Imaging lipophilic regions in rodent brain tissue with halogenated BODIPY probes.

The effect of halogen substitution in fluorescent BODIPY species was evaluated in the context of staining lipids in situ within brain tissue sections. Herein we demonstrate that the halogenated species maintain their known in vitro affinity when applied to detect lipids in situ in brain tissue sections. Interestingly, the chlorine substituted compound revealed the highest specificify for white matter lipids. Furthermore, the halogen substituted compounds rapidly detected lipid enriched cells, in situ, associated with a case of brain pathology and neuroinflammation.

Is a difficult gallbladder worth removing in its entirety? - Outcomes of subtotal cholecystectomy.

BACKGROUND: Laparoscopic Cholecystectomy one of the commonest procedures performed worldwide isn't spared from the risks of disastrous iatrogenic complications. In patients with obscured anatomy, the idea of performing a safe total cholecystectomy can be hindered with a high risk of biliovascular injuries. In such a situation STC (subtotal cholecystectomy) comes to the rescue, where the diseased organ can be tackled fairly, without any further damage. AIMS AND OBJECTIVES: The primary aim was to look at the immediate and long-term outcomes of subtotal cholecystectomy. Subgroup analysis was done based on demographics, indications and surgical approach. MATERIALS AND METHODS: We reviewed our prospectively maintained computerized operation database over nine years. STC was defined as leaving behind any portion of gallbladder other than the cystic duct. They were subclassified as per the description given by Palanivelu. Patients were evaluated with laboratory and radiological assessment. RESULTS: A total of 70 out of 602 patients (11.6%) underwent STC. Dense adhesion at the calot's was the most important reason for STC. Subtype B was the most common. Nine patients (12.85%) had a bile leak in the postoperative period. There were no biliary/vascular injuries and 30-day mortality was zero. 22.8% developed SSI (surgical site infection). Over a median follow up of 38 months (range 5-98), clinical examination, LFT and USG revealed no abnormality in any of the patients. CONCLUSION: Subtotal cholecystectomy is a useful alternative during difficult gallbladder surgery. It should be considered early into the procedure preferably prior to conversion to an open procedure. Biliovascular injuries can be avoided and the Immediate and long-term outcomes are acceptable.

Distributed representation of vocalization pitch in marmoset primary auditory cortex.

The pitch of vocalizations is a key communication feature aiding recognition of individuals and separating sound sources in complex acoustic environments. The neural representation of the pitch of periodic sounds is well defined. However, many natural sounds, like complex vocalizations, contain rich, aperiodic or not strictly periodic frequency content and/or include high-frequency components, but still evoke a strong sense of pitch. Indeed, such sounds are the rule, not the exception but the cortical mechanisms for encoding pitch of such sounds are unknown. We investigated how neurons in the high-frequency representation of primary auditory cortex (A1) of marmosets encoded changes in pitch of four natural vocalizations, two centred around a dominant frequency similar to the neuron's best sensitivity and two around a much lower dominant frequency. Pitch was varied over a fine range that can be used by marmosets to differentiate individuals. The responses of most high-frequency A1 neurons were sensitive to pitch changes in all four vocalizations, with a smaller proportion of the neurons showing pitch-insensitive responses. Classically defined excitatory drive, from the neuron's monaural frequency response area, predicted responses to changes in vocalization pitch in <30% of neurons suggesting most pitch tuning observed is not simple frequency-level response. Moreover, 39% of A1 neurons showed call-invariant tuning of pitch. These results suggest that distributed activity across A1 can represent the pitch of natural sounds over a fine, functionally relevant range, and exhibits pitch tuning for vocalizations within and outside the classical neural tuning area.

Auditory motion does not modulate spiking activity in the middle temporal and medial superior temporal visual areas.

The integration of multiple sensory modalities is a key aspect of brain function, allowing animals to take advantage of concurrent sources of information to make more accurate perceptual judgments. For many years, multisensory integration in the cerebral cortex was deemed to occur only in high-level "polysensory" association areas. However, more recent studies have suggested that cross-modal stimulation can also influence neural activity in areas traditionally considered to be unimodal. In particular, several human neuroimaging studies have reported that extrastriate areas involved in visual motion perception are also activated by auditory motion, and may integrate audiovisual motion cues. However, the exact nature and extent of the effects of auditory motion on the visual cortex have not been studied at the single neuron level. We recorded the spiking activity of neurons in the middle temporal (MT) and medial superior temporal (MST) areas of anesthetized marmoset monkeys upon presentation of unimodal stimuli (moving auditory or visual patterns), as well as bimodal stimuli (concurrent audiovisual motion). Despite robust, direction selective responses to visual motion, none of the sampled neurons responded to auditory motion stimuli. Moreover, concurrent moving auditory stimuli had no significant effect on the ability of single MT and MST neurons, or populations of simultaneously recorded neurons, to discriminate the direction of motion of visual stimuli (moving random dot patterns with varying levels of motion noise). Our findings do not support the hypothesis that direct interactions between MT, MST and areas low in the hierarchy of auditory areas underlie audiovisual motion integration.

Laminar-specific encoding of texture elements in rat barrel cortex.

KEY POINTS: For rats texture discrimination is signalled by the large face whiskers by stick-slip events. Neural encoding of repetitive stick-slip events will be influenced by intrinsic properties of adaptation. We show that texture coding in the barrel cortex is laminar specific and follows a power function. Our results also show layer 2 codes for novel feature elements via robust firing rates and temporal fidelity. We conclude that texture coding relies on a subtle neural ensemble to provide important object information. ABSTRACT: Texture discrimination by rats is exquisitely guided by fine-grain mechanical stick-slip motions of the face whiskers as they encounter, stick to and slip past successive texture-defining surface features such as bumps and grooves. Neural encoding of successive stick-slip texture events will be shaped by adaptation, common to all sensory systems, whereby receptor and neural responses to a stimulus are affected by responses to preceding stimuli, allowing resetting to signal novel information. Additionally, when a whisker is actively moved to contact and brush over surfaces, that motion itself generates neural responses that could cause adaptation of responses to subsequent stick-slip events. Nothing is known about encoding in the rat whisker system of stick-slip events defining textures of different grain or the influence of adaptation from whisker protraction or successive texture-defining stick-slip events. Here we recorded responses from halothane-anaesthetized rats in response to texture-defining stimuli applied to passive whiskers. We demonstrate that: across the columnar network of the whisker-recipient barrel cortex, adaptation in response to repetitive stick-slip events is strongest in uppermost layers and equally lower thereafter; neither whisker protraction speed nor stick-slip frequency impede encoding of stick-slip events at rates up to 34.08 Hz; and layer 2 normalizes responses to whisker protraction to resist effects on texture signalling. Thus, within laminar-specific response patterns, barrel cortex reliably encodes texture-defining elements even to high frequencies.

Sensitivity of neurons in the middle temporal area of marmoset monkeys to random dot motion.

Neurons in the middle temporal area (MT) of the primate cerebral cortex respond to moving visual stimuli. The sensitivity of MT neurons to motion signals can be characterized by using random-dot stimuli, in which the strength of the motion signal is manipulated by adding different levels of noise (elements that move in random directions). In macaques, this has allowed the calculation of "neurometric" thresholds. We characterized the responses of MT neurons in sufentanil/nitrous oxide-anesthetized marmoset monkeys, a species that has attracted considerable recent interest as an animal model for vision research. We found that MT neurons show a wide range of neurometric thresholds and that the responses of the most sensitive neurons could account for the behavioral performance of macaques and humans. We also investigated factors that contributed to the wide range of observed thresholds. The difference in firing rate between responses to motion in the preferred and null directions was the most effective predictor of neurometric threshold, whereas the direction tuning bandwidth had no correlation with the threshold. We also showed that it is possible to obtain reliable estimates of neurometric thresholds using stimuli that were not highly optimized for each neuron, as is often necessary when recording from large populations of neurons with different receptive field concurrently, as was the case in this study. These results demonstrate that marmoset MT shows an essential physiological similarity to macaque MT and suggest that its neurons are capable of representing motion signals that allow for comparable motion-in-noise judgments.NEW & NOTEWORTHY We report the activity of neurons in marmoset MT in response to random-dot motion stimuli of varying coherence. The information carried by individual MT neurons was comparable to that of the macaque, and the maximum firing rates were a strong predictor of sensitivity. Our study provides key information regarding the neural basis of motion perception in the marmoset, a small primate species that is becoming increasingly popular as an experimental model.

Direct current stimulation of prefrontal cortex modulates error-induced behavioral adjustments.

Commission of errors and conflict between choices might induce behavioral modulations through adjustments in the executive control of behavior and altered patterns of these modulations are detected in neuropsychiatric disorders. We examined the effects of transcranial Direct Current Stimulation (tDCS) applied over the dorsolateral prefrontal cortex (DLPFC) on error- and conflict-induced behavioral modulations. Two separate cohorts of participants performed two clinically relevant tests of executive control, respectively. In the Wisconsin Card Sorting Test (WCST), the relevant rule for matching items frequently changed and therefore participants had to detect these unannounced changes by trial and error and alter their rule-based behavior. In the Stop task, participants had to rapidly respond to a directional go-signal but inhibit their responses when a stop signal appeared after the go-signal. Each participant received tDCS (sham, cathodal or anodal) in three separate sessions. Errors led to a slower response in the next trial (post-error slowing) in both tasks. The tDCS significantly modulated the post-error slowing in both tasks but did not affect the behavioral adjustments induced by the conflict. The modulation of post-error slowing by tDCS were polarity-dependent and also trial specific appearing immediately after errors. In the WCST and Stop task, the post-error slowing may reflect different processes involved in shifting the behavior-guiding rule and adjustments in inhibitory control of responses, respectively, and we found that the effective tDCS polarity differed between the two tasks. Here, we show that in two separate cognitive tasks direct current stimulation of DLPFC significantly modulated error-induced behavioral modulations.

Effect of background noise on neuronal coding of interaural level difference cues in rat inferior colliculus.

Humans can accurately localize sounds even in unfavourable signal-to-noise conditions. To investigate the neural mechanisms underlying this, we studied the effect of background wide-band noise on neural sensitivity to variations in interaural level difference (ILD), the predominant cue for sound localization in azimuth for high-frequency sounds, at the characteristic frequency of cells in rat inferior colliculus (IC). Binaural noise at high levels generally resulted in suppression of responses (55.8%), but at lower levels resulted in enhancement (34.8%) as well as suppression (30.3%). When recording conditions permitted, we then examined if any binaural noise effects were related to selective noise effects at each of the two ears, which we interpreted in light of well-known differences in input type (excitation and inhibition) from each ear shaping particular forms of ILD sensitivity in the IC. At high signal-to-noise ratios (SNR), in most ILD functions (41%), the effect of background noise appeared to be due to effects on inputs from both ears, while for a large percentage (35.8%) appeared to be accounted for by effects on excitatory input. However, as SNR decreased, change in excitation became the dominant contributor to the change due to binaural background noise (63.6%). These novel findings shed light on the IC neural mechanisms for sound localization in the presence of continuous background noise. They also suggest that some effects of background noise on encoding of sound location reported to be emergent in upstream auditory areas can also be observed at the level of the midbrain.

Scanning electron microscopic analysis of pancreatic tissue in alcoholic and tropical chronic pancreatitis.

INTRODUCTION: Chronic Pancreatitis (CP) is a heterogenous disease with alcoholic chronic pancreatitis (ACP) dominating in the West, and idiopathic or tropical chronic pancreatitis (TCP) in the tropics. The aim of this study is to assess the feasibility of using a scanning electron microscope (SEM) to analyze the ultra-structural changes in alcoholic and tropical subtypes of CP. METHODS: Chronic pancreatitis tissue samples were taken from the biopsy samples of 16 patients (seven ACP and nine TCP) who underwent drainage procedures for CP. These samples were subjected to SEM analysis and findings of normal pancreas were compared with those of CP for appreciating differences in their architectural changes. RESULTS: Normal architecture of pancreas could be observed as lobules of parenchyma, ductal system and definite loci of Islets of Langerhans (IOL). CP samples showed loss of architecture in the form of severe fibrosis and calcifications. In ACP, the fibrosis was predominantly seen towards the periphery of the gland sparing the periductal areas. These fibres were strangulating and damaging the parenchyma. Crystals were seen over these fibres. In TCP, fibrosis was moderate and uniform throughout the parenchyma. Moreover the crystals were larger and intraluminal. Total fatty replacement of parenchyma was a striking feature in TCP, seen exclusively in diabetics with gross atrophy of IOL. CONCLUSION: SEM gives the real-life pictures of fibrosis, fatty change, ductal changes, calcifications and thus the actual extent of damage in CP better than the ordinary light microscopy.

Role of Pancreatic Attenuation Index in Assessing Pancreatic Fat Content and Postpancreatectomy Outcomes.

Background High fat content of pancreas can contribute to its soft texture, which is a strong predictor for postoperative pancreatic fistula (POPF). We propose to assess the relationship of pancreatic computed tomography (CT) attenuation index (PAI) with histopathological fat content of pancreas and postpancreatectomy outcomes. Methodology Data was collected prospectively from patients who underwent pancreatic resections from February 2021 to January 2023. CT attenuation was measured in pancreas and spleen in three regions of interest each. The mean of the three values was taken as the mean pancreatic attenuation (P) and splenic attenuation(S). PAI was calculated (P-S and P/S) preoperatively. The fat content was calculated histologically in resected specimens. The pancreatic texture was also assessed intraoperatively by the operating surgeon to classify it as soft or firm. The relationship of PAI with fat content and postpancreatectomy outcomes such as delayed gastric emptying (DGE), postpancreatectomy hemorrhage (PPH) and POPF was assessed. Results Seventy patients underwent pancreatic resections of which 59 were taken for analysis after satisfying the exclusion criteria. The PAI ranged from P-S (-23 to +19) and P/S (0.54-1.5). The histologic fat content of pancreas ranged from 0.4 to 42% (mean= 9.5076/standard deviation: 9.19520). Significant correlation was found between P-S and P/S (Spearman's rank correlation coefficient ρ = -0.775[95% confidence interval [CI]: -0.919 to -0.583], -0.743[95% CI: -0.896 to -0.467]) with pancreatic fat content. Postpancreatectomy outcomes noted were POPF(B/C):13, DGE:33, and PPH:3. Statistical significance was not seen between PAI and postpancreatectomy outcomes (POPF, p = 0.067 DGE; p = 0.456; PPH, p = 0.891). Conclusion PAI may be used as a reliable tool in predicting pancreatic fat content. However, it did not show a statistically significant association in predicting postpancreatectomy outcomes.

Auditory cortex of the marmoset monkey - complex responses to tones and vocalizations under opiate anaesthesia in core and belt areas.

Many anaesthetics commonly used in auditory research severely depress cortical responses, particularly in the supragranular layers of the primary auditory cortex and in non-primary areas. This is particularly true when stimuli other than simple tones are presented. Although awake preparations allow better preservation of the neuronal responses, there is an inherent limitation to this approach whenever the physiological data need to be combined with histological reconstruction or anatomical tracing. Here we tested the efficacy of an opiate-based anaesthetic regime to study physiological responses in the primary auditory cortex and middle lateral belt area. Adult marmosets were anaesthetized using a combination of sufentanil (8 µg/kg/h, i.v.) and N2 O (70%). Unit activity was recorded throughout the cortical layers, in response to auditory stimuli presented binaurally. Stimuli consisted of a battery of tones presented at different intensities, as well as two marmoset calls ('Tsik' and 'Twitter'). In addition to robust monotonic and non-monotonic responses to tones, we found that the neuronal activity reflected various aspects of the calls, including 'on' and 'off' components, and temporal fluctuations. Both phasic and tonic activities, as well as excitatory and inhibitory components, were observed. Furthermore, a late component (100-250 ms post-offset) was apparent. Our results indicate that the sufentanil/N2 O combination allows better preservation of response patterns in both the core and belt auditory cortex, in comparison with anaesthetics usually employed in auditory physiology. This anaesthetic regime holds promise in enabling the physiological study of complex auditory responses in acute preparations, combined with detailed anatomical and histological investigation.

The discrimination of interaural level difference sensitivity functions: development of a taxonomic data template for modelling.

BACKGROUND: A major cue for the position of a high-frequency sound source in azimuth is the difference in sound pressure levels in the two ears, Interaural Level Differences (ILDs), as a sound is presented from different positions around the head. This study aims to use data classification techniques to build a descriptive model of electro-physiologically determined neuronal sensitivity functions for ILDs. The ILDs were recorded from neurons in the central nucleus of the Inferior Colliculus (ICc), an obligatory midbrain auditory relay nucleus. The majority of ICc neurons (~ 85%) show sensitivity to ILDs but with a variety of different forms that are often difficult to unambiguously separate into different information-bearing types. Thus, this division is often based on laboratory-specific and relatively subjective criteria. Given the subjectivity and non-uniformity of ILD classification methods in use, we examined if objective data classification techniques for this purpose. Our key objectives were to determine if we could find an analytical method (A) to validate the presence of four typical ILD sensitivity functions as is commonly assumed in the field, and (B) whether this method produced classifications that mapped on to the physiologically observed results. METHODS: The three-step data classification procedure forms the basic methodology of this manuscript. In this three-step procedure, several data normalization techniques were first tested to select a suitable normalization technique to our data. This was then followed by PCA to reduce data dimensionality without losing the core characteristics of the data. Finally Cluster Analysis technique was applied to determine the number of clustered data with the aid of the CCC and Inconsistency Coefficient values. RESULTS: The outcome of a three-step analytical data classification process was the identification of seven distinctive forms of ILD functions. These seven ILD function classes were found to map to the four "known" ideal ILD sensitivity function types, namely: Sigmoidal-EI, Sigmoidal-IE, Peaked, and Insensitive, ILD functions, and variations within these classes. This indicates that these seven templates can be utilized in future modelling studies. CONCLUSIONS: We developed a taxonomy of ILD sensitivity functions using a methodological data classification approach. The number and types of generic ILD function patterns found with this method mapped well on to our electrophysiologically determined ILD sensitivity functions. While a larger data set of the latter functions may bring a more robust outcome, this good mapping is encouraging in providing a principled method for classifying such data sets, and could be well extended to other such neuronal sensitivity functions, such as contrast tuning in vision.

Diffuse traumatic brain injury and the sensory brain.

In this review we discuss the consequences to the brain's cortex, specifically to the sensory cortex, of traumatic brain injury. The thesis underlying this approach is that long-term deficits in cognition seen after brain damage in humans are likely underpinned by an impaired cortical processing of the sensory information needed to drive cognition or to be used by cognitive processes to produce a response. We take it here that the impairment to sensory processing does not arise from damage to peripheral sensory systems, but from disordered brain processing of sensory input.

Discriminating spatialised speech in complex environments in multiple sclerosis.

People with multiple sclerosis (pwMS) frequently present with deficits in binaural processing used for sound localization. This study examined spatial release from speech-on-speech masking in pwMS, which involves binaural processing and additional higher level mechanisms underlying streaming, such as spatial attention. 26 pwMS with mild severity (Expanded Disability Status Scale score <3) and 20 age-matched controls listened via headphones to pre-recorded sentences from a standard list presented simultaneously with eight-talker babble. Virtual acoustic techniques were used to simulate sentences originating from 0°, 20°, or 50° on the interaural horizontal plane around the listener whilst babble was presented continuously at 0° azimuth, and participants verbally repeated the target sentence. In a separate task, two simultaneous sentences both containing a colour and number were presented, and participants were required to report the target colour and number. Both competing sentences could originate from 0°, 20°, or 50° on the azimuthal plane. Participants also completed a series of neuropsychological assessments, an auditory questionnaire, and a three-alternative forced-choice task that involved the detection of interaural time differences (ITDs) in noise bursts. Spatial release from masking was observed in both pwMS and controls, as response accuracy in the two speech discrimination tasks improved in the spatially separated conditions (20° and 50°) compared with the co-localised condition. However, pwMS demonstrated significantly less spatial release (18%) than controls (28%) when discriminating colour/number coordinates. At 50° separation, pwMS discriminated significantly fewer coordinates (77%) than controls (89%). In contrast, pwMS had similar performances to controls when sentences were presented in babble, and for the basic ITD discrimination task. Significant correlations between speech discrimination performance and standardized neuropsychological scores were observed across all spatial conditions. Our findings suggest that spatial hearing is likely to be implicated in pwMS, thereby affecting the perception of competing speech originating from various locations.

Normative Data for Single-Letter Controlled Oral Word Association Test in Older White Australians and Americans, African-Americans, and Hispanic/Latinos.

Background: The Controlled Oral Word Association Test (COWAT) is a commonly used measure of verbal fluency. While a normal decline in verbal fluency occurs in late adulthood, significant impairments may indicate brain injury or diseases such as Alzheimer's disease. Normative data is essential to identify when test performance falls below expected levels based on age, gender, and education level. Objective: This study aimed to establish normative performance data on single-letter COWAT for older community-dwelling adults. Methods: Over 19,000 healthy men and women, without a diagnosis of dementia or a Modified Mini-Mental State Examination score below 77/100, were recruited for the ASPREE trial. Neuropsychological assessments, including the COWAT with letter F, were administered at study entry. Results: Median participant age was 75 years (range 65-98), with 56.5% being women. The majority of participants had 9-11 years of education in Australia and over 12 years in the U.S. The COWAT performance varied across ethno-racial groups and normative data were thus presented separately for 16,335 white Australians, 1,084 white Americans, 896 African-Americans, and 316 Hispanic/Latinos. Women generally outperformed men in the COWAT, except for Hispanic/Latinos. Higher education levels consistently correlated with better COWAT performance across all groups, while the negative association with age was weaker. Conclusions: This study provides comprehensive normative data for the COWAT stratified by ethno-racial groups in Australia and the U.S., considering age, gender, and education level. These norms can serve as reference standards for screening cognitive impairments in older adults in both clinical and research settings.

Temporal activity patterns of layer II and IV rat barrel cortex neurons in healthy and injured conditions.

Neurons are known to encode information not just by how frequently they fire, but also at what times they fire. However, characterizations of temporal encoding in sensory cortices under conditions of health and injury are limited. Here we characterized and compared the stimulus-evoked activity of 1210 online-sorted units in layers II and IV of rat barrel cortex under healthy and diffuse traumatic brain injury (TBI) (caused by a weight-drop model) conditions across three timepoints post-injury: four days, two weeks, and eight weeks. Temporal activity patterns in the first 50 ms post-stimulus recording showed four categories of responses: no response or 1, 2, or 3 temporally-distinct response components, that is, periods of high unit activity separated by silence. The relative proportions of unit response categories were similar between layers II and IV in healthy conditions but not in early post-TBI conditions. For units with multiple response components, inter-component timings were reliable in healthy and late post-TBI conditions but disrupted by injury. Response component times typically shifted earlier with increasing stimulus intensity and this was more pronounced in layer IV than layer II. Surprisingly, injury caused a reversal of this trend and in the late post-TBI condition no stimulus intensity-dependence differences were observed between layers II and IV. We speculate this indicates a potential compensatory mechanism in response to injury. These results demonstrate how temporal encoding features maladapt or functionally recover differently in sensory cortex after TBI. Such maladaptation or functional recovery is layer-dependent, perhaps due to differences in thalamic input or local inhibitory neuronal makeup.

Can Empirical Segmental Angioembolization of Splenic Artery Salvage Pancreatic Intraluminal Bleed?

Background Postpancreatectomy hemorrhage (PPH) and Hemosuccus Pancreaticus (HP) may present with slow but significant intraluminal bleed which may not be evident on imaging. We evaluated the efficacy of empirical segmental-angioembolization of splenic artery in intraluminal PPH and HP. Result This is a cross-sectional study done by analyzing all consecutive patients with PPH and HP who underwent empirical coil embolization of splenic artery. There were total of 137 pancreaticoduodenectomies (PD), 68 distal pancreatectomies (DP), 11 patients with median pancreatectomies (MP) and 134 admissions for acute pancreatitis and exacerbation of chronic pancreatitis during the study period. Eleven (5.1%) patients had PPH, of which two were managed surgically. Among nine patients, 4/9 (44.4%) with pseudoaneurysm on computed tomography angiography (CTA) were excluded. Among pancreatitis, 7 (5.2%) had HP, and 5/7 (71.4%) patients with pseudoaneurysm on CTA were excluded. Hence, seven patients, PPH-5 and HP-2, were included. Both HP patients were managed successfully with empirical segmental coil embolization of splenic artery. Among PPH, one patient required laparotomy for failed embolization. Overall, 6/7 (85.7%) had successful coil embolization. No reintervention, continued bleed, or blood transfusions were required postprocedure, and no splenic infarct or abscess was seen in any of the seven patients postembolization. The 72-hour rebleed rate was 1/7 (14.3%), which was managed surgically. Conclusion Empirical segmental coil embolization of splenic artery in intraluminal pancreatic bleed holds promise as a salvage life-saving procedure even when no blush or pseudoaneurysm is evident.

Fibrovascular Polyp of the Cervical Esophagus: A Rare Neoplasm.

Fibrovascular polyps are rare benign epithelial neoplasia of the cervical esophagus. Usually they are large and frequently require a thoracotomy/thoracoscopy. This is a case report of an elderly lady with a large Fibrovascular polyp who had anemia and weight loss due to dysphagia, managed by rendezvous technique.

Sensing and processing whisker deflections in rodents.

The classical view of sensory information mainly flowing into barrel cortex at layer IV, moving up for complex feature processing and lateral interactions in layers II and III, then down to layers V and VI for output and corticothalamic feedback is becoming increasingly undermined by new evidence. We review the neurophysiology of sensing and processing whisker deflections, emphasizing the general processing and organisational principles present along the entire sensory pathway-from the site of physical deflection at the whiskers to the encoding of deflections in the barrel cortex. Many of these principles support the classical view. However, we also highlight the growing number of exceptions to these general principles, which complexify the system and which investigators should be mindful of when interpreting their results. We identify gaps in the literature for experimentalists and theorists to investigate, not just to better understand whisker sensation but also to better understand sensory and cortical processing.

Speech discrimination impairments as a marker of disease severity in multiple sclerosis.

BACKGROUND: Multiple Sclerosis (MS) pathology is likely to disrupt central auditory pathways, thereby affecting an individual's ability to discriminate speech from noise. Despite the importance of speech discrimination in daily communication, it's characterization in the context of MS remains limited. This cross-sectional study evaluated speech discrimination in MS under "real world" conditions where sentences were presented in ecologically valid multi-talker speech or broadband noise at several signal-to-noise ratios (SNRs). METHODS: Pre-recorded Bamford-Kowal-Bench sentences were presented at five signal-to-noise ratios (SNR) in one of two background noises: speech-weighted noise and eight-talker babble. All auditory stimuli were presented via headphones to control (n = 38) and MS listeners with mild (n = 20), moderate (n = 16) and advanced (n = 10) disability. Disability was quantified by the Kurtzke Expanded Disability Status Scale (EDSS) and scored by a neurologist. All participants passed a routine audiometric examination. RESULTS: Despite normal hearing, MS psychometric discrimination curves which model the relationship between signal-to-noise ratio (SNR) and sentence discrimination accuracy in speech-weighted noise and babble did not change in slope (sentences/dB) but shifted to higher SNRs (dB) compared to controls. The magnitude of the shift in the curve systematically increased with greater disability. Furthermore, mixed-effects models identified EDSS score as the most significant predictor of speech discrimination in noise (odds ratio = 0.81; p < 0.001). Neither age, sex, disease phenotype or disease duration were significantly associated with speech discrimination performance in noise. Only MS listeners with advanced disability self-reported audio-attentional difficulty in a questionnaire designed to reflect auditory processing behaviours in daily life. CONCLUSION: Speech discrimination performance worsened systematically with greater disability, independent of age, sex, education, disease duration or disease phenotype. These results identify novel auditory processing deficits in MS and highlight that speech discrimination tasks may provide a viable non-invasive and sensitive means for disease monitoring in MS.