Neurology of Sepsis

Incidence of seizures in ICU patients with diffuse encephalopathy and its predictors

Encephalopathy is a diffuse brain dysfunction that results from systemic disorder. Patients with diffuse encephalopathy are at risk of developing clinical and electrographic seizures. The aim of this study is to assess the prevalence of electrographic seizures in a setting of encephalopathy and the clinical and electroencephalogram predictors. We retrospectively reviewed all continuous electroencephalograms done between 2019 and 2022. Continuous electroencephalograms with diffuse encephalopathy were included in the study. A total of 128 patients with diffuse encephalopathy were included in this study. Patients' ages ranged from 18 to 96 years old with a mean age of 55.3 ± 19.2 years old. Nine out of 128 patients had seizures with an incidence of 7%. Sixty-six point six percent were nonconvulsive electrographic seizures. Fourteen point three percent of the female patients with diffuse encephalopathy had seizures as compared to none of the male patients (P = .002). Also, 12% of patients with a history of epilepsy experienced seizures versus 5.8% of patients without this history (P = .049). Among electrographic features, 25% of patients with delta background had seizures versus 2.3% of the other patients (P = .048). Likewise, 90% of patients with periodic discharges developed seizures in comparison with none of the patients without (P = .001). Seizures are seen in 7% of patients with diffuse encephalopathy. Female gender, past history of epilepsy, delta background and periodic discharges are significant predictors of seizure development in patients with diffuse encephalopathy.

Lanthanide luminescence nanothermometer with working wavelength beyond 1500 nm for cerebrovascular temperature imaging in vivo

Nanothermometers enable the detection of temperature changes at the microscopic scale, which is crucial for elucidating biological mechanisms and guiding treatment strategies. However, temperature monitoring of micron-scale structures in vivo using luminescent nanothermometers remains challenging, primarily due to the severe scattering effect of biological tissue that compromises the imaging resolution. Herein, a lanthanide luminescence nanothermometer with a working wavelength beyond 1500 nm is developed to achieve high-resolution temperature imaging in vivo. The energy transfer between lanthanide ions (Er3+ and Yb3+) and H2O molecules, called the environment quenching assisted downshifting process, is utilized to establish temperature-sensitive emissions at 1550 and 980 nm. Using an optimized thin active shell doped with Yb3+ ions, the nanothermometer's thermal sensitivity and the 1550 nm emission intensity are enhanced by modulating the environment quenching assisted downshifting process. Consequently, minimally invasive temperature imaging of the cerebrovascular system in mice with an imaging resolution of nearly 200 μm is achieved using the nanothermometer. This work points to a method for high-resolution temperature imaging of micron-level structures in vivo, potentially giving insights into research in temperature sensing, disease diagnosis, and treatment development.

Clinical characteristics of tuberculous meningitis in older patients compared with younger and middle-aged patients: a retrospective analysis

BACKGROUND

Few studies have analyzed the clinical characteristics and adverse factors affecting prognosis in older patients with tuberculous meningitis (TBM). This study aimed to compare the clinical characteristics of TBM in older patients with those in younger and middle-aged patients.

METHODS

This single-center retrospective study extracted data on the clinical features, cerebrospinal fluid changes, laboratory results, imaging features, and outcomes of patients with TBM from patient medical records and compared the findings in older patients (aged 60 years and older) with those of younger and middle-aged patients (aged 18-59 years).

RESULTS

The study included 197 patients with TBM, comprising 21 older patients aged 60-76 years at onset, and 176 younger and middle-aged patients aged 18-59 years at onset. Fever was common in both older (81%) and younger and middle-aged patients (79%). Compared with younger and middle-aged patients, older patients were more likely to have changes in awareness levels (67% vs. 40%), peripheral nerve dysfunction (57% vs. 29%), changes in cognitive function (48% vs. 20%), and focal seizures (33% vs. 6%), and less likely to have headache (71% vs. 93%), neck stiffness on meningeal stimulation (38% vs. 62%), and vomiting (47% vs. 68%). The Medical Research Council staging on admission of older patients was stage II (52%) and stage III (38%), whereas most younger and middle-aged patients had stage I (33%) and stage II (55%) disease. Neurological function evaluated on the 28th day of hospitalization was more likely to show poor prognosis in older patients than in younger and middle-aged patients (76% vs. 25%). Older patients had significantly higher red blood cell counts and blood glucose levels, and significantly lower serum albumin and sodium levels than those in younger and middle-aged patients. The cerebrospinal fluid protein levels, nucleated cell counts, glucose levels, and chloride levels did not differ significantly by age.

CONCLUSION

In patients with TBM, older patients have more severe clinical manifestations, a higher incidence of hydrocephalus and cerebral infarction, and longer hospital stays than younger and middle-aged patients. Older patients thus require special clinical attention.

Effect of Systemic Inflammation in the CNS: A Silent History of Neuronal Damage

Central nervous system (CNS) infections including meningitis and encephalitis, resulting from the blood-borne spread of specific microorganisms, provoke nervous tissue damage due to the inflammatory process. Moreover, different pathologies such as sepsis can generate systemic inflammation. Bacterial lipopolysaccharide (LPS) induces the release of inflammatory mediators and damage molecules, which are then released into the bloodstream and can interact with structures such as the CNS, thus modifying the blood-brain barrier's (BBB´s) and blood-cerebrospinal fluid barrier´s (BCSFB´s) function and inducing aseptic neuroinflammation. During neuroinflammation, the participation of glial cells (astrocytes, microglia, and oligodendrocytes) plays an important role. They release cytokines, chemokines, reactive oxygen species, nitrogen species, peptides, and even excitatory amino acids that lead to neuronal damage. The neurons undergo morphological and functional changes that could initiate functional alterations to neurodegenerative processes. The present work aims to explain these processes and the pathophysiological interactions involved in CNS damage in the absence of microbes or inflammatory cells.

Prior exposure to stress exacerbates neuroinflammation and causes long-term behavior changes in sepsis

Background

Neuroinflammation can occur during sepsis and is now regarded as the main mechanism underlying various related central nervous system (CNS) disorders. Another well-known factor causing neuroinflammation is psychological stress. In the current study, we examined the effects of prior exposure to stress on sepsis-induced neuroinflammation and CNS symptoms.

Experimental procedure

Balb/c mice were subjected to wet bedding stress for 2 days, then lipopolysaccharide (LPS) was intraperitoneally administered. For examining the neuroinflammation, the expression of proinflammatory cytokines and NF-κB activity in the brain was analyzed by RT-PCR and ELISA-based assay. Additionally, immunohistochemical study using Iba-1 was performed. Finally, behavior tests were examined one month after LPS treatment.

Result and conclusion

Stress exposure induced the upregulation of IL-1β, IL-6 and TNFα mRNA in the cerebral cortex 4 h after LPS administration. Suggesting an underlying mechanism, LPS-induced NF-κB activation was significantly upregulated with stress in the brain. Histologically, microglia in the cerebral cortex were reactive and became more abundant with stress, while these effects were further increased with LPS injection. Behavioral analysis conducted showed a significant increase of anxiety-like behaviors in the stressed mice. These results suggest that prior exposure to stress exacerbates neuroinflammation during sepsis and induces long-term behavior changes.

Neuropsychological Outcome of Critically Ill Patients with Severe Infection

Sepsis and septic shock represent important burdens of disease around the world. Sepsis-associated neurological consequences have a great impact on patients, both in the acute phase and in the long term. Sepsis-associated encephalopathy (SAE) is a severe brain dysfunction that may contribute to long-term cognitive impairment. Its pathophysiology recognizes the following two main mechanisms: neuroinflammation and hemodynamic impairment. Clinical manifestations include different forms of altered mental status, from agitation and restlessness to delirium and deep coma. A definite diagnosis is difficult because of the absence of specific radiological and biological criteria; clinical management is restricted to the treatment of sepsis, focusing on early detection of the infection source, maintenance of hemodynamic homeostasis, and avoidance of metabolic disturbances or neurotoxic drugs.

The pathophysiology of sepsis - 2021 update: Part 2, organ dysfunction and assessment

DISCLAIMER

In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

This is the second article in a 2-part series discussing the pathophysiology of sepsis. Part 1 of the series reviewed the immunologic response and overlapping pathways of inflammation and coagulation that contribute to the widespread organ dysfunction. In this article (part 2), major organ systems and their dysfunction in sepsis are reviewed, with discussion of scoring systems used to identify patterns and abnormal vital signs and laboratory values associated with sepsis.

SUMMARY

Sepsis is a dysregulated host response to infection that produces significant morbidity, and patients with shock due to sepsis have circulatory and cellular and metabolic abnormalities that lead to a higher mortality. Cardiovascular dysfunction produces vasodilation, reduced cardiac output and hypotension/shock requiring fluids, vasopressors, and advanced hemodynamic monitoring. Respiratory dysfunction may require mechanical ventilation and attention to volume status. Renal dysfunction is a frequent manifestation of sepsis. Hematologic dysfunction produces low platelets and either elevation or reduction of leucocytes, so consideration of the neutrophil:lymphocyte ratio may be useful. Procoagulant and antifibrinolytic activity leads to coagulation that is stimulated by inflammation. Hepatic dysfunction manifest as elevated bilirubin is often a late finding in sepsis and may cause reductions in production of essential proteins. Neurologic dysfunction may result from local endothelial injury and systemic inflammation through activity of the vagus nerve.

CONCLUSION

Timely recognition and team response with efficient use of therapies can improve patient outcome, and pharmacists with a complete understanding of the pathophysiologic mechanisms and treatments are valuable members of that team.

Basic research and clinical progress of sepsis-associated encephalopathy

Sepsis-associated encephalopathy (SAE), a major cerebral complication of sepsis, occurs in 70% of patients admitted to the intensive care unit (ICU). This condition can cause serious impairment of consciousness and is associated with a high mortality rate. Thus far, several experimental screenings and radiological techniques (e.g., electroencephalography) have been used for the non-invasive assessment of the structure and function of the brain in patients with SAE. Nevertheless, the pathogenesis of SAE is complicated and remains unclear. In the present article, we reviewed the currently available literature on the epidemiology, clinical manifestations, pathology, diagnosis, and management of SAE. However, currently, there is no ideal pharmacological treatment for SAE. Treatment targeting mitochondrial dysfunction may be useful in the management of SAE.

Seizures and Sepsis: A Narrative Review

Patients with sepsis-associated encephalopathy (SAE) can develop convulsive or nonconvulsive seizures. The cytokine storm and the overwhelming systemic inflammation trigger the electric circuits that promote seizures. Several neurologic symptoms, associated with this disease, range from mild consciousness impairment to coma. Focal or generalized convulsive seizures are frequent in sepsis, although nonconvulsive seizures (NCS) are often misdiagnosed and prevalent in SAE. In order to map the trigger zone in all patients that present focal or generalized seizures and also to detect NCS, EEG is indicated but continuous EEG (cEEG) is not very widespread; timing, duration, and efficacy of this tool are still unknown. The long-term risk of seizures in survivors is increased. The typical stepwise approach of seizures management begins with benzodiazepines and follows with anticonvulsants up to anesthetic drugs such as propofol or thiopental, which are able to induce burst suppression and interrupt the pathological electrical circuits. This narrative review discusses pathophysiology, clinical presentation, diagnosis and treatment of seizures in sepsis.

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.

Chronic molecular hydrogen inhalation mitigates short and long-term memory loss in polymicrobial sepsis

The central nervous system (CNS) is one of the first physiological systems to be affected in sepsis. During the exacerbated systemic inflammatory response at the early stage of sepsis, circulatory inflammatory mediators are able to reach the CNS leading to neuroinflammation and, consequently, long-term impairment in learning and memory formation is observed. The acute treatment with molecular hydrogen (H₂) exerts important antioxidative, antiapoptotic, and anti-inflammatory effects in sepsis, but little is known about the mechanism itself and the efficacy of chronic H₂ inhalation in sepsis treatment. Thus, we tested two hypotheses. We first hypothesized that chronic H₂ inhalation is also an effective therapy to treat memory impairment induced by sepsis. The second hypothesis is that H₂ treatment decreases sepsis-induced neuroinflammation in the hippocampus and prefrontal cortex, important areas related to short and long-term memory processing. Our results indicate that (1) chronic exposure of hydrogen gas is a simple, safe and promising therapeutic strategy to prevent memory loss in patients with sepsis and (2) acute H₂ inhalation decreases neuroinflammation in memory-related areas and increases total nuclear factor E2-related factor 2 (Nrf2), a transcription factorthat regulates a vast group of antioxidant and inflammatory agents expression in these areas of septic animals.

The dynamic change of serum S100B levels from day 1 to day 3 is more associated with sepsis-associated encephalopathy

We investigated the role of dynamic changes of serum levels S100B protein in brain injury and poor outcome of sepsis. This is a prospective cohort study designed to include 104 adult patients with sepsis who are admitted to ICU from Jan 2015 to Aug 2016. Sepsis was defined as sepsis 3.0. Patients with a GCS score of <15, or at least one positive CAM-ICU score were thought to have brain dysfunction. 59 patients were diagnosed with SAE and the rest 45 patients were diagnosed with non-SAE. Serum S100B was measured on day 1 and 3 after ICU admission. Primary outcomes included brain dysfunction and 28-day/180-day mortality. The SAE group showed a significantly higher APACHE II score, SOFA scores, length of ICU stay, 28-day and 180-day mortality, serum S100B levels on day 1 and day 3. S100B levels on day 1 of 0.226 μg/L were diagnostic for SAE with 80.0% specificity and 66.1% sensitivity, and the area under (AUC) the curve was 0.728, S100B levels on day 3 of 0.144 μg/L were diagnostic for SAE with 84.44% specificity and 69.49% sensitivity, and the AUC was 0.819. In addition, the AUC for S100B on day 3 for predicting 180-day mortality was larger than for S100B on day 1 (0.731 vs. 0.611). Multiple logistic regression analysis showed that S100B3 (p = 0.001) but not S100B1 (p = 0.927) were independently correlated with SAE. Kaplan-Meier survival analysis showed that patients with S100B levels higher than 0.144 μg/L had a lower probability of survival at day 180. There were more patients with encephalopathy and a higher 28-day or 180-day mortality in the ΔS100B + group than in the ΔS100B- group. Multiple logistic regression analysis showed that SAE and IL-6 on day 3 were independently correlated with S100B dynamic increase. These findings suggest that elevated serum S100B levels on day 3 and the dynamic changes of serum S100B levels from day three to one were more associated with brain dysfunction and mortality than that on day 1 in patients with sepsis.

Serum glial fibrillary acidic protein and ubiquitin C-terminal hydrolase-L1 for diagnosis of sepsis-associated encephalopathy and outcome prognostication

PURPOSE

We investigated the role of serum Glial Fibrillary Acidic Protein (GFAP) and Ubiquitin C-Terminal Hydrolase-L1 (UCH-L1) in diagnosis of sepsis-associated encephalopathy(SAE), predicting prognosis and long-term quality of life with patients of sepsis.

MATERIALS AND METHODS

This is a prospective single center study entailed 105 patients whosuffered from sepsis from Jan 2015 to Aug 2016. Serum concentrations of GFAP and UCH-L1 for diagnosis of SAE and predicting prognosis and long-term quality of life with patients of sepsis were analyzed.

RESULTS

The serum concentrations of GFAP and UCH-L1 were higher in SAE group than in no-SAE group (p < .001). GFAP and UCH-L1 produced an AUC of 0.824 and 0.812 respectively for diagnosis of SAE with optimal cut-off values 0.532 ng/ml and 7.72 ng/ml respectively. The optimal cut-off values of GFAP and UCH-L1 to distinguish patients with survivors from non-survivors were 0.536 ng/ml and 8.06 ng/ml with an area under the curve of 0.773 and 0.746. Patients with a higher GFAP levels had worse long-term usual activities and patients with a higher UCH-L1 levels had more long-term pain (P = .026).

CONCLUSIONS

Serum concentrations GFAP and UCH-L1 early elevated and associated with sepsis-associated encephalopathy, poor prognosis and quality of life.

Intraperitoneal hypertension, a novel risk factor for sepsis-associated encephalopathy in sepsis mice

Sepsis associated encephalopathy (SAE), appears often indicates the deterioration of the sepsis disease and which have high risk of death. Although several mechanism and hypotheses have been proposed and studied, there is no breakthrough in the treatment of SAE. We performed a systematic research to evaluate the effect of intraperitoneal pressure on SAE. A mice model of sepsis was established by intraperitoneal injection of endotoxin. A total of 48 female BALB/c mouse (30 days old) were randomly divided into a control group (n = 12) and an injection of endotoxin referred to bacterial lipopolysaccharide (LPS) group (n = 12). Intraperitoneal hypertension (IAH) referred to IAH group (n = 12), and LPS + IAH group (n = 12). Following sepsis induction, diagnosis, the brains were analyzed for both function and ultrastructural morphology.We determined that IAH exacerbated sepsis induces sepsis-associated encephalopathy when examining low score of neurological function and more delta wave in EEG, increased neuronal edema in LPS + IAH group, as well as an escalation of Bax and Cleaved-caspase-3, Cleaved-parp, and reduction of Bcl-2 and Mfsd2a in LPS + IAH group. Therefore, IAH can exacerbate and increase incident rate of sepsis-related encephalopathy in sepsis mice by promoting neuronal apoptosis and destruction of the blood-brain barrier.

Role of G protein-coupled receptor kinase 2 in oxidative and nitrosative stress-related neurohistopathological changes in a mouse model of sepsis-associated encephalopathy

Sepsis-associated encephalopathy (SAE), characterized as diffuse brain dysfunction and neurological manifestations secondary to sepsis, is a common complication in critically ill patients and can give rise to poor outcome, but understanding the molecular basis of this disorder remains a major challenge. Given the emerging role of G protein-coupled receptor 2 (GRK2), first identified as a G protein-coupled receptor (GPCR) regulator, in the regulation of non-G protein-coupled receptor-related molecules contributing to diverse cellular functions and pathology, including inflammation, we tested the hypothesis that GRK2 may be linked to the neuropathogenesis of SAE. When mouse MG6 microglial cells were challenged with lipopolysaccharide (LPS), GRK2 cytosolic expression was highly up-regulated. The ablation of GRK2 by small interfering RNAs (siRNAs) prevented an increase in intracellular reactive oxygen species generation in LPS-stimulated MG6 cells. Furthermore, the LPS-induced up-regulation of inducible nitric-oxide synthase expression and increase in nitric oxide production were negated by GRK2 inhibitor or siRNAs. However, GRK2 inhibition was without effect on overproduction of tumor necrosis factor-α, interleukin (IL)-6, and IL-1β in LPS-stimulated MG cells. In mice with cecal ligation and puncture-induced sepsis, treatment with GRK2 inhibitor reduced high levels of oxidative and nitrosative stress in the mice brains, where GRK2 expression was up-regulated, alleviated neurohistological damage observed in cerebral cortex sections, and conferred a significant survival advantage to CLP mice. Altogether, these results uncover the novel role for GRK2 in regulating cellular oxidative and nitrosative stress during inflammation and suggest that GRK2 may have a potential as an intriguing therapeutic target to prevent or treat SAE.

Multiple Organ Dysfunction: The Defining Syndrome of Sepsis

BACKGROUND

Sepsis as a process has been recognized since the time of the Ancient Greeks. The concept has evolved recently to reflect a disease process of a severe, systemic response to infection. Acute, life-threatening but potentially reversible organ dysfunction is its hallmark, and unresolving organ dysfunction is the dominant cause of death in critical illness. Its evolution, persistence, and resolution reflect a complex interplay of factors originating in the initial inciting insult, the innate immune and metabolic response of the host, and the beneficial and harmful consequences of intensive care unit (ICU) supportive care.

DISCUSSION

We describe the common clinical manifestations of the six prototypic organ system dysfunction syndromes of severe sepsis and review the associated epidemiology and suspected pathophysiology.

Individual differences in the brain are associated with resilience versus susceptibility to lipopolysaccharide-induced memory impairment

Sepsis impairs learning and memory function, yet marked interindividual variability exists in the degree to which sepsis compromises learning and memory function. Thus, testing resilience versus susceptibility to systemic inflammation induced-memory impairment and the underlying mechanism is needed. In the present study, we firstly used lipopolysaccharide (LPS) to induce memory impairment, and then evaluated cognitive function on days 4-7 after the first LPS challenge. Subjects' scores on both behavioral measures were subjected to a hierarchical cluster analysis, identifying two clusters that differed notably on the Y-maze and fear conditioning tests. This analysis divided these subjects into two groups, one cluster (13 of 34 subjects) displayed impaired working and associative memory, named "Susceptive". The remaining cluster (21 of 34 subjects) showed normal memory, named "Resilient". We have also included another group receiving normal saline to serve as the control group. The three groups underwent a battery of biochemical detections. In addition, we investigated whether the individual differences would disappear between the "Resilient" and "Susceptive" groups by using microglia inhibitor minocycline. We showed that as compared with the "Resilient" or control group, the "Susceptive" group was accompanied by increased tumor necrosis factor-alpha, interleukin-1beta (IL-1β), IL-6, and biomarkers of microglia activation ionized calcium binding adaptor molecule-1 and cluster of differentiation 68. Notably, after decreasing the activation of microglia, the differences in cognitive function between the "Resilient" and "Susceptive" groups disappeared. Collectively, our study suggests that individual differences in the brain are associated with resilience versus susceptibility to LPS-induced memory impairment.

Long-term risk of seizures in adult survivors of sepsis

OBJECTIVE

To examine the association between sepsis and the long-term risk of seizures.

METHODS

We conducted a retrospective population-based cohort study using administrative claims data from all emergency department visits and hospitalizations at nonfederal acute care hospitals in California, Florida, and New York from 2005 to 2013. Using previously validated diagnosis codes, we identified all adult patients hospitalized with sepsis. Our outcome was any emergency department visit or hospitalization for seizure. Poisson regression and demographic data were used to calculate age-, sex-, and race-standardized incidence rate ratios (IRR). To confirm our findings, we used a matched cohort of hospitalized patients without sepsis for comparison and additionally assessed claims data from a nationally representative 5% sample of Medicare beneficiaries.

RESULTS

We identified 842,735 patients with sepsis. The annual incidence of seizure was 1.29% (95% confidence interval [CI] 1.27%-1.30%) in patients with sepsis vs 0.16% (95% CI 0.16%-0.16%) in the general population (IRR 4.98; 95% CI 4.92-5.04). A secondary analysis using matched hospitalized patients confirmed these findings (IRR 4.33; 95% CI 4.13-4.55), as did a separate analysis of Medicare beneficiaries, in whom we found a similar strength of association (IRR 2.72; 95% CI 2.60-2.83), as we did in patients ≥65 years of age in our primary statewide data (IRR 2.83; 95% CI 2.78-2.88).

CONCLUSIONS

We found that survivors of sepsis faced a significantly higher long-term risk of seizures than both the general population and other hospitalized patients. Our findings suggest that sepsis is associated with pathways that lead to permanent neurologic sequelae.

Brain Oxidative Stress During Experimental Sepsis Is Attenuated by Simvastatin Administration

During sepsis, brain damage is associated with oxidative stress due to overproduction of reactive oxygen species (ROS). Although there are recent reports about the benefits of statins in experimental sepsis and endotoxemia in peripheral organs, little is known about their effects in the CNS. Here, we investigated the antioxidant properties of simvastatin and its possible neuroprotective role during experimental sepsis. Male Wistar rats (250-300 g) were submitted to cecal ligation and puncture (CLP, n = 34) or remained as non-manipulated (naive, n = 34). Both groups were treated by gavage with simvastatin (20 mg/kg) or an equivalent volume of saline. The animals submitted to CLP were treated 4 days before and 48 h after surgery. One animal group was decapitated and the blood and brain were collected to quantify plasma levels of cytokines and assess astrogliosis and apoptosis in the prefrontal cortex and hippocampus. Another group was perfused with PBS (0.01 M), and the same brain structures were dissected to analyze oxidative damage. The CLP rats treated with simvastatin showed a reduction in nitric oxide (P < 0.05), IL1-β (P < 0.001), IL-6 (P < 0.01), and TBARS levels (P < 0.001) and an increase in catalase activity (P < 0.01), citrate synthase enzyme (P < 0.05), and normalized GSH/GSSG ratio. In addition, the histopathological analysis showed a reduction (P < 0.001) in reactive astrocytes and caspase 3-positive apoptotic cells. The results suggest a possible neuroprotective effect of simvastatin in structures responsible for spatial learning and memory and indicate the need for behavioral studies evaluating the impact on cognitive damage, as frequently seen in patients surviving sepsis.