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Toshisuke Sakaki

Publications and source records attributed to Toshisuke Sakaki.

At least 37 records · Page 2Linked to original sources
PubMed2005

Effects of nitrous oxide on spike activity on electrocorticogram under sevoflurane anesthesia in epileptic patients.

We sought to investigate the effects of nitrous oxide on intraoperative electrocorticogram (ECoG) spike activities in 11 patients with intractable epilepsy. Grid electrodes were placed on the brain surface, and ECoG was recorded under the following conditions: 1.5 minimal alveolar anesthetic concentration (MAC) sevoflurane without nitrous oxide and 1.5 MAC sevoflurane with 50% nitrous oxide. The number of spikes for 5 minutes and the percentage of leads with spikes of total leads measured were assessed in each condition. The median numbers (25-75th) of spikes without and with nitrous oxide were 127 (87-368) and 61 (43-247), respectively. The numbers of spikes with nitrous oxide were significantly lower than those without nitrous oxide (P<0.05). The median percentages of leads with spikes without and with nitrous oxide were 68 (25-81) and 61 (28-70), respectively, and there were no significant differences in percentages of leads with spikes between the conditions. These results indicate that nitrous oxide attenuated the frequency of spikes on ECoG in epileptic patients, although it did not affect the extent of areas with spike activity.

Adult↗
PubMed2005

Secondary spinal cord hypoperfusion of circumscribed areas after injury in rats.

OBJECTIVES: The evaluation of the spatial spread of ischemia following spinal cord injury (SCI) is important for planning therapeutic strategies for secondary injury. The purpose of this study was to investigate in detail the change in regional spinal cord blood flow (rSCBF) after SCI. METHODS: Thirty-four male Wistar rats were used, for which laminectomies of the T11-13 vertebrae were performed. SCI was produced by a directed impact through a laminectomy site at the level of the Th12 using a pneumatic impact device. We measured the sequential and spatial changes of rSCBF using a laser Doppler scanning technique before and after SCI in rats not only at the injured myelomere but also at the circumferent myelomeres. SCBF mapping was carried out before and after SCI on each site. RESULTS: After SCI, the rSCBF value gradually decreased for each site for the SCI group (n=26), while it globally decreased at the epicenter. Moreover, a decrease in SCBF was observed at the caudal and rostral sites. The mean value of the %SCBF 120 minutes after SCI for each site was 63.6+/-2.3% (Th11), 74.4+/-4.5% (Th12), 75.8+/-3.2% (Th13), and was significantly lower for the rostral site compared with the caudal site (p<0.05, one-way analysis of variance). DISCUSSION: This study found that SCBF is significantly decreased not only at the injured myelomere but also at the circumferent myelomeres. Circumferentially extending ischemia after SCI is related to secondary injury after SCI. The improvement in SCBF after SCI, therefore, can be attributed to the treatment of SCI.

Analysis of Variance↗
PubMed2005

Transplantation of embryonic stem cell-derived neural stem cells for spinal cord injury in adult mice.

AIMS: To investigate the efficacy of embryonic stem cell-derived neural stem cells (NSCs) for spinal cord injury (SCI) in mice and whether a combination treatment with thyroid hormone provides a more effective ES cell-based therapy. METHODS: Nestin-positive NSCs were induced from undifferentiated mouse ES cells by a step-by-step culture and used as grafts. Thirty-six mice were subjected to an SCI at Th10 and divided into three groups of 12. Graft cells were transplanted into the injury site 10 days after injury. Group 1 mice were left under observation without receiving graft cells, while mice in Group 2 received 2 x 104 graft cells, and those in Group 3 received 2 x 104 graft cells and were treated with a continuous intraperitoneal injection of thyroxin using osmotic mini-pumps. Behavioral improvement was assessed by a scoring system throughout the experimental period until post-transplantation day (PD) 28. RESULTS: Mice in Groups 2 and 3 demonstrated an improved behavioral function, as compared to those in Group 1 after PD 14. There was no significant difference in behavioral recovery between Groups 2 and 3. CONCLUSIONS: Transplantation of ES-NSCs into the injury site was effective for SCI, while thyroxine did not deliver additional effectiveness.

Animals↗
PubMed2005

The effects of sevoflurane and hyperventilation on electrocorticogram spike activity in patients with refractory epilepsy.

UNLABELLED: We investigated the effects of sevoflurane and hyperventilation on intraoperative electrocorticogram (ECoG) spike activity in 13 patients with intractable epilepsy. Grid electrodes were placed on the brain surface and ECoG was recorded under the following conditions: 1) 0.5 minimal alveolar anesthetic concentration (MAC) sevoflurane, 2) 1.5 MAC sevoflurane, and 3) 1.5 MAC sevoflurane with hyperventilation. The number of spikes per 5 min and the percentage of leads with spikes were assessed in each condition. In 4 patients with chronically implanted-subdural electrodes, the leads with seizure onset and with spikes during the interictal periods in the awake state were compared with those during sevoflurane anesthesia at 0.5 MAC and 1.5 MAC. The number of spikes and the percentage of leads with spikes were significantly more under 1.5 MAC sevoflurane anesthesia compared with those under 0.5 MAC sevoflurane (P < 0.05). The induction of hyperventilation significantly increased the number of spikes and percentage of leads with spikes (P < 0.05). With 0.5 MAC sevoflurane, the leads with spikes were similar to those at seizure onset in the awake state, whereas with 1.5 MAC sevoflurane, spikes were similar to those occurring during interictal periods in the awake state. These results indicate that sevoflurane and hyperventilation can affect the frequency and extent of ECoG spike activity in patients with intractable epilepsy. Careful attention should be paid to the concentration of sevoflurane used and ventilatory status when intraoperative EcoG is used to localize epileptic lesions. IMPLICATIONS: Electrocorticogram can be used to define the location and extent of epileptic foci during epilepsy surgery. However, electrocorticogram can be affected by anesthetic technique. The present study found that sevoflurane concentration and hyperventilation affected the frequency and the extent of electrocorticogram spike activity in epileptic patients.

Adult↗
PubMed2005

Postoperative hyperperfusion associated with steal phenomenon caused by a small arteriovenous malformation.

A 41-year-old woman presented with a small occipital arteriovenous malformation (AVM) manifesting as headache. Cerebral angiography showed an AVM in the right occipital lobe fed by the right temporooccipital artery and draining into the superior sagittal sinus and right transverse sinus. Single photon emission computed tomography showed the steal phenomenon in the ipsilateral temporal cortex fed by the main feeding artery preoperatively, and hyperperfusion in the same cortex after removal of the AVM. Postoperative systolic blood pressure was maintained between 100 and 120 mmHg to avoid disastrous hemorrhagic complications. Cerebral blood flow evaluation before and after surgery is important to avoid postoperative disastrous complications even in patients with small AVM.

Adult↗
PubMed2005

New device for endoscopic image display during microsurgical clipping of cerebral aneurysms--technical note--.

Endoscopy in microsurgery is most effective when a single surgeon can monitor both endoscopic and microscopic images simultaneously. However, monitoring systems of this kind, such as a contemporary microscope equipped with a picture-in-mode function, are expensive. The present display system is connected to the endoscope video camera and mounted on the surgeon's head. The liquid crystal display is positioned just under the microscope eyepieces, so reducing the need for the surgeon to refocus and redirect the gaze during surgery. This system allows nearly simultaneous endoscopic and microscopic monitoring. No changes to the surgical microscope are necessary.

Angioscopy↗
PubMed2005

[Putaminal hemorrhage in a case of Turner's syndrome with hyperaldosteronemia].

A case of Turner's syndrome complicated with intracerebral hemorrhage in a 21-year-old female is presented. The patient experienced acute onset of unconsciousness and the left-sided hemiparesis due to the right-sided putaminal hemorrhage. Severe hypertension was seen at the hospitalization. Cerebral angiography revealed no vascular lesion other than the displacement of lenticulostriate arteries. Emergent surgical evacuation of the hematoma was successfully performed with her favorable outcome. Postoperatively, several hormonal tests indicated hyperaldosteronemia secondary to the increased levels of ACTH and renin as a result of hyper-response to the environmental stress, leading to critical hypertension. Other examinations including CT scan, MRI, MRA, and laboratory data showed no abnormalities suggestive of renal lesions. It is supposed that hypertension, as a frequent presenting feature, should be strictly controlled in Turner's syndrome from the first time of diagnosis.

Adult↗
PubMed2005

Diffusion tensor imaging in cases with visual field defect after anterior temporal lobectomy.

BACKGROUND AND PURPOSE: Visual defect due to optic radiation injury is a complication of temporal lobectomy for temporal epilepsy. To investigate whether diffusion tensor imaging can delineate the changes in optic radiations after lobectomy, we evaluated parameters on tensor images for optic radiations and correlated them with visual defect. METHODS: We examined 14 cases after temporal lobectomy. Durations after surgeries ranged from 3 weeks to 9 years. The cases were classified into three groups on the basis of the severity of visual field defect (A-C, with group C the most severe). We evaluated signals on T2-weighted images and parameters of tensor images, including fractional anisotropy (FA) and apparent diffusion coefficient (ADC), for the optic radiation in both the operated and intact side. RESULTS: On T2-weighted images, high signals in optic radiations were seen in four cases, occurring more than 4 weeks after surgery. The mean operated-to-intact side FA ratio in the optic radiation decreased according to severity of visual defect (group A, 0.88; group B, 0.89; group C, 0.73). The mean operated-to-intact side ADC ratio showed no significant difference in the overall cases. The ratio for ADC, however, tended to increase according to visual defect in cases after 10 weeks postsurgery. CONCLUSION: Optic radiation showed a decreased FA value in cases after temporal lobectomy. In later stages, ADC values tended to increase and high signal intensities on T2-weighted images were observed. The FA value can be used for evaluating Wallerian degeneration of optic radiation even in the early stages after surgery.

Adult↗
PubMed2005

[A case of systemic Lupus erythematosus complicated with multiple subcortical hemorrhage].

We described a case of systemic lupus erythematosus (SLE) complicated with multiple intracerebral hemorrhage. A 52-year-old female with no history of hypertension had been treated with steroid hormone therapy for more than 15 years. Four days before admission, she experienced acute onset of headache and nausea. On the day of admission, the patient suffered from headache and nausea again followed by a deteriorated level of consciousness. The computed tomographic scan revealed two subcortical hematomas in the right frontal and left temporo-occipital area with atypical findings compared to those of the usual intracerebral hemorrhage. Cerebral angiography demonstrated that cortical arteries around the hematomas were markedly stretched and displaced. Multiple segmental stenosis and irregular lumen of the internal carotid artery and bilateral cortical arteries were possibly representative of vasculopathy. Transit time of blood flow was severely delayed with no apparent obstruction of the cerebral arteries, veins and dural sinuses. These findings suggested the existence of severely increased intracranial pressure. Emergent surgical evacuation of the hematomas was successfully performed with a favorable outcome for the patient. Intraoperatively, the brain was congested even after the evacuation of the hematomas. Surgical manipulation was able easily to cause bleeding from the cavity of the hematomas, which was hard to control. It is supposed that vasculopathy including fibrinoid degeneration and vasculitis may have affected the susceptibility of small arteries and veins to rupture in the present case. Subsequent increase of intracranial pressure might cause another hematomas by adding of hemodynamic stress to small vessels apart from those at the site of the first hemorrhage.

Cerebral Angiography↗
PubMed2005

[A case of intracranial neurinoma arising from the maxillary branch of the trigeminal nerve].

The intracranial portion of the trigeminal branches is rarely involved in neurinomas. The clinical characteristics including symptoms, neuroradiological findings and results of surgical excision of the previously reported 11 neurinomas and the present case arising from the intracranial trigeminal branches are reviewed. A 59-year-old female patient complained of paresthesia and hypesthesia in the infraorbital region with no other neurological abnormalities. Neuroradiological examinations revealed a round cyst-like tumor located at the middle fossa with enlargement of the foramen rotundum and pterygopalatine fossa. No vascular abnormalities were found by angiography. At surgery, the solid tumor with no cystic component arising from the intracranial maxillary nerve was removed totally via a frontotemporal extradural and interdural approach with zygomatic osteotomy. Histopathology revealed a typical neurinoma. The paresthesia disappeared following surgery. Clinical features of neurinomas arising from the trigeminal branches are varied but distinct depending upon the site of origin of the tumors. These tumors can be removed totally in most cases through the extradural and interdural approach without critical morbidity. Special care should be taken not to cause injuries to the surrounding neurovascular structures such as cranial nerves and internal carotid artery. A small amount of residue is acceptable in cases of tumors with tenacious adhesion to these critical structures.

Cranial Nerve Neoplasms↗
PubMed2005

[Clinical study of cervical myeloradiculopathy with carpal tunnel syndrome, double crush syndrome].

The hypothesis, "double crush syndrome (DCS)", is that neural function could be impaired when single axons, having been compressed in one region, become especially susceptible to damage in another. We retrospectively review our surgical cases with both cervical lesion and carpal tunnel syndrome, i.e., DCS. From January 2001 to January 2005, we have treated 7 patients (Male-4, Female-3, average age-59.9 years old) under the diagnosis of DCS. Cervical lesions were cervical spondylosis in 4 and cervical narrow canal in 3 patients. Peripheral entrapment neuropathy was carpal tunnel syndrome in all 7 cases. Initial operation was performed for cervical lesion in 2, carpal tunnel syndrome in 2, and 3 cases were operated simultaneously. The improvement rate by Neurosurgical Cervical Spine Scale (NCSS) was average 65.8%. The average follow-up period was 18.2 months. Good results can be obtained in 5 cases, and poor results in 2 cases who underwent initial operation under the diagnosis of single lesion. It is well known that a discrepancy between neurological manifestation and neuro-imaging sometimes occurs in cervical lesions, and then DCS should be considered as a possible pathogenetic mechanism.

Adult↗
PubMed2005

[A case of acute cervical epidural abscess].

Spinal epidural abscess (SEA) is a rare condition with potentially devastating consequences and more aggressive diseases than previously recognized. We report a case with cervical epidural abscess treated successfully by emergent neural decompression. A 49-year-old man presented with fever and cervical pain. An magnetic resonance imaging (MRI) showed an epidural abscess at C5-6. His condition deteriorated with the development of complete sensory loss and tetraparesis. Emergent anterior neural decompression was performed, and pus was aspirated which grew Staphylococcus aureus. Adequate antibiotics were administered, and the patient showed remarkable improvement of neurological signs and symptoms. He underwent reconstruction surgery 3 weeks after the first operation, and returned to his original job 3 months after the operation. Prompt diagnosis and satisfactory surgical decompression are essential to avoid irreversible neurological sequelae in epidural abscess of the cervical spine.

Acute Disease↗
PubMed2005

[Case report of spontaneous cervical epidural hematoma in elderly].

Spontaneous spinal epidural hematomas (SSEH) are relatively rare clinical entities and associated with coagulopathies, tumors, or vascular malformation. In addition, these are often neurosurgical emergencies; therefore, prompt diagnosis and treatment are paramount. We reported a case of an 87-year-old woman with spontaneous cervical epidural hematoma. She presented with the sudden onset of neck pain, rt. upper arm sensory disturbance and rt. hemiparesis. MRI revealed a C3-Th1 dorsally placed extradural lesion. The lesion was iso-to hypointense on T1-weighted images and was hyperintense on T2-weighted images. She underwent surgery within 9 hours after symptom onset, removal of hematoma through the right hemilaminectomy was performed. She was a very high age, but she was discharged from the hospital without neurological deficit. To obtain good prognosis for patients with SSEH, early diagnosis and treatment are important. We also review the current literature concerning diagnosis and treatment of SSEH.

Aged, 80 and over↗
PubMed2004

A 4-year-old girl with autosomal dominant polycystic kidney disease complicated by a ruptured intracranial aneurysm.

UNLABELLED: In patients with autosomal dominant polycystic kidney disease (ADPKD), intracranial aneurysms (ICAs) are extrarenal manifestations and may result in serious and potentially fatal outcome following rupture. Although ICAs are a well-known complication of ADPKD, nearly all cases of ICA occurring in the context of ADPKD are adults. Here, we report the case of a Japanese girl with ADPKD who developed a subarachnoid haemorrhage (SAH) due to a ruptured ICA at the age of 4 years. CONCLUSION: This report is intended to raise awareness that the use of noninvasive screening techniques such as three-dimensional CT angiography or magnetic resonance angiography to detect intracranial aneurysms should also be performed in paediatric patients with autosomal dominant polycystic kidney disease.

Aneurysm, Ruptured↗
PubMed2004

Jugular bulb oxygen saturation under propofol or sevoflurane/nitrous oxide anesthesia during deliberate mild hypothermia in neurosurgical patients.

Sevoflurane and propofol have been widely used as anesthetic agents for neurosurgery. Recent evidence has suggested that the influence of these anesthetics on cerebral oxygenation may differ. In the present study, the authors investigated jugular bulb oxygen saturation (SjO2) during propofol and sevoflurane/nitrous oxide anesthesia under mildly hypothermic conditions. After institutional approval and informed consent, 20 patients undergoing elective craniotomy were studied. Patients were randomly divided to the group S/N2O (sevoflurane/nitrous oxide/fentanyl anesthesia) or the group P (propofol/fentanyl anesthesia). After induction of anesthesia, the catheter was inserted retrograde into the jugular bulb and SjO2 was analyzed. During the operation, patients were cooled and tympanic membrane temperature was maintained at 34.5 degrees C. SjO2 was measured at normocapnia during mild hypothermia and at hypocapnia during mild hypothermia. There were no statistically significant differences in demographic variables between the groups. During mild hypothermia, SjO2 values were significantly lower in group P than in group S/N2O. The incidence of SjO2 less than 50% under mild hypothermic-hypocapnic conditions was significantly higher in group P than in group S/N2O. These results suggest that hyperventilation should be more cautiously applied during mild hypothermia in patients anesthetized with propofol and fentanyl versus sevoflurane/nitrous oxide/fentanyl.

Analysis of Variance↗
PubMed2004

Intraventricular transplantation of embryonic stem cell-derived neural stem cells in intracerebral hemorrhage rats.

In the present study, we attempted to explore cell transplantation therapy for intracerebral hemorrhage (ICH) using embryonic stem (ES) cells. Collagenase-induced ICH rats were used as model animals. Mouse ES cells were differentiated into nestin-positive neural stem cells in vitro by alltrans retinoic acid (ATRA). ATRA-treated ES cells (10(5)) were transplanted into the lateral ventricle in the hemisphere contralateral to the hemorrhage 7 days after collagenase infusion. Twenty-eight days after transplantation, ES-derived neurons and astrocytes were observed around the hematoma cavities of the brain in all of the ten rats receiving grafts. Graft-derived neurons were found in the subependymal area of the lateral ventricle as cellular nodules. Although one of the ten rats receiving grafts showed uncontrolled growth of astroglia derived from the ES cells, intraventricular transplantation of ATRA-treated ES cells is an effective delivery system of neuronal lineage-committed progenitor cells toward the site of ICH.

Animals↗
PubMed2004

Retinotopy with coordinates of lateral occipital cortex in humans.

OBJECT: The lateral occipital cortex in humans is known as the "extrastriate visual cortex." It is, however, an unexplored field of research, and the anatomical nomenclature for its surface has still not been standardized. This study was designed to investigate whether the lateral occipital cortex in humans has retinotopic representation. METHODS: Four right-handed patients with a diagnosis of intractable epilepsy from space-occupying lesions in the occipital lobe or epilepsy originating in the occipital lobe received permanently implanted subdural electrodes. Electrical cortical stimulation was applied directly applied to the brain through metal electrodes by using a biphasic stimulator. The location of each electrode was measured on a lateral skull x-ray study. Each patient considered a whiteboard with vertical and horizontal median lines. The patient was asked to look at the midpoint on the whiteboard. If a visual hallucination or illusion occurred, the patient recorded its outline, shape, color, location, and motion on white paper one tenth the size of, and with vertical and horizontal median lines similar to those on, the whiteboard. Polar angles and eccentricities of the midpoints of the phosphenes from the coordinate origin were measured on the paper. On stimulation of the lateral occipital lobe, 44 phosphenes occurred. All phosphenes were circular or dotted, with a diameter of approximately 1 cm, except one that was like a curtain in the peripheral end of the upper and lower visual fields on stimulation of the parietooccipital region. All phosphenes appeared in the visual field contralateral to the cerebral hemisphere stimulated. On stimulation of the lateral occipital lobe, 22 phosphenes moved centrifugally or toward a horizontal line. From three-dimensional scatterplots and contour maps of the polar angles and eccentricities in relation to the x-ray coordinates of the electrodes, one can infer that the lateral occipital cortex in humans has retinotopic representation. CONCLUSIONS: The authors found that phosphenes induced by electrical cortical stimulation of the lateral occipital cortex represent retinotopy. From these results one can assert that visual field representation with retinotopic relation exists in the extrastriate visual cortex.

Adult↗