Sepsis-associated encephalopathy and its differential diagnosis

Abstract

Sepsis is often complicated by an acute and reversible deterioration of mental status, which is associated with increased mortality and is consistent with delirium but can also be revealed by a focal neurologic sign. Sepsis-associated encephalopathy is accompanied by abnormalities of electroencephalogram and somatosensory-evoked potentials, increased in biomarkers of brain injury (i.e., neuron-specific enolase, S-100 beta-protein) and, frequently, by neuroradiological abnormalities, notably leukoencephalopathy. Its mechanism is highly complex, resulting from both inflammatory and noninflammatory processes that affect all brain cells and induce blood-brain barrier breakdown, dysfunction of intracellular metabolism, brain cell death, and brain injuries. Its diagnosis relies essentially on neurologic examination that can lead one to perform specific neurologic tests. Electroencephalography is required in the presence of seizure; neuroimaging in the presence of seizure, focal neurologic signs or suspicion of cerebral infection; and both when encephalopathy remains unexplained. In practice, cerebrospinal fluid analysis should be performed if there is any doubt of meningitis. Hepatic, uremic, or respiratory encephalopathy, metabolic disturbances, drug overdose, withdrawal of sedatives or opioids, alcohol withdrawal delirium, and Wernicke's encephalopathy are the main differential diagnoses of sepsis-associated encephalopathy. Patient management is based mainly on controlling infection, organ system failure, and metabolic homeostasis, at the same time avoiding neurotoxic drugs.

Neuro-oxidative-nitrosative stress in sepsis

“…Brain dysfunction in sepsis may involve a number of alternative mechanisms, which have been reviewed extensively elsewhere (Papadopoulos et al, 2000;Ebersoldt et al, 2007;Iacobone et al, 2009), and will only briefly be outlined here. These mechanisms and the six principal components of the oxidativenitrosative stress cascade proposed above are not mutually exclusive, and may to different extents interact to affect brain function in sepsis.…”

“…In the latter setting, organ dysfunction, including acute brain dysfunction, termed sepsis-associated encephalopathy (SAE) or sepsis-associated delirium, occurs in up to two thirds of patients (Vincent et al, 2006). SAE may be the first symptom of sepsis, and is characterized by confusion, agitation, and impaired consciousness (Young et al, 1990;Bolton et al, 1993;Ebersoldt et al, 2007, Iacobone et al, 2009). These symptoms may be an independent predictor of death (Sprung et al, 1990;Ebersoldt et al, 2007).…”

Electrographic seizures in pediatric ICU patients

“…Encephalopathy in the setting of sepsis is often associated with neurophysiologic and neuroradiologic abnormalities and is likely multifactorial in etiology. 22 A study of septic children demonstrated background patterns on EEG consistent with moderate to severe encephalopathy and elevated serum S100 beta and neuron-specific enolase compared to controls, indicating that neurologic injury may occur with sepsis. 23 A study of adults in a medical intensive care unit reported that about one-third of patients with sepsis had electrographic seizures or periodic epileptiform discharges and the presence of sepsis was the only predictor of electrographic seizures or periodic epileptiform discharges.…”

Serotonin syndrome: take a closer look at the unwell surgical patient

“…Drug-related permanent brain damage is well documented in SAE and the coexistence of SS is likely to be a factor in a worsening prognosis. 20 …”