Beyond Urinary Tract Infections (UTIs) and Delirium: A Systematic Review of UTIs and Neuropsychiatric Disorders

Diagnosing Late-Onset Psychosis in a Medically Complex Patient: A Diagnostic Challenge

This case report explores various possible causes of late-onset psychosis and highlights the importance of follow-up care. We report the case of a 65-year-old female with minimal available medical history or contacts, who presented to the hospital after being found unconscious after three weeks of strange behaviors, including partition delusions, multiple phone calls and texts to her friend, and lack of sleep. In the following days, she had various symptoms consistent with delirium, psychosis, and mania. However, she was also found to have a dural calcification and urinary tract infection on imaging and laboratories, respectively. We attempted to distinguish these possible etiologies and understand the best course of action for such a patient with a limited medical history who was subsequently lost to medical follow-up. Utilizing the psychiatric interview, mental status examination, laboratory work, imaging, and available medical and psychiatric history can all help narrow down the most likely etiologies. However, the lack of data given during follow-up visits, regarding patient response to treatment, their full medical and psychiatry history, as well as their understanding of their diagnosis, poses a significant challenge in reaching a definitive diagnosis in such a patient. This underscores the critical need for follow-up care, especially for patients treated for psychosis in acute settings.

There's No Place Like Home: Delirium as a Barrier in Geriatric Trauma

INTRODUCTION

Delirium is associated with a three-fold increase in frequency of 6-mo mortality following intensive care unit admission. Outside of mortality, it has been linked with severe morbidity including long-term cognitive decline, loss of autonomy, and increased risk of institutionalization. There is a paucity of literature regarding delirium and geriatric trauma patients. The aim of our study is to determine predictive factors of delirium in geriatric trauma patients.

METHODS

This is a retrospective review of all geriatric (>65 y) trauma patients with a documented frailty score at a Level I Trauma Center from 1/2019 to 9/2021. Univariate and multivariate logistic regressions were performed. Geriatric patients with delirium (D) and those without delirium (ND) were compared. Patients were excluded if they did not have a documented frailty score or died before admission.

RESULTS

One thousand three hundred and seventeen patients met criteria; 40 (3%) patients developed delirium. Neither age nor gender was different between the two groups. Frailty scores were not different between the two groups. Patients with documented delirium had a higher incidence of a positive drug screen on admission (85% versus 62.2%, P = 0.0034), higher median injury severity score (10 versus 9, P = 0.0088), and longer hospital (7 d versus 3 d, P < 0.001) and intensive care unit (1 d versus 0 d, P < 0.001) length of stay (LOS) than their ND counterparts. The D group had a higher frequency of benzodiazepine (47.5% versus 19.3%, P < 0.001) and narcotic use (77.5% versus 56.5%, P = 0.0085). Tethers nor bedrest orders were significantly associated with delirium. Incidence of urinary tract infection (12.5% versus 1%, P < 0.001) and restraint use (P < 0.001) were significantly associated with increased risk of delirium. Additionally, those with a diagnosis of delirium were more often discharged to a skilled nursing facility than those in the ND group (45% versus 30.8%, P = 0.0006).

CONCLUSIONS

We aimed to identify key predictive factors of delirium in our study population and found that certain factors correlated with higher frequencies of delirium in our geriatric trauma patients. Preadmission and early controlled substance use were significantly associated with delirium, as were the presence of urinary tract infection and extended intensive care unit LOS. By recognizing some of these modifiable factors, LOS may decrease while increasing the likelihood of discharge home.

Proteomics for the Discovery of Clinical Delirium Biomarkers: A Systematic Review of Major Studies

Delirium represents a significant health care burden, diagnosed in more than 2 million elderly Americans each year. In the surgical population, delirium remains the most common complication among elderly patients, and is associated with longer hospital stays, higher costs of care, increased mortality, and functional impairment. The pathomechanism of disease is poorly understood, with current diagnostic approaches somewhat subjective and arbitrary, and definitive diagnostic biomarkers are currently lacking. Despite the recent interest in delirium research, biomarker discovery for it remains new. Most attempts to discover biomarkers are targeted studies that seek to assess the involvement of one or more members of a focused panel of candidates in delirium. For a more unbiased, system-biology view, we searched literature from Medical Literature Analysis and Retrieval System Online (MEDLINE), Cochrane Central, Web of Science, SCOPUS, and Dimensions between 2016 and 2021 for untargeted proteomic discovery studies for biomarkers of delirium conducted on human geriatric subjects. Two reviewers conducted an independent review of all search results and resolved discordance by consensus. From an overall search of 1172 publications, 8 peer-reviewed studies met our defined inclusion criteria. The 370 unique perioperative biomarkers identified in these reports are enriched in pathways involving activation of the immune system, inflammatory response, and the coagulation cascade. The most frequently identified biomarker was interleukin-6 (IL-6). By reviewing the distribution of protein biomarker candidates from these studies, we conclude that a panel of proteins, rather than a single biomarker, would allow for discriminating delirium cases from noncases. The paucity of hypothesis-generating studies in the peer-reviewed literature also suggests that a system-biology view of delirium pathomechanisms has yet to fully emerge.

17β-estradiol ameliorates delirium-like phenotypes in a murine model of urinary tract infection

Urinary tract infections (UTIs) are common and frequently precipitate delirium-like states. Advanced age coincident with the postmenopausal period is a risk factor for delirium following UTIs. We previously demonstrated a pathological role for interleukin-6 (IL-6) in mediating delirium-like phenotypes in a murine model of UTI. Estrogen has been implicated in reducing peripheral IL-6 expression, but it is unknown whether the increased susceptibility of postmenopausal females to developing delirium concomitant with UTIs reflects diminished effects of circulating estrogen. Here, we tested this hypothesis in a mouse model of UTI. Female C57BL/6J mice were oophorectomized, UTIs induced by transurethral inoculation of E. coli, and treated with 17β-estradiol. Delirium-like behaviors were evaluated prior to and following UTI and 17β-estradiol treatment. Compared to controls, mice treated with 17β-estradiol had less neuronal injury, improved delirium-like behaviors, and less plasma and frontal cortex IL-6. In vitro studies further showed that 17β-estradiol may also directly mediate neuronal protection, suggesting pleiotropic mechanisms of 17β-estradiol-mediated neuroprotection. In summary, we demonstrate a beneficial role for 17β-estradiol in ameliorating acute UTI-induced structural and functional delirium-like phenotypes. These findings provide pre-clinical justification for 17β-estradiol as a therapeutic target to ameliorate delirium following UTI.

Urinary Tract Infections Impair Adult Hippocampal Neurogenesis

Simple Summary

Urinary tract infections are associated with features of cognitive decline and memory deficits, where the underlying correlation or mechanism is still not clear. In this study, we investigate the effect of urinary tract infections on cognitive functions in rodents and whether it is associated with adult hippocampal neurogenesis, a process that is detrimental for memory formation. We have shown that urinary tract infection affects the time spent exploring a novel arm in the Y-maze test. This was accompanied with a decrease in the proliferation of neural stem cells at an early time point post infection and a persistent decrease in neurogenesis at a later time point (34 days). We also detected decreased levels of neurotrophic factors important for neurogenesis and an elevated expression of interleukin 1β in the hippocampus. Treatment with either anti-inflammatory drugs or anti-biotics does not recover proliferation of neural stem cells. Here, we present hippocampal neurogenesis as a possible contributor to cognitive changes associated with urinary tract infections. Given the significant increase in urinary tract infection occurrence, it is important to address some of the detrimental effects that such an infection can have at the level of the brain.

Abstract

Previous studies have suggested a link between urinary tract infections (UTIs) and cognitive impairment. One possible contributing factor for UTI-induced cognitive changes that has not yet been investigated is a potential alteration in hippocampal neurogenesis. In this study, we aim to investigate the effect of UTI on brain plasticity by specifically examining alterations in neurogenesis. Adult male Sprague Dawley rats received an intra-urethral injection of an Escherichia coli (E. coli) clinical isolate (10⁸ CFU/mL). We found that rats with a UTI (CFU/mL ≥ 10⁵) had reduced proliferation of neural stem cells (NSCs) at an early time point post infection (day 4) and neurogenesis at a later time point (day 34). This was associated with the decreased expression in mRNA of BDNF, NGF, and FGF2, and elevated expression of IL-1β in the hippocampus at 6 h post infection, but with no changes in optical intensity of the microglia and astrocytes. In addition, infected rats spent less time exploring a novel arm in the Y-maze test. Treatment with an anti-inflammatory drug did not revert the effect on NSCs, while treatment with antibiotics further decreased the basal level of their proliferation. This study presents novel findings on the impact of urinary tract infections on hippocampal neurogenesis that could be correlated with cognitive impairment.

Diagnosing, managing and preventing urinary tract infections in older people with dementia in hospital

Urinary tract infections (UTIs) are common in older people and are frequently more complicated to diagnose than in younger adults. There are often challenges associated with distinguishing symptomatic UTIs from asymptomatic bacteriuria, particularly in people with cognitive impairment. Older people with dementia are at increased risk of developing a UTI because dementia can lead to voiding issues, impede personal hygiene and increase the need for urinary catheterisation. Furthermore, while a UTI is usually diagnosed based on an individual's physical signs and symptoms, people with dementia may only exhibit signs of sudden altered mental status such as increased confusion, agitation or withdrawal, making diagnosis challenging. This article discusses the main considerations regarding UTIs in people with dementia in hospital and outlines prevention strategies that nurses can implement in their practice.

Intracerebral Infection with E. coli Impairs Spatial Learning and Induces Necrosis of Hippocampal Neurons in the Tg2576 Mouse Model of Alzheimer’s Disease

Background:

In patients with Alzheimer’s disease (AD), bacterial infections are often associated with a cognitive decline. Animal models of genuine acute infections with viable bacteria which induce deterioration of neurodegenerative diseases are missing.

Objective:

We assessed the effect of an intracerebral infection with E. coli in a mouse model of AD.

Methods:

13-month-old Tg2576 +/- mice and transgene negative littermates (Tg2576 -/-) received an intracerebral injection with E. coli K1 or saline followed by treatment with ceftriaxone starting 41 h post infection (p.i.) for 5 days. For 4 weeks, mice were monitored for clinical status, weight, motor functions, and neuropsychological status using the Morris water maze. ELISAs, stainings, and immunohistochemistry in brains were performed at the end of the experiment.

Results:

Mortality of the infection was approximately 20%. After 4 weeks, spatial learning of infected Tg2576 +/- mice was compromised compared to non-infected Tg2576 +/- mice (p < 0.05). E. coli infection did not influence spatial learning in Tg2576 -/- mice, or spatial memory in both Tg2576 +/- and -/- mice within 4 weeks p.i.. Necrosis of hippocampal neurons was induced in infected compared to non-infected Tg2576 +/- mice 4 weeks p.i., whereas brain concentrations of Aβ_1–40, Aβ_1–42, and phosphoTau as well as axonal damage and microglia density were not altered.

Conclusion:

Here, we proved in principle that a genuine acute bacterial infection can worsen cognitive functions of AD mice. Mouse models of subacute systemic infections are needed to develop new strategies for the treatment of bacterial infections in patients with AD in order to minimize their cognitive decline.

Mechanical Learning for Prediction of Sepsis-Associated Encephalopathy

Objective: The study aims to develop a mechanical learning model as a predictive model for predicting the appearance of sepsis-associated encephalopathy (SAE).

Materials and Methods: The prediction model was developed in a primary cohort of 2,028 sepsis patients from June 2001 to October 2012, retrieved from the Medical Information Mart for Intensive Care (MIMIC III) database. Least absolute shrinkage and selection operator (LASSO) regression model was used for data dimension reduction and feature selection. The model was developed using multivariable logistic regression analysis. The performance of the nomogram has been evaluated in terms of calibration, discrimination, and clinical utility.

Results: There were nine particular features in septic patients that were significantly associated with SAE. Predictors of individualized prediction nomograms included age, rapid sequential evaluation of organ failure (qSOFA), and drugs including carbapenem antibiotics, quinolone antibiotics, steroids, midazolam, H₂-antagonist, diphenhydramine hydrochloride, and heparin sodium injection. The area under the curve (AUC) was 0.743, indicating good discrimination. The prediction model showed calibration curves with minor deviations from the ideal predictions. Decision curve analysis (DCA) suggested that the nomogram was clinically useful.

Conclusion: We propose a nomogram for the individualized prediction of SAE with satisfactory performance and clinical utility, which could aid the clinician in the early detection and management of SAE.

Gestational urinary tract infections and the risk of antenatal and postnatal depressive and anxiety symptoms: A longitudinal population-based study

OBJECTIVE

Urinary tract infections (UTIs) are among the most common bacterial infections in pregnant women. This is the first longitudinal study investigating the association between gestational UTIs and the risk of maternal antenatal and postnatal depressive and anxiety symptoms.

METHODS

Data were utilised from the Avon Longitudinal Study of Parents and Children (ALSPAC). Maternal depressive and anxiety symptoms during pregnancy and the postpartum period were assessed using the Edinburgh Postnatal Depression Scale (EPDS) and the Crown-Crisp Experiential Index (CCEI), respectively. We used logistic regression analyses to examine the associations using the recommended EPDS and CCEI cut-off scores. We also ran sensitivity analyses and repeated the analyses with the continuous scores.

RESULTS

More than 10,000 mothers had completed exposure and outcome measures during pregnancy and the postpartum period. After adjustments were made for a wide range of confounders, our findings showed that mothers with UTI during pregnancy were 1.72 (95% CI; 1.45-2.04) and 1.70 (95% CI: 1.44-1.99) times more likely to report antenatal depressive and anxiety symptoms compared with mothers without UTI, respectively. Mothers with UTI also had a 35% and a 28% higher risk of postnatal depressive symptoms at eight weeks and eight months, respectively, and the risk of postnatal anxiety was 55% higher in mothers who had UTI during pregnancy (aOR = 1.55; 95% CI, 1.26-1.91).

CONCLUSIONS

The present study found positive associations between UTI during pregnancy and antenatal and postnatal depressive and anxiety symptoms. Replication and further research determining the cause of these associations is warranted.

Interleukin-6 mediates delirium-like phenotypes in a murine model of urinary tract infection

Background

Urinary tract infection (UTI) is frequently implicated as a precipitant of delirium, which refers to an acute confusional state that is associated with high mortality, increased length of stay, and long-term cognitive decline. The pathogenesis of delirium is thought to involve cytokine-mediated neuronal dysfunction of the frontal cortex and hippocampus. We hypothesized that systemic IL-6 inhibition would mitigate delirium-like phenotypes in a mouse model of UTI.

Methods

C57/BL6 mice were randomized to either: (1) non-UTI control, (2) UTI, and (3) UTI + anti-IL-6 antibody. UTI was induced by transurethral inoculation of 1 × 10⁸Escherichia coli. Frontal cortex and hippocampus-mediated behaviors were evaluated using functional testing and corresponding structural changes were evaluated via quantification of neuronal cleaved caspase-3 (CC3) by immunohistochemistry and western blot. IL-6 in the brain and plasma were evaluated using immunohistochemistry, ELISA, and RT-PCR.

Results

Compared to non-UTI control mice, mice with UTI demonstrated significantly greater impairments in frontal and hippocampus-mediated behaviors, specifically increased thigmotaxis in Open Field (p < 0.05) and reduced spontaneous alternations in Y-maze (p < 0.01), while treatment of UTI mice with systemic anti-IL-6 fully reversed these functional impairments. These behavioral impairments correlated with frontal and hippocampal neuronal CC3 changes, with significantly increased frontal and hippocampal CC3 in UTI mice compared to non-UTI controls (p < 0.0001), and full reversal of UTI-induced CC3 neuronal changes following treatment with systemic anti-IL-6 antibody (p < 0.0001). Plasma IL-6 was significantly elevated in UTI mice compared to non-UTI controls (p < 0.01) and there were positive and significant correlations between plasma IL-6 and frontal CC3 (r² = 0.5087/p = 0.0028) and frontal IL-6 and CC3 (r² = 0.2653, p < 0.0001).

Conclusions

These data provide evidence for a role for IL-6 in mediating delirium-like phenotypes in a mouse model of UTI. These findings provide pre-clinical justification for clinical investigations of IL-6 inhibitors to treat UTI-induced delirium.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02304-x.

Acute Psychosis and COVID-19 Infection: Psychiatric Symptoms in Hospitalized Patients

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has resulted in various medical and psychosocial consequences globally. Respiratory infections are common among patients infected with the SARS-CoV-2 virus, the causative virus of coronavirus disease 2019 (COVID-19). However, various psychiatric and neurocognitive symptoms and sequelae of COVID-19 have been reported as well.  This study aimed to describe two clinical case reports of patients with no prior history of psychiatric illnesses admitted to the psychiatric inpatient unit with acute onset of psychosis. A 49-year-old woman with no past medical history and no past psychiatric history was admitted to the inpatient psychiatric unit with suicidal ideation and was noted to have acute psychosis. A 56-year-old woman with a history of hypertension with no past psychiatric history was admitted to the hospital with acute hypoxic respiratory failure secondary to COVID-19 pneumonia and was noted to have acute psychosis.  Various psychiatric and neurocognitive symptoms and sequelae of COVID-19 have been reported. However, the pathophysiology, direct biological effects of the disease, treatment modalities, worsening of symptoms due to various medications, and other long-term sequelae are not fully understood. Therefore, clinicians should be mindful of neuropsychiatric symptoms and conduct a detailed history and physical examination on all patients presenting with psychiatric symptoms in the context of COVID-19. It is also essential to assess for signs and symptoms of delirium in patients presenting with neuropsychiatric symptoms. Further research is needed to identify the etiology, predisposing factors, exacerbating or precipitating factors contributing to neuropsychiatric symptoms associated with infection with the SARS-CoV-2 virus. In addition, the pathophysiology contributing to these symptoms and pharmacological interventions for managing these sequelae need to be evaluated.

Associations of delirium with urinary tract infections and asymptomatic bacteriuria in adults aged 65 and older: A systematic review and meta-analysis

Objective

To determine the associations of delirium with urinary tract infection (UTI) and asymptomatic bacteriuria (AB) in individuals aged 65 and older.

Methods

The protocol for this systematic review and meta‐analysis was published on PROSPERO (CRD42020164341). Electronic databases were searched for relevant studies, professional associations and experts in the field were additionally contacted. Studies with control groups reporting associations between delirium and UTI as well as delirium and AB in older adults were included. The random effects model meta‐analysis was conducted using odds ratios (ORs) with 95% confidence intervals (CIs) as effect size measures. The Newcastle‐Ottawa scale was used to rate the studies' quality. Heterogeneity was assessed using the Q and I² tests. The effects of potential moderators were investigated by both subgroup and meta‐regression analyses. The risk of publication bias was evaluated using the funnel plot and Egger's test.

Results

Twenty nine relevant studies (16,618 participants) examining the association between delirium and UTI in older adults were identified. The association between delirium and UTI was found to be significant (OR 2.67; 95% CI 2.12–3.36; p < 0.001) and persisted regardless of potential confounders. The association between delirium and AB in older adults in the only eligible study found (192 participants) was insignificant (OR 1.62; 95% CI 0.57–4.65; p = 0.37). All included studies were of moderate quality.

Conclusion

The results of this study support the association between delirium and UTI in older adults. Insufficient evidence was found to conclude on an association between delirium and AB in this age group. These findings are limited due to the moderate quality of the included studies and a lack of available research on the association between delirium and AB. Future studies should use the highest quality approaches for defining both delirium and UTI and consider AB in their investigations.

Evaluating the Hypothesis That Schizophrenia Is an Inflammatory Disorder

The investigation of immune system abnormalities in schizophrenia, although ongoing for decades, has become a popular area of research. The authors present a selected review of studies informing on schizophrenia as a potential inflammatory disorder, emphasizing replicated findings. The authors summarize evidence for inflammation over the illness course, discuss relationships between inflammation and psychopathology, present studies of imaging of neuroinflammation, consider inflammation as a marker of treatment response and treatment target, and review potential mechanisms for the effects of inflammation on the brain in schizophrenia. Although there is not clear and convincing evidence to support the assertion that schizophrenia is an inflammatory disorder, this area of study shows promise toward a greater understanding of the etiopathophysiology of this heterogeneous disorder.

Psychosis as an adverse effect of antibiotics

Adverse neuropsychiatric effects of antibiotic medications have been well documented. There is evidence suggesting a direct relationship between acute psychosis and antibiotic exposure. Conversely, the tetracycline antibiotic minocycline has been associated with improvements in psychopathology in patients with psychotic disorders. The purpose of the present study was to investigate the prevalence of spontaneously reported adverse drug reactions (ADRs) of psychotic symptoms in adults for antibiotics and the odds of psychosis compared to minocycline for individual antibiotics and antibiotic classes. We searched the publicly available U.S. F.D.A. Adverse Event Reporting System (FAERS) from inception through March 2020 for which an antibiotic was the suspected agent of an adverse drug reaction (ADR). We investigated 23 different antibiotics, comprising 183,265 adverse event reports and 2955 psychosis ADRs. For individual antibiotics, the prevalence of psychosis ADRs ranged from 0.3 to 3.8%. Fifteen antibiotics were associated with a significantly increased odds of psychosis (OR ​= ​1.67-9.48), including penicillins, fluoroquinolones, macrolides, cephalosporins, and doxycycline. Our results suggest that psychosis is a potential adverse effect of antibiotic treatment, but risks vary by specific agents. Future studies in this area are needed to identify specific underlying biological mechanisms that contribute to these associations. Findings may also inform on clinical decisions regarding the selection of antibiotic therapy in vulnerable patient populations.

Workload, diagnostic work-up and treatment of urinary tract infections in adults during out-of-hours primary care: a retrospective cohort study

Background

Urinary tract infections (UTIs) are one of the most common infections in primary care. Previous research showed that GPs find it challenging to diagnose UTIs and frequently divert from guidelines leading to unwarranted antibiotic prescriptions and inefficient use of diagnostics such as urinary cultures. We hypothesise that management of UTIs during out-of-hours care may be extra challenging due to a higher workload and logistical issues regarding diagnostic work-up and obtaining results. We therefore aimed to study the workload, diagnostic work-up and treatment of UTIs during out-of-hours primary care.

Methods

We performed a retrospective observational cohort study in which we analysed a full year (2018) of electronic patient records of two large Dutch GP out-of-hours centres. All adult patients with UTI symptoms were included in this study. Descriptive statistics and multivariate regression were used to analyse diagnostics and subsequent management.

Results

A total of 5657 patients were included (78.9% female, mean age of 54 years), with an average of eight patients per day that contact a GP out-of-hours centre because of UTI symptoms. Urinary dipsticks were used in 87.5% of all patients visiting the out-of-hours centres with UTI symptoms. Strikingly, urinary cultures were only requested in 10.3% of patients in which urinary culture was indicated. Seventy-four percent of the patients received antibiotics. Seventy-nine percent of the patients with a negative nitrite test still received antibiotics. Remarkably, patients at risk of complications because of a UTI, such as men, received fewer antibiotic prescriptions.

Conclusions

In total, 74% of the patients received antibiotics. 8 out of 10 patients still received an antibiotic prescription in case of a negative nitrite test, and 9 out of 10 patients with an indication did not receive a urine culture. In conclusion, we found that correctly diagnosing UTIs and prescribing antibiotics for UTIs is a challenge that needs major improvement, especially during out-of-hours GP care.

Acute Psychosis Precipitated by Urinary Tract Infection in a Patient with Gliosis of the Basal Ganglia

BACKGROUND

Urinary tract infections (UTI) have been found to be associated with a variety of neuropsychiatric disorders, and could play a role in the pathophysiology of relapse of affective and nonaffective psychosis. In addition, prior history of infarction in areas of the brain such as the cerebellum, basal ganglia, and mid-brain have been reported in patients with new onset psychotic symptoms.

CASE PRESENTATION

A 29-year-old woman was brought to the hospital with acute mental status changes and signs of sepsis. Infectious work-up was initiated including blood cultures, brain imaging, lumbar tap and urinalysis. Brain MRI revealed abnormalities in the basal ganglia and the urinalysis revealed signs of a urinary tract infection (UTI). Further history revealed episodes of mania and depression compatible with bipolar disorder with psychotic features that had acutely worsened. The patient's condition improved with intravenous antibiotics and the introduction of anti-psychotics. She was discharged in stable condition with outpatient psychiatric follow-up.

CONCLUSION

Infectious diseases (UTIs in particular) are not only more prevalent among patients with acute relapse of psychiatric disorders, but have also been found to have triggered acute psychosis among stable psychiatric patients. Organic brain lesions must be thoroughly investigated among patients presenting with new psychiatric disorders in order to initiate appropriate therapy to control the symptoms.

The endotoxin hypothesis of neurodegeneration

The endotoxin hypothesis of neurodegeneration is the hypothesis that endotoxin causes or contributes to neurodegeneration. Endotoxin is a lipopolysaccharide (LPS), constituting much of the outer membrane of gram-negative bacteria, present at high concentrations in gut, gums and skin and in other tissue during bacterial infection. Blood plasma levels of endotoxin are normally low, but are elevated during infections, gut inflammation, gum disease and neurodegenerative disease. Adding endotoxin at such levels to blood of healthy humans induces systemic inflammation and brain microglial activation. Adding high levels of endotoxin to the blood or body of rodents induces microglial activation, priming and/or tolerance, memory deficits and loss of brain synapses and neurons. Endotoxin promotes amyloid β and tau aggregation and neuropathology, suggesting the possibility that endotoxin synergises with different aggregable proteins to give different neurodegenerative diseases. Blood and brain endotoxin levels are elevated in Alzheimer's disease, which is accelerated by systemic infections, including gum disease. Endotoxin binds directly to APOE, and the APOE4 variant both sensitises to endotoxin and predisposes to Alzheimer's disease. Intestinal permeability increases early in Parkinson's disease, and injection of endotoxin into mice induces α-synuclein production and aggregation, as well as loss of dopaminergic neurons in the substantia nigra. The gut microbiome changes in Parkinson's disease, and changing the endotoxin-producing bacterial species can affect the disease in patients and mouse models. Blood endotoxin is elevated in amyotrophic lateral sclerosis, and endotoxin promotes TDP-43 aggregation and neuropathology. Peripheral diseases that elevate blood endotoxin, such as sepsis, AIDS and liver failure, also result in neurodegeneration. Endotoxin directly and indirectly activates microglia that damage neurons via nitric oxide, oxidants and cytokines, and by phagocytosis of synapses and neurons. The endotoxin hypothesis is unproven, but if correct, then neurodegeneration may be reduced by decreasing endotoxin levels or endotoxin-induced neuroinflammation.

Common bacterial infections and risk of incident cognitive decline or dementia: a systematic review protocol

INTRODUCTION

The global burden of dementia is rising, emphasising the urgent need to develop effective approaches to risk reduction. Recent evidence suggests that common bacterial infections may increase the risk of dementia, however the magnitude and timing of the association as well as the patient groups affected remains unclear. We will review existing evidence of the association between common bacterial infections and incident cognitive decline or dementia.

METHODS AND ANALYSIS

We will conduct a comprehensive search of published and grey literature from inception to 18 March 2019. The following electronic databases will be searched; MEDLINE, EMBASE, Global health, PsycINFO, Web of Science, Scopus, Cochrane Library, the Cumulative Index to Nursing and Allied Health Literature, Open Grey and the British Library of Electronic Theses databases. There will be no restrictions on the date, language or geographical location of the studies. We will include longitudinal studies with a common clinically symptomatic bacterial infection as an exposure and incident cognitive decline or dementia as an outcome. Study selection, data extraction and risk of bias will be performed independently by two researchers. We will assess the risk of bias using the Cochrane collaboration approach. The overall quality of the studies will be assessed using the Grading of Recommendations, Assessment, Development and Evaluations criteria. We will explore the heterogeneity of relevant studies and, if feasible, a meta-analysis will be performed, otherwise we will present a narrative synthesis. We will group the results by exposure and outcome definitions and differences will be described by subgroups and outcomes.

ETHICS AND DISSEMINATION

Ethical approval will not be required as this is a systematic review of existing research in the public domain. Results will be disseminated in a peer-reviewed journal and presented at national and international meetings and conferences.

PROSPERO REGISTRATION NUMBER

CRD42018119294.

Association between induced abortion, spontaneous abortion, and infertility respectively and the risk of psychiatric disorders in 57,770 women followed in gynecological practices in Germany

AIM

Our goal was to analyze the association between induced abortion, spontaneous abortion, and infertility respectively and the risk of psychiatric disorders in 57,770 women followed in gynecological practices in Germany.

METHODS

This case-control study was based on data from the Disease Analyzer database (IQVIA). Women with a first documentation of depression, anxiety, adjustment disorder, or somatoform disorder in one of 281 gynecological practices in Germany between January 2013 and December 2017 were included in this study (index date). Controls without depression, anxiety, adjustment disorder, or somatoform disorder were matched (1:1) to cases by age, index year, and physician. A total of 57,770 women were included in the present study. The main outcome of the study was the risk of psychiatric disorders (i.e. depression, anxiety, adjustment disorder, somatoform disorder) as a function of induced abortion, spontaneous abortion, and infertility.

RESULTS

The mean age was 29.2 years (SD = 6.4 years) in women with and without psychiatric disorders. Induced abortion (odds ratios [ORs] ranging from 1.75 to 2.01), spontaneous abortion (ORs ranging from 2.16 to 2.60), and infertility (OR = 2.13) were positively associated with the risk of psychiatric disorders.

CONCLUSIONS

A positive relationship between induced abortion, spontaneous abortion, and infertility respectively and psychiatric disorders was observed in gynecological practices in Germany.

Age-Associated Changes in the Immune System and Blood⁻Brain Barrier Functions

Age is associated with altered immune functions that may affect the brain. Brain barriers, including the blood-brain barrier (BBB) and blood-CSF barrier (BCSFB), are important interfaces for neuroimmune communication, and are affected by aging. In this review, we explore novel mechanisms by which the aging immune system alters central nervous system functions and neuroimmune responses, with a focus on brain barriers. Specific emphasis will be on recent works that have identified novel mechanisms by which BBB/BCSFB functions change with age, interactions of the BBB with age-associated immune factors, and contributions of the BBB to age-associated neurological disorders. Understanding how age alters BBB functions and responses to pathological insults could provide important insight on the role of the BBB in the progression of cognitive decline and neurodegenerative disease.

Refining Delirium: A Transtheoretical Model of Delirium Disorder with Preliminary Neurophysiologic Subtypes

The development of delirium indicates neurophysiologic disruption and predicts unfavorable outcomes. This relationship between delirium and its outcomes has inspired a generation of studies aimed at identifying, predicting, and preventing both delirium and its associated sequelae. Despite this, evidence on delirium prevention and management remains limited. No medication is approved for the prevention or treatment of delirium or for its associated psychiatric symptoms. This unmet need for effective delirium treatment calls for a refined approach. First, we explain why a one-size-fits-all approach based on a unitary biological model of delirium has contributed to variance in delirium studies and prevents further advance in the field. Next, in parallel with the shift from dementia to "major neurocognitive disorder," we propose a transtheoretical model of "delirium disorder" composed of interactive elements-precipitant, neurophysiology, delirium phenotype, and associated psychiatric symptoms. We explore how these relate both to the biopsychosocial factors that promote healthy cognition ("procognitive factors") and to consequent neuropathologic sequelae. Finally, we outline a preliminary delirium typology of specific neurophysiologic disturbances. Our model of delirium disorder offers several avenues for novel insights and clinical advance: it univocally differentiates delirium disorder from the phenotype of delirium, highlights delirium neurophysiology as a treatment target, separates the core features of delirium from associated psychiatric symptoms, suggests how procognitive factors influence the core elements of delirium disorder, and makes intuitive predictions about how delirium disorder leads to neuropathologic sequelae and cognitive impairment. Ultimately, this model opens several avenues for modern neuroscience to unravel this disease of antiquity.

Acute Encephalitis in an Adult with Diffuse Large B-Cell Lymphoma with Secondary Involvement of the Central Nervous System: Infectious or Non-Infectious Etiology?

Both infectious and non-infectious etiologies of acute encephalitis have been described, as well as their specific presentations, diagnostic tests, and therapies. Classic findings of acute encephalitis include altered mental status, fever, and new lesions on neuroimaging or electroencephalogram (EEG). We report an interesting case of a 61-year-old male with a history of diffuse large B-cell lymphoma with secondary involvement of the central nervous system (SCNS-DLBCL). He presented with acute encephalitis: altered mental status, fever, leukocytosis, neuropsychiatric symptoms, multiple unchanged brain lesions on computed tomography scan of the head, and EEG showed mild to moderate diffuse slowing with low-moderate polymorphic delta and theta activity. With such a wide range of symptoms, the differential diagnosis included paraneoplastic and autoimmune encephalitis. Infectious and autoimmune/paraneoplastic encephalitis in patients with SCNS-DLBCL are not well documented in the literature, hence diagnosis and therapy becomes challenging. This case report describes the patient’s unique presentation of acute encephalitis.

Can antibiotics cause a psychosis?: Case report and review of the literature

It is relatively unknown that some of the possible side effects of antibiotic treatment can be transient psychotic episodes and other encephalopathies such as seizure disorders. Since these are rare events, there have not been many studies about them, nor is there a clear understanding of the underlying basis for these symptoms. This phenomenon was recently brought to our attention by a patient whose case history is discussed here. For the past few years, he has been diagnosed at different times with schizophrenia, schizoaffective disorder, bipolar disorder with psychosis, temporal lobe epilepsy, and psychogenic nonepileptic seizures. He was seen by a neurologist and placed on carbamazepine, which by his admittance helped him tremendously. During this same time period, psychiatrists placed him on various antipsychotic medications as well. The patient researched many medical conditions and came to the conclusion that his symptoms are caused by a large dose of an "antibiotic" given to him on his first day of basic training for the military, the so called "peanut butter shot", although he has not been able to convince his physicians of this theory. Whether or not this patient has a chronic schizophrenia-like illness or an adverse reaction to antibiotics, this case is presented so that clinicians are aware that neurological and psychiatric side effects can occur as rare reactions to antibiotic therapy and that treatment with an anti-seizure drug concurrently used as a mood stabilizer may be warranted in such cases.

Acute Neuropsychiatric Symptoms Associated With Antibiotic Treatment of Helicobacter Pylori Infections: A Review

Helicobacter pylori infects half the global population. Because serious complications can result from this infection, a so-called "triple therapy" is recommended: treatment with a proton-pump inhibitor and clarithromycin, along with amoxicillin or metronidazole. Although these antibiotics have been associated with neuropsychiatric symptoms, it is difficult to disentangle the effects of antibiotics from the effects of acute infections that may precipitate acute neuropsychiatric symptoms. Study of patients with chronic H. pylori infections who undergo antibiotic treatment may provide a clearer view of the associations between acute neuropsychiatric symptoms and antibiotics. The literature concerning this association in patients with H. pylori has not been reviewed. We therefore undertook a review of MEDLINE and postmarket surveillance data concerning this issue and identified 25 cases. Postmarket data indicated that gastrointestinal symptoms were the most commonly reported adverse reactions, followed by neurological adverse reactions; neuropsychiatric symptoms were less commonly reported, with variable and nonspecific terminology used to describe them. More specific, yet still variable terminology was found in the literature. Anxiety, delirium, dissociation, mania, and psychosis were reported, with approximately half of these neuropsychiatric symptoms occurring without symptoms of delirium. The use of standardized neuropsychiatric symptom rating scales and the Confusion Assessment Method for monitoring adverse reactions may improve our knowledge of neuropsychiatric symptoms and their association with antibiotics and thus mitigate underreporting. Physicians should remain alert to the possibility that neuropsychiatric symptoms may occur during antibiotic treatment of H. pylori and recognize that rapid resolution typically occurs with discontinuation of the antibiotics.

Medical mimics: Differential diagnostic considerations for psychiatric symptoms

Patients with underlying medical disease can present to the health care system with psychiatric symptoms predominating. Identification of an underlying medical condition masquerading as a psychiatric disorder can be challenging for clinicians, especially in patients with an existing psychiatric condition. The term medical mimic or secondary psychosis has been used to describe this clinical situation. Diagnostic categories from The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, that may encompass medical mimics include substance-induced disorders, which includes medications, and unspecified mental disorder due to another medical condition in situations where the clinician may lack needed information for a complete diagnosis. At this time, there is no single diagnostic test or procedure available to differentiate primary versus secondary psychosis on the basis of psychopathology presentation alone. When considering a diagnosis, clinicians should evaluate for the presence of atypical features uncharacteristic of the psychiatric symptoms observed; this may include changes in functionality and/or age of onset and symptom presentation severity. The purpose of this work is to provide a structured clinical framework for evaluation for medical mimics, identify groups considered to be at highest risk for medical mimics, and present common syndromic features suggestive of a medical mimic. Selected case scenarios are used to illustrate key concepts for evaluating and assessing a patient presenting with acute psychiatric symptomatology to improve judgment in ruling out potential medical causality.

Individuals hospitalized with acute mania have increased exposure to antimicrobial medications

OBJECTIVES

We have preciously documented that many individuals with acute mania have immune activation. However, the sources of immune activation have not been identified. We investigated whether individuals hospitalized with acute mania have evidence of bacterial infections as determined by the prescription of systemic antimicrobial agents.

METHODS

We assessed the recent prescription of systemic antimicrobial medications and the site of presumed bacterial infection in 234 individuals hospitalized for acute mania in either an inpatient unit or a day hospital. We also assessed individuals hospitalized for other psychiatric disorders (n=368) and controls (n=555). We employed logistic regression models to compare the rates of antibiotic prescription in individuals with the different diagnoses, employing demographic variables as covariates.

RESULTS

We found that individuals hospitalized with acute mania had a substantially increased rate of recent antimicrobial prescription, defined as exposure within three days of ascertainment (adjusted odds ratio=5.5, 95% confidence interval: 2.2-14.1, P<.0002). Overall, a total of 18 of the 234 (7.7%) individuals hospitalized for acute mania were prescribed antibiotics as opposed to seven of 555 (1.3%) controls. The prescription of antibiotics was associated with being on an inpatient unit as opposed to being in the day hospital, and having increased mania symptom severity but not with other clinical ratings, demographic variables, or psychiatric medications. Hospitalization for other psychiatric disorders was not associated with the recent prescription of antimicrobial medications. The urinary tract was the most common site of infection in women, while the respiratory tract and mucosal surfaces were the most common sites in men.

CONCLUSIONS

Individuals hospitalized with acute mania have a markedly increased rate of bacterial infections, as evidenced by the recent prescription of antimicrobial agents. The prevention and effective treatment of bacterial infections may be important interventions for the management of individuals with mania.