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Biomedical subjects

K Koshu

Publications and source records attributed to K Koshu.

At least 37 records · Page 2Linked to original sources
PubMed1994

Acute cervical spinal epidural hematoma with spontaneous resolution--case report.

A 54-year-old male presented with spontaneous acute epidural hematoma in the ventral cervical spine. The neurological deficits gradually improved spontaneously before surgery commenced. Serial magnetic resonance imaging demonstrated disappearance of the hematoma. He was managed conservatively and was discharged without deficits about 1 month after onset. Immediate surgical decompression may not be necessary if neuroimaging and clinical examinations suggest that spinal epidural hematoma will resolve spontaneously.

Acute Disease↗
PubMed1994

Posterolateral extradural approach for lateral thoracic meningocele--case report.

A 26-year-old female presented with a lateral thoracic meningocele associated with neurofibromatosis. The development of the thoracic meningocele was documented on serial chest roentgenograms. Magnetic resonance imaging and three-dimensional bone computed tomography scans were particularly useful to identify organic changes in the surrounding structures and the osseous orifice of the dural sac, respectively. The large thoracic meningocele was successfully treated through the posterolateral extradural approach in combination with resection of the adjacent ribs and cerebrospinal fluid drainage from the dural sac.

Adult↗
PubMed1993

Quadraparesis after a shunting procedure in a case of cervical spinal neurinoma associated with hydrocephalus: case report.

The authors report a rare case of cervical spinal neurinoma in a patient who presented with symptoms originating from hydrocephalus. Her symptoms improved after a ventriculoperitoneal shunt was inserted, although progressive quadraparesis appeared when she began to walk. Magnetic resonance imaging revealed a cervical tumor. When it was removed, the patient's quadraparesis improved. Associated spinal tumors should be considered in the treatment of hydrocephalus of unknown origin.

Cerebrospinal Fluid Shunts↗
PubMed1993

Combined endovascular and neurosurgical approach for paraclinoid internal carotid artery aneurysms.

The authors review the surgical management of nine complex paraclinoid aneurysms treated with the endovascular balloon catheter technique. With the patient under general anesthesia, the balloon catheter was guided into the feeding artery of the aneurysm by the Seldinger technique. After the aneurysm was exposed, the balloon was inflated temporarily to prevent premature rupture and to facilitate the dissection of the aneurysm. For the larger paraclinoid aneurysm, the double-lumen catheter was introduced into the cervical internal carotid artery (ICA). After temporarily trapping the aneurysm by balloon occlusion of the cervical ICA and clipping the intracranial ICA distal to the aneurysm, retrograde aspiration was performed to collapse the aneurysm. The complete collapse of the large aneurysm by this technique allows an easier dissection of the aneurysm and a safer application of suitable clips. Such a retrograde suction decompression method was used in six large aneurysms. Intraoperative digital subtraction angiography was performed in all cases after the aneurysmal clipping; in three aneurysms, repositioning the clip was required. Only one case of embolic complication was related to the vessel catheterization in this series, which was discovered during the operation. An embolectomy was performed immediately, and there were no postoperative sequelae. We conclude that the combined endovascular and neurosurgical approach, particularly for the large ICA aneurysms, which are difficult to control proximally, can be a useful method of treatment. To prevent complications related to thrombus formation, further refinement in the balloon catheter itself is still needed.

Adult↗
PubMed1993

Prospective study on the prevention of cerebral vasospasm by intrathecal fibrinolytic therapy with tissue-type plasminogen activator.

The authors have evaluated the efficacy of postoperative intrathecal injections of tissue-type plasminogen activator (tPA) in preventing cerebral vasospasm in patients with a diffuse thick subarachnoid hemorrhage (SAH). The present study examined 105 patients who underwent direct surgery within 48 hours of SAH and whose computerized tomography (CT) findings were classified as Fisher CT Group 3. Patients showing diffuse thick subarachnoid blood clots on CT with greater than 75 Hounsfield units (HU) were included in the tPA therapy group and those with below 75 HU comprised the control group. The surgical method was the same in both groups, and both groups had cisternal drainage instituted. On the day following the operation, the tPA group was given an intrathecal injection of tPA (2 mg), and this was continued for several days until all of the cisterns exhibited low density on CT scans. Follow-up angiography showed that 26 cases (87%) in the tPA group had no vasospasm, three (10%) had moderate vasospasm, and one (3%) had severe vasospasm. All four patients showing spasm on angiography were asymptomatic, and there were no cases of delayed ischemic neurological deficits (DIND). In contrast, there were 11 cases (15%) with DIND in the control group. In the tPA group, there was one case of SAH caused by drainage catheter removal, one with a small epidural hematoma, and one with subgaleal fluid accumulation; all of these were treated conservatively with favorable results. Overall, there were no infectious complications related to cisternal drainage and intrathecal injection of tPA. These results indicate that multiple intrathecal injections of small doses of tPA are effective and safe in preventing vasospasm. On the basis of this experience, the authors conclude that injection of 2 mg of tPA daily for 5 days (a total of 10 mg) is effective in preventing the development of vasospasm.

Adult↗
PubMed1991

Prevention of vasospasm by clot removal and intrathecal bolus injection of tissue-type plasminogen activator: preliminary report.

In this study, we evaluated the efficacy of postoperative intrathecal injections of tissue-type plasminogen activator (tPA) in preventing cerebral vasospasm in cases with a diffuse severe subarachnoid hemorrhage. All 10 cases were graded Group 3 according to the classification of Fisher and associates, and the CT number (Hounsfield number) of the subarachnoid clot was over 75. After clipping the aneurysm and removing the clot, three cisternal drainage catheters were inserted into both sylvian cisterns and the prepontine cistern, and continuous ventricular drainage was performed routinely. Postoperatively, tPA (0.5 mg/2.5 ml) was infused as a bolus into both basal cisterns and the lateral ventricle twice daily for about 6 days. Angiography and cerebral blood flow studies using single photon emission computed tomography were performed on Day 4 or 5 and between Days 7 and 10 after onset of the hemorrhage. To date, there have been no cases that have shown angiographic vasospasm or delayed ischemic neurological deficits. This preliminary study indicates that the intrathecal bolus injection of tPA produces a marked effect on vasospasm.

Adult↗
PubMed1991

Transoral decompression evaluated by cine-mode magnetic resonance imaging: a case of basilar impression accompanied by Chiari malformation.

Cine-mode magnetic resonance imaging provides simultaneous images of cerebrospinal fluid flow dynamics. A patient with a basilar impression accompanied by a Chiari malformation and von Recklinghausen's disease who underwent transoral decompression is reported. Preoperative cine-mode magnetic resonance imaging visualized an associated obstruction of cerebrospinal fluid pulsatile flow at the level of the foramen magnum. Tonsilar herniation (Chiari I malformation) and hydrocephalus were also present. Postoperatively, the obstruction of cerebrospinal fluid flow was resolved concomitant with the correction of the cervicomedullary angulation. On the basis of observations made by magnetic resonance imaging, the surgical treatment of basilar impression accompanied by Chiari malformation is briefly discussed.

Adult↗
PubMed1989

[A new thermal diffusion flow probe for continuous monitoring of cerebral blood flow in small animals].

The Peltier stack, which allows quantitative measurement of cerebral blood flow (CBF) by means of thermal diffusion, has a probe too large for use in small animals. However, it is difficult to measure CBF by a thermal diffusion method involving the use of a constantan heating wire, because of heat conduction between the two gold plates. The authors developed a new thermal diffusion flow probe, using a constantan wire as a heat source rather than the Peltier stack. With the new probe, separation of the gold plates and attachment of a pair of long thermocouples minimize heat conduction between the two plates. Moreover, the probe itself is considerably smaller than that of the Peltier stack. The new probe was inserted to the subdural space of rabbits and the voltage (V; mV) was measured with an amplifier by the circuit of constant current method. CBF (F; ml/100 g/min) was measured simultaneously by the hydrogen clearance method in the adjacent cortex. A regression equation of F = 29, 111 (1/V-1/226) was obtained between 35 pairs of F and V (r = 0.92, p less than 0.001), which verified that CBF can be accurately measured with the new probe.

Animals↗
PubMed1989

Anterior communicating artery aneurysm associated with bilateral occlusion of the middle cerebral artery--case report.

A female who had had no previous cerebrovascular events suffered a subarachnoid hemorrhage and was referred to our hospital. Angiography revealed an anterior communicating artery aneurysm and bilateral occlusion of the middle cerebral artery at its origin. She exhibited mild ischemic symptoms after clipping of the aneurysm, possibly as a consequence of disturbance of the collateral blood flow during surgery. This is the third such case reported in the literature.

Adult↗
PubMed1988

Evaluation of dead cases of ruptured intracranial aneurysms with special reference to a comparison between patients with early operations and unoperated cases.

The authors have analysed dead cases of ruptured intracranial aneurysms. This analysis included 270 patients with ruptured intracranial aneurysms, admitted to Mito National Hospital over an 8 yr period. Of the 98 patients who had surgery within 48 h after SAH, 17 cases died (mortality rate 17.3%); 7 deaths were due to massive haemorrhage, 5 due to vasospasm and 5 to other causes. Analysis of the causes of death in the non-surgical group (62 cases) disclosed that massive haemorrhage was the most common (29 cases), followed by rerupture after admission (14 cases), vasospasm (7 cases) and miscellaneous cases (5 cases). The possibility of improving the mortality rate in the early surgical group and the non-surgical group is discussed.

Adult↗
PubMed1988

[Subacute subdural hematoma associated with moyamoya phenomenon--a case report].

A case of subacute subdural hematoma associated with moyamoya phenomenon is reported. On May 8, 1986, a 61-year-old female was referred to Mito National Hospital for evaluation of a left-sided hemiparesis and headache 8 days after minor head injury. Seventeen years ago she experienced the sudden onset of a left-sided hemiparesis which improved by rehabilitation. CT scans showed a thin high density area on the right cerebral convexity and a small low density area in the right semiovale center. On May 12, she was admitted because of aggravation of her symptoms. A repeat CT scan showed an enlarged right temporoparietal subdural hematoma with significant mass effect. Cerebral angiograms revealed the occlusion of right internal carotid artery. There were so-called moyamoya vessels bilaterally and transdural anastomosis on the right side. Avascular area confirmed subdural hematoma. The hematoma was evacuated via two burr holes with preservation of the middle meningeal and superficial temporal arteries. By the time of discharge two months postoperatively, she was walking well without assistance. We reviewed four cases of acute or subacute subdural hematoma associated with moyamoya phenomenon and emphasized the possibility of occurrence of acute or subacute subdural hematoma due to rupture of vault moyamoya vessels.

Arterial Occlusive Diseases↗
PubMed1987

Continuous recording of cerebral blood flow by means of a thermal diffusion method using a Peltier stack.

The thermal diffusion method is known to be effective for making quantitative measurements of blood flow, but cannot be easily applied to problems concerning quantitative changes in blood flow. Carter et al. found that the thermal diffusion technique using a Peltier stack as the probe produced extremely stable recordings and was suitable for quantitative work. We made a more stable probe containing an air space and having a stainless cap that added weight. A stable recording of blood flow was then possible. For calibration of the probe, we used blood flow values measured by means of an electrolytic technique and the equation proposed by Carter et al. In the present study, we have shown that it is theoretically possible to perform the calibration even without obtaining data on blood flow after cardiac arrest. Experimentally, the validity of such calibration was confirmed. This technique for measuring blood flow should be applicable in various fields and its use in a clinical setting, particularly in the monitoring of blood flow during neurosurgical operations, can be expected.

Animals↗
PubMed1985

[Neurofibromatosis associated with intra- and extracranial aneurysms and extracranial vertebral arteriovenous fistula].

Neurofibromatosis associated with vascular disorders is generally known as a vascular neurofibromatosis. In the neurosurgical aspect, it has been pointed out that "moyamoya disease" -like stenosis and/or occlusion of the internal carotid artery are seen in some of the patients with neurofibromatosis. This 58-year-old female with multiple café-au-lait spots and neurofibromas all over the body was admitted to our hospital with complaints of left orbital tumor and tinnitus. She had been suffering from the left intraorbital neurofibroma since ten years of age. Radiological examinations revealed left intraorbital neurofibroma extending into the intracranial cavity, multiple aneurysms and arteriovenous fistula. The aneurysms were located at the left vertebral-posterior interior cerebellar artery junction and at the extracranial internal carotid artery. The arterio-venous fistula was demonstrated at the left extracranial vertebral artery. Pathological changes of the blood vessels in the vascular neurofibromatosis are essentially obstructive lesions due to intimal thickening. Only few cases of neurofibromatosis associated with aneurysms and arteriovenous fistula have been reported, and eleven cases of them could be reviewed in the literature. Six are with intracranial aneurysms, two with extracranial aneurysms and three with extracranial vertebral arteriovenous fistula,. It is interesting that in all cases the extracranial vertebral arteriovenous fistula are located on the left side. This is corresponding to the fact that the bone defect around the asterion is predominantly seen on the left side in cases of neurofibromatosis.

Arteriovenous Malformations↗
PubMed1984

[Unilateral visual field defect due to optic nerve compression by non-sclerotic internal carotid and ophthalmic arteries. A case report].

A case of unilateral visual field defect due to optic nerve compression by non-sclerotic internal carotid and ophthalmic arteries was reported. A 14-year-old boy was admitted to our department because of constricted visual field of the right eye. The right ophthalmic artery originated from more distal portion of the internal carotid artery than usual on angiogram. CT, PEG and other roentgenologic examinations revealed no abnormalities. But the possibility of para-sellar tumor still remained, so the right optic nerve was explored by a right frontotemporal approach. The optic nerve was found to be compressed not by any sort of mass lesion but by the non-sclerotic internal carotid and ophthalmic arteries against the rim of the optic canal. Then a microsurgical unroofing of the optic canal was performed to relieve the nerve from the compression. The decompressed upper surface of the nerve was found to be discolored yellow-white. Unfortunately, no improvement in the visual field was obtained after operation. Visual field defect due to vascular compression of the optic nerve has been discussed in only several reports. There have been only 8 cases of surgically treated unilateral visual field defect due to vascular compression. Most of them were the results of compression by the sclerotic or fusiformly enlarged internal carotid arteries and were found in the patients of middle age. Four cases presented with lower half visual field defects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗