Stronger Top-Down and Weaker Bottom-Up Frontotemporal Connections During Sensory Learning Are Associated With Severity of Psychotic Phenomena

Recent theories in computational psychiatry propose that unusual perceptual experiences and delusional beliefs may emerge as a consequence of aberrant inference and disruptions in sensory learning. The current study investigates these theories and examines the alterations that are specific to schizophrenia spectrum disorders vs those that occur as psychotic phenomena intensify, regardless of diagnosis. We recruited 66 participants: 22 schizophrenia spectrum inpatients, 22 nonpsychotic inpatients, and 22 nonclinical controls. Participants completed the reversal oddball task with volatility manipulated. We recorded neural responses with electroencephalography and measured behavioral errors to inferences on sound probabilities. Furthermore, we explored neural dynamics using dynamic causal modeling (DCM). Attenuated prediction errors (PEs) were specifically observed in the schizophrenia spectrum, with reductions in mismatch negativity in stable, and P300 in volatile, contexts. Conversely, aberrations in connectivity were observed across all participants as psychotic phenomena increased. DCM revealed that impaired sensory learning behavior was associated with decreased intrinsic connectivity in the left primary auditory cortex and right inferior frontal gyrus (IFG); connectivity in the latter was also reduced with greater severity of psychotic experiences. Moreover, people who experienced more hallucinations and psychotic-like symptoms had decreased bottom-up and increased top-down frontotemporal connectivity, respectively. The findings provide evidence that reduced PEs are specific to the schizophrenia spectrum, but deficits in brain connectivity are aligned on the psychosis continuum. Along the continuum, psychotic experiences were related to an aberrant interplay between top-down, bottom-up, and intrinsic connectivity in the IFG during sensory uncertainty. These findings provide novel insights into psychosis neurocomputational pathophysiology.

Multi-dimensional predictions of psychotic symptoms via machine learning

The diagnostic criteria for schizophrenia comprise a diverse range of heterogeneous symptoms. As a result, individuals each present a distinct set of symptoms despite having the same overall diagnosis. Whilst previous machine learning studies have primarily focused on dichotomous patient-control classification, we predict the severity of each individual symptom on a continuum. We applied machine learning regression within a multi-modal fusion framework to fMRI and behavioural data acquired during an auditory oddball task in 80 schizophrenia patients. Brain activity was highly predictive of some, but not all symptoms, namely hallucinations, avolition, anhedonia and attention. Critically, each of these symptoms was associated with specific functional alterations across different brain regions. We also found that modelling symptoms as an ensemble of subscales was more accurate, specific and informative than models which predict compound scores directly. In principle, this approach is transferrable to any psychiatric condition or multi-dimensional diagnosis.

The impact of pre-admission morbidity level on 3-year mortality after intensive care: a Danish cohort study

BACKGROUND

Chronic diseases are common among intensive care unit (ICU) patients and may worsen their prognosis. We examined the prevalence and impact of pre-admission/index morbidity among ICU patients compared with a general population cohort.

METHODS

Our study encompassed all 28,172 adult patients admitted to ICUs in northern Denmark in 2005-2007 and 281,671 age- and sex-matched individuals from the general population. We used a nationwide hospital registry to obtain a 5-year history of 19 chronic diseases and computed Charlson Comorbidity Index (CCI) for each study participant and grouped them into low (CCI=0), moderate (CCI=1-2), and high (CCI=3+) morbidity levels. We computed mortality and mortality rate ratios (MRRs) adjusted for confounders, and compared the mortality between ICU patients and the general population cohort.

RESULTS

Low, moderate, and high pre-admission morbidity levels were present in 51.5%, 34.1%, and 14.4% of ICU patients, respectively. In these groups, 30-day mortality was 10.8%, 18.4%, and 26.7%, respectively. Three-year mortality was 21.3%, 43.1%, and 63.2%, respectively. The adjusted 30-day MRR was 1.30 [95% confidence intervals (CI): 1.21-1.39] and 1.86 (95% CI: 1.71-2.01) for ICU patients with moderate and high morbidity levels, both compared with a low morbidity level. The general population had a lower morbidity level and mortality at all morbidity levels throughout the study period. Interaction between ICU admission and high morbidity level added 5.1% to the mortality during the second and third year of follow-up.

CONCLUSION

A high pre-admission morbidity level was frequent among ICU patients and associated with a worsened prognosis. Morbidity had more impact on mortality among ICU patients compared with a general population cohort.

Transthoracic echocardiography for cardiopulmonary monitoring in intensive care

BACKGROUND AND OBJECTIVE

To evaluate the feasibility of an abbreviated focus assessed transthoracic echocardiographic protocol, consisting of four standardized acoustic views for cardiopulmonary screening and monitoring.

METHODS

The protocol was applied in 210 patients in a 20-bed multidisciplinary intensive care unit in a university hospital. When inconclusive, an additional transoesophageal echocardiographic examination was performed. Diagnosis, indication, acoustic window, position and value were recorded. Significant pathology, load, dimensions and contractility were assessed.

RESULTS

Two-hundred-and-thirty-three transthoracic and four transoesophageal echoes were performed. The protocol provided usable images of the heart in 97% of the patients, 58% subcostal, 80% apical and 69% parasternal. Images through one window were obtainable in 23%, through two windows in 41% and through three windows in 34%. In 227 patients (97.4%) the focus assessed echo protocol contributed positively. In 24.5% of cases the information was decisive, in 37.3% supplemental and in 35.6% supportive.

CONCLUSIONS

By means of an abbreviated, focus assessed transthoracic echo protocol it is feasible to visualize the haemodynamic determinants for assessment and optimization. One or more useful images are obtainable in 97% of critically ill patients.

ICP during anaesthesia with sevoflurane: a dose-response study. Effect of hypocapnia

In patients with a supratentorial cerebral tumor, an increase in sevoflurane concentration from 1.5% (0.7 MAC) to 2.5% (1.3 MAC) did not change the intracranial pressure (ICP) significantly (12 to 14 mm Hg (medians)). However, a significant increase in cerebral blood flow (CBF) from 29 to 39 ml/100 g/min (medians) was disclosed. During administration of sevoflurane 1.5% and 2.5%, a significant decrease in ICP (3.5 and 3.0 mm Hg (median) respectively) was found when PaCO2 was decreased by 0.8 kPa.

Effects of sevoflurane on intracranial pressure, cerebral blood flow and cerebral metabolism. A dose-response study in patients subjected to craniotomy for cerebral tumours

BACKGROUND

Studies concerning the cerebrovascular effects of sevoflurane in patients with space-occupying lesions are few. This study was carried out as a dose-response study comparing the effects of increasing sevoflurane concentration (1.5% (0.7 MAC) to 2.5% (1.3 MAC)) on cerebral blood flow (CBF), intracranial pressure (ICP), cerebrovascular resistance (CVR), metabolic rate of oxygen (CMRO2) and CO2-reactivity in patients subjected to craniotomy for supratentorial brain tumours.

METHODS

Anaesthesia was induced with propofol/fentanyl/atracurium and maintained with 1.5% sevoflurane in air/oxygen at normocapnia. Blood pressure was maintained constant by ephedrine. In group 1 (n = 10), the patients received continuously 1.5% sevoflurane. Subdural ICP, CBF and CMRO2 were measured twice at 30-min intervals. In group 2 (n = 10), sevoflurane concentration was increased from 1.5% to 2.5% after CBF1. CBF2 was measured after 20 min during 2.5% sevoflurane. Finally, CO2-reactivity was studied in both groups.

RESULTS

In group 1, no time-dependent alterations in CBF, CVR, ICP and CMRO2 were found. In group 2, an increase in sevoflurane from 1.5% to 2.5% resulted in an increase in CBF from 29 +/- 10 to 34 +/- 12 ml 100 g-1 min-1 and a decrease in CVR from 2.7 +/- 0.9 to 2.3 +/- 1.2 mmHg ml-1 min 100 g (P < 0.05), while ICP and CMRO2 were unchanged. CO2-reactivity was maintained at 1.5% and 2.5% sevoflurane.

CONCLUSION

Sevoflurane is a cerebral vasodilator in patients with cerebral tumours. Sevoflurane increases CBF and decreases CVR in a dose-dependent manner. CO2-reactivity is preserved during 1.5% and 2.5% sevoflurane.

Unilateral vocal cord paralysis following endotracheal intubation

The present report describes a case of postoperative paralysis of the left recurrent laryngeal nerve in a patient undergoing surgery at a site far from the anatomic course of the nerve. Possible aetiological factors, symptoms, management and prophylaxis are discussed.

Rupture of the stomach caused by manual ventilation during laryngospasm

We report a case, in which laryngospasm developed due to a failed intubation under sedation. During ventilation tension pneumoperitoneum developed resulting in cardiac and respiratory failure. Laparotomy revealed two tears on the lesser curvature of the stomach. Factors influencing stomach rupture are discussed.

[Respiratory insufficiency caused by a vocal cord polyp. An accidental finding during respiratory function tests]

We present a case in which a 58-year-old woman was admitted for spirometry due to progressive dyspnoea. She had a history of chronic obstructive pulmonary disease treated for more than 20 years. The flow-volume loop indicated an upper airway obstruction. An otolaryngologic examination revealed a vocal cord polyp. It was excised and the patient's dyspnoea was relieved. The following spirometry indicated that the upper airway obstruction had been removed. The aim of this case report is to demonstrate that the flow-volume loop is a useful method in diagnosing and quantifying upper airway obstructions.

[Pulmonary edema after upper airway obstruction]

Post obstructive pulmonary edema (POPE) is a rare, but potentially dangerous condition. We present two patients with post-anaesthetic POPE. The literature is reviewed and aetiology, risk factors, pathogenesis, symptoms, prophylaxis and management are discussed. The condition is often associated with upper airway obstruction related to anaesthesia, but is also related to other causes of upper airway obstruction. Development of pulmonary edema can be delayed for up to 90 minutes. The treatment consists of oxygen therapy by nasal catheter or by mask with continuous positive airway pressure. In severe cases, intubation and mechanical ventilation by respirator with positive end-expiratory pressure is necessary. Further therapy is controversial and without significant effect. With sufficient therapy, almost all patients regain their habitual condition within 24-48 hours and present a normal chest X-ray.

Effect of previous frequency of headache, duration of fasting and caffeine abstinence on perioperative headache

We have examined the relationship between perioperative headache and various factors in 219 patients who fasted from midnight and underwent minor surgery under general anaesthesia. Four to six hours after operation all patients completed a questionnaire on previous frequency of headache, daily consumption of caffeine and occurrence of perioperative headache. The duration of fasting, type of surgery, premedication and anaesthetic agents used were obtained from the anaesthetic record. After multivariate logistic regression analysis a significant risk of preoperative headache was found in patients who normally experienced headache more than twice a month (odds ratio (OR): 7.7; confidence interval (CI): 2.9-20.1), had a daily caffeine consumption > 400 mg/24 h (OR: 5.0; CI: 1.6-14.8) and who were anaesthetized after 12:00 (OR: 3.7; CI: 1.4-9.8). The risk of postoperative headache was significantly greater in patients with preoperative headache (OR: 16.9; CI: 6.5-43.8), daily caffeine consumption > 400 mg/24 h (OR: 3.9; CI: 1.5-9.6) and in those patients who received atracurium, which was similar to the risk of tracheal intubation.

Working with the resident in difficulty

The resident in difficulty is an omnipresent and seemingly intractable problem. Some definitions of this concept are explored, as are means and methods of problem identification. Principles of successful intervention are discussed, as well as some obstacles to successful intervention. Utilization of interpersonal process recall, behavioral techniques, and a more insight-oriented approach in the remediation process are emphasized. The role of the faculty in responding to the resident in difficulty is explored, with special consideration to pitfalls and possibilities. The article concludes with a series of questions and directions for future exploration.

Identification of endogenous gibberellins from sorghum

Gibberellins (GA) A(1), A(19), and A(20) were identified in shoot cylinders containing the apical meristems from sorghum (Sorghum bicolor L.). Extracts were purified by sequential SiO(2) partition chromatography and reversed-phase C(18) high performance liquid chromatography and biologically active (dwarf rice cv Tan-ginbozu microdrop assay) fractions were subjected to gas chromatography-selected ion monitoring. Based on the use of [(3)H]GA and [(2)H](d(2))GA internal standards, amounts of GA(1), GA(19), and GA(20) were estimated to be 0.7, 8.8, and 1.5 namograms per gram dry weight of tissue, respectively.

Sequential nonverbal behavior in the patient-physician interview

This study demonstrates that there is a definite constancy to nonverbal behavioral interaction between patient and physician in a defined office interview setting. This work also introduces the technique of lag sequential analysis into family medicine research. Further refinements of study design and technique are needed in future studies to elucidate information that would be helpful to physicians in the management and care of patients and in patient education.

Procedures performed by family physicians, internists, and a Medex in a small group practice

Encounter forms for all patient visits to a small group practice (two internists, three family physicians, and one Medex) were examined retrospectively for October 1979 and January, April, and July 1980. A total of 5,694 patient encounters (2,327 male, 3,367 female) were recorded during the four months studied. Diagnostic and therapeutic procedures were performed on 592 patients (9.6 percent), 321 male and 271 female. The family physicians performed fewer procedures on their patients (6.1, 7.5, and 8.6 percent of the total patients seen). The Medex did 18.4 percent of all office procedures for that time period. The ten most commonly performed procedures included electrocardiogram (ECG), rhythm strip or ambulatory ECG, splint application, suture removal, pulmonary function test, suturing, exercise treadmill test, wart removal, removal of skin lesion or punch biopsy, application or removal of plaster cast, and application of ace wrap, sling, or collar. The majority of the procedures performed by the family physicians were also done by the Medex; however, the diversity of the procedures performed by the family physicians was comparable with that of the internists. There were large economic differences between groups, with the internists having the highest total billings and the Medex the lowest average charge per procedure performed.

Assessment of nonverbal communication in the patient-physician interview

The interview portion of 34 patient-physician visits at a family medical center was videotaped. Videotapes were screened by two judges in two major nonverbal categories, immediacy and relaxation. Physician and patient were scored separately at 40-second intervals for 11 component parameters of the two major categories. These scores were correlated with patient satisfaction and understanding, ascertained by post-interview questionnaire. For analytical purposes, patients were assigned to low or high satisfaction groups and low or high understanding groups. Statistically significant (P less than or equal to 05) differences between low and high satisfaction groups were demonstrated with respect to overall physician immediacy; five individual physician nonverbal parameters; and two individual patient nonverbal parameters. Similar statistical results were obtained for understanding groups. This preliminary investigation suggests that nonverbal behavior of the physician in the patient-physician interview is important in determining patient satisfaction and understanding.