Frontal Placement Research Articles

Evaluation of the capacity and effective angle of thalamic damage for 2 commercially available captive bolt tool types on cadaver heads from sows >200 kg body weight.

This study evaluated the ability of 2 penetrating captive bolt (PCB) types (PISTOL, INLINE) to reach and disrupt the thalamus when applied in 2 placements (FRONTAL, BEHIND EAR) to chilled cadaver heads (N = 60) from sows >200 kg. Heads were randomly distributed across 6 treatments (n = 10): FRONTAL-INLINE, FRONTAL-PISTOL, FRONTAL-NO SHOT, BEHIND EAR-INLINE, BEHIND EAR-PISTOL, and BEHIND EAR-NO SHOT. The FRONTAL shot was placed 3.5 cm superior to the optic orbits at the midline; the BEHIND EAR shot was placed directly caudal to the pinna of the ear on the same plane as the eyes and targeting the middle of the opposite eye. For INLINE treatments, a Jarvis PAS-Type C 0.25R Super Heavy Duty PCB with a Long Bolt and 6.0 GR power loads was used. For PISTOL treatments, a Jarvis PAS-Type P 0.25R Pistol PCB with a Long Stunning Rod Nosepiece Assembly and 3.5 GR power loads was used. Heads were split along the bolt with a band saw. Tissue depth measurements are reported as Mean ± SE followed by 97.5% one-sided upper reference limit (URL). Total tissue thickness was less (P < 0.0001) at the FRONTAL (56.31 ± 1.76 mm; URL: 73.17 mm) than the BEHIND EAR placement (95.52 ± 3.30 mm; URL: 126.53 mm). Thalamic depth was less (P < 0.0001) at the FRONTAL (78.31 ± 1.32 mm; URL: 88.19 mm) than the BEHIND EAR placement (111.86 ± 3.22 mm; URL: 135.99 mm). The effective angle was greater (P < 0.0001) at the FRONTAL (4.72 ± 0.20°) than the BEHIND EAR placement (3.22 ± 0.17°). Potential for bolt-brain contact was not different (P = 1.0000) between FRONTAL-INLINE (10/10, 100% ± 0.01%), FRONTAL-PISTOL (10/10, 100% ± 0.01%), BEHIND EAR-INLINE (9/10, 90% ± 9.49%), and BEHIND EAR-PISTOL (10/10, 100% ± 0.01%); brain damage (P = 0.5577) between FRONTAL-INLINE (9/9, 100% ± 0.02%), FRONTAL-PISTOL (10/10, 100% ± 0.02%), BEHIND EAR-INLINE (4/10, 40% ± 15.49%), and BEHIND EAR-PISTOL (1/10, 10% ± 9.49%); potential for bolt-thalamus contact (P = 0.0683) for FRONTAL-INLINE (2/10, 20% ± 12.65%), FRONTAL-PISTOL (8/10, 80% ± 12.65%), BEHIND EAR-INLINE (7/9, 77.78% ± 13.86%), and BEHIND EAR-PISTOL (9/9, 100% ± 0.02%); or thalamic damage (P = 0.8041) for FRONTAL-INLINE (1/10, 10% ± 9.49%), FRONTAL-PISTOL (1/10, 10% ± 9.49%), BEHIND EAR-INLINE (2/8, 25% ± 15.31%), and BEHIND EAR-PISTOL (0/9, 0% ± 0.00%). The FRONTAL placement with an INLINE PCB may present the least risk of failure for the PCB euthanasia of mature sows >200 kg body weight due to less total tissue thickness and thalamic depth, greater effective angle, and prevalent brain damage.

213 Evaluation of tissue depths and thalamic measurements for two captive bolt placements and types on cadaver heads from sows &amp;gt; 200 kg body weight

Abstract Penetrating captive bolt (PCB) is a common method of euthanasia for mature sows but limited data exist regarding PCB efficacy for these animals. Two PCB placements were evaluated on cadaver heads from sows with an estimated body weight (BW) of &amp;gt;200 kg (Mean ± SD: 225.4 ± 21.1 kg). The objectives were to determine the thalamic diameter, distance to the thalamus, effective angle, and tissue depths associated with the FRONTAL and BEHIND EAR PCB placements for sows &amp;gt;200 kg. Cadaver heads were obtained from sows (n = 60) from a regional slaughter establishment following electrical stunning, then cooled at 2-4°C for approximately 64 h. Heads were randomly assigned to one of six treatments (n = 10): FRONTAL-INLINE, FRONTAL-PISTOL, FRONTAL-NO SHOT, BEHIND EAR-INLINE, BEHIND EAR PISTOL, BEHIND EAR-NO SHOT. The FRONTAL placement was 3.5 cm superior to the optic orbits at midline; the BEHIND EAR placement was directly caudal to the pinna of the ear on the same plane as the eyes and targeting the middle of the opposite eye. For INLINE treatments, a Jarvis PAS-Type C 0.25R Super Heavy Duty PCB with a Long Bolt and 6.0 GR power load was used. For PISTOL treatments, a Jarvis PAS-Type P 0.25R with a Long Stunning Rod Nosepiece Assembly and 3.5 GR power load was used. All heads were split along the bolt path or theoretical bolt path using a band saw. Thalamic diameter, distance to thalamus, and effective angle were measured only on heads that received the NO SHOT treatment. Tissue depths were measured only for the heads that received the INLINE and PISTOL treatments. Comparisons between PCB placements were made using Student’s T Tests. All results are reported as Means±SE. There was no evidence to support a difference (P = 0.5163) in thalamic diameter between the FRONTAL (12.86 ± 0.40 mm) and BEHIND EAR (12.38 ± 0.60 mm) placements. The distance from the proper PCB placement to the thalamus was less (P &amp;lt; 0.0001) for the FRONTAL placement (78.31 ± 1.32 mm) than the BEHIND EAR placement (111.86 ± 3.22 mm). Effective angle was greater (P &amp;lt; 0.0001) for the FRONTAL placement (4.72 ± 0.20°) than the BEHIND EAR placement (3.22 ± 0.17°). Type of PCB did not impact tissue thicknesses, so PCB types were pooled for each placement. Soft tissue thickness was less (P &amp;lt; 0.0001) in the FRONTAL placement (7.83 ± 0.29 mm) than the BEHIND EAR placement (56.01 ± 3.25 mm). Cranial thickness was greater (P &amp;lt; 0.0001) in the FRONTAL placement (48.49 ± 1.81 mm) than the BEHIND EAR placement (39.51 ± 2.49 mm). Total tissue thickness was less (P &amp;lt; 0.0001) in the FRONTAL placement (56.31 ± 1.76 mm) than the BEHIND EAR placement (95.52 ± 3.30 mm). Overall, the data suggest that the FRONTAL placement may have a greater likelihood for successful euthanasia of sows &amp;gt;200 kg BW due to the lesser distance to the thalamus and total tissue thickness, as well as larger effective angle.

Quantification of cooling effects on basic tissue measurements and exposed cross-sectional brain area of cadaver heads from Holstein cows > 30 mo of age.

Penetrating captive bolt (PCB) is the primary method of preslaughter stunning for cattle and is also used for on-farm euthanasia. The objective of this study was to quantify the impact of cooling on the soft tissue thickness, cranial thickness, total tissue thickness, and cross-sectional brain area of cadaver heads collected from mature (> 30 mo of age) dairy cows following the application of a PCB stun in a frontal placement. Hide-on cadaver heads were obtained from culled dairy cows (N = 37) stunned in a frontal location using a handheld PCB device (Jarvis Model PAS-Type C 0.25R Caliber Captive Bolt, Long Bolt) at a commercial slaughter establishment. Following transport to the University of Wisconsin-River Falls, heads were split at midline along the bolt path by a bandsaw and then underwent FRESH, CHILL24, CHILL48, and CHILL72 refrigeration treatments. The FRESH treatment involved images collected immediately after splitting each head, the CHILL24 treatment involved images collected after 24h of refrigeration, the CHIL48 treatment involved images collected after 48h of refrigeration, and the CHILL72 treatment involved images collected after 72h of refrigeration. Measurements of soft tissue thickness, cranial thickness, total tissue thickness, and cross-sectional brain area were recorded for each refrigeration treatment. Soft tissue thickness did not differ caudal to (P = 0.3751) or rostral to (P = 0.2555) the bolt path. Cranial thickness did not differ caudal to (P = 0.9281) or rostral to (P = 0.9051) the bolt path. Total tissue thickness did not differ caudal to (P = 0.9225; FRESH: 24.77mm, CHILL24: 23.93mm, CHILL48: 24.27mm, CHILL72: 42.30, SE: 0.86) or rostral to (P = 0.8931; FRESH: 24.09mm, CHILL24: 23.99, CHILL48: 24.26, CHILL72: 24.43mm, SE: 0.79mm) the bolt path. Cross-sectional brain area was not different (P = 0.0971) between refrigeration treatments (FRESH: 9,829.65 ± 163.87mm2, CHILL24: 10,012.00 ± 163.87mm2, CHILL48: 9,672.43 ± 163.87mm2, CHILL72: 10,235.00 ± 166.34mm2). This study demonstrated that FRESH tissue parameters can be determined from cattle cadaver heads refrigerated for 24, 48, or 72h.

Evaluating the Potential of an Oral-Based Bioguard to Estimate Heart Rate Using Photoplethysmography.

The reliable monitoring of heart rate during intense exercise is imperative to effectively manage training loads while providing insights from a healthcare perspective. However, current technologies perform poorly in contact sports settings. This study aims to evaluate the best approach for heart rate tracking using photoplethysmography sensors embedded into an instrumented mouthguard (iMG). Seven adults wore iMGs and a reference heart rate monitor. Several sensor placements, light sources and signal intensities were explored for the iMG. A novel metric related to the positioning of the sensor in the gum was introduced. The error between the iMG heart rate and the reference data was assessed to obtain insights into the effect of specific iMG configurations on measurement errors. Signal intensity was found to be the most important variable for error prediction, followed by the sensor light source, sensor placement and positioning. A generalized linear model combining an infrared light source, at an intensity of 5.08 mA, and a frontal placement high in the gum area resulted in a heart rate minimum error of 16.33%. This research shows promising preliminary results for the use of oral-based heart rate monitoring, but highlights the need for the careful consideration of sensor configurations within these systems.

Supralabial Site: An Alternative Site for Bispectral Index Monitoring: A Cross-sectional Study

Abstract Background Bi-spectral index (BIS) has been traditionally used to monitor the depth of anesthesia, with the forehead being the usual site for electrode placement. When the manufacturer-recommended site is itself an operative field or the placement interferes with the surgery, the search for an alternative position of electrode placement is warranted. In our endeavor to do so, we conducted this study to compare BIS scores derived from frontal and supralabial electrode placement. Methods A cross-sectional study was conducted on a group of 50 patients using two BIS Quatro sensors attached to the frontal and supralabial regions of each patient and connected to two different sets of monitors. BIS values, electromyography (EMG) values, and signal quality index (SQI) were noted from both sites every 15 min during the maintenance phase of anesthesia. Collected data were analyzed using the Bland–Altman analysis. Results Data analysis of BIS values showed negative bias at most time points with a minimum negative bias of 0.2 with a limit of agreement of −3.67/3.27 and a maximum negative bias of 1.14 with a limit of agreement of −7.61/5.33. The overall 95% limit of agreement for pooled BIS data ranged from −6.63 to 6.1. Conclusion BIS sensor placement at the supralabial site can be used as an alternative to the frontal placement in scenarios where the frontal position is the surgical site or is inaccessible during the maintenance of general anesthesia as in neurosurgery with particular emphasis on skin preparation and proper positioning of BIS electrodes to improve the signal quality.

Technical Note: Validation of the effectiveness of electric stunning for euthanasia of mature swine (Sus scrofa domesticus).

Electrocution and the use of a penetrating captive bolt gun (PCBG) are both acceptable methods of euthanasia for market weight swine. Research has demonstrated that a PCBG is effective in both growing and mature swine. Given limited to no published research base on electrocution in mature swine, the objectives of the present study were to evaluate the efficacy of a two-stage (head only followed by head to heart, 10s contact for each) mobile electric stunner (E-STUN, Hubert HAAS TBG 96N) and to assess euthanasia outcomes when comparing E-STUN with the frontal placement of a heavy-duty PCBG (Jarvis, In-line Cylinder Style) when applied to heavy-weight (>200kg) mature boars and sows. Effectiveness of the E-STUN and PCBG was evaluated first in unconscious anesthetized mature swine (n = 7 boars and sows per treatment; average weight 282±48kg, n = 28) to reduce the risk of failure in a conscious animal and then in conscious mature swine (n = 3 boars and sows per treatment; average weight 282±63kg, n = 12). Data from both stages were combined for analyses. Treatment efficacy was defined as any pig that achieved cardiac and respiratory arrest within 10min after treatment application. A three-point traumatic brain injury score (0 = normal; 1 = some abnormalities; and 2 = grossly abnormal, unrecognizable) was used to evaluate six neuroanatomical structures (cerebral cortex, cerebellum, hypothalamus, thalamus, pons, and brain stem), and the presence of intracranial hemorrhage was also noted. All animals were immediately rendered insensible with E-STUN and PCBG, and no difference was noted between treatments for the detection of corneal reflex following treatment application (P = 0.11). Rhythmic breathing was absent following the administration of either E-STUN or PCBG. When evaluating the time to last heartbeat, there was a significant interaction between sex and treatment. Boars euthanized via E-STUN had a 346.8-s decrease in time to last heartbeat compared with boars euthanized via PCBG (P < 0.001), and females euthanized via E-STUN had a 479.3-s decrease in time to last heartbeat compared with females euthanized via PCBG (P < 0.001). Intracranial hemorrhage was common for both methods, and visible disruption of neural tissue was evident due to the physical nature of the PCBG. This study demonstrated that a mobile E-STUN system is as effective as a heavy-duty PCBG in inducing insensibility and death and shows promise as an alternative method for euthanizing mature pigs on-farm.

Validation of a nasal SedLine® sensor placement: Going beyond the forehead when depth of anesthesia is important

IntroductionSince the inception of general anesthesia, the assessment of anesthetic depth has been challenging and a goal that anesthesiologists constantly strive for. Nowadays, an increasing number of monitors allow us to have a more specific assessment of depth of anesthesia. However, the conventional sensor-lead positioning on the forehead recommended by manufacturers may sometimes coincide with the surgical field thereby posing a clinical challenge. This study compares the conventional frontal placement on the forehead with an experimental nasal placement for the standard Masimo SedLine® EEG sensor in surgical neuromonitoring, analyzing and comparing numeric values (Patient State Index-PSi) and EEG waveform traces. MethodsAuthors performed a single-center, observational, prospective study enrolling 40 patients under a standardized anesthesia protocol. Three contiguous time periods (induction, steady-state anesthesia and awakening) were used to stratify data analysis so that within-patient correlations between nasal and frontal readings could be examined by time period independently. ResultsA total of 106,209 matched numeric values and 3,543 min of EEG data from each sensor’s positions were collected from 40 patients. Total average alignment between two sensor positions, keeping in mind that 5 PSi units were used as acceptable limit of agreement, was 83.01% and p-values associated with R2 correlation coefficients were statistically significant at 0.001 level. Steady-state anesthesia phase alignment (with full muscle-relaxation), which present 73% of all collected data, show a concordance within 5 PSi unit alignment in 95.77%. One hundred and twenty tracings from 40 patients were presented to two epileptologists and inter-rater agreement or reliability was achieved in 88% of EEG-traces’ analysis. ConclusionsThe current results suggest that SedLine® Brain Function Monitoring sensor is acceptable for clinical use when standard sensor position in the forehead is not possible. This allows for the possibility of utilization of the sensor whenever the forehead placement cannot be utilized.

88 Foundational Investigations of Tissue Dimensions and Their Relation to Captive Bolt application Sites on Cadaver Heads from Mature Swine–A Preliminary Report

Abstract The objective of this study was to contrast the soft tissue thickness, cranial thickness, total tissue thickness, and cross-sectional brain area from the common frontal captive bolt placement for the captive bolt euthanasia of swine with the alternative temporal and caudal to pinna placements. One hundred and fifty-seven cadaver heads from sows and boars with estimated body weights greater than 200 kg were collected from a regional slaughter establishment following electrical stunning and assigned to the FRONTAL, TEMPORAL, or CAUDAL to pinna captive bolt placement treatments after cooling at 2–4°C for approximately 64 h. In sows, soft tissue thickness was different (P ˂ 0.0001) between the three placements (FRONTAL: 13.9±1.1 mm, TEMPORAL: 45.93±1.1 mm, CAUDAL TO PINNA: 53.8±1.1 mm), cranial thickness was different (P ˂ 0.0001) between the three placements (FRONTAL: 47.1±1.4 mm, TEMPORAL: 17.6±1.4 mm, CAUDAL TO PINNA: 30.2±1.4 mm), total tissue thickness was different (P &amp;lt; 0.0001) between the three placements (FRONTAL: 61.03±1.4 mm, TEMPORAL: 63.49±1.4 mm, CAUDAL TO PINNA: 84.05±1.4 mm), and cross-sectional brain area was different (P &amp;lt; 0.0001) between the three placements (FRONTAL: 4509.0±238.0 mm2, TEMPORAL: 1964.4±238.0 mm2, CAUDAL TO PINNA: 2767.5±238.0 mm2). In boars, soft tissue thickness was different (P &amp;lt; 0.0001) between the three placements (FRONTAL: 12.9±1.7mm, TEMPORAL: 45.3±1.7 mm, CAUDAL TO PINNA: 54.7±1.7 mm), cranial thickness was different (P = 0.0193) between the FRONTAL and TEMPORAL treatments (FRONTAL: 34.8±3.2mm, TEMPORAL: 22.1±3.2 mm, CAUDAL TO PINNA: 31.7±3.2 mm), total tissue thickness was different (P &amp;lt; 0.0001) between the three placements (FRONTAL: 47.7±3.2 mm, TEMPORAL: 67.4±3.2 mm, CAUDAL TO PINNA: 86.4±3.2mm), and cross-sectional brain area was different (P &amp;lt; 0.0001) between the three placements (FRONTAL: 4031.9±153.2mm2, TEMPORAL: 1241.8±153.2 mm2, CAUDAL TO PINNA: 2467.5±153.2 mm2). Overall, the preliminary data indicated that the FRONTAL placement appears to have the greatest likelihood for successful euthanasia and may present less risk than the alternative TEMPORAL or CAUDAL TO PINNA placements.

Validating the effectiveness of alternative euthanasia techniques using penetrating captive bolt guns in mature swine (Sus scrofa domesticus).

Euthanasia of mature swine is challenging. Temporal and behind-the-ear locations are two sites that have been identified as alternatives to the more commonly used frontal placement. In stage one, the effectiveness of two penetrating captive bolt gun styles (cylinder or pistol) was evaluated using frontal, temporal, and behind-the-ear placement in anesthetized mature swine (n = 36; weight: 267 ± 41 kg). For stage one, when evaluating treatment efficacy by sex, the cylinder-style equipment was 100% effective in achieving death when applied to all cranial locations (frontal, temporal, and behind-the-ear) for sows; however, the pistol-style equipment was only 100% effective when applied at the behind-the-ear location for sows. For boars, the cylinder-style equipment was 100% effective when applied to the frontal and behind-the-ear location, but the pistol-style equipment was not effective for any cranial location in boars. Therefore, the pistol-frontal, pistol-temporal, pistol-behind-the-ear, and cylinder-temporal were not included for boars, and pistol-frontal and pistol-temporal were not included for sows in stage two. In stage two, commercial, mixed-breed, mature swine (n = 42; weight: 292 +/- 56 kg) were randomly assigned to one of four treatments based on the inclusion criteria described in stage one. A three-point traumatic brain injury (TBI) score (0 = normal; 1 = some abnormalities; 2 = grossly abnormal, unrecognizable) was used to evaluate six neuroanatomical structures (cerebral cortex, cerebellum, hypothalamus, thalamus, pons, and brain stem), and the presence of hemorrhage was also noted. All treatments were 100% effective in stage two. A significant interaction between gun style and placement was determined on predicting total TBI as the cylinder style produced a higher total TBI score compared with the pistol type of the magnitude of +2.8 (P < 0.01). The cylinder style tended to produce a greater TBI score than the pistol in the temporal location (+1.2; P = 0.08). No difference was noted for TBI score behind-the-ear between the cylinder- and pistol-style gun (P > 0.05). TBI tended to be less in boars compared with sows (-0.6; P = 0.08). Hemorrhage was observed in frontal, parietal, occipital, and temporal lobes. This study demonstrated that the cylinder-style captive bolt gun more effectively resulted in brain trauma and death compared with a pistol-style gun and the behind-the-ear and temporal placement showed promise as an alternative placement site for euthanizing mature pigs on-farm.

Frontal placement of subdural drain for subdural hemorrhage: A single center experience

Placing a drain following evacuation of Chronic Subdural Hemorrhage (CSDH) has beneficial outcome for patients. The placement of the drain’s tip however is debatable as it has different rationale among neurosurgeons. Objective: The objective is to see whether the outcome is satisfactory by putting the tip of the drain at the frontal region of the sub dural space. Methodology: We retrospectively studied all patients who had CSDH underwent surgery in our center between January 2013 to December 2016. A total of 34 patients with CSDH underwent drilling of one burr hole and irrigation of CSDH. Silicone catheter placed in the sub dural space and the tip of the drain in the frontal region. We measured the SDH volume reduction and volume of pneumocranium post operatively as our outcomes of the study. Results: The mean reduction of SDH volume after surgery is 8.11 cc (73%), while the mean volume of pneumocranium post SDH drainage is 1.58 cc with a range of 0 cc to 9 cc. The mean Global Outcome Score is 2.85 and the recurrence, which need re-operation are 2 cases (6%). Conclusion: The retrospective case series shows a good potential outcome based on the reduction of SDH volume after surgery. A proper randomized trial is needed to determine the efficacy of the frontal placement of the subdural catheter for a comparable outcome.

Anesthesia depth monitoring using alternative placement of entropy sensors: a prospective study.

Spectral entropy is based on analysis of variations in electroencephalography and frontal electromyography, and is a safe and reliable method for anesthesia depth monitoring. However, standard frontal positioning of entropy electrodes in patients undergoing cardiac surgery is sometimes challenging. The present study aimed to compare standard entropy sensor placement with an alternative (infraorbital) site. This prospective study included 20 patients who underwent cardiovascular surgery at the authors' center. Monitoring was performed with standard and alternative entropy electrode positions from patient admission to surgery to transfer to the intensive care unit. Data were recorded every 15s; all data were analyzed and compared using Bland-Altman, scatter plot with Pearson correlation coefficient, and sensitivity/specificity analyses. Overall, 20,784 pairs of response entropy (RE) and state entropy (SE) indexes were collected. Bland-Altman analysis revealed a mean difference in RE of 0.37 (95% LOA - 7.09, 7.88) and SE 0.69 (95% LOA - 5.95, 7.31); with 3.46% (720/20,784) RE and 3.40% (706/10,790) SE values lying outside of the limits of agreement. Correlation analysis revealed strong positive correlation in both cases: RE, r = 0.983, p < 0.05; SE, r = 0.984; p < 0.05. Sensitivity/specificity analysis revealed 98.1% sensitivity, 93.3% specificity and 97.1% test efficiency for RE, and 99.2%, 95.1% and 98.5% for SE, respectively. Infraorbital entropy sensor placement in patients undergoing cardiovascular surgery is reliable and effective. The strong positive correlation between the two methods of registration enables alternative entropy measurement when frontal placement is not possible.

Dynamic Ensemble Analysis of Frontal Placement Impacts in the Presence of Elevated Thunderstorms during PRECIP Events

The Program for Research on Elevated Convection with Intense Precipitation (PRECIP) field campaign sampled 10 cases of elevated convection during 2014 and 2015. These intense observing periods (IOP) mostly featured well-defined stationary or warm frontal zones, over whose inversion elevated convection would form. However, not all frontal zones translated as expected, with some poleward motions being arrested and even returning equatorward. Prior analyses of the observed data highlighted the downdrafts in these events, especially diagnostics for their behavior: the downdraft convective available potential energy (DCAPE) and the downdraft convective inhibition (DCIN). With the current study, the DCAPE and DCIN are examined for four cases: two where frontal motion proceeded poleward, as expected, and two where the frontal motions were slowed significantly or stalled altogether. Using the Weather Research and Forecasting (WRF) model, a multi-model ensemble was created for each of the four cases, and the best performing members were selected for additional deterministic examination. Analyses of frontal motions and surface cold pools are explored in the context of DCAPE and DCIN. These analyses further establish the DCAPE and DCIN, not only as a means to classify elevated convection, but also to aid in explaining frontal motions in the presence of elevated convection.

Examination of feline extraocular motoneuron pools as a function of muscle fiber innervation type and muscle layer.

This study explores two points related to the pattern of innervation of the extraocular muscles. First, species differences exist in the location of the motoneurons supplying multiply innervated fibers (MIFs) and singly innervated fibers (SIFs) in eye muscles. MIF motoneurons are located outside the extraocular nuclei in primates, but are intermixed with SIF motoneurons within rat extraocular nuclei. To test whether this difference is related to visual capacity and frontal placement of eyes, we injected retrograde tracers into the medial rectus muscle of the cat, a highly visual nonprimate with frontally placed eyes. Distal injections labeled smaller MIF motoneurons located ventrolaterally and rostrally within the oculomotor nucleus (III). More central injections also labeled a separate population of larger cells located dorsally in III. Thus, the cat shares with the nocturnal rat the feature of having MIF motoneurons located within the bounds of III. On the other hand, just as with monkeys, cats show segregation of the MIF and SIF medial rectus motoneuron pools, albeit in a different pattern. Second, extraocular muscles are divided into two layers; the inner, global layer inserts into the sclera, and the outer, orbital layer inserts into the connective tissue pulley. To test whether these layers are supplied by anatomically discrete motoneuron pools, we injected tracer into the orbital layer of the cat lateral rectus muscle. No evidence of either morphological or distributional differences was found, suggesting that the functional differences in these layers may be due mainly to their orbital anatomy, not their innervation. J. Comp. Neurol. 525:919-935, 2017. © 2016 Wiley Periodicals, Inc.

A hybrid procedure for classifying synoptic weather types for Louisiana, USA

ABSTRACTA hybrid synoptic classification procedure for classifying Louisiana weather types based on the manual Muller system is presented. This procedure produces a synoptic classification system for Louisiana that harnesses the strengths of both manual and automated classifications, while eliminating the weaknesses. The Muller weather types archive from 1981 to 2001 is used in conjunction with the National Center for Atmospheric Research (NCAR)/National Centers for Environmental Prediction (NCEP) Reanalysis dataset to develop sea level pressure composites for each Muller weather type. The composites are used as seeds in an automated correlation‐based algorithm to generate weather types from 1981 to 2001. Results of the automated procedure are compared to the Muller weather type catalog. Despite systematic differences between the two classifications, including the inability of the hybrid procedure to identify frontal placement, the hybrid classification correctly matched the Muller weather type for 52% of the seed days. In addition, the automated catalog captured the seasonal distribution and interannual variability of the Muller types remarkably well. The hybrid synoptic weather classification system applied to weather properties at Shreveport and New Orleans showed significant differences between weather types. The automated procedure does not replicate the Muller weather type classification exactly; however, it is homogenous within itself and has value for describing the variability of surface weather in Louisiana. In fact, it is arguably advantageous for some applications, owing to its objectivity, speed, and reproducibility.

In-Office Use of a Steroid-Eluting Implant for Maintenance of Frontal Ostial Patency after Revision Sinus Surgery

Achieving long-term, successful outcomes with endoscopic sinus surgery (ESS) can be challenging in patients with recalcitrant chronic rhinosinusitis (CRS). Local complications, including scar formation and ostial stenosis, can lead to recurrent blockage and subsequent relapse. The frontal sinus is particularly vulnerable to surgical failure given its narrow outflow and inaccessibility to topical therapies. The advent of steroid-eluting sinus implants has enhanced ESS outcomes, with significant reductions in synechiae, inflammation, and secondary postoperative interventions when placed in the ethmoid cavity. However, use of this technology in the frontal sinus has yet to be described. The purpose of this report is to present two cases, in which in-office frontal placement of a mometasone furoate (MF)-eluting implant facilitated maintenance of ostial patency after revision ESS. The clinical presentation, in-office intervention, and treatment outcomes were examined. Two patients (male, 63 and 68 years of age) with a history of multiple ESS presented with recurrent unilateral frontal headache refractory to medical therapy. Nasal endoscopy/imaging revealed frontal sinus outflow obstruction. Both declined revision ESS under general anesthesia and underwent endoscopic frontal sinustomy/ostial dilation in the clinic. A MF-eluting implant was placed in the frontal sinus at the end of the procedure, with preservation of ostial patency upon last follow-up at 3 and 11 months, respectively. In-office placement of a MF-eluting implant successfully maintained frontal ostial patency in patients with a history of multiple ESS. Additional randomized trials are necessary to determine statistical significance, cost-effectiveness analysis, and long-term efficacy of frontal sinus implantation.

Catatonia: Clinical Aspects and Neurobiological Correlates

Catatonia is a neuropsychiatric syndrome that can occur due to medical or psychiatric disorder. This review synthesizes over 20 years of original research and comprehensive review articles with attention to the most recent findings. Though catatonia is common and highly treatable, there have been few research studies investigating the syndrome. Pooled case reports suggest that catatonia due to an underlying general medical condition and catatonia due to a psychiatric illness can be treated similarly and that the catatonic symptoms and the underlying illness must be addressed in both types. Benzodiazepines and ECT continue to be mainstays of treatment. Evidence is mounting for the use of NMDA antagonists in catatonia refractory to lorazepam.

Perioperative risk factors for short term shunt revisions in adult hydrocephalus patients

Objectives:The aim of this study was to prospectively study perioperative variables associated with revision after shunt surgery for adult hydrocephalus.Methods:Two protocols were designed to prospectively study perioperative risk factors during...

The pigeon's distant visual acuity as a function of viewing angle

Distant visual acuity was determined for several viewing angles in two restrained White Carneaux pigeons. The behavioral technique was a classical conditioning procedure that paired presentation of sinusoidal gratings with shock. A conditioned heart rate acceleration during the grating presentation indicated resolution of the grating. The birds' acuity was fairly uniform across a large range of their lateral visual field; performance decreased slightly for posterior stimulus placement and sharply for frontal placements. The data suggest that foveal viewing is relatively less advantageous for acuity in pigeons than in humans. The data are also consistent with the current view that pigeons are myopic in frontal vision.

Age differences in the contingent negative variation (CNV): reduced frontal activity in the elderly.

The effects of distraction on the contingent negative variation (CNV) were investigated in a group of 11 elderly (mean = 72.2 years) and a group of 12 young (mean = 23.3 years) subjects. Scalp electrical activity was recorded from midline sites at frontal, central, and parietal locations. Three experimental conditions included Recall, No Recall, and Control situations. In the Recall, or distraction condition, spoken consonant-vowel-consonant (CVC) letters were presented concurrently with the CNV signal interval and were recalled by the subjects after each trial. The No Recall condition was similar to the Recall task except that subjects were not required to repeat the CVSs. The Control condition presented a standard S1 - S2 CNV situation without CVCs. Amplitudes of the CNV, reaction times (RTs), and heart rate (HR) served as indices of distraction. The effects of distraction for both age groups indicated reduced CNVs, lengthened RTs, and elevated HRs. However, a significant age by electrode interaction revealed that while CNV amplitudes at central and parietal sites were comparable between age groups, amplitudes at the frontal placement were consistently reduced in the elderly compared to the young in all conditions. The finding of diminished frontal activity, as measured by the CNV, suggests a process of selective cortical aging and possible cellular loss which may be linked to performance deficits.

Masking in audiometry. III. Reflections upon the present position.

The rules governing the use of masking in air and bone conduction audio-metry are discussed and the situations leading to cross-hearing are presented. The advantages and disadvantages of the bone conduction masking procedure (Rainville) are considered. The authors at present prefer a frontal placement of the bone conduction receiver, the masking noise being led to the ear by an ear canal insert. The latter increases the interaural attenuation by 15 to 20 db and thus facilitates bone conduction audiometry.