Alterations in the brain electrical activity in a rat model of sepsis-associated encephalopathy

Sepsis and septic shock are the commonest causes of death in the intensive care units. Although recent research have improved our understanding of the progress and pathophysiology of sepsis and septic shock, underlying mechanisms in sepsis-associated encephalopathy is still poorly understood. The incidence of sepsis-associated encephalopathy has been reported to vary from 8% to 70% of septic patients. We aimed at investigating the brain's electrical activity using somatosensory-evoked potentials and electrocorticographical recordings in cecal ligation and puncture rat model of sepsis. Significant decrease in mean arterial pressure, increase in heart rate, deteriorated neurological reflexes together with positive blood cultures results, thrombocytopenia and increased blood lactate levels suggesting the successful induction of sepsis in the present study. Elongated latencies and increased amplitudes were observed in somatosensory recordings of septic group, while electrocorticograms revealed slight decrease in median and spectral edge frequencies amplitudes and significantly increased delta activities in 50% of the septic rats. These results would suggest that the studies based on the investigation of the sepsis-associated encephalopathy in animal models needs to be combined with the electrophysiological confirmations of the brain dysfunction following the induction of sepsis.