Katsuzo Fujita

Aneurysms of the distal posterior inferior cerebellar artery: experience with three cases and review of the literature.

We report 3 surgically treated aneurysms of the distal posterior inferior cerebellar artery (PICA) and review 36 cases in the literature. More than half of the distal PICA aneurysms arose distal to the choroidal arch. These lesions often arose at a turning point (i.e., a hairpin curve) of an artery instead of at a junction of vessels. Distal PICA aneurysms are likely to be missed and it is necessary to investigate carefully with four-vessel angiography even if computed tomography is done. Eighty-two per cent of the surgically treated 39 patients had good recoveries and 8% had fair results. The mortality rate was 10%. Although clipping of the aneurysm neck is preferable, trapping is useful when neck clipping is impossible in segments distal to the choroidal arch.

Surgical treatment of moyamoya disease in children: which is more effective procedure, EDAS or EMS?

At present, encephaloduroarteriosynangiosis (EDAS) and encephalomyosynangiosis (EMS) are the treatments of choice for moyamoya disease in children, but no attempts have been made to determine which is the more effective procedure, for the ischemic lesions in moyamoya disease. Ten patients (seven children and three adults) underwent EDAS and/or EMS: three patients EDAS on both sides; seven patients EDAS on one side and EMS on the other. These ten patients were followed up with a neurological examination and r-CBF and angiographic studies. Postoperative angiograms and r-CBF studies demonstrated more revascularization from the external carotid artery in sides treated with EDAS than with sides treated with EMS. From these results, it is concluded that the EDAS surgical procedure is superior to that of EMS for moyamoya disease.

Brain Edema in Intracranial Venous Hypertension

Few reports on experimental brain edema caused by occlusion of the intracranial sagittal sinus have appeared, because there has been no good experimental model of brain edema of venous origin. In the present studies a new experimental model of brain has been attempted by occlusion of the intracranial sinus and investigation of its pathophysiology by means of an embolization technique.

Anterior choroidal artery syndrome after surgery for internal carotid artery aneurysms.

We report five patients with anterior choroidal artery syndrome after surgery for internal carotid artery aneurysms. All patients suffered hemiparesis, and hemisensory loss and homonymous hemianopsia were identified in 2 patients. The characteristic triad of the syndrome was recognized in only 1 patient. Dominant and nondominant cerebral hemisphere signs have been reported in association with this syndrome, and 2 patients had a speech disturbance in our series. In previous reports, neurological deficits were mild and patient prognosis was good in anterior choroidal artery infarct, in spite of the fact that the artery supplied the corticobulbar and corticospinal tracts. This report suggests the possible causes of this syndrome after surgery for internal carotid aneurysms, which involve vasospasm after subarachnoid hemorrhage, mechanical obstruction, thromboembolism, and distortion of the aneurysm clip.

Germinoma of the Basal Ganglia

We describe a case of germinoma of the left basal ganglia. An 11-year-old boy, who demonstrated calcification of the left basal ganglia on CT scan following a head injury at the age of 3 years, presented with a weakness of the right upper extremity for 2 months. MRI demonstrated high intensity in the left basal ganglia on a T1-weighted image without enhancement as well as high intensity on a T2-weighted image. Ipsilateral hemiatrophy of the hemisphere and midbrain was also noted. In addition, high intensity in the left internal capsule and cerebral peduncle was demonstrated on T2-weighted image. Surgical specimens obtained by stereotactic biopsy showed germinoma with a two-cell pattern. The patient had remained asymptomatic for 8 years after abnormal calcification was initially detected on CT scan. Ipsilateral hemiatrophy of the hemisphere and midbrain was demonstrated before the onset of weakness.

Cranial Fasciitis Presenting with Intracranial Mass: A Case Report

We describe a very rare case of cranial fasciitis presenting with intracranial mass in a 3-year-old girl. There was no palpable scalp mass. CT scan and MRI demonstrated an epidural mass adherent to the dura with destruction of the inner table of the skull. The tumor was extirpated completely and the resected specimens were diagnosed as cranial fasciitis. When neurosurgeons, pediatricians and radiologists encounter an epidural tumor in a pediatric patient, cranial fasciitis should be kept in mind.

Anterior choroidal artery arteriovenous malformation. Its clinical manifestations and surgical treatment

Four cases of arteriovenous malformation of the anterior choroidal artery are reported. Three cases showed the typical triad of the anterior choroidal syndrome, but in one case there was a subarachnoid hemorrhage without other symptoms. There were no surgical deaths after removal of the arteriovenous malformation. We have emphasized in this report that these arteriovenous malformations should be dealt with as a distinct entity from other paraventricular arteriovenous malformations because of their operability and characteristic clinical manifestations.

Cerebral ischemia alters glucose transporter kinetics across rat brain microvascular endothelium. Quantitative analysis by an in situ brain perfusion method.

The purpose of this study was to quantify the changes of blood-brain barrier glucose transporter kinetics following cerebral ischemia using an in situ brain perfusion technique. Sixty-four adult male Sprague-Dawley rats were divided into control and ischemia groups, and a four-vessel occlusion model was used to provide an ischemic insult. To obtain regional capillary permeability area products of glucose and regional perfusion fluid flow rates, the perfusion fluid was dually labeled with 2-deoxy[14C]glucose and [3H]diazepam, and the brain was perfused at a constant rate via the external carotid artery. After sampling tissues from the brain, dual scintillation counting was performed and both regional perfusion fluid flow rates and regional capillary permeability area products were calculated. We determined kinetic parameters, including Vmax, Km and Kd as described in the Michaelis-Menten equation, by the non-linear least squares method. In the ischemia group, a decrease in Vmax and an increase in Km were recognized, which mean decreases in the affinity and the number of functioning glucose transporters. These results suggest that cerebral ischemia downregulates the blood-brain barrier glucose transporters.

C-Arm Multi-Axis Rotation Stereotactic Linac Radiosurgery System

We developed a C-arm multi-axis, stereotactic linear accelerator radiosurgical system combined with 3-dimensional (3D) dose planning software. The linac beam generator is mounted on a C-arm frame that allows rotation parallel and diagonal to the patient table. As a result of the new structural design, the positional deviation of the beam from mechanical isocenter during rotation of the gantry is almost less than 0.5 mm. The system can provide 3D stereotactic radiosurgery using precessional convergent irradiation (PCI) without movement of the patient table, which improves accuracy of the irradiation. A satisfactory dose gradient suitable for radiosurgery with fewer arcs was achieved by PCI than was possible with noncoplanar multi-converging arcs (MCA). The 3D dose planning system can accurately optimize the dose plan even for an irregularly shaped target. We have treated 60 cases since 1996 with a reduction of total treatment time.

Cerebral hyperperfusion during surgical resection of high-flow arteriovenous malformations

Cerebral hemodynamics were evaluated in 16 patients with arteriovenous malformations (AVMs) using intraoperative thermogradient or laser Doppler flowmeter. The postexcision/preexcision blood flow ratio was determined. Two of seven patients with large AVMs (> or = 4 cm) developed a postoperative hematoma. Their flow ratios were larger than 1.9. In 4 patients with large AVMs, their blood flow ratios were reduced from an initial ratio exceeding 2.0 to less than 1.5 using carotid or special flow regulation clamps. These patients did not develop any hemorrhagic complication. In 9 patients of small AVMs (< 4 cm), the ratio was significantly low and there were no hemorrhagic complications.