Surgery and intraoperative neurophysiologic monitoring for aneurysm clipping.

This chapter describes the feasibility, utilization, and value of intraoperative neurophysiologic monitoring (IONM) in cerebrovascular cases. Practical advice on the integration of these adjunct methods into the modern neurosurgical operating room is based on our own neurophysiologic and neurosurgical experience. Most IONM is done for anterior circulation aneurysms.

Mapping and monitoring of brainstem surgery.

The surgical morbidity of brainstem lesions is higher than in other areas of the central nervous system because the compact brainstem is highly concentrated with neural structures that are often distorted or even unrecognizable under microscopic view. Intraoperative neurophysiologic mapping helps identify critical neural structures to avoid damaging them. With the trans-fourth ventricular floor approach, identifying the facial colliculi and vagal and hypoglossal triangles enables incising and approaching the brainstem through the safe entry zones, the suprafacial or infrafacial triangle, with minimal injury.

Transient Retinal Ischemia During Carotid Endarterectomy Estimated by Intraoperative Visual Evoked Potential Monitoring: Technical Note.

Objective: Carotid revascularization surgery is known to carry a risk of postoperative visual deterioration associated with retinal ischemia. We checked intraoperative visual evoked potential (VEP) monitoring in carotid endarterectomy (CEA).

Methods: Ten consecutive patients who underwent CEA in Shinshu University Hospital under total intravenous anesthesia were checked by intraoperative VEP and electroretinogram (ERG) recording in addition to somatosensory evoked potential monitoring.

Neurocysticercosis in Japan.

Neurocysticercosis is a condition rarely reported in Japan, and therefore, the specific route of infestation in our set up has not been conclusively elucidated. Preoperative diagnosis remains difficult to make with certainty due to the slowly evolving nature of the disease and the fact that there are no typical characteristic clinical findings particularly associated with the disease. The hematological, serological, serum biochemistry, stool, and radiological tests were nonspecific for neurocysticercosis.

Intraoperative neurophysiological monitoring during resection of infratentorial lesions: the surgeon's view.

OBJECTIVE Methods of choice for neurophysiological intraoperative monitoring (IOM) within the infratentorial compartment mostly include early brainstem auditory evoked potentials, free-running electromyography, and direct cranial nerve (CN) stimulation. Long-tract monitoring with somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) is rarely used. This study investigated the incidence of IOM alterations during posterior fossa surgery stratified for lesion location.

Role of superior hypophyseal artery in visual function impairment after paraclinoid carotid artery aneurysm surgery.

Object: Although a number of studies have assessed the surgical treatment of paraclinoid-segment carotid artery aneurysms and resulting visual complications, less attention has been given to the results with respect to the superior hypophyseal artery (SHA). The authors evaluated the relationship between the aneurysm, the SHA itself, and postoperative visual function in patients with ruptured and unruptured SHA aneurysms.

Methods: From January 1991 through December 2013, 181 patients with 190 paraclinoid carotid artery aneurysms received treatment at Shinshu University Hospital and its affiliated hospitals.

Subtemporal transtentorial approach for recurrent trigeminal neuralgia after microvascular decompression via the lateral suboccipital approach: case report.

Microvascular decompression (MVD) via lateral suboccipital craniotomy is the standard surgical intervention for trigeminal neuralgia (TN). For recurrent TN, difficulties are sometimes encountered when performing reoperation via the same approach because of adhesions and prosthetic materials used in the previous surgery. In the present case report the authors describe the efficacy of the subtemporal transtentorial approach for use in recurrent TN after MVD via the lateral suboccipital approach.

Conjunct SEP and MEP monitoring in resection of infratentorial lesions: lessons learned in a cohort of 210 patients.

Object: During the surgical removal of infratentorial lesions, intraoperative neuromonitoring is mostly focused on cranial nerve assessment and brainstem auditory potentials. Despite the known risk of perforating vessel injury during microdissection within the vicinity of the brainstem, there are few reports about intraoperative neuromonitoring with somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) assessing the medial lemniscus and corticospinal tract. This study analyses the occurrence of intraoperative changes in MEPs and SEPs with regard to lesion location and postoperative neurological outcome.

The posterior cervical triangle approach for high carotid artery exposure in carotid endarterectomy.

A new approach in carotid endarterectomy (CEA) was developed for high carotid artery lesions. With the authors' use of the posterior cervical triangle approach, 20 patients with a high carotid artery lesion were successfully treated with CEA. Accessory nerve palsy in 1 patient and hoarseness in 4 patients were encountered postoperatively as transient complications.

Intraoperative Monitoring of Motor Evoked Potential for the Facial Nerve Using a Cranial Peg-Screw Electrode and a "Threshold-level" Stimulation Method.

Transcranial motor evoked potential (MEP) for the facial nerve (facial MEP) has been recognized as a good method for quantitative monitoring of facial nerve function in skull base surgery. To improve the feasibility and safety of facial MEP monitoring, a peg-screw electrode and a "threshold-level" method were investigated. From 2007 to 2009, intraoperative facial MEP monitoring with the peg-screw electrode and threshold-level method was successfully achieved in 26 of 29 patients who underwent surgery for the posterior fossa extra-axial tumor.

Gliosarcoma arising from a fibrillary astrocytoma.

We report a 67-year-old woman who was diagnosed with a gliosarcoma at a second operation after diagnosis of a fibrillary astrocytoma 5 months previously. Initially, she underwent a CT-guided stereotactic biopsy. Histological examination showed fibrillary astrocytoma (World Health Organization [WHO] grade II).

Standard and limitation of intraoperative monitoring of the visual evoked potential.

Background: Visual evoked potential (VEP) has been installed as one of the intraoperative visual function monitoring. It remains unclear, however, whether intraoperative VEP monitoring facilitates as a real time visual function monitoring with satisfactory effectiveness and sensitivity. To evaluate this, relationships between VEP waveform changes and postoperative visual function were analysed retrospectively.

Primary ALK-1-negative anaplastic large cell lymphoma of the brain: case report and review of the literature.

Anaplastic large cell lymphoma (ALCL) is a type of non-Hodgkin lymphoma composed of CD30-positive cells. Anaplastic lymphoma kinase (ALK) -1 positive ALCL frequently involves both lymph nodes and extranodal sites. While primary extranodal involvement of ALK-1 negative ALCL is rare, this case is unique in that it is a case of primary ALK-1 negative ALCL of the brain.

Staple electrodes: an innovative alternative for intraoperative electrophysiological monitoring.

Intraoperative electrophysiological monitoring is essential for minimally invasive neurosurgery. The authors developed an innovative recording method using a staple electrode, consisting of a surgical skin staple and an integrated circuit (IC) test clip with a cable. The staple is put on the patient's skin after the induction of general anesthesia.

Anatomical study of the trigeminal and facial cranial nerves with the aid of 3.0-tesla magnetic resonance imaging.

Object: Neuroimages often reveal that the trigeminal or facial nerve comes in contact with vessels but does not produce symptoms of trigeminal neuralgia (TN) or hemifacial spasm (HFS). The authors conducted this study to determine how often the trigeminal and facial nerves came in contact with vessels in individuals not suffering from TN or HFS. They also investigated the correlation between aging and the anatomical measurements of the trigeminal and facial nerves.

Loss of visual evoked potential following temporary occlusion of the superior hypophyseal artery during aneurysm clip placement surgery. Case report.

The authors report a case in which a 62-year-old woman with a history of subarachnoid hemorrhage due to a ruptured aneurysm was found to have a de novo paraclinoid aneurysm in the right internal carotid artery during a routine medical examination. Surgical clip placement was performed via a contralateral pterional approach under visual evoked potential (VEP) monitoring. The superior hypophyseal artery (SHA) was found to originate from the aneurysm body.

[Clinical analysis of treatment and long-term outcome in 56 craniopharyngiomas].

In order to improve QOL in patients with craniopharyngioma, retrospective analysis was performed to discover factors for influencing functional outcome and the best treatment strategy. 56 patients were treated between 1978 and 2005. They were initially treated with surgery and surgical cure was obtained in 29 patients (Group A).

Presynaptic K+ channel modulation is a crucial ionic basis of neuronal damage induced by ischemia in rat hippocampal CA1 pyramidal neurons.

The ischemia-induced synaptic potentiation (ISP) during and/or after brain ischemia has been suggested to be one of the crucial factors responsible for irreversible neuronal damage of hippocampal CA1 pyramidal neurons. However, the presynaptic modulation mechanism that leads to neuronal damage during and/or after ischemia was still unknown. By combining electrophysiological methods and infra-red differential interference contrast (IR-DIC) imaging procedures, we showed for the first time that ISP is the result of extraordinary presynaptic depolarization in association with the suppression of 4-aminopyridine (4-AP) sensitive K(+) channels at the presynaptic sites.

Phase-resolved fluorescence study of mono-L-aspartyl chlorin E6.

The properties of a photosensitizer for photodynamic therapy, mono-L-aspartyl chlorin e6 (NPe6), were investigated using phase-resolved fluorescence. NPe6 was analyzed in water solution at concentrations ranging from 3.13x10(-7) to 8.