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ABSTRACT: In surgeries for epilepsy, electrocorticography (ECoG) enables tailored resection of the epileptogenic brain and pharmacological stimulation should be employed in surgeries under general anesthesia. To identify the efficacy of continuous remifentanil in surgeries for epilepsy, ECoG findings with remifentanil and those with sevoflurane were compared.
Sixteen patients with intractable epilepsy were included with institutional ethics committee approval and informed consent. General anesthesia was induced and maintained with sevoflurane, remifentanil and rocuronium. After dural opening, ECoG recordings were obtained before stimulation, with sevoflurane-stimulation (ET-sevoflurane 2.5%) and with remifentanil-stimulation (0.7 microg x kg(-1) x min(-1) for 2 min followed by 0.35 microg x kg(-1) x min(-1)).
In 11 of the 16 cases, activation was confirmed with remifentanil and numbers of spikes with remifentanil- and sevoflurane-stimulation were larger than those before stimulation.
There have been some reports on bolus remifentanil on ECoG but not on its continuous infusion. This is the first report of the effect of remifentanil on ECoG as compared to sevoflurane. In this study, continuous infusion of remifentanil showed a stimulating effect on ECoG with the same potency as sevoflurane. Remifentanil may be used as an alternative to sevoflurane.
Masui. The Japanese journal of anesthesiology 02/2010; 59(2):188-92.
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ABSTRACT: Integration of neuronavigation into brain tumor surgery can improve the accuracy and precision of resection, but most neuronavigation systems require rigid pin fixation of the patient's head throughout the operation. We describe use of a noninvasive skull reference tool, which can replace rigid pin fixation in awake craniotomy and pediatric surgery, when standard pin fixation cannot be used.
The skull reference tool (BrainLAB, Munich, Germany) is directly attached to the outer skull with a small self-tapping screw. Virtual scanning of the surface of the face and head achieves patient registration in seconds without requiring the use of fiducial markers or head fixation. This procedure improves patient comfort, cooperativeness, and compliance, resulting in better operating procedures. This skull reference tool is available for children younger than 3 years of age, in whom pin fixing is dangerous. Twelve patients underwent awake surgery and four pediatric patients younger than 3 years old underwent five procedures using this skull reference tool in our hospital between January 2005 and December 2008. The method of utilizing this skull reference tool was easy and sufficiently accurate in these patients.
The use of this skull reference tool provides an accurate and comfortable method of frameless navigation in patients undergoing awake craniotomy and pediatric patients.
No shinkei geka. Neurological surgery 12/2009; 37(12):1193-9. · 0.13 Impact Factor
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ABSTRACT: The negative motor area and anterior and posterior language areas were localized by intraoperative electrical cortical stimulation under the awake condition to evaluate the clinical significance of these areas. Thirty-seven awake craniotomies with language mapping were performed in 36 patients with brain tumors. The negative motor area was determined in 17 cases, and the anterior and posterior language areas were found in 12 and 6 cases, respectively. The negative motor area was located in the precentral gyrus inferior to the orofacial motor area in 16 cases, and in the inferior frontal gyrus anterior to the orofacial motor area in one case. Both the negative motor area and the anterior language area were determined in 8 cases. Anterior language areas in these 8 cases were located anterior and/or inferior to the negative motor areas. The negative motor area is an easily determined, important landmark for intraoperative language mapping.
No shinkei geka. Neurological surgery 09/2008; 36(8):693-700. · 0.13 Impact Factor
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ABSTRACT: Intensive hypotension is an important technique in neurosurgical perioperative management. However, it could decrease urine volume, and induce fluid retention resulting in cardiac failure. We evaluated the efficacy of human atrial natriuretic peptide (hANP) on diuresis in a hypotensive condition.
In 245 patients undergoing neurosurgical operations under general anesthesia in our hospital, 26 patients demonstrated a urine volume less than 50 ml/h at 1 hour after the skin incision, despite receiving a large volume of intravenous fluid. In these 26 patients, we administered hANP (0.05 microg/kg/min) continuously, and evaluated the effect of hANP on diuresis in a hypotensive condition.
After the administration of hANP, the urine volume increased significantly (p<0.01) from 28.7 to 229.4 (ml/h, mean). The heart rate increased from 66.6 to 71.7 (bpm, mean), whereas the systolic blood pressure decreased from 110.3 to 102.2 (mmHg, mean). The electrocardiogram did not change during the administration of hANP.
Despite the hypotensive condition, hANP showed a strong diuretic effect in our study. In neurosurgical perioperative management, administration of hANP can be a useful tool for a fluid balance in the patient.
No shinkei geka. Neurological surgery 09/2008; 36(8):687-92. · 0.13 Impact Factor
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ABSTRACT: Early detection of complications after craniotomies are important and remifentanil may be beneficial for that purpose because of the short and constant context-sensitive half time. To examine the efficacy of remifentanil in neuroanesthesia, we investigated hemodynamic properities and recovery from anesthsia in craniotomies.
Fifty patients undergoing scheduled neurosurgical procedures were included. Anesthesia was induced and maintained with propofol, vecuronium and fentanyl (group C, 25 cases) or remifentanil (group R, 25 cases).
There were no diffirences between the groups in age, sex distribution, procedure, duration of anesthesia, and amount of bleeding. Total dose of propofol was lower in group R (3.4+/-1.0 mg x kg(-1) x hr(-1)) than group C (4.9+/-0.8) (P<0.001). Incidence of hemodynamic changes at tracheal intubation was higher in group C (P<0.01) and bradycardia (HR<45) was more frequent in group R (P<0.001). Recovery time was shorter in group R (12.7+/-4.7 min) than that in group C (20.7+/-7.3) (P<0.001).
Remifentanil is suitable for neuroanesthesia because of the hemodynamic stability and quick recovery from anesthesia.
Masui. The Japanese journal of anesthesiology 06/2008; 57(6):704-7.
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ABSTRACT: To avoid the neurological deficits after neurosurgical procedures, awake craniotomy applying intraoperative awake functional brain mapping has been employed. Anesthesia for awake craniotomy requires particular attention to airway management, control of seizures and measures for decreasing the anxiety of the patients. We investigated the current status of anesthetic management for awake craniotomy in Japan to establish a standard procedure for safe anesthesia. A questionnaire was sent to 80 universities with departments of anesthesia in Japan and 34 (43%) responded. In 19 institutes, awake craniotomies are being practiced. The first experience of awake craniotomy was in 1996 in Japan and since then most of the institutes have experienced only three or fewer cases. Airway management, control of nausea and vomiting, stable awakening during functional mapping and control of seizures were pointed out as problems during awake craniotomy. Based on the present results, our experience and the information from previous investigations, standard anesthetic management for awake craniotomy in our country will be documented.
Masui. The Japanese journal of anesthesiology 05/2008; 57(4):492-6.
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Journal of Anesthesia 02/2008; 22(4):493-7. · 0.83 Impact Factor
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ABSTRACT: In carotid endarterectomy (CEA), it is essential to maintain the systemic blood pressure (BP) and cerebral perfusion pressure, especially during cross clamping, and vasopressors are often required. To elucidate the effect of norepinephrine (NE) on the cerebral circulation in patients undergoing CEA, regional oxygen saturation (rSO2) in bilateral frontal poles was monitored by near infrared spectroscopy during NE infusion.
Seven patients undergoing CEA were enrolled. Bilateral frontal rSO2 was monitored with transcranial optical spectroscopy. Anesthesia was induced and maintained with propofol, fentanyl and vecuronium.
NE increased MAP (P<0.001) and decreased HR (P<0.001) and bilateral rSO2 (ipsilateral P<0.01, contralateral P<0.05).
NE used to maintain the MAP decreased the brain rSO2. NE would aggravate the balance between cerebral oxygen supply and consumption in patients undergoing CEA. Further investigations are necessary to clarify the effect of systemically administered norepinephrine on the cerebral circulation.
Masui. The Japanese journal of anesthesiology 07/2007; 56(6):634-8.
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ABSTRACT: Dexmedetomidine could be beneficial for preoperative sedation of patients with aneurysmal subarachnoid hemorrhage (SAH) because of its sympathetic suppressive effect without respiratory depression.
Thirteen patients were sedated with continuous intravenous administration of dexmedetomidine (group D) and 13 were with intermittent intravenous administration of diazepam and pentazocine (group C).
Blood pressure (BP) and heart rate (HR) on admission to OR in group D were lower than those in group C. On tracheal intubation, BP and HR increased in both groups, but the differences between the values before and after the intubation were larger in group C than in D.
Preoperative dexmedetomidine infusion is suitable for patients with SAH.
Masui. The Japanese journal of anesthesiology 02/2006; 55(1):51-4.
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ABSTRACT: Hypotension after positioning is sometimes seen especially in patients with cervical spinal lesion operated on under prone position. Patients with spinal lesion and those with brain lesion are compared in the frequency of hypotension after positioning to prone. Sixty-one cases operated on with prone position were studied. Ages ranged from 40 to 82 (mean 61) years and ASA grade was 1 or 2 in each case. Cervical laminoplasty (group C) or craniotomy (group B) are performed in 40 and 21 patients, respectively. Ephedrine was administrated when the systolic blood pressure decreased under 80 mmHg and the frequency of ephedrine use was compared. There were no differences in age and sex distribution between group C and B. The induction doses of propofol and fentanyl in group B were larger than those of group C, but ephedrine use in group C was more frequent than in group B. In T2-weighted image of the cervical cord, high signal intensity areas were depicted in cases with hypotension. The sympathetic flow descends in the medial part in the lateral funiculus. Damage of this pathway would cause autonomic dysfunction in patients with cervical spinal lesion and strict monitoring is necessary during positioning to prone.
Masui. The Japanese journal of anesthesiology 02/2003; 52(1):46-8.
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ABSTRACT: Intra-aneurysmal embolization by Guglielmi detachable coil (GDC) is becoming an important method in treatment of intracranial aneurysm. However, intraoperative bleeding remains an essential problem. We reviewed our anesthesia records in patients treated with GDC embolization. Ninety four cases of ruptured cerebral aneurysms were treated with GDC embolization, including 59 females and 35 males. Their ages ranged from 21 to 88, with mean age of 67 years. Preoperative Hunt and Hess grading scales were 1 in 3 cases, 2 in 31, 3 in 40, 4 in 16 and 5 in 4. Intraoperative re-bleeding occurred in 3 cases. These were confirmed by extravasation in angiography or by increased HDA in CT. Each case has berry aneurysm. Acute hypertension at re-bleeding was treated with nicardipine as well as by increasing dose of anesthetic, and hemostasis was obtained by hypotension and reversal of heparin with protamine. After disappearance of extravasation, the procedures were continued. Anesthesia was maintained with fentanyl-propofol in 1 case and sevoflurane in 2 cases. Direct hemostasis is impossible during endovascular surgery and management of systemic circulation by an anesthesiologist is necessary.
Masui. The Japanese journal of anesthesiology 12/2002; 51(11):1238-42.
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ABSTRACT: The authors report on a 38-year-old woman with a dislocated hangman fracture associated with unilateral vertebral artery (VA) occlusion. The patient presented with a mild central cord syndrome, as well as anterior subluxation of the C-2 vertebral body upon C-3, bilateral neural arch fractures, and a unilateral locked facet joint. Digital subtraction angiography revealed occlusion of the right VA, with the posterior cerebral circulation entirely dependent on the left VA. Intraoperative angiography demonstrated that complete reduction of the dislocation would have caused severe stenosis of the left VA; partial reduction and anterior fixation were performed instead, with excellent neurological outcome. In this case, intraoperative angiography was particularly useful for preventing brain-related ischemic complications during reduction.
Journal of Neurosurgery 11/2002; 97(3 Suppl):355-8. · 2.96 Impact Factor
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ABSTRACT: Circulating blood volume (cBV) is reported to decrease in patients who suffer a subarachnoid hemorrhage (SAH), but little is known about the correlation between changes in cBV, and patient clinical condition and time course after SAH, especially during the very acute stage. To determine appropriate management of patients with SAH, the authors measured cBV by using pulse spectrophotometry immediately after patient admission. They also evaluated whether the timing of surgery influenced changes in cBV.
Circulating blood volume was measured in a total of 73 patients who were divided into the following three groups: Group A (very acute SAH) consisted of 14 SAH cases, Group B (acute SAH) included 34 SAH cases, and Group C (controls) included 25 other neurosurgical cases. All patients in Group A underwent aneurysm clipping within 6 hours after onset of SAH, whereas all patients in Group B underwent aneurysm clipping within 72 hours after onset. Hypervolemic therapy was not performed in patients with SAH. Before surgery, cBV was significantly lower in patients in Group B than in those in Group C, but there was no significant difference in this parameter when comparing Groups A and C. Although there was a transient drop in cBV in Group B patients for at least 3 days after surgery, there was no significant change in cBV in Group A patients during the study period. None of the Group A patients suffered from symptomatic vasospasm; however, four Group B patients did experience symptomatic vasospasm.
The authors assert that normovolemic fluid management is appropriate for patients who undergo surgery during the very acute stage of SAH, whereas a relatively hypervolemic therapy is necessary for 3 to 5 days after operation to prevent early hypovolemia in patients who undergo surgery during the acute stage of SAH.
Journal of Neurosurgery 09/2002; 97(2):268-71. · 2.96 Impact Factor
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ABSTRACT: Arterial Mg2+ concentrations were analyzed in 108 patients with cerebral aneurysms. There was no difference in Mg2+ concentrations between patients with ruptured and unruptured aneurysms. Mg2+ concentrations in patients with ST depression or elevation were lower than in those without ST changes (0.34 +/- 0.05 vs. 0.38 +/- 0.07 mmol.l-1). Decreased arterial Mg2+ could be caused by cardiac ischemia rather than subarachnoid hemorrhage. For prevention of fatal arrhythmias, perioperative brain protection and ameliorating vasospasm, correcting the depressed Mg2+ concentrations is suggested.
Masui. The Japanese journal of anesthesiology 04/2002; 51(3):247-9.
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ABSTRACT: A 53 year old male was admitted with the diagnosis of brain stem infarction. Severe stenosis of the bilateral internal carotid arteries was revealed by cerebral angiography. During the angiography, he complained of acute abdominal pain and was referred to abdominal surgical department. He was diagnosed as thrombo-embolism of the superior mesenteric artery and treated conservatively. The symptoms improved, but renal function became worse and the toe was found to be blue. Cholesterol embolism was suspected by nephrologists and thrombolytic therapy was discontinued. Steroid was administrated and LDL-apheresis was performed. The renal function was aggravating and hemodialysis was required. Emergency neurosurgical operations are sometimes performed immediately after cerebral angiography and the neuroanesthesiologists should be aware of the pathology of cholesterol embolism in perioperative management.
Masui. The Japanese journal of anesthesiology 03/2002; 51(2):166-8.
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ABSTRACT: To clarify the epileptogenicity of sevoflurane, electrocorticograms were monitored in seven patients with unruptured cerebral aneurysm under sevoflurane anesthesia. They had no history of epilepsy or other complications. Spike activities on electrocorticography were seen in all seven patients at 3.3% end-tidal sevoflurane. These results suggest that further study is required to evaluate the suitability of sevoflurane for neurosurgical procedures.
Journal of Neurosurgical Anesthesiology 02/2002; 14(1):63-5. · 2.23 Impact Factor
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ABSTRACT: Fentanyl-droperidol technique is the choice for epilepsy surgery. It requires intraoperative electrocorticography (ECoG), but a large dose of fentanyl is needed for this technique. On the other hand, sevoflurane reportedly may be beneficial for intraoperative ECoG. To reveal whether the combined technique with fentanyl and sevoflurane is beneficial for epilepsy surgery, we investigated ECoG in 10 patients with intractable temporal lobe epilepsy without sevoflurane, with 0.5 minimum alveolar concentration (MAC) sevoflurane, and with 1.5 MAC sevoflurane under fentanyl-based anesthesia. The mean number of spikes for 1 minute decreased from 38.3 to 14.1 after 1.5 MAC sevoflurane was induced, which was statistically significant ( P <.05). Our results showed that balanced technique with neurolepto-analgesia (NLA) and sevoflurane is not suitable for epilepsy surgery requiring intraoperative ECoG. When epilepsy surgeries are performed under sevoflurane anesthesia, it is important to consider that sevoflurane may suppress electric activities when it is used with other anesthetic agents.
Journal of Neurosurgical Anesthesiology 01/2002; 14(1):59-62. · 2.23 Impact Factor
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ABSTRACT: In order to evaluate the methionine uptake of a glioma with positron emission tomography (PET), the kinetics of carbon-11 methionine was investigated in 11 patients by measuring the free 11C-methionine in plasma as an input function following intravenous administration. When the mean clearance curve of free 11C-methionine in plasma instead of individual 11C-methionine clearance curves was used, mean differences in uptake rate and distribution volume were 4.0% and 4.6% respectively. By applying the mean clearance curve of free 11C-methionine in 18 glioma patients, significant differences in 11C-methionine uptake rate and distribution volume were found according to pathological grading. For the accurate evaluation of the metabolism of 11C-methionine, it is therefore preferable that the actual level of free 11C-methionine in the plasma be measured, especially for the follow-up of individual cases. The study also demonstrated that the mean clearance curve of 11C-methionine in plasma might be employed as an input curve for calculating the uptake rate and distribution volume with small errors.
European journal of nuclear medicine and molecular imaging 05/1992; 19(6):426-430. · 4.99 Impact Factor
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ABSTRACT: In this study, regional cerebral blood flow (rCBF) and the cerebral metabolic rate of oxygen (rCMRO2) were measured using positron emission tomography (PET) with oxygen-15 radiopharmaceuticals to clarify the pathophysiology of ventriculomegaly in the developing brain. Four hydrocephalic infants without severe neurological deficit were studied. Hypoperfusion was observed in the frontal, parietal, and visual association cortices which surrounded dilated anterior or posterior horns of the lateral ventricle. Lower rCMRO2 values than adult rates were observed in all cases. In the infants with markedly enlarged anterior or posterior horns, the surrounding cortices showed relatively lower rCMRO2 values with the fall of rCBF. Postoperative studies were performed in two infants. rCMRO2 increased in every region after ventriculoperitoneal shunting, but little change was observed in rCBF. These results indicate that metabolic deterioration occurs in the developing brain with hydrocephalus.
Child s Nervous System 01/1992; 8(3):118-123. · 1.54 Impact Factor
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ABSTRACT: The existence of two polymorphs of palmitoleic acid was observed by differential scanning calorimetry. Powder X-ray diffraction pattern showed that the two polymorphs correspond to the α and γ forms, which have bee observed in other cis-monounsaturated fatty acids, oleic acid and erucic acid. γ reversibly transformed to α at −18.7°C on heating and α melted at 2.0°C. The effect of hydrostatic pressure on the γ-α transformation temperature, Ttr and the α-melt transition temperature, Tm, were studied by means of high-pressure differential thermal analysis. Ttr and Tm were elevated by pressure, as expreessed by dT/dp at atmospheric pressures of 0.190 and 0.202 K/MPa, respectively. The volume increases were estimated to be 5.6 cm3/mol for the γ-α transformation and 23/.6 cm3/mol for the α-melt transition by applying the Clausius-Clapeyron equation. The results were discussed compared with those observed in oleic acid.
Chemistry and Physics of Lipids. 56(1):59-63.
