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Kiyoyuki Yanaka

Publications and source records attributed to Kiyoyuki Yanaka.

At least 19 recordsLinked to original sources
PubMed2006

Subarachnoid hemorrhage not due to ruptured aneurysm in moyamoya disease.

A patient with moyamoya disease presenting with subarachnoid hemorrhage (SAH) is reported. A 38-year-old Japanese woman developed a sudden onset headache and nausea during hospitalization for a cerebral infarct in the right frontal lobe. CT scan showed SAH in the left frontal sulci. Cerebral angiogram showed stenosis of the distal bilateral internal carotid arteries with moyamoya vessels, and significant transdural anastamoses from the left external carotid artery to cortical arteries on the left frontal cortex. The patient was kept normotensive and underwent a right-sided surgical revascularization procedure, remaining well for three years. SAH not due to ruptured aneurysm in moyamoya disease is rare. The cause of the SAH was thought to be disruption of the transdural anastomotic vessels. Recognition of these fragile vessels in moyamoya disease is essential.

Adult↗
PubMed2006

Predictors of angiographic changes in neck remnants of ruptured cerebral aneurysms treated with Guglielmi detachable coils.

The angiographic changes in neck remnants of ruptured cerebral aneurysms treated with Guglielmi detachable coils (GDCs) were evaluated in the acute stage to analyze the important radiological and clinical factors. The clinical and radiological data of 37 patients with a residual neck of a ruptured cerebral aneurysm treated with GDC were reviewed. The angiographic changes on follow-up angiography were classified into three groups: recanalization of the neck remnant, progressive thrombosis, and unchanged. The effects of the clinical and angiographic findings, such as patient age, follow-up period, type of aneurysm (terminal type or side wall type), dome diameter, neck size, dome/neck ratio, obliteration rate, and volume embolization ratio were investigated. Recanalization of the neck remnant was observed in 18 of 37 cases, progressive thrombosis in nine, and unchanged in 10. The type of aneurysm, dome diameter, neck size, and volume embolization ratio were correlated with changes in the neck remnant. The aneurysm dome diameter and type of aneurysm were independent predictive factors for the recanalization of neck remnants on follow-up angiography. Dome diameter of less than 4.5 mm and volume embolization ratio of more than 31% in side wall aneurysms were likely to lead to progressive thrombosis.

Adult↗
PubMed2006

Dynamic computed tomography myelography for the investigation of cervical degenerative disease.

Dynamic computed tomography (CT) myelography was conducted in 15 patients with cervical degenerative disease to assess the lesions responsible for their symptoms. CT myelography was performed using a multi-detector row helical CT system in dynamic positions (flexion or extension or both) in addition to the neutral position. Fine sagittal reconstructed images could be obtained in addition to axial images. This method provided static information including cervical vertebral body deformities, and good contrast images of the spinal cord, nerve roots, and cerebrospinal fluid space. In addition, laterality of the offending lesion and changes exaggerated by cervical motion were clearly shown in both axial and sagittal images. Ten of 15 patients demonstrated dynamic changes including dynamic canal stenosis or spinal cord impingement. The operative strategies were changed based on dynamic CT myelography findings in three of the 15 patients. Dynamic CT myelography can provide the axial and sagittal images required for flexion-extension studies, and in combination with conventional imaging modalities, provides valuable information for determining treatment strategies and objectives.

Adult↗
PubMed2005

Traumatic central cord syndrome: analysis of factors affecting the outcome.

BACKGROUND: The indications and timing of treatment, as well as the best treatment method for traumatic central cord syndrome (CCS), remain controversial. The aims of this study are to determine the prognostic factors of traumatic CCS and to determine appropriate surgical indications. METHODS: We reviewed the clinical and radiological data of 47 patients with this syndrome. The data collected included age, neurological status as measured on a scale defined by the Japanese Orthopaedic Association (JOA), anteroposterior (AP) diameter of the spinal canal on computed tomography, signal intensity change of the spinal cord on T2-weighted magnetic resonance imaging (MRI), associated spinal diseases, and the type of treatment received. The correspondence between the clinical and radiological findings and the neurological outcome was investigated. RESULTS: The patient's age, JOA score on admission, signal intensity change of the spinal cord on MRI, and associated spinal diseases were not significant in predicting the patient's recovery. On the other hand, the AP diameter of the spinal canal (P = .0402) and the interval between injury and surgery (P < .0001) were factors predictive of excellent recovery. In the surgical treatment group, timely surgery was found to improve the outcome, while conservative treatment did not improve the outcome of patients with a low JOA score, a relatively small AP diameter of the spinal canal, or a positive signal intensity change of the spinal cord on T2-weighted MRI. CONCLUSION: The AP canal diameter of the spinal canal and the interval between injury and surgery may be reliable predictors of excellent recovery in patients with CCS. We recommend timely surgery, preferably within 2 weeks of injury, to achieve a better functional outcome in selected patients.

Central Cord Syndrome↗
PubMed2004

Transient long segment spinal cord hyperintensity after anterior cervical discectomy.

A 69-year-old man was admitted to our hospital with progressive numbness in both feet and gait disturbance. MR imaging revealed a large cervical disc herniation resulting in significant spinal cord compression with hyperintensity of the spinal cord on T2-weighted images at C-5/6. Immediately after undergoing anterior cervical discectomy, the patient developed severe weakness of his left hand and lower extremities. MR imaging obtained 5 days after surgery revealed a long segment hyperintensity between C-3 and T-2 on T2-weighted images. This long segment hyperintensity disappeared after 2 weeks of steroid administration. We suspect that the persistent, localised, patchy C-5/6 cord hyperintensity represents spinal cord degeneration due to ischaemia and trauma resulting from the disc herniation. However, the transient long segment hyperintensity may represent oedema, probably due to minor trauma of an already compromised cord, during the decompression surgery. Clinicians should be aware that even careful surgery can result in a significant change in radiological studies and neurological condition.

Aged↗
PubMed2004

Traumatic acute subdural hygroma mimicking acute subdural hematoma.

Subdural hygroma is a frequent delayed complication of head trauma. Most hygromas are clinically 'silent' and a few cases have shown slow deterioration in the chronic stage. We report a case of subdural hygroma showing unique radiological findings and rapid deterioration. A 74-years-old female presented with a mild headache and consciousness disturbance after head injury. Computed tomography showed a midline shift as a result of two components piling up in the subdural space; the outer components showed low density, the inner components high density. Magnetic resonance imaging demonstrated that these two subdural components were subdural hygroma and subarachnoid hematoma. Simple burr hole irrigation, rather than large craniotomy, was thought to be more appropriate treatment to reduce the mass effect. Simple burr hole irrigation was performed to remove the subdural hygroma and the patient showed an excellent recovery. Careful examination of the radiological findings prevented an unnecessary procedure in this case. A possible mechanism of this phenomenon is discussed.

Acute Disease↗
PubMed2004

Management of unruptured cerebral aneurysms in patients with polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (PKD) is a hereditary disorder characterized by bilateral multiple renal cysts and early onset chronic renal failure. PKD patients tend to suffer their subarachnoid hemorrhage at a younger age. Unruptured aneurysms in PKD patients are not always innocuous, and proactive treatment has been indicated for these lesions. However, the management of PKD patients undergoing unruptured cerebral aneurysm surgery has been documented on only a few occasions. The purpose of this study was to better define the management of unruptured cerebral aneurysms in patients with PKD. METHODS: We present a retrospective review of the management of unruptured cerebral aneurysms in 16 patients with PKD. Eight patients were maintained through chronic hemodialysis whereas the remaining 8 patients did not require hemodialysis, at the time of treatment of their cerebral aneurysms. The mean follow-up period was 24 months. RESULTS: In the nonhemodialysis patients prophylactic hemodialysis was routinely performed after cerebral angiography to prevent deterioration of the pre-existing renal dysfunction. Microsurgical clipping of the aneurysm was performed in 15 patients (7 nonhemodialysis and 8 hemodialysis patients) and intravascular coil embolization was performed in 1 nonhemodialysis patient. One nonhemodialysis patient who underwent microsurgical clipping required a temporary hemodialysis after surgery, but the patient was not shifted to chronic hemodialysis. No patients developed postprocedural complications, and each showed an excellent recovery. CONCLUSION: PKD patients with unruptured cerebral aneurysms can be safely treated with an appropriate treatment strategy including the use of prophylactic hemodialysis.

Adult↗
PubMed2004

Shaken baby syndrome manifesting as chronic subdural hematoma: importance of single photon emission computed tomography for treatment indications--case report.

A boy with shaken baby syndrome first presented at age 3 months with acute subdural hematoma (SDH) and was treated by subdural tapping at a local hospital. Chronic SDH was identified at a rehabilitation center at age 19 months. The chronic SDH appeared to have developed within the preceding 16 months. His physical and mental development was already delayed. Magnetic resonance (MR) imaging revealed a 20-mm thick right chronic SDH with midline shift and small bilateral subdural effusions. The chronic SDH had compressed the right cerebral hemisphere. MR imaging also disclosed bilateral cerebral atrophy. 99mTc-ethylcysteinate dimer single photon emission computed tomography (SPECT) revealed decreased cerebral blood flow (CBF) in the non-hematoma hemisphere, although CBF is said to decrease on the chronic SDH side, especially if midline shift is present. Burr hole craniotomy with external drainage was performed, but the patient showed no change in CBF postoperatively, although the volume of hematoma decreased. The patient was clinically unchanged immediately after the operation. In this case, SPECT measurement of CBF was important in evaluating the pathophysiology of the delays in physical and mental growth. Atrophy of the bilateral hemispheres was the major mechanism in the decreased CBF, not the compression by chronic SDH. MR imaging and SPECT can determine the surgical indications for chronic SDH in patients with cortical atrophy.

Atrophy↗
PubMed2004

Subdural hematoma caused by intracranial hypotension after syringosubarachnoid shunting--case report.

A 32-year-old man developed an extremely rare subdural hematoma after syringosubarachnoid shunting for syringomyelia. He presented with a 4-year history of neck pain and spastic paraparesis resulting from T-7 and T-8 vertebral body fracture suffered in a traffic accident at age 22 years. Magnetic resonance imaging revealed syringomyelia between the craniocervical junction and the T-10 level. The symptoms were slowly progressive, and a syringosubarachnoid shunting was performed. His spasticity improved after surgery, but he developed orthostatic headache 7 days after surgery. Magnetic resonance imaging of the brain demonstrated a thin subdural hematoma over the right cerebral convexity. The subdural hematoma resolved spontaneously within a week with conservative treatment. Vigorous cerebrospinal fluid outflow observed during surgery presumably lowered the pressure in the syrinx cavity, leading to significant but transient intracranial hypotension and consequently the formation of subdural hematoma.

Adult↗
PubMed2003

Stable nitroxide Tempol ameliorates brain injury by inhibiting lipid peroxidation in a rat model of transient focal cerebral ischemia.

Oxygen free radicals have been implicated in the pathogenesis of cerebral ischemia and reperfusion injury. 4-Hydroxy-2,2,6,6-tetramethylpiperidene-1-oxyl (Tempol) has been reported as a stable nitroxide and a membrane-permeable free radical scavenger. This study was performed to investigate the mechanism of Tempol in attenuating ischemia-reperfusion injury in a rat model of transient focal cerebral ischemia. We measured the cerebral 2,3-dihydroxybenzoic acid (DHBA) level as the amount of hydroxyl radical production using a microdialysis technique with salicylic acids trapping during ischemia and reperfusion. The concentration of cerebral thiobarbituric acid reactive substances (TBARS), representing the extent of lipid peroxidation by free radicals, and the area of cerebral infarction were also measured. The level of cerebral 2,3-DHBA was increased during ischemia and reperfusion, especially during the early reperfusion stage at the periphery of the infarct area (nearly 500-fold). Intravenous administration of Tempol at the time of reperfusion reduced 2,3-DHBA production (Vehicle group: 472.2+/-196.2, Tempol group: 238.3+/-77.2) and the cerebral TBARS level (Vehicle group: 541.7+/-84.7, Tempol group: 339.0+/-147.2 nmol/g), and decreased the size of the cerebral infarction (Vehicle group: 202.2+/-98.4, Tempol group: 98.5+/-13.7 mm(3)). In contrast, Tempol administered 15 min prior to reperfusion reduced neither the TBARS level nor the size of the infarction. These results indicate that Tempol administration at the time of reperfusion reduced lipid peroxidation by scavenging free radicals, resulting in a reduction of the infarct size.

Animals↗