Multistable Perception

Multistable perception is produced by stimuli that are consistent with two or more different comparably likely perceptual interpretations. After the initial perception is resolved in favor of one of the interpretations, continued viewing leads to fluctuating subjective experience, as perception spontaneously switches between alternative states. Multistable perception occurs for different modalities, including visual, auditory, tactile, olfactory perception and proprioception, and various conflicting sensory representations, such as eye dominance, depth, motion, or meaning. Despite large differences, multistable stimuli produce quantitatively similar perceptual experience with stereotypical distribution of durations of dominance phases, similar dependence on the absolute and relative strength of competing perceptual interpretations, prior perceptual history, presentation method, attention, and volitional control, and so on. Taken together, this shows that multistable perception reflects the action of general canonical perceptual mechanisms whose purpose is to resolve the conflicting evidence and ensure a single dominant perception that can be used for action. Thus, it informs us about mechanisms of perceptual decision making, including the importance of feedback mechanisms in resolving perceptual ambiguity and the role of parietal and frontal regions in facilitating changes in perception. Multistable perception provides useful constraints for models, inspiring a plethora of models of perception that combine neurally plausible mechanisms, such as neural adaptation and inhibition, or are based on the idea of predictive coding. The sensitive nature of multistable perception makes a valuable experimental tool that can reveal even minor differences due to low- or high-level influences, including genetic or clinical cases. As such, it is an important tool in studying neural and behavioral correlates of consciousness as it dissociates perception from the stimulus.

A Case of Gallstones Causing Pelvic Pain

Introduction. Assessing abdominal pain, particularly in women of reproductive age, requires thorough history taking, clinical examination, and investigations to obtain an accurate diagnosis. Both surgical and gynecological causes need to be considered, particularly previous relevant surgical history. Presentation of case. We report a case of pelvic pain secondary to multiple gallstones found within the pelvic cavity postlaparoscopic cholecystectomy. Thorough investigations have been conducted without any obvious cause found. The pain was debilitating and largely affecting the patient’s quality of life. Therefore, decision to perform diagnostic laparoscopy and gallstones was found all over pelvic cavity and retrieved. Her pain resolved post operatively. Conclusions. Gallbladder perforation and stone spillage are the most common complications of laparoscopic cholecystectomy that arise during the removal and dissection of gallbladder and can cause significant morbidity if not managed early, especially retrieval of the stones intraoperatively. Therefore, patient with history of previous cholecystectomy with stone spillage presenting with undifferentiated abdominal pain and early diagnostic laparoscopy should be considered.

H type tracheo-oesophageal fistula: 2 cases with review of literature

Tracheo-oesophageal fistula (TEF) with oesophageal atresia is a common life threatening congenital malformation. H type TEF is a rare subtype (1.8 to 4.2% of all TEF) with the least association with congenital anomalies. We report two cases of H type TEF, first patient was a 2 month old girl who presented with the classical triad of symptoms, and the second patient was a 2 year old girl who presented with recurrent attacks of pneumonia, choking on feeding and noisy breathing. After radiological confirmation, optimization of pulmonary status and nutritional improvement, both underwent right cervicotomy with disconnection of the H fistula. Both patients are doing well on regular follow up. Detection of H fistula is difficult as compared to TEF since the clinical symptoms are variable, radiological detection difficult and diagnosis is based on a high degree of clinical suspicion. We present these two cases to document the history, presentation, clinical management and surgical procedure done in these patients.

Lyme Carditis in Hospitalized Children and Adults, a Case Series

Background Lyme carditis is an uncommon manifestation of Lyme disease. This report compares Lyme carditis presentation, management, and outcomes in pediatric and adult populations. Methods Charts of pediatric and adult patients with heart block (PR >300ms) and positive Lyme serologies hospitalized in Portland, Maine between January 2010 and December 2018 were analyzed. Data on medical history, presentation, treatment, and outcomes are described. Results Ten children and 20 adults were admitted for Lyme carditis between June and October. Ninety percent were male, and 87% had no prior cardiac history. Seventeen had outpatient evaluation prior to admission. Of these, a minority (41%) had Lyme disease suspected in the outpatient setting, and fewer (12%) were initiated on Lyme disease treatment. The most common alternate diagnoses were viral illness and erythema multiforme. More children than adults had disseminated erythema migrans and fever. First-degree heart block was more prevalent in children, and Mobitz type 2 heart block was more prevalent in adults. Ten patients presented with syncope. Proportionately more adults needed temporary pacing. Children had shorter antibiotic durations compared to adults. Of the 30 cases, twenty-seven had improved heart block, while 3 adults required a pacemaker at discharge. Nine children and 14 adults were discharged with a PR 200-300ms. There was a single death in this series. Conclusion Cases tended to be younger males. Most patients had some heart block on discharge. Of patients evaluated as outpatients, Lyme disease was suspected in 41%. Improved early recognition and treatment of Lyme disease may decrease Lyme carditis.

Echocardiographic assessment and critical care management of peri-partum women with unexpected left ventricular failure

Introduction Cardiac disease remains the largest single cause of maternal death. Whilst uncommon, left ventricular failure during pregnancy and delivery can be devastating to both mother and child. Echocardiography can play a significant role in rapidly establishing a diagnosis, guiding initial therapy and then monitoring response. Clinical vignettes The history, presentation and management of three cases of peri-partum left ventricular failure is examined: stress cardiomyopathy in a 34 year old with twins, left ventricular dysfunction secondary to pre-eclampsia in a 22 year old with a singleton pregnancy and a true peri-partum cardiomyopathy in a 42 year old with IVF twins. The defining risk factors, presenting characteristics and echocardiographical findings for each pathology are highlighted. Conclusion Echocardiography is playing an increasingly important role in the immediate assessment and management of left ventricular failure. This is especially true in the peri-partum woman, where establishing the correct therapy is both challenging and crucial due to the significant cardiovascular changes that occur around the time of delivery. To this end we believe that echocardiography should be rapidly available to guide the management of these patients by a multidisciplinary team made up of obstetricians, cardiologists, anaesthetists and intensive care physicians.

Benefits of the Subdural Evacuating Port System (SEPS) Procedure Over Traditional Craniotomy for Subdural Hematoma Evacuation

Background: There remains no consensus on the optimal primary intervention for subdural hematoma (SDH). Although historically favored, craniotomy carries substantial morbidity and incurs significant costs. Contrastingly, the subdural evacuating port system (SEPS) is a minimally invasive bedside procedure. We assessed the benefits of SEPS over traditional craniotomy for SDH evacuation. Methods: A single-center retrospective cohort study of SDH patients receiving craniotomy or SEPS between 2012 and 2017 was performed. Information regarding demographics, medical history, presentation, surgical outcomes, cost, and complications was collected. Pre- and postoperative hematoma volumes were calculated using 3D image segmentation using Vitrea software. Multivariate regression models were employed to assess the influence of intervention choice. Results: Of 107 patients, 68 underwent craniotomy and 39 underwent SEPS. There were no differences in age, sex, blood thinner use, platelet count, INR, hematoma lateralization, age, volume, or midline shift at presentation between intervention groups. Although there was no difference in percent residual hematoma volume 24-hour postintervention (44.1% vs 45.1%, P = .894), SEPS was associated with lower hospitalization costs ($108 391 vs $166 318, * P = .002), shorter length of stay (4.0 vs 5.8 days, * P = .0002), and fewer postoperative seizures (2.6% vs 17.7%, * P = .048). Reoperation rate was higher after SEPS overall (33.3% vs 13.2%, * P = .048) but comparable to craniotomy in chronic SDH (12.50% vs 7.69%, P = 1.000). Conclusion: In this retrospective cohort, SEPS was noninferior to craniotomy at reducing SDH hematoma volume. The SEPS procedure was also associated with decreased length of stay hospitalization costs, and postoperative seizures and demonstrated a comparable recurrence rate to craniotomy for chronic SDH in particular.

134. A Comparison of Lyme Carditis in Children and Adults, a Case Series

Background Lyme disease is a common entity in Maine, and Lyme carditis is an uncommon manifestation of this disease. This case series describes and compares the presentation, management, and outcomes of Lyme carditis in pediatric and adult populations. Methods Charts of pediatric and adult patients with heart block and positive Lyme serologies hospitalized in Portland, Maine between January 2010 and December 2018 were analyzed. Data on medical history, presentation, treatment, and outcomes are described. Results Ten children (range 7–17, mean 12.4 years) and 20 adults (range 22–81, mean 41.4 years) were admitted for Lyme carditis in the examined period. All cases presented between June and October. Twenty-seven (90%) were male, and 26 (87%) had no prior cardiac history. Of the adults, 1 (5%) reported using cocaine, 4 (20%) opioids, and 6 (30%) marijuana. Seventeen (57%) had outpatient evaluation prior to admission. Ten patients (59%) were not recognized as having Lyme disease. One case suspected to have Lyme was not initially treated with doxycycline. The most common alternative diagnoses were a viral illness and erythema multiforme. No coinfections were noted. Proportionately more children than adults had disseminated erythema migrans (40% vs. 20%) and fever (60% vs. 35%). First degree heart block was more prevalent in children (40%), and Mobitz type 2 heart block was more prevalent in adults (55%). Ten patients (30%) presented with syncope. More adults than children needed temporary pacing, 9 (45%) vs. 2 (20%). Children had shorter antibiotic durations compared with adults (mean 19.8 days vs. 23.6 days) Twenty-seven (90%) had improved heart block. Three adult patients (10%) required a pacemaker following hospitalization. Nine (90%) children and 14 (70%) adults were discharged with a PR 200-300ms. There was a single death in this series, which occurred after discharge to another state. Conclusion Cases tended to be in younger patients with male predominance. Most patients still had some degree of heart block on discharge. The majority of patients were evaluated prior to hospitalization but Lyme disease was suspected in only 41%. Improved recognition of early Lyme disease and more prompt treatment may lead to decreased complications of Lyme carditis. Disclosures All authors: No reported disclosures.

Chondro-Osseous Respiratory Epithelial Adenomatoid Hamartoma (COREAH): Case Report and Literature Review

Chondro-osseous respiratory epithelial adenomatoid hamartoma (COREAH) is an extremely rare lesion of the nasal cavity with only 11 reported cases in the literature. COREAH is of interest as it may be easily mistaken for other diseases of the nasal cavity with higher morbidity, which require significantly different management strategies. We report, to the best of our knowledge, the oldest documented case of COREAH in the literature: an 83-year-old female who presented with headaches and was found to have a posterior nasal septal lesion. Uniquely, the patient had sequential scans performed 1 year apart demonstrating only minor interval growth. We describe our experience in managing a patient with COREAH and review the world literature, to better define aspects of the history, presentation, and investigations that may allow differentiation from more sinister disease.

Preterm Parturient with Polyhydramnios and Pancreatitis: Primary Presentation of Hyperparathyroidism

Objective. To report a case of severe hypercalcemia secondary to primary hyperparathyroidism in a late-preterm pregnant patient and review medical and surgical treatments as well as obstetric and neonatal outcomes. Background. Diagnosis of parathyroid disease during pregnancy can be difficult due to nonspecific presentation. Management decisions are complex and require multidisciplinary collaboration. Case. A 29-year-old G2P1001 woman at 35 weeks and 3 days’ gestation presented with preterm contractions, polyhydramnios, pancreatitis, and severe hypercalcemia. Work-up revealed primary hyperparathyroidism with multiple thyroid nodules. Patient history, presentation, and biopsy were suspicious for parathyroid carcinoma. Despite severe hypercalcemia, both patient and fetus remained stable and medical management was pursued in an attempt to optimize mother and fetus prior to delivery. Due to recalcitrant hypercalcemia, surgical resection was ultimately required. She was subsequently delivered in the setting of preterm labor. Final pathology revealed parathyroid adenoma with atypia and occult papillary thyroid carcinoma. Conclusion. Symptoms of hypercalcemia can mimic those of a normal third trimester pregnancy and can have serious maternal and fetal effects if left untreated. A coordinated, multidisciplinary approach to these patients is necessary.