Preoperative evaluation for risk of venous air embolism in the sitting position.

We report a patient with meningioma and radiological findings of erosive bony change, who developed venous air embolism via the diploic vein in the eroded inner table of the skull during craniotomy in the sitting position. The findings in our case suggest that preoperative radiological imaging evaluation can increase an awareness of the possibility of venous air embolism.

Cerebral revascularization using gracilis muscle transplantation for childhood moyamoya disease.

Background: Omental transplantation is effective in the management of ischemia in the territories of the anterior and posterior cerebral arteries in childhood moyamoya disease. We introduced a surgical revascularization using gracilis muscle transplantation to these territories.

Methods: Between January 1991 and May 1993, six children with moyamoya disease, between the age of 3 and 13 years, underwent gracilis muscle transplantation to the territory of either the anterior or the posterior cerebral artery.

Intraoperative electrophysiologic monitoring of cranial motor nerves in skull base surgery.

Background: Intraoperative cranial nerve monitoring has been applied for the preservation of nerve function during skull base surgery. However, its usefulness is controversial because clinical results reported are limited.

Methods: We evaluated the usefulness of intraoperative electrophysiologic monitoring of the third to seventh cranial motor nerves in 15 patients undergoing skull base surgery.

An intra-arterial electrode for intracranial electro-encephalogram recordings.

A new method for intracranial monitoring of brain electrical activity by means of an intra-arterial guide wire as electrode is described. We carried out intracranial electro-encephalography (EEG) using an insulated Seeker Lite-10 guide wire 18 times in 14 patients: ten times in 6 patients with cerebral arteriovenous malformation (AVM) before embolization, and another 8 times in 8 patients with epilepsy. In all cases, a 2-5 times stronger high voltage potential EEG compared with scalp EEG could be recorded.

Traumatic arteriovenous fistula treated by superselective embolisation with microcoils: case report.

A 27-year-old man with a traumatic direct dural arteriovenous fistula (DAVF) was treated using embolisation microcoils. He had suffered blunt trauma to the head while drunk and was aware of no neurological deficit. A few days after the accident, however, he noticed a bruit in the right temple.

Percutaneous transluminal angioplasty for severe stenosis of the posterior cerebral artery: case report.

The Stealth dilation catheter was used for the intravascular treatment of a patient who had hemodynamically significant stenosis of the posterior cerebral artery and had a history of recurrent transient ischemic attacks associated with right hemiparesis and ipsilateral hemianopia dating from March 1993. Cerebral perfusion studies prior to and after the intravenous administration of acetazolamide demonstrated regions of moderately low perfusion and low hemodynamic reserve in the territories of the left middle and posterior cerebral arteries. Cerebral angiograms demonstrated severe stenosis of the left posterior cerebral artery and occlusions of both middle cerebral arteries, which had leptomeningeal anastomoses with the posterior cerebral arteries.

Total excision of a thalamic arteriovenous malformation using an orbito-fronto-malar approach: case report.

A 37-year-old woman was admitted to Osaka Neurological Institute after the sudden onset of left hemiplegia, hemihypesthesia, and ipsilateral hemianopia on February 4, 1992. Computed tomography (CT) disclosed the presence of hemorrhage in the right thalamus extending to the ipsilateral internal capsule. Cerebral angiography after CT scanning disclosed the presence of a cerebral arteriovenous malformation (AVM) fed by copsulothalamic and lateral geniculate body arteries originating from the right anterior choroidal artery.

Pituitary adenoma invading the skull base--a strategy for skull base surgery.

A strategy for surgical management, including the approach and preoperative evaluation, of pituitary adenoma invading the skull base is described. Preoperative evaluation requires a balloon occlusion test of the internal carotid artery (ICA) to determine tolerance to occlusion. Failure to tolerate occlusion indicates administration of brain protective agents and/or a bypass procedure before tumor removal.

Cerebellar primary germ-cell tumor in a young boy.

Germ cell tumors originating in the posterior fossa are very rare. Described herein is a case of primary germ cell tumor (yolk sac tumor) found in the cerebellar vermis. A 5-year-old boy who complained of headache was admitted.

Vasculopathy of the anterior choroidal artery following intra-arterial chemotherapy--case report.

A 40-year-old male, treated with radiotherapy and supraophthalmic intracarotid artery (ICA) ACNU infusion for glioblastoma in the right occipital lobe, developed cerebral infarction secondary to vasculopathy manifesting as hemiparesis 3 months after a second ICA injection. The initial diagnosis was focal neurotoxicity, but angiography revealed severe vasospasm of the anterior choroidal artery. The symptoms improved gradually with therapy for the vasospasm.

Intravascular treatment of spinal arteriovenous malformations using a microcatheter--with special reference to serial xylocaine tests and intravascular pressure monitoring.

Spinal arteriovenous malformations (spinal AVMs) are now treated using microcatheters and various embolic materials. Interventional techniques of this type are thought to be the first choice for treatment of spinal AVMs. In this study, we used the Tracker vascular access system and MAGIC catheter for intravascular treatment of spinal AVMs in order to avoid proximal occlusion.

Dural arteriovenous fistula caused by sinus thrombosis--case report.

A 58-year-old male with a history of idiopathic sinus thrombosis presented with gradual onset of gait disturbance, dementia, and involuntary movement in the upper extremities. Cerebral angiography demonstrated a dural arteriovenous fistula fed by a falx cerebelli branch originating from the left vertebral artery and draining into the inferior vermian vein, the straight sinus, a cortical vein lying on the inferolateral surface of the left cerebellar hemisphere, the ipsilateral superior petrosal sinus, the sigmoid sinus, and the internal jugular vein. Endovascular embolization under fluoroscopic control resulted in complete disappearance of the involuntary movement.

Lateral approach for anterior thoracic spinal lesions.

A lateral approach, consisting of a modified transversectomy, hemilaminectomy, and adequate transversectomy with costectomy of 7-8 cm, was used to treat four cases of anterior or anterolateral thoracic lesions, including two cases of thoracic disc herniations, one of thoracic meningioma, and one of hypertrophic pachymeningitis. All patients presented with gait disturbance, but recovered well postoperatively except for one who needed rehabilitation of the lower extremities. This approach provides a greater access to the anterior thoracic canal, and can achieve effective anterior decompression, and a good outcome for thoracic spinal disease if recognized early.

Disturbance of autoregulation in patients with ruptured intracranial aneurysms: mechanism of cortical and motor dysfunction.

Serial measurements of local cerebral blood flow were obtained with inhalation of stable xenon and computed tomography prior to and during induced hypertension with continuous infusion of dopamine (7-15 micrograms/kg/min) in 34 patients who underwent surgery for treatment of subarachnoid hemorrhage due to ruptured intracranial aneurysm. Cerebral vasospasm was detected angiographically in all but one of the patients studied. Vasospasm was not symptomatic in 19 patients, but was in the other 15 patients.

Successful intra-arterial fibrinolysis of the anterior choroidal artery in the acute stage of internal carotid artery occlusion: case report.

A 27-year-old man was admitted to our institution with the sudden development of right hemiparesis and dysarthria beginning an hour after the onset of symptoms on August 9, 1992. The patient was found on admission to have right hemiparesis (2/5), hemihypesthesia, hemianopia, dysarthria; he had transient atrial fibrillation. No abnormalities were detected on computed tomography (CT) scans, and cerebral blood flow studies undertaken following conventional CT scans revealed no low flow regions in the left cerebral hemisphere.

Percutaneous transluminal angioplasty of stenotic primitive hypoglossal artery--case report.

A 76-year-old female presented with vertebrobasilar insufficiency due to a severe stenosis of the right primitive hypoglossal artery (an unusual carotid-basilar anastomosis) manifesting as recurrent transient ischemic attacks (TIA) associated with quadriparesis and cerebellar ataxia with vertigo, nausea, and vomiting. She had been treated with 100 mg of aspirin per day, but TIA associated with the same symptoms persisted. Cerebral blood flow (CBF) studies disclosed a region of moderately low flow in the posterior fossa.

Emergency X ray-guided nasotracheal intubation in a patient with a spinal epidural haematoma.

A patient with a spinal epidural haematoma who developed tetraparesis and respiratory insufficiency is described. Nasotracheal intubation was successfully and rapidly undertaken with the aid of continuous fluoroscopy.

[Preoperative sedation for childhood moyamoya disease--clinical evaluation of rectally administered midazolam].

We evaluated the effectiveness of rectally administered midazolam for preoperative sedation in 26 cases of childhood moyamoya disease. The patients, aged 5.0 +/- 1.

Percutaneous transluminal angioplasty for acute stroke due to stenosis of major cerebral vessels: report of two cases.

The Stealth dilation catheter was introduced for the intravascular treatment of two patients with acute and unstable ischemic stroke due to hemodynamically significant stenosis in the one case of the middle cerebral artery and in the other of the vertebral artery. Cerebral perfusion study on the two cases showed a moderately low flow area in the right cerebral hemisphere and in the left cerebellar hemisphere, respectively. Percutaneous transluminal angioplasty (PTA) using the Stealth catheter was conducted.

Large ependymal cyst of the cerebello-pontine angle in a child.

Most ependymal cysts occur intracerebrally, with a few cases situated in the subarachnoid space. The cerebellopontine angle is a common site for arachnoid cysts, but a very rare site for ependymal cysts. A case is described here of a large ependymal cyst in the cerebellopontine angle.

Local cerebral blood flow measured by stable xenon CT during fentanyl-diazepam anesthesia.

We assessed the local cerebral blood flow (LCBF) in 40 patients under fentanyl-diazepam anesthesia. The measurement of LCBF was made using 50%-70% stable xenon with 20 min of inhalation interval and a shuttle method for computed tomography imaging. All patients were anesthetized with 5.

The "turn-over" technique for selective cerebral angiography.

In older patients with severe aortic atherosclerosis or pronounced tortuosity of the brachiocephalic vessels, selective catheterisation may be impossible. In order to overcome this difficulty we introduced a new "turn-over" technique. This involves introduction of a long guidewire through the catheter, advancing it and turning it over just above the aortic valves and finally introducing it into each major vessel, followed by the catheter.

Effect of thiopentone on motor evoked potentials induced by transcranial magnetic stimulation in humans.

We have studied the effect of repeated doses of thiopentone on motor evoked potentials (MEP) after transcranial magnetic stimulation in 13 patients. Thiopentone was administered i.v.