Visualization of axonal and volume currents in median nerve compound action potential using magnetoneurography.

Objective: Reconstruct compound median nerve action currents using magnetoneurography to clarify the physiological characteristics of axonal and volume currents and their relationship to potentials.

Methods: The median nerves of both upper arms of five healthy individuals were investigated. The propagating magnetic field of the action potential was recorded using magnetoneurography, reconstructed into a current, and analyzed.

Magnetoneurography to investigate the mechanisms underlying the P9 far-field potential.

Objective: The mechanism underlying the generation of P9 far-field somatosensory evoked potentials (SEPs) is unresolved. Accordingly, we used magnetoneurography to visualize the current distribution in the body at the P9 peak latency and elucidate the origin of P9 generation.

Methods: We studied five healthy male volunteers without neurological abnormalities.

Comparison of intraoperative neurophysiological monitoring methods for lumbosacral lipoma surgery in infants.

Background: Stable intraoperative neurophysiology monitoring of infants, especially very young infants, is challenging. In this study, motor evoked potentials (MEPs), the bulbocavernosus reflex (BCR), and somatosensory evoked potentials (SEPs) were simultaneously monitored in infants with lumbosacral lipomas, and these methods were compared retrospectively.

Methods: A total of 21 surgeries performed for lumbosacral lipoma in patients less than 1 year old were studied.

Intraoperative transcranial facial motor evoked potential monitoring in surgery of cerebellopontine angle tumors predicts early and late postoperative facial nerve function.

Objective: We propose a novel method that predicts facial nerve function (FNF) calculated from the drop and recovery of facial motor evoked potential (FMEP) amplitude ratio during the surgery of cerebellopontine angle tumors.

Methods: We enrolled 73 patients with cerebellopontine angle tumor, and used a biphasic, constant current, and suprathreshold stimulation (BCS) protocol to record FMEP of the orbicularis oris. We measured the intraoperative minimum-to-baseline amplitude ratio (MBR), the final-to-baseline amplitude ratio (FBR), and the recovery value (RV).

A novel needle electrode for intraoperative fourth cranial nerve neurophysiological mapping.

Objectives: Trochlear nerve (CN-IV) mapping method has not been confirmed to date. The compound muscle action potential (CMAP) of CN-IV cannot be recorded because of the low mapping sensitivity and anatomical characteristics of the superior oblique muscle (SOM). The aim of this study was to evaluate the effectiveness of a novel needle electrode (NNE), for the intraoperative mapping of CN-IV.

Motor evoked potential monitoring of the vagus nerve with transcranial electrical stimulation during skull base surgeries.

Object: Dysphasia is one of the most serious complications of skull base surgeries and results from damage to the brainstem and/or cranial nerves involved in swallowing. Here, the authors propose a method to monitor the function of the vagus nerve using endotracheal tube surface electrodes and transcranial electrical stimulation during skull base surgeries.

Methods: Fifteen patients with skull base or brainstem tumors were enrolled.

Evoked potentials elicited on the cerebellar cortex by electrical stimulation of the rat spinocerebellar tract.

Background: In the current study, as a first step to develop a monitoring method of cerebellar functions, we tried to record evoked potentials on the cerebellar cortex by electrical stimulation of the rat SCT, which is located in the Inf-CPed.

Methods: The experimental study was performed on rats. Unilateral muscular contractions of quadriceps femoris muscle were elicited by electrical stimulation.

[Case of ruptured carotid-ophthalmic aneurysm splitting the optic nerve].

A rare case of ruptured carotid-ophthalmic aneurysm splitting the optic nerve was reported. A 52-year-old man presented with a sudden severe headache and bilateral visual deterioration. His right visual acuity was hand motion and the left was 2.

Intraoperative monitoring of visual evoked potential: introduction of a clinically useful method.

Object: To obtain a clinically useful method of intraoperative monitoring of visual evoked potentials (VEPs), the authors developed a new light-stimulating device and introduced electroretinography (ERG) to ascertain retinal light stimulation after induction of venous anesthesia.

Methods: The new stimulating device consists of 16 red light-emitting diodes embedded in a soft silicone disc to avoid deviation of the light axis after frontal scalp-flap reflection. After induction of venous anesthesia with propofol, the authors performed ERG and VEP recording in 100 patients (200 eyes) who were at intraoperative risk for visual impairment.

Histologic study of arteriovenous shunts in the normal dura mater adjacent to the transverse sinus.

Background: Although AV shunts are known to exist in the normal dura mater, their histologic appearance has not been examined in detail. Arteriovenous shunts in the normal dura mater adjacent to the transverse sinus, the most frequent site of DAVFs, were studied histologically.

Methods: Normal dura mater adjacent to the transverse sinus was obtained from 8 cadavers.

Arsenic recovery from water containing arsenite and arsenate ions by hydrothermal mineralization.

Recovery of arsenic as precipitate of natural mineral from model wastewater containing various initial concentrations and oxidation states of inorganic arsenic oxoanions was investigated by hydrothermal mineralization treatment. The treatment is an earth-mimetic method to produce natural minerals by hydrothermal treatment using Ca(OH)2 as a mineralizer. The treatment of model wastewater containing arsenate ion or mixed aqueous solution of arsenate and arsenite ions by using Ca(OH)2 mineralizer and H2O2 oxidizer was found to precipitate arsenate apatite which is a natural mineral containing high concentration of arsenic.

[Intraoperative monitoring of visual evoked potentials].

Our success rate of intraoperative monitoring of visual evoked potential (VEP) had been approximately 30% in the past. In order to improve recording rate of intraoperative VEP, we developed a new stimulating device using high power light emitting diodes. Electroretinogram was simultaneously recorded to understand whether flash stimulation reached the retina.

Intraoperative monitoring of blood flow insufficiency during surgery of middle cerebral artery aneurysms.

Object: The usefulness of motor evoked potential (MEP) monitoring to detect blood flow insufficiency (BFI) in the cortical branches of the middle cerebral artery (MCA) and lenticulostriate arteries (LSAs) during MCA aneurysm surgery was investigated based on the correlation between MEP and somatosensory evoked potential (SEP) monitoring.

Methods: Fifty-three patients with MCA aneurysms underwent surgery accompanied by intraoperative MEP and SEP monitoring. There was no postoperative motor paresis in 43 patients in whom MEP and SEP results remained unchanged.

Optic nerve evoked potentials elicited by electrical stimulation.

This study investigated whether the optic nerve evoked potential (ONEP) elicited by electrical stimulation of the optic nerve can serve as a reliable intraoperative indicator of visual function. In the experimental study, two silver-ball stimulating electrodes were placed on the dog optic nerve adjacent to the apex of the orbit and one recording electrode was placed on the optic nerve near the chiasm. The nerve was stimulated with 0.

Precipitation recovery of boron from wastewater by hydrothermal mineralization.

It is well known that boric acid exhibits various toxic effects on plant, animal and human beings even at very low concentrations. Thus, the development of boron-removal technique from wastewater has been intensively investigated. In this study, a new hydrothermal treatment technique was developed to recover boron as recyclable precipitate Ca(2)B(2)O(5).

Monitoring and preventing blood flow insufficiency due to clip rotation after the treatment of internal carotid artery aneurysms.

The authors report a case in which anterior choroidal artery (AChA) blood flow insufficiency due to aneurysm clip rotation was detected intraoperatively by motor evoked potential (MEP) monitoring and ischemia was successfully avoided. The patient had an incidentally discovered aneurysm for which occlusion of its neck was performed through a standard frontotemporal craniotomy without changing the MEP amplitude. After it was confirmed that the surrounding arteries were not stenotic, the brain retractor on the frontal lobe was released; MEP amplitude subsequently decreased.