[Septic encephalopathy]

Review on the Role of Mitochondrial Dysfunction in Septic Encephalopathy

Septic Encephalopathy (SE) is a frequent and severe complication of sepsis, characterized by a range of neurocognitive impairments from mild confusion to deep coma. The underlying pathophysiology of SE involves systemic inflammation, neuroinflammation, blood-brain barrier (BBB) disruption, and mitochondrial dysfunction. Among these factors, mitochondrial dysfunction plays a pivotal role, contributing to impaired ATP production, increased reactive oxygen species (ROS) generation, and activation of apoptotic pathways, all of which exacerbate neuronal damage and cognitive deficits. Diagnosis of SE relies on clinical evaluation, neuroimaging, electroencephalography (EEG), and laboratory tests, though specific diagnostic markers are still lacking. Epidemiological data show SE is prevalent in intensive care unit (ICU) patients, especially those with severe sepsis or septic shock, with incidence rates varying widely depending on the population and diagnostic criteria used. Recent research highlights the importance of mitochondrial dynamics, including biogenesis, fission, and fusion, in the development of SE. Mitophagy, a selective form of autophagy that degrades damaged mitochondria, plays a critical role in maintaining mitochondrial health and protecting against dysfunction. Targeting mitochondrial pathways and enhancing mitophagy offers a promising therapeutic strategy to mitigate the effects of SE, reduce oxidative stress, prevent apoptosis, and support the resolution of neuroinflammation. Further research is essential to elucidate the mechanisms of mitochondrial dysfunction and mitophagy in SE and develop effective interventions to improve patient outcomes.

Toxic leukoencephalopathy versus delayed post-hypoxic leukoencephalopathy after oral morphine sulphate overdose

Toxic leukoencephalopathy (TLE) is a rare pathology caused by various substances including opioids (notably heroin), immunosuppressants, chemotherapy agents, cocaine, alcohol and carbon monoxide. However, although heroin is metabolised by the body into morphine, there is a striking paucity in cases of primary oral morphine-induced TLE, especially in the adult population. We present the case of a man in his 40s admitted to hospital in respiratory depression with a Glasgow Coma Scale (GCS) score of 6 after taking an overdose of oral morphine sulphate. Following a complete recovery to baseline, he was then readmitted with an acute deterioration in his neurobehavioural condition. Initial investigations returned normal but MRI showed changes characteristic for TLE.In cases of opioid toxicity such as ours, TLE is difficult to differentiate from delayed post-hypoxic leukoencephalopathy, due to their similar clinical presentation, disease progression and radiological manifestation. We explore how clinicians can approach this diagnostic uncertainty.

Treating the body to prevent brain injury: lessons learned from the coronavirus disease 2019 pandemic

PURPOSE OF REVIEW

We aim to provide the current evidence on utility and application of neuromonitoring tools including electroencephalography (EEG), transcranial Doppler (TCD), pupillometry, optic nerve sheath diameter (ONSD), cerebral near-infrared spectroscopy (cNIRS), somatosensory-evoked potentials (SSEPs), and invasive intracranial monitoring in COVID-19. We also provide recent evidence on management strategy of COVID-19-associated neurological complications.

RECENT FINDINGS

Despite the common occurrence of neurological complications, we found limited use of standard neurologic monitoring in patients with COVID-19. No specific EEG pattern was identified in COVID-19. Frontal epileptic discharge was proposed to be a potential marker of COVID-19 encephalopathy. TCD, ONSD, and pupillometry can provide real-time data on intracranial pressure. Additionally, TCD may be useful for detection of acute large vessel occlusions, abnormal cerebral hemodynamics, cerebral emboli, and evolving cerebral edema at bedside. cNIRS was under-utilized in COVID-19 population and there are ongoing studies to investigate whether cerebral oxygenation could be a more useful parameter than peripheral oxygen saturation to guide clinical titration of permissive hypoxemia. Limited data exists on SSEPs and invasive intracranial monitoring.

SUMMARY

Early recognition using standardized neuromonitoring and timely intervention is important to reduce morbidity and mortality. The management strategy for neurological complications is similar to those without COVID-19.

The Use of Electroencephalography in Patients with Sepsis: a Review of The Literature

Sepsis-associated encephalopathy (SAE) is the term used to define brain dysfunction related to infections that are principally located outside the central nervous system (CNS). A number of published studies report that electroencephalography (EEG) has been used in the evaluation of patients with sepsis, alone or usually in combination, to evoked potentials and neuroimaging. This was in an effort to assess if EEG can be a tool in the diagnosis and monitoring of the neurological status in sepsis patients. Although there is no specific test for the diagnosis and prognosis of sepsis related encephalopathy, our literature review suggests that EEG has a role in the assessment of this clinical entity. Due to its low cost and simplicity in its performance, EEG could be a potential aid in the assessment of sepsis neurological complications even in the early, subclinical stages of the syndrome. The aim of this review is to summarize the published literature regarding the application and utility of electroencephalography in adult patients with sepsis.

AChE-activity in critically ill patients with suspected septic encephalopathy: a prospective, single-centre study

Background

Up to 70% of septic patients develop a diffuse brain dysfunction named “septic associated encephalopathy” which is often solely based on clinical impressions. However, the diagnosis of septic associated encephalopathy is outcome-relevant due to an increase in mortality in these patients. Neuroinflammation as well as a disturbance of cholinergic transmission are assumed to be the causes of both delirium and septic associated encephalopathy. An alteration in cholinergic activity can be objectified by measuring the erythrocytic acetylcholinesterase-activity. Single-point measurements of acetylcholinesterase-activity are of limited value because individual and dynamic changes over time have to be anticipated. Therefore, the hypothesis should be tested whether a longitudinal analysis of acetylcholinesterase-activity in critically ill patients can help to diagnose a suspected septic-associated encephalopathy and whether acetylcholinesterase-activity differs in comparison to non-septic patients.

Methods

In this prospective, observational, single-center study, 175 patients (45 with sepsis, 130 without sepsis) were included. All patients were admitted to the surgical Intensive Care Unit of the University hospital Ulm, Germany. Patients were examined daily for the presence of delirium using the CAM-ICU. Daily measurement of the acetylcholinesterase-activity was performed in all patients. The possible time-dependent change in acetylcholinesterase-activity was analyzed with a linear regression model considering repeated measurements. Using a time-adjusted model further factors able to affect AChE-activity were investigated. For nonparametric distributions quantitative data were compared using Wilcoxon matched-pairs test. For analysis of independent samples the Mann-Whitney test was performed.

Results

About 90% of septic patients with suspected septic associated encephalopathy exhibited a statistically significant time-dependent in- or decrease in acetylcholinesterase-activity over a period of at least 5 consecutive days.

Conclusion

Longitudinal measurement of acetylcholinesterase-activity over several consecutive days revealed a change from baseline only in septic patients with suspected septic-associated encephalopathy. Therefore, longitudinal measurement of acetylcholinesterase-activity is able to diagnose septic associated encephalopathy in septic patients with delirious symptoms.

Trial registration

Retrospectively registered at German Clinical Trials Register, registration number DRKS00020542, date of registration: January 27, 2020.

Neurologic complications of sepsis

Over the past decades, the incidence of sepsis and resultant neurologic sequelae has increased, both in industrialized and low- or middle-income countries, by approximately 5% per year. Up to 300 patients per 100 000 population per year are reported to suffer from sepsis, severe sepsis, and septic shock. Mortality is up to 30%, depending on the precision of diagnostic criteria. The increasing incidence of sepsis is partially explained by demographic changes in society, with aging, increasing numbers of immunocompromised patients, dissemination of multiresistant pathogens, and greater availability of supportive medical care in both industrialized and middle-income countries. This results in more septic patients being admitted to intensive care units. Septic encephalopathy is a manifestation especially of severe sepsis and septic shock where the neurologist plays a crucial role in diagnosis and management. It is well known that timely treatment of sepsis improves outcome and that septic encephalopathy may precede other signs and symptoms. Particularly in the elderly and immunocompromised patient, the brain may be the first organ to show signs of failure. The neurologist diagnosing early septic encephalopathy may therefore contribute to the optimal management of septic patients. The brain is not only an organ failing in sepsis (a "sepsis victim" - as with other organs), but it also overwhelmingly influences all inflammatory processes on a variety of pathophysiologic levels, thus contributing to the initiation and propagation of septic processes. Therefore, the best possible pathophysiologic understanding of septic encephalopathy is essential for its management, and the earliest possible therapy is crucial to prevent the evolution of septic encephalopathy, brain failure, and poor prognosis.

Neurological manifestations of scrub typhus

OBJECTIVE

To evaluate the neurological manifestations of scrub typhus and correlate their clinical, EEG and MRI findings.

METHODS

A cross-sectional study over 2 years included patients with scrub typhus diagnosed by solid phase immunochromatographic assay or Weil-Felix test. A detailed clinical evaluation including Glasgow Coma Scale (GCS) was documented. Blood counts, chemistry, ECG, chest radiograph, cerebrospinal fluid (CSF), EEG and cranial MRI were performed. Outcome on discharge and at 1 month were categorised into good and poor based on modified Rankin Scale.

RESULTS

Thirty-seven patients with ages ranging between 3 and 71 years were included; 51% of whom were females. All patients had fever and myalgia. Thirty-one (84%) patients had impaired consciousness, and six were deeply comatose (GCS score ≤8). Eight patients presented with status epilepticus. MRI revealed meningeal enhancement in only 1/25 (4%) patient and EEG showed generalised slowing in 6/28 (21.4%). Among 31 patients with altered sensorium, CSF studies were conducted on 28. Nineteen patients had meningoencephalitis and 9 encephalopathy, but no significant differences were observed in clinical, laboratory, EEG and MRI findings. All patients responded within 48 h to doxycycline and had good recovery at 1 month. Patients with low GCS score had significantly more focal neurological deficit (r=0.5; p=0.002), longer hospital stay (r=-0.4; p=0.03) and more disability on discharge (r=-0.4; p=0.01).

CONCLUSIONS

Meningoencephalitis/encephalopathy may be seen in two-third of patients with scrub typhus. Scrub typhus should be included in the differential diagnosis of febrile encephalopathy.

Early prediction and outcome of septic encephalopathy in acute stroke patients with nosocomial coma

Background

Septic encephalopathy (SE) is the most common acute encephalopathy in ICU; however, little attention has been focused on risk of SE in the course of acute stroke. Our aim is to investigate the early prediction and outcome of SE in stroke patients with nosocomial coma (NC).

Methods

A retrospective cohort study was conducted in an ICU of the tertiary teaching hospital in China from January 2006 to December 2009. Ninety-four acute stroke patients with NC were grouped according to with or without SE. Risk factors for patients with SE were compared with those without SE by univariate and multivariate analysis.

Results

Of 94 stroke patients with NC, 46 (49%) had NC with SE and 48 (51%) had NC without SE. The onset-to-NC time was significant later in stroke patients with SE than those without SE (P < 0.01). There was a significant difference in body temperature, heart rate, respiratory rate, white blood cell (WBC), systolic blood pressure (SBP), diastolic blood pressure (DBP), systemic inflammatory response syndrome (SIRS), acute respiratory failure, septic shock, hypernatremia, and sequential organ failure assessment (SOFA) score between the SE and non-SE group (P < 0.05). On a repeat head imaging, vasogenic edema (P = 0.023) and subcortical white matter lesions (P = 0.011) were significantly higher in patients with SE than those without SE, while hematoma growth (P = 0.000), infarction progress (P = 0.003), and recurrent subarachnoid hemorrhage (SAH) (P = 0.011) were significantly lower in patients with SE than those without SE. Patients with SE had higher adjusted rates of fever ≥ 39 °C (odds ratio (OR): 2.753; 95% confidence interval (CI): 1.116 - 6.794; P = 0.028) and SIRS ≥ 3 items (OR: 6.459; 95% CI: 2.050 - 20.351; P = 0.001). The 30-day mortality in stroke patients with SE was higher than those without SE (76.1% vs. 45.8%, P = 0.003).

Conclusion

High fever and severe SIRS are two early predictors of stroke patients with SE, and survival rates were worse in stroke patients with SE than those without SE.

[Neurological and psychological long-term effects of sepsis]

BACKGROUND

In addition to the limitations to the health-related quality of life that have been compiled with validated test instruments, a number of former sepsis patients suffer from functional impairments, which are categorized under the terms critical illness polyneuropathy (CIP) or critical illness myopathy (CIM), which have been in existence for over 20 years now.

CURRENT FOCUS

The issues of delirium during intensive therapy and persistent residual neurocognitive impairments, posttraumatic stress disorder (PTSD) and states of depression related to perihospital functional development have increasingly attracted notice.

FUTURE

The degree of functional deficits resulting from sepsis and the actual quality of life of those affected may, however, be influenced by taking appropriate rehabilitation measures. However, neither therapeutic rehabilitation standards nor any rehabilitation facilities tailored to the needs of these patients currently exist.

Septic encephalopathy

Every year, more cases of sepsis appear in intensive care units. The most frequent complication of sepsis is septic encephalopathy (SE), which is also the essential determinant of mortality. Despite many years of research, it still is not known at which stage of sepsis the first signs of SE appear; however, it is considered the most frequent form of encephalopathy. Patients have dysfunction of cognitive abilities and consciousness, and sometimes even epileptic seizures. Despite intensive treatment, the effects of SE remain for many years and constitute an important social problem. Numerous studies indicate that changes in the brain involve free radicals, nitric oxide, increased synthesis of inflammatory factors, disturbances in cerebral circulation, microthromboses, and ischemia, which cause considerable neuronal destruction in different areas of the brain. To determine at what point during sepsis the first signs of SE appear, different experimental models are needed to detect the aforementioned changes and to select the proper therapy for this syndrome.

Predictors and outcome of hypoxemia in severely malnourished children under five with pneumonia: a case control design

BACKGROUND

There is lack of information in the medical literature on predictors of hypoxemia in severely malnourished children with pneumonia, although hypoxemia is common and is often associated with fatal outcome in this population. We explored the predictors of hypoxemia in under-five children who were hospitalized for the management of pneumonia and severe acute malnutrition (SAM).

METHODS

In this unmatched case-control design, SAM children of both sexes, aged 0-59 months, admitted to the Dhaka Hospital of the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B) with radiological pneumonia and hypoxemia during April 2011 to April 2012 were studied. SAM children with pneumonia and hypoxemia (SpO(2)<90%) constituted the cases (n = 37), and randomly selected SAM children with pneumonia but without hypoxemia constituted controls (n = 111).

RESULTS

The case-fatality was significantly higher among the cases than the controls (30% vs. 4%; p<0.001). In logistic regression analysis, after adjusting for potential confounders such as nasal flaring, head nodding, inability to drink, and crackles in lungs, fast breathing (95% CI = 1.09-13.55), lower chest wall in-drawing (95% CI = 2.48-43.41), and convulsion at admission (95% CI = 3.14-234.01) were identified as independent predictors of hypoxemia in this population. The sensitivity of fast breathing, lower chest wall in-drawing and convulsion at admission and their 95% confidence intervals (CI) to predict hypoxemia were 84 (67-93)%, 89 (74-96)%, and 19 (9-36)% respectively, and their specificity were 53 (43-63)%, 60 (51-69)% and 98 (93-100)% respectively.

CONCLUSION AND SIGNIFICANCE

Fast breathing and lower chest wall in-drawing were the best predictors of hypoxemia in SAM children with pneumonia. There thus, in resources poor settings where pulse oximetry is not available, identification of these simple clinical predictors of hypoxemia in such children could be reliably used for early O(2) supplementation in addition to other appropriate management to reduce morbidity and deaths.