Toward Inter-isolated Island Cooperation for the Drip, Ship, and Retrieve Method in the Sakishima Islands: A Case Report.

Objective: Based on the findings of preferable outcomes from recanalization therapy in recent studies, regional partnerships for the endovascular treatment of acute ischemic stroke are being promoted. However, reports of inter-island cooperation between remote islands located far from high-volume centers on the mainland are rare. Case Presentation: A 63-year-old man experienced an acute ischemic stroke on a small, isolated island in Okinawa, Japan. He was transferred by helicopter to the primary emergency hospital on Ishigaki Island, which was the nearest island on which he could be administered recombinant tissue plasminogen activator (rtPA). After this, he was carried again by helicopter and ambulance to the primary stroke center on Miyako Island using the drip and ship method. Mechanical thrombectomy with a stent retriever achieved recanalization of the occluded major vessels and improved the neurological disturbance. The patient became neurologically independent and could be discharged only 11 days after onset. Conclusion: Building a local area network that includes hospitals providing mechanical thrombectomy is a meaningful approach to treating acute ischemic stroke occurring on isolated islands. It is necessary to recognize the specific restrictions imposed by helicopter transportation and to make efforts to shorten the time required for key processes to provide faster treatment.

Cross-wire assist suit concept, for mobile and lightweight multiple degree of freedom hip assistance.

In this paper, we present our cross-wire assist concept, for assisting a single joint in multiple degrees of freedom. It is comprised of four motor driven Bowden cable actuators (wires) per assisted joint, with the wires crossed over each other at the front and rear. Simulation results show that selectively actuating a subset of these wires allows torque to be generated in 6 directions, with the torque magnitude dependent on joint angle. We have built a fully wearable prototype of our assistance device for both hip joints, with 8 high-speed and independently controllable actuators each providing force up to 100 N. The prototype has a total mass of 9.3 kg, and is shown in motion capture testing to generate movement in 6 directions around the users joint, including internal and external rotation. Mobile, multi-degree of freedom assistance cross-wire system will enable assistive devices to better match human movement, allowing support and rehabilitation in tasks beyond straight line walking.

Early event-related brain potentials that reflect interest for content information in the media.

This study investigated the relationship between event-related brain potentials (ERPs) to abridged content information in the media and the subsequent decisions to view the full content. Student volunteers participated in a task that simulated information selection on the basis of the content information. Screenshots of television clips and headlines of news articles on the Web were used as content information for the image condition and the headline condition, respectively. Following presentation of a stimulus containing content information, participants decided whether or not they would view the full content by pressing a select or a reject button. When the select button was pressed, participants were presented with a television clip or a news article. When the reject button was pressed, participants continued on to the next trial, without viewing further. In comparison with rejected stimuli, selected stimuli elicited a larger negative component, with a peak latency of ∼250 ms. The increase in the negative component was independent of the type of visual stimulus. These results suggest that interest toward content information is reflected in early-stage event-related brain potential responses.

Estimating uncomfortable loudness levels using evoked potentials to auditory stimuli for hearing aid fitting.

Determining the loudest sound level that a person can comfortably tolerate (uncomfortable loudness level: UCL) imposes a strain on people suffering from hearing loss. In the present study, we propose a method of estimating UCL based on auditory evoked potentials (AEPs). Adults with normal hearing (18 men aged 25-56 years) participated in the study. Three tone bursts (S1, S2 and S3; a triplet) of the same frequency (either 1k, 2k or 4k Hz) were presented to the right or left ear with an interstimulus interval of 300 ms. The sound intensity decreased gradually by 5 dB HL from 80 dB (S1) to 70 dB HL (S3). The interval between triplets was 450 ± 50 ms. The frequency of a given triplet differed from the frequency of the preceding triplet. An electroencephalogram was recorded from three scalp electrode sites (Cz, C3, and C4) with the right mastoid reference. The 900-ms period after the onset of the triplet was transformed to a wavelet coefficient and averaged separately by stimulated ear and tone frequency. The UCLs were estimated by linear discriminant analysis on the basis of trained data of the other participants' subjective UCLs and the wavelet coefficients. The mean estimation error was 4.9 ± 5.0 dB. This result suggests that the UCLs could be estimated successfully on the basis of AEPs to triplets of auditory tones.

Identification of event-related potentials elicited by conceptual mismatch between expectations and self-chosen TV images.

When a voluntary action is followed by an unexpected stimulus, a late positive potential (LPP) with a posterior scalp distribution is elicited in a latency range of 500-700 ms. In the present study, we examined what type of mismatch between expectations and action outcomes was reflected by the LPP. Twelve student volunteers participated in a task simulating choice of TV programs. After choosing one of three options displayed as a cue stimulus, they viewed a second stimulus (still TV image). To manipulate the type of expectation, three kinds of cue conditions were used: thumbnail image condition (three small TV images), category label condition (three words), and no cue condition (three question marks). Over trials, the second stimulus either matched (p = .80) or mismatched (p = .20) the chosen option. As compared to matched TV images, mismatched TV images elicited a larger LPP (500-700 ms) in the thumbnail image and category label conditions. In addition, a larger centroparietal P3 (400-450 ms) was elicited to mismatched TV images in the thumbnail image condition alone. LPP reflects a conceptual mismatch between a category-based expectation and an ensuing action outcome, whereas P3 reflects a perceptual mismatch between an image-based expectation and an action outcome.

Direct and primary carotid endarterectomy for common carotid artery occlusion. Report of 2 cases.

BACKGROUND: Cerebral ischemia associated with chronic CCA occlusion is a rare condition and raises strategic dilemma when the revascularization is needed. METHODS: Two patients with CCA occlusion presented with ischemic symptom associated with the affected side. Both patients underwent vascular reconstruction by direct carotid endarterectomy to achieve primary restoration of CCA to ICA flow. RESULTS: Successful reopening of the vessels was obtained in both patients without the evidence of postsurgical ischemic event. Follow-up MRA was obtained at later than 6 months after surgery, which demonstrated patent CCA-ICA in both patients. CONCLUSIONS: Direct carotid endarterectomy of the occluded CCA can be safely performed if the preoperative angiography suggest still patent vessels distal to carotid bifurcation and the substantial "back flow" is obtained from ICA during arteriotomy.

Event-related potentials elicited by unexpected visual stimuli after voluntary actions.

Event-related potentials from visual stimuli that were presented after voluntary actions were recorded to examine how people expect their action effects. Participants pressed a button in response to a cue stimulus (L or R) either in the fixed condition where participants always pressed a center button or in the choice condition where they selectively pressed the corresponding left or right button. Immediately after the button press, a second stimulus (left or right) was presented visually to inform that their action was registered. When the second stimulus did not match the cue stimulus (p=.20), a late positive potential (LPP) with a posterior scalp distribution occurred in a latency range of 500-700 ms. The amplitude of this mismatch-related LPP was larger in the choice condition than in the fixed condition. The results suggest that the cognitive mismatch between the expected and actual action effects is reflected in the LPP, and the selection of a specific action strengthens the expectation of its action effect.

Clipping and superficial temporal artery-M2 bypass for unruptured anterior communicating artery aneurysm associated with atherosclerotic internal carotid artery occlusion: report of 2 cases.

BACKGROUND: The management of the unruptured AcomA aneurysm associated with atherosclerotic occlusion of the unilateral internal carotid artery (ICA) raises several strategic dilemmas. METHODS: Two such patients with unruptured aneurysm on the AcomA, which supply cross-flow toward the hemisphere with ICA occlusion, are presented. RESULTS: Both patients were treated with STA-M2 bypass followed by clipping of the unruptured AcomA aneurysm in 1 stage through the transsylvian route. Both patients were doing well without neurological deficit nor cognitive impairment at 1 year follow-up. CONCLUSIONS: In the surgical treatment of unruptured AcomA aneurysm with atherosclerotic ICA occlusion, preceding bypass would be ideal in case of intraoperative rupture as well as to reduce perioperative ischemia if the bypass procedure itself could be performed with minimal risk. Enough and atraumatic exposure of the sylvian fissure contributed to reduce brain retraction during the clipping of AcomA aneurysm and, in addition, to ease the STA-M2 bypass.

Training of A3-A3 side-to-side anastomosis in a deep corridor using a box with 6.5-cm depth: technical note.

BACKGROUND: Cerebral revascularization in the deep surgical field is technically challenging. Especially, side-to-side anastomosis like A3-A3 could be technically more difficult compared with end-to-side anastomosis. To improve surgeon's dexterity and maneuverability in the deep surgical field, the authors developed an easily accessible and well-simulating training system using prosthetic tubes and a box. METHODS: Two prosthetic tubes (silicon tube, 1.2 mm in diameter) are mounted in parallel on the bottom of 6.5-cm-deep emptied 'tissue paper box.' The orifice of the box is restricted to 2 x 2 cm to simulate a deep and narrow surgical corridor. Using bayonet-shaped micro needle holder and forceps, the side-to-side anastomosis of the tubes is performed with 10-0 nylon under operative microscope. RESULTS: Prosthetic tubes well simulated real A3-A3 anastomosis. From the standpoint of technical difficulty, this training system needed slightly higher level of dexterity compared with real A3-A3 anastomosis because of narrower and deeper surgical corridor, and the wall of prosthetic tube was slightly thicker and more inflexible. After this training, the surgical technique in real A3-A3 anastomosis was improved. CONCLUSIONS: This training system worked well to ease the transition from anastomosis in shallow surgical field to deep and narrow surgical field. The prosthetic tube we used approximates real A3 relatively well, and the ease in setting up this system enabled repeated practice, which resulted in steep learning curve of the technique.

Incidence of ischemic lesions by diffusion-weighted imaging after carotid endarterectomy with routine shunt usage.

Temporary intraluminal shunt was used during 72 consecutive carotid endarterectomies (CEAs) in 61 patients (bilateral CEA in 11 patients) during October 2001 and September 2005. The medical records of these patients were retrospectively reviewed. All procedures were performed with routine shunt insertion without monitoring such as electroencephalography. Pre- and postoperative diffusion-weighted magnetic resonance (MR) imaging was used to detect ischemic complications. Postoperative angiography was performed in 70 cases to detect abnormalities such as major stenosis or dissection of the distal end. Symptomatic ischemic complication occurred in one patient at 1 month. Postoperative diffusion-weighted MR imaging detected new hyperintense lesions in three patients including the symptomatic patient. Postoperative angiography confirmed that the distal end was satisfactory in all cases. The incidence of ischemic lesions of embolic origin after CEA with routine shunt usage is acceptably low if the procedure of shunt device insertion and removal is meticulously conducted.

Effectiveness of suturing training with 10-0 nylon under fixed and maximum magnification (x 20) using desk type microscope.

BACKGROUND: Microvascular anastomosis using 10-0 nylon needs a higher level of technical dexterity compared with routine neurosurgical maneuvers. Although this technique remains an important part of treating complex intracranial aneurysms or cerebrovascular disease, the surgeon's clinical experience in using this technique is not so common. METHODS: To improve dexterity and maneuverability in the limited clinical case volume, we developed an easily accessible training system, using commercially available desk type microscope and simply suturing neighboring fibers of the gauze with 10-0 nylon under fixed and highest (x 20) magnification. RESULT: This training system is somewhat of a drawback compared to the simulation of a real clinical setting. However, because of the extremely easy availability and accessibility of the dark type microscope repeated training and the accumulation of more than 10000 stitches, on average, was accomplished. This resulted in a steep learning curve of the technique. CONCLUSION: For residency and post-residency year young neurosurgeons, who need to brush up their skills due to lower surgical case volume compared with what senior neurosurgeons have experienced this easily available training would contribute to establishing daily and long-lasting microsurgical practice.

[Relationship between classification of CSDH according to the Internal architecture and hematoma contents].

BACKGROUND: Based on the finding of temporal changes in the internal architecture on CT scans, we classified CSDH into 4 types: the homogeneous type, the laminar type, the separated type, and the trabecular type. The purpose of this study was to statistically analyze the relationship between the type of CSDH and the hematoma contents. METHODS: This study assessed 45 consecutive CSDH patients. All of them were assigned to our 4 types of CT classification of CSDH, and the counts of blood cells including WBC, RBC, Hb, Ht, and platelets, as well as FDP and fibrinogen levels in the hematoma and peripheral venous blood were examined. RESULTS: The mean RBC count was 345.3 (SD = 177.9) in all the subjects versus 426.4 (SD = 165.6) in Hm, 408.3 (SD = 79.2) in Lm, 357.2 (SD = 298.7) in Sp, and 200.0 (SD = 129.2) in Tr. The mean Hb concentration was 10.2 (SD = 5.2) in all the subjects versus 12.9 (SD = 5.3) in Hm, 12.3 (SD = 2.7) in Lm, 9.2 (SD = 6.5) in Sp, and 5.9 (SD = 4.2) in Tr. The eosinophil and lymphocyte counts were high in all the types (15.0% and 48.4% on average). The FDP concentration was high in all patients (500-5,000). Fibrinogen levels were less than 10 in all hematoma types. CRP was an average of 3.1 (SD = 4.9) in all the subjects versus 7.5 (SD = 9.8) in Hm, 2.5 (SD = 1.6) in Lm, 3.0 (SD = 2.9) in Sp, and 1.1 (SD = 1.6) in Tb. CONCLUSION: There were relationships between the type of CSDH and the RBC, Hb, Ht, and CRP values.

[Efficacy of dynamic CT perfusion imaging in conjunction with three dimensional CT angiography for the evaluation of acute ischemic stroke].

BACKGROUND AND PURPOSE: Through the use of a high-speed spiral CT scanner (GEMedical HiSpeedZX/i), CT/P/A technique, where conventional CT, CT perfusion imaging (CTP) and CT angiography (CTA) are consecutively performed, can now be performed with an imaging time of 90 seconds and a total contrast medium volume of 100 ml. A prospective clinical study was performed to ascertain the effectiveness of CT/P/A in diagnosing acute ischemic strokes. METHODS: 29 consecutive patients of Teraoka Memorial Hospital suspected of suffering from the occlusion or constriction of cerebral arteries and who underwent CT/P/A within 3 hours from the onset served as subjects. The sensitivity, specificity, or Odds ratio of CTP and CTA in detecting lesions that caused cerebral infarction was calculated. RESULTS: CTP detected a hypoperfusion area with a sensitivity, specificity, and Odds ratio of 80%, 64%, and 7.2. The sensitivity in lobar infarcts, white matter infarcts, basal ganglia infarcts, and brainstem infarcts was 100%, 100%, 100%, 0% (p = 0.0022). The sensitivity and Odds ratio of CT/P/A in cerebral infarcts differed according to the diameter of the infarcts. That with infarcts of 10 mm or more was 91%, 20. That with infarcts smaller than 10 mm was 50%, 2. CTA detected arterial lesions that caused cerebral ischemic attack with a sensitivity of 94% and specificity of 90%. The examination time for CT/P/A was 18 minutes, total radiation time being 90 seconds. CONCLUSIONS: Although CT/P/A was ineffective for the diagnosis of brainstem infarcts and lesions smaller than 10 mm, CT/P/A was useful in detecting moderate-sized hypoperfusion areas and arterial lesions three-dimensionally before an infarct is completed.