hypertension.

The effects of antihypertensive drugs, such as nifedipine, chlorpromazine, reserpine and thiopental on mean arterial blood pressure (ABP), mean intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were studied in 43 patients with systemic hypertension and intracranial hypertension due to hemorrhagic cerebrovascular diseases and other causes. These drugs are commonly used in neurosurgical practice for the treatment of systemic hypertension. Nifedipine, chlorpromazine and reserpine reduced the mean ABP, raised the mean ICP and decreased the CPP. The effects of these drugs on mean ICP and CPP were more pronounced in patients with severely increased ICP (more than 40 mmHg) than in patients with moderately increased ICP (20-40 mmHg). Thiopental reduced both mean ABP and ICP, whereas the CPP was unchanged from the preadministration level. During thiopental administration, however, respiratory depression was observed, and hence, intubation and ventilation were required. We suggest that, in the treatment of systemic hypertension in patients with increased ICP, barbiturates are more desirable than agents with calcium channel or alpha-adrenergic blocking actions, despite the problem of respiratory control.

Adult↗
PubMed1991

Effect of cyclosporine on the development of cerebral vasospasm in a primate model.

The authors studied the effect of the immunosuppressive drug cyclosporine (CS) on the development of cerebral vasospasm after subarachnoid hemorrhage (SAH) using a primate model of vasospasm. Eighteen monkeys were randomly divided into three groups: a sham-operated control group, an SAH group, and a CS-treated group. To induce SAH, the right side of the circle of Willis was dissected free of the arachnoid and an autologous blood clot was placed around the arteries. In the CS group, CS (5 mg/kg/day) was administered intramuscularly for 7 days after the induction of SAH. The vessel caliber was evaluated on angiograms before the induction of SAH (Day 0) and 7 days after SAH (Day 7). Histological changes and the deposition of IgG in the arterial wall were studied in the three groups. The combined values of the average reduction of the right cerebral arteries at Day 7 was significant (P less than 0.05) in the SAH group (-43.3%) and in the CS group (-31.3%) as compared with the Sham group (-0.7%); however, there was no significant difference between the values in the SAH and the CS groups. In the CS group, the average reduction in vessel caliber of the right middle and anterior cerebral arteries was significantly (P less than 0.05) less than in the SAH group; this did not prove true for the internal carotid artery, however. Although the deposition of IgG in the media and an inflammatory reaction were observed in the spastic arterial wall in both the SAH and CS groups, there was no definitive difference in these immune/inflammatory reactions between the two groups. It is suggested that CS may be helpful in reducing the severity of vasospasm, but may not have a major therapeutic effect, considering its systemic toxicity.

Animals↗
PubMed1990

Blood-brain barrier disruption caused by impairment of cerebral autoregulation during chronic cerebral vasospasm in primates.

Impairment of the cerebral autoregulation and its effects on the development of brain oedema during chronic cerebral vasospasm after subarachnoid haemorrhage (SAH) were studied in primates. The unilateral induction of SAH by clot placement around cerebral arteries produced a moderate degree of vasospasm (more than 40% reduction of vessel caliber on angiogram) seven days after SAH. Abolishment of autoregulation was observed in the territories of the cerebral hemisphere supplied by the vasospastic arteries. It was found that in this region an increase in cerebral perfusion pressure easily produced a marked elevation of the cerebral blood flow over the upper limit of autoregulation threshold resulting in disruption of the blood-brain barrier.

Animals↗