Effects of superficial temporal artery-middle cerebral artery bypass on hemodynamics and clinical outcomes in the patients with atherosclerotic stenosis in the intracranial segment of internal carotid artery and middle cerebral artery.

OBJECTIVE: To observe the effects of superficial temporal artery-middle cerebral artery bypass (STA-MCA bypass) on hemodynamics and clinical outcomes in the patients with atherosclerotic stenosis in the intracranial segment of internal carotid artery and (or) middle cerebral artery. PATIENTS AND METHODS: The data of 63 patients who had the symptoms of cerebral ischemia in recent 3 months, intracranial segment of internal carotid artery (ISICA) and (or) middle cerebral artery (MCA) stenoses or occlusion showed by digital subtraction angiography (DSA), and reduced cerebral perfusion displayed by CT perfusion (CTP) imaging were retrospectively collected in this study. According to the patient's choice of different treatment methods (STA-MCA bypass and drugs), these patients were allocated into two groups: Bypass group (30 cases) and Drug group (33 cases). Postoperative symptoms, anastomotic patency and hemodynamics were observed in the Bypass group. Post-treatment ischemic events and clinical outcomes were recorded in the two groups and were compared between the two groups. RESULTS: In the Bypass group, DSA all showed anastomotic patency in 28 patients (93.3%, 28/30), and the improvement rate of CTP was all significantly higher in the patients with stage-III CTP than in the patients with stage-II CTP at post-operative 3 days and 6 months (95% vs 60%). Post-treatment ischemic event incidence (13.3% vs 48.5%) and annual stroke rate (6.7% vs 25.6%) were significantly lower in the Bypass group than in the Drug group (All P < 0.05). Pre-treatment National Institutes of Health Stroke Scale (NIHSS) score and Modified Rankin Scale (MRS) score were not significantly different between the two groups, but the NIHSS (2.87±0.19 and 2.4±0.19 vs 4.03±0.47 and 3.97±0.49) and MRS (1.13±0.09 and 1.0±0.07 vs 1.55±0.14 and 1.52±0.15) all were significantly lower in the Bypass group than in the Drug group at post-treatment 6 and 24 months (all P < 0.05). CONCLUSION: STA-MCA bypass can improve cerebral blood perfusion and reduce the incidence of stroke in the patients who have ISICA and (or) MCA-related symptoms, 70%-100% of stenosis, and above stage-ⅠCTP. However, this conclusion remains to be further confirmed.

Effect of pituitary adenylate cyclase-activating polypeptide-27 on cerebral hemodynamics in healthy volunteers: A 3T MRI study.

Pituitary adenylate cyclase-activating polypeptide (PACAP) has emerged as an important signaling peptide in migraine pathogenesis. Recently, we have shown that the less-abundant PACAP isoform, PACAP27, induced migraine and headache in patients equipotently to PACAP38. The present study examined the effect of PACAP27 on cerebral hemodynamics in healthy volunteers using high resolution magnetic resonance angiography (MRA). Eighteen healthy volunteers received infusion of PACAP27 (10 pmol/kg/min) or placebo over 20 min and were scanned repeatedly in fixed intervals for 5 h in a double-blind, randomized, placebo-controlled study. The circumference of extra-intracerebral arteries was measured and compared with PACAP38 data. We found significant dilation of middle meningeal artery (MMA) (p = 0.019), superficial temporal artery (p = 0.001) and external carotid artery (p = 0.039) after PACAP27 infusion compared to placebo. Whereas the middle cerebral artery (MCA) (p = 0.011) and internal carotid artery (ICA) (pICAcervical = 0.015, pICAcerebral = 0.019) were constricted. No effects on basilar artery (p = 0.708) and cavernous portion of ICA were found. Post hoc analyses revealed significant larger area under the curve for MMA after PACAP38 compared to PACAP27 (p = 0.033). We also found that PACAP27 induced headache in nine out of twelve (75%) volunteers and one (17%) after placebo. In conclusion, PACAP27 induced headache and dilated extracerebral arteries (>5 h) and slightly constricted MCA in healthy volunteers. Post hoc analysis of PACAP38 data compared with PACAP27 showed that PACAP isoforms dilates MMA with significantly different magnitude.

Accuracy of Temporal Artery Thermometry as an Indicator of Core Body Temperature in Patients Receiving General Anesthesia.

PURPOSE: To evaluate the agreement of temporal artery temperature (Tat) with esophageal temperature (Tes) and oral temperature (Tor), and explore potential factors associated with the level of agreement between the thermometry methods in different clinical settings. DESIGN: A prospective repeated measures (induction, emergence, and postanesthesia care unit) design was used. METHODS: Temperature data were collected for 54 patients receiving general anesthesia. Analyses included descriptive statistics, paired t tests for the within-patient comparison of temperature methods, Bland-Altman plots to examine agreement between methods, and multiple linear regression to identify factors associated with the agreement between methods. FINDINGS: Tat was significantly higher compared with Tes and Tor (P < .05) and was poor at detecting hypothermia. The use of a muscle relaxant and surgical site were suggested to be associated with the difference between Tat and Tes at emergence. CONCLUSIONS: Tat is more convenient, but less accurate, than other thermometry methods. These inaccuracies are exacerbated by common anesthetic medications.

A comparison of temporal artery thermometers with internal blood monitors to measure body temperature during hemodialysis.

BACKGROUND: Thermometers that measure core (internal) body temperature are the gold standard for monitoring temperature. Despite that most modern hemodialysis machines are equipped with an internal blood monitor that measures core body temperature, current practice is to use peripheral thermometers. A better understanding of how peripheral thermometers compare with the dialysis machine thermometer may help guide practice. METHODS: The study followed a prospective cross-sectional design. Hemodialysis patients were recruited from 2 sites in Calgary, Alberta (April - June 2017). Body temperatures were obtained from peripheral (temporal artery) and dialysis machine thermometers concurrently. Paired t-tests, Bland-Altman plots, and quantile-quantile plots were used to compare measurements from the two devices and to explore potential factors affecting temperature in hemodialysis patients. RESULTS: The mean body temperature of 94 hemodialysis patients measured using the temporal artery thermometer (36.7 °C) was significantly different than the dialysis machine thermometer (36.4 °C); p < 0.001. The mean difference (0.27 °C) appeared to be consistent across average temperature (range: 35.8-37.3 °C). CONCLUSIONS: Temperature measured by the temporal artery thermometer was statistically and clinically higher than that measured by the dialysis machine thermometer. Using the dialysis machine to monitor body temperature may result in more accurate readings and is likely to reduce the purchasing and maintenance costs associated with manual temperature readings, as well as easing the workload for dialysis staff.

Increased Ratio of Superficial Temporal Artery Flow Rate After Superficial Temporal Artery-to-Middle Cerebral Artery Anastomosis: Can It Reflect the Extent of Collateral Flow?

OBJECTIVE: There are several ways to identify donor artery patency and success of surgery after an anastomosis of the superficial temporal artery (STA) to the middle cerebral artery (MCA). The purpose of this study was to evaluate the ratio of bilateral STA mean flow rate (MFR) with the use of color Doppler ultrasonography (CDUS) after bypass surgery and to confirm the possibility of this value as a predictor of the extent of collateral flow. METHODS: Eleven consecutive patients who had undergone STA-MCA anastomosis were included. In every case, bilateral STA MFR, mean velocity, and cross-sectional diameter were measured preoperatively and postoperatively at 1 week, 1 month, and 2 months via CDUS. We measured the bilateral STA MFR ratio changes to compensate for systemic hemodynamic variables. RESULTS: One month after surgery, 9 of the 11 patients who underwent STA-MCA anastomosis had good patency on DSA. In patients with good patency, there was a significant increase in the baseline STA MFR ratio compared with those at 1 week, 1 month, and 2 months postoperatively (2.88, 3.07, and 4.38, respectively, P < 0.05). The mean STA cross-sectional diameter ratio also was significantly increased postoperatively in the good patency group (1.35, 1.41, and 1.49, respectively, P = 0.044). In addition, the mean STA mean velocity ratio was increased postoperatively in the good patency group (1.48, 1.40, and 1.67, respectively, P = 0.042). CONCLUSIONS: We conclude that using CDUS to measure both STA MFR ratio is a potential method to predict the extent of collateral flow through an STA-MCA anastomosis.

Conventional and novel body temperature measurement during rest and exercise induced hyperthermia.

Despite technological advances in thermal sensory equipment, few core temperature (TCORE) measurement techniques have met the established validity criteria in exercise science. Additionally, there is debate as to what method serves as the most practically viable, yet upholds the proposed measurement accuracy. This study assessed the accuracy of current and novel TCORE measurement techniques in comparison to rectal temperature (TREC) as a reference standard. Fifteen well-trained subjects (11 male, 4 female) completed 60min of exercise at an intensity equating to the lactate threshold; measured via a discontinuous exercise test. TREC was significantly elevated from resting values (37.2±0.3°C) at the end of moderate intensity exercise (39.6±0.04°C; P=0.001). Intestinal telemetric pill (TPILL) temperature and temporal artery temperature (TTEM) did not differ significantly from TREC at rest or during exercise (P>0.05). However, aural canal temperature (TAUR) and thermal imaging temperature (TIMA) were both significantly lower than TREC (P<0.05). Bland Altman analysis revealed only TPILL was within acceptable limits of agreement (mean bias; 0.04°C), while TTEM, TAUR and TIMA demonstrated mean bias values outside of the acceptable range (>0.27°C). Against TREC, these results support the use of TPILL over all other techniques as a valid measure of TCORE at rest and during exercise induced hyperthermia. Novel findings illustrate that TIMA (when measured at the inner eye canthus) shows poor agreement to TREC during rest and exercise, which is similar to other 'surface' measures.

A practical comparison of temporal artery thermometry and axillary thermometry in neonates under different environments.

AIM: Thermoregulatory stability and monitoring are crucial in neonatal care. However, the current standard of temperature measurement using Axillary Thermometry (AT) poses multiple limitations. Temporal Artery Thermometry (TT) is a promising new method, which thus begs the question: Can TT replace AT in neonates? Previous studies reveal conflicting results, with none involving a Southeast-Asian multi-ethnic neonatal population under different environments. METHODS: A 6-month prospective comparative study involving neonates managed in a tertiary neonatal centre. Subjects were divided into 4 groups based on the required nursing environment: A) Room air B) Phototherapy C) Radiant warmers D) Incubators. Six hundred and sixty-one paired TT and AT temperature readings were obtained, with concurrent FLACC scoring to evaluate the discomfort associated with each thermometry method. RESULTS: TT readings were higher than AT in all groups. The mean temperature difference between both methods (TT-AT) was lowest in Group A (0.10 ± 0.19°C), followed by Groups B (0.50 ± 0.33°C), C (0.97 ± 0.76°C) and D (1.15 ± 0.57°C) respectively. Bland-Altman analysis revealed good clinical agreement (± 0.5°C) between both methods in Group A (7-0.27,0.47). However, Groups B (-0.14,1.13), C (-0.51,2.45) and D (0.03,2.27) showed poor agreement. Multiple GEE analysis revealed Malay ethnicity to be an additional predictor of decreased TT-AT ( ß = -0.13, p = 0.012). Compared to TT, AT was associated with higher discomfort levels (p <0.001). CONCLUSIONS: Given the good agreement and increased comfort with TT use, our study confirms that TT is comparable to AT for neonates nursed in room air. TT is therefore recommended for the temperature screening and monitoring of neonates nursed on ambient air. Its use in other environments and factors predictive of comparability of both methods requires further study.

Predicting Cerebral Hyperperfusion Syndrome Following Superficial Temporal Artery to Middle Cerebral Artery Bypass based on Intraoperative Perfusion-Weighted Magnetic Resonance Imaging.

Moyamoya disease leads to the formation of stenosis in the cerebrovasculature. A superficial temporal artery to middle cerebral artery (STA-MCA) bypass is an effective treatment for the disease, yet it is usually associated with postoperative cerebral hyperperfusion syndrome (CHS). This study aimed to evaluate cerebral hemodynamic changes immediately after surgery and assess whether a semiquantitative analysis of an intraoperative magnetic resonance perfusion-weighted image (PWI) is useful for predicting postoperative CHS. Fourteen patients who underwent the STA-MCA bypass surgery were included in this study. An atlas-based registration method was employed for studying hemodynamics in different cerebral regions. Pre- versus intraoperative and group-wise comparisons were conducted to evaluate the hemodynamic changes. A postoperative increase in relative cerebral blood flow (CBF) at the terminal MCA territory (P = 0.035) and drop in relative mean-time-transit at the central MCA territory (P = 0.012) were observed in all patients. However, a significant raise in the increasing ratio of relative-CBF at the terminal MCA territory was only found in CHS patients (P = 0.023). The cerebrovascular changes of the patients after revascularization treatment were confirmed. Intraoperative PWI might be helpful in predicting the change in relative-CBF at MCA terminal territory which might indicate a risk of CHS.

Improving Pediatric Temperature Measurement in the ED.

OVERVIEW: ED care providers have long debated which of the various methods of temperature measurement of pediatric patients is best. While the efficacy and accuracy of temporal artery, tympanic membrane, axillary, and infrared temperature measurement have been studied, the gold standard has been rectal temperature measurement. But despite its accuracy, this method causes children with noninfectious complaints and their families unnecessary distress and adds significant time to the triage process. In response, a group of ED staff nurses at a multihospital health system conducted an evidence-based quality improvement project to determine the best practice for accurate temperature measurement in children younger than five years who presented to the ED. The project included an exhaustive literature search, a review of relevant studies, the development of a table of evidence, a presentation of the findings, and recommendations for practice change. This article describes the project and the adoption of temporal artery thermometry, a painless, noninvasive screening method that provided consistently accurate temperature measurement as well as increased patient and nurse satisfaction and a shorter triage process.

Influence of skin blood flow and source-detector distance on near-infrared spectroscopy-determined cerebral oxygenation in humans.

Most near-infrared spectroscopy (NIRS) apparatus fails to isolate cerebral oxygenation from an extracranial contribution although they use different source-detector distances. Nevertheless, the effect of different source-detector distances and change in extracranial blood flow on the NIRS signal has not been identified in humans. This study evaluated the extracranial contribution, as indicated by forehead skin blood flow (SkBF) to changes in the NIRS-determined cerebral oxyhaemoglobin concentration (O2 Hb) by use of a custom-made multidistance probe. Seven males (age 21 ± 1 year) were in a semi-recumbent position, while extracranial blood flow was restricted by application of four different pressures (+20 to +80 mmHg) to the left temporal artery. The O2 Hb was measured at the forehead via a multidistance probe (source-detector distance; 15, 22·5 and 30 mm), and SkBF was determined by laser Doppler. Heart rate and blood pressure were unaffected by application of pressure to the temporal artery, while SkBF gradually decreased (P<0·001), indicating that extracranial blood flow was manipulated without haemodynamic changes. Also, O2 Hb gradually decreased with increasing applied pressure (P<0·05), and the decrease was related to that in SkBF (r = 0·737, P<0·01) independent of the NIRS source to detector distance. These findings suggest that the NIRS-determined cerebral oxyhaemoglobin is affected by change in extracranial blood flow independent of the source-detector distance from 15 to 30 mm. Therefore, new algorithms need to be developed for unbiased NIRS detection of cerebral oxygenation.

Temporal artery thermometry in children younger than 5 years: a comparison with rectal thermometry.

BACKGROUND: Temporal artery (TA) thermometry has come as one of the new methods for temperature measurement, especially in children in whom accurate temperature monitoring can save lives. The device which is convenient and simple to use is yet to gain popularity in several parts of the world, as there are conflicting reports of its accuracy. This study compares the accuracy of the TA thermometry in children younger than 5 years using the rectal thermometry as the gold standard. METHODS: Temperature was measured simultaneously in eligible children younger than 5 years from the forehead and rectum using the TA thermometer (TAT-2000C Exergen, USA) and standard mercury in glass rectal thermometer, respectively. The difference between the mean temperatures obtained by the 2 thermometry methods was tested using the paired t test. Pearson correlation coefficient, linear regression, and Bland-Altman plot were also used to test the relationship and agreement between the 2 instruments. The sensitivity, specificity, and positive and negative predictive values were also calculated. RESULTS: Overall, the mean TA temperature (37.80°C ± 1.07°C) was significantly lower than the mean rectal temperature (38.07°C ± 0.95°C), P < 0.001. In neonates, however, the mean difference was not significant, 0.02 ± 0.59 (P = 0.810). There was a significant positive correlation between the rectal and the temporal temperatures (r = 0.80, P < 0.01). The Bland-Altman plot showed wide variation in the limit of agreement between the rectal and the TA temperatures which ranged from -1.02°C to +1.56°C. The sensitivity of the TA thermometer was 64.6% and 83.5%, respectively, at a TA fever cutoff of 38.0°C and 37.7°C. CONCLUSIONS: Temporal artery thermometer is not accurate enough for the measurement of core body temperature in children younger than 5 years. However, it may be used as a tool for screening for fever in very busy clinics and emergency room at a fever cutoff of 37.7°C.

[Cerebral blood flow monitoring].

Cerebral ischemic events remain a major problem in patients undergoing cardiac and thoracic aortic surgery. Efforts to improve outcomes have been made in many aspects which include cerebral monitoring. New technology is making it possible to shed a light to the brain, which historically used to be a black box during general anesthesia in the operating room. Cerebral brain monitoring methods include cerebral oxymetry using near infrared spectroscopy, trans cranial Doppler, Jugular venous oxygen saturation, bispectral index, temporal artery pressure monitoring. Cerebral oxymetry probably is the most commonly used method among these based on its simplicity and reproducibility. Though it is easy to obtain numbers from cerebral oxymetry, it is important to understand the principle and the limitations to interpret the results, properly.

Intraoperative visualization of cerebral oxygenation using hyperspectral image data: a two-dimensional mapping method.

PURPOSE: Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass is an important technique for cerebrovascular reconstruction. Intraoperative hemodynamic imaging is needed to perform cerebrovascular reconstruction safely and effectively. Optical intrinsic signal (OIS) imaging is commonly used for assessing cerebral hemodynamics in experimental studies, because it can provide high-resolution mapping images. However, OIS is not used clinically due to algorithm, instrumentation and spectral resolution limitations. We tested the feasibility of a hyperspectral camera (HSC) for assessment of cortical hemodynamics with spectral imaging of the cerebral cortex in rats and in vivo humans. METHODS: A hyperspectral camera (HSC) was tested in a rat model of cerebral ischemia (middle cerebral artery occlusion) and during human revascularization surgery (STA-MCA anastomosis). Changes in cortical oxygen saturation were derived from spectral imaging data (400-800 nm) collected by exposing the cortex to Xenon light. Reflected light was sampled using the HSC. The system was then tested intraoperatively during superficial temporal artery to middle cerebral artery anastomosis procedures. Comparison with single-photon emission computed tomography (SPECT) imaging data was done. RESULTS: During middle cerebral artery occlusion in rats, the HSC technique showed a significant decrease in cortical oxygen saturation in the ischemic hemisphere. In clinical cases, the cortical oxygen saturation was increased after STA-MCA anastomosis, which agreed with the SPECT imaging data. CONCLUSION: Continuous collection of imaging spectroscopic data is feasible and may provide reliable quantification of the hemodynamic responses in the brain. The HSC system may be useful for monitoring intraoperative changes in cortical surface hemodynamics during revascularization procedures in humans.

Triple-balloon shunt placement for carotid endarterectomy: a novel intraluminal shunt designed to preserve the internal and external carotid blood flow.

OBJECTIVE: To report a newly developed intraluminal triple-balloon shunt designed to preserve the blood flow of both the internal carotid artery (ICA) and the external carotid artery (ECA) during carotid endarterectomy in patients with a previous ipsilateral extracranial-intracranial bypass, in whom hemodynamic cerebral ischemia might be caused by cross-clamping at the ICA as well as the ECA. METHODS: The novel device consists of 3 silicone tubes equipped with balloons at each end. The design facilitates insertion proximally to the common carotid artery and distally to both the ICA and the ECA. RESULTS: The new shunt tube was used in 3 patients, each of whom had previously undergone ipsilateral superficial temporal artery-middle cerebral artery bypass for proximal middle cerebral artery occlusion. The blood flow of the middle cerebral artery and anterior cerebral artery was supplied independently from the ECA via the bypass and from the ICA, respectively. There were no shunt-related complications. CONCLUSIONS: This novel shunt device can be used safely and effectively in cases requiring preservation of the blood supply to both the ICA and the ECA during carotid endarterectomy.

Prostaglandins and prostaglandin receptor antagonism in migraine.

Human models of headache may contribute to understanding of prostaglandins' role in migraine pathogenesis. The current thesis investigated the migraine triggering effect of prostaglandin E2 (PGE2) in migraine patients without aura, the efficacy of a novel EP4 receptor antagonist, BGC20-1531, in prevention of PGE2-induced headache and the ability of prostaglandin F2α (PGF2α) to trigger headache without any vasodilatation in healthy volunteers. All studies were designed as double-blind, placebo-controlled, cross-over experiments, where PGE2/PGF2α or saline were infused over 20-25 min. In the study with EP4 receptor antagonist healthy volunteers were pre-treated with two different doses of BGC20-1531 or placebo followed by PGE2 infusion over 25 min. The headache data were collected during the whole study day, whereas the possible vascular changes were measured during the in-hospital phase of 1.5 h. The infusion of PGE2 caused the immediate migraine-like attacks and vasodilatation of the middle cerebral artery in migraine patients without aura. The highly specific and potent EP4 receptor antagonist, BGC20-1531, was not able to attenuate PGE2-induced headache and vasodilatation of both intra- and extra-cerebral arteries. The intravenous infusion of PGF2α did not induce headache or statistically significant vasoconstriction of cerebral arteries in healthy volunteers. Novel data on PGE2-provoked immediate migraine-like attacks suggest that PGE2 may be one of the important final products in the pathogenesis of migraine. The lack of efficacy of EP4 receptor antagonist suggests that a single receptor blockade is not sufficient to block PGE2 responses, hence EP2 receptor should be investigated as a potential drug target for the treatment of migraine. The absence of headache during the PGF2α infusion demonstrates that vasodilating properties are necessary for the induction of headache and migraine.

A new noninvasive device for continuous arterial blood pressure monitoring in the superficial temporal artery.

Continuous recording of arterial blood pressure (ABP) has many applications in cardiovascular physiology, but existing alternatives rely on measurements performed in the fingers or radial artery. Peripheral recordings have significant differences from central ABP regarding the pattern of the waveform and corresponding systolic and diastolic values. To address the need for noninvasive measurements closer to the ascending aorta, a new device was constructed to measure ABP in the superficial temporal artery (STA) using photoplethysmography and the arterial volume clamping technique. The optoelectronic circuitry to generate the photoplethysmogram is contained in a specially designed probe placed over the STA and kept in place with a head frame. The prototype (STAbp) also includes original designs for the pneumatic, electronic, signal processing, control and display sub-systems. A self-calibration feature regularly updates the photoplethysmogram operating point to improve accuracy. The performance of the STAbp was compared against the Finapres in 19 healthy subjects. At rest, the bias (SDd) was -23.1 (15.05), -10.8 (13.83) and -12.4 (12.93) mmHg for systolic, mean and diastolic pressures respectively, without significant differences in drift between the two devices. The 99% bandwidth (SD) for the spectral distribution of ABP waveforms was 5.3 (1.46) Hz for STAbp and 6.8 (0.73) Hz for the Finapres (p < 0.01). Handgrip manoeuvre showed a very similar response to the Finapres, including the rapid return to baseline on release. The new STAbp device has considerable potential as a new tool for clinical and research applications where continuous recording of more central ABP is advantageous compared to peripheral alternatives.

[Accuracy, precision, and validity of fever detection using non-invasive temperature measurement in adult coronary care unit patients with pulmonary catheters].

PURPOSE: To investigate the accuracy, precision and validity of fever detection of tympanic membrane (TM), temporal artery (TA) and axillary temperature (AT) compared with pulmonary artery temperature (PA). METHODS: Repeated-measures design was conducted for one year on 83 adult cardiac care unit patients with pulmonary artery catheters after open heart surgery. Sequential temperature measurements were taken three times at 20-minute intervals. Accuracy, precision, repeatability, and validity of fever detection were analyzed. RESULTS: Mean pulmonary artery temperature was 37.04°C (SD 0.70°C). The mean (SD) offsets from PA, with the mean reflecting accuracy and SD reflecting precision, were -1.31°C (0.75°C) for TA, -0.20°C (0.24°C) for TM, and -0.97°C (0.64°C) for AT. Percentage of pairs with differences within ±0.5°C was 9.6% for TA, 19.7% for AT, and 91.6% for TM. Repeated measurements with all three methods had mean SD values within 0.04°C. Sensitivity, specificity, and positive and negative predictive values of tympanic measurements were 0.76, 1.0, and 1.0, and 0.90, respectively. CONCLUSION: Results show that TM best reflects PA, and is most consistent, accurate, and precise. AT tends to underestimate PA, and TA is least accurate and precise. Therefore tympanic membrane measurement is a reliable alternative to other non-invasive methods of measuring temperatures.

Bypass surgery for moyamoya disease: concept and essence of sugical techniques.

This review describes the basic concepts of surgical revascularization for moyamoya disease, including direct and indirect bypass surgery. Direct bypass surgery can improve cerebral hemodynamics and reduce further ischemic events immediately after surgery, but may be technically challenging in some pediatric patients. Indirect bypass surgery is simple and has widely been used. However, its beneficial effects can be achieved 3 to 4 months after surgery, and surgical design is quite important to determine the extent of surgical collateral pathways. Combined bypass procedure, especially superficial temporal artery (STA) to middle cerebral artery anastomosis and indirect bypass, encephalo-duro-myo-arterio-pericranial synangiosis, is a safe and effective option to improve the short- and long-term outcome in patients with moyamoya disease. Alternative techniques are also described for specific cases with profound cerebral ischemia in the anterior cerebral artery or posterior cerebral artery territory. Special techniques to safely complete bypass surgery and avoid perioperative complications are presented, including methods to prevent delayed wound healing, to avoid facial nerve palsy after surgery, and to preserve the STA and middle meningeal artery during skin incision and craniotomy. Finally, the importance of careful management of patients is emphasized to reduce the incidence of perioperative complications, including ischemic stroke and hyperperfusion syndrome.

The role of autonomic nervous system in the pathophysiology of hemifacial spasm.

OBJECTIVES: Despite the vascular compression of the seventh cranial nerve has been verified by the microvascular decompression surgery as the cause of hemifacial spasm (HFS), the mechanism of the disease is still unknown. We believe that the autonomic nervous system in adventitia of the offending artery may contribute to the HFS. To prove our hypothesis, we performed an experiment in SD rats. METHODS: Moller's HFS model was adopted and the abnormal muscle response (AMR) wave was electrophysiologically monitored. With randomization, some HFS rats underwent exclusion of the offending artery or removal of the ipsilateral superior cervical ganglion. Some HFS rats with negative AMR following exclusion of the offending artery were dripped with norepinephrine onto the neurovascular conflict site. RESULTS: With exclusion of the offending artery, AMR disappeared in 14 (70%) of the 20 HFS rats, while in three (30%) of the 10 from sham operation group (P<0·05). With ganglionectomy, AMR disappeared in 12 (75%) of the 16 HFS rats, while in two (25%) of the eight from the sham operation group (P<0·05). With norepinephrine drip, AMR reappeared in four (67%) of the six from those offending-artery-excluded HFS rats, while in zero of the six from normal-saline-dripped group (P<0·05). DISCUSSION: The neurotransmitter releasing from the autonomic nervous endings in the worn adventitia of the offending artery may induce an ectopia action potential in those demyelinated facial nerve fibers expanding to the neuromuscular conjunction and trigger an attack of HFS.