View clinical trials related to Mismatch Negativity.
Filter by:Sepsis-associated encephalopathy (SAE), is one of the most common organ dysfunction during the acute phase in sepsis and septic shock. Electroencephalogram (EEG) and auditory evoked potentials (AEPs), which reflect different aspects of brain function, are the most commonly used neurophysiological indices to detect acute brain dysfunction in critically ill patients including sepsis and septic shock. AEPs show the systemic responsiveness of the central nervous to auditory stimuli, so they can be considered a direct measure of brain responsiveness. Mismatch negativity (MMN) is a change-specific component of ERPs, which elicited by a deviant stimulus occurring in a sequence of repetitive stimuli. This component is thought to represent the automatic and unconscious detection of acoustic changes which requires good perceptual discriminative capacity and iconic memory. The peaks of MMN appear at 100 ~ 250 ms from deviant stimulus onset; with increasing magnitude of stimulus change, the peak latency of MMN was shortened and the amplitude increased. Since MMN can be elicited even in the absence of attention, subjects do not need to actively participate. The MMN has been extensively demonstrated to be used in the prediction of awakening in comatose patients for various reasons, and also has been reported to predict awakening in deeply sedated critically ill patients recently. However, it remains unclear whether SAE affects MMN in amplitude and latency that reflects cognitive processing of the auditory information. Patients with sepsis and septic shock who met the inclusion criteria were screened daily on the CAM-ICU scale, and those with positive CAM-ICU were diagnosed with SAE.All patients were tested for event-evoked potentials on Day 1 and Day 3 after inclusion and were followed up to Day 28 after discharge. The investigators intend to observe the dynamic change of MMN amplitude and latency between SAE and non-SAE groups. Logic regression analysis was used to determine whether the change of MMN was a predictor of SAE.
Auditory mismatch negativity deficit is a robust neurophysiological biomarker of schizophrenia. Repetitive transcranial magnetic stimulation (rTMS) is a neuromodulation method and can be used to modulate excitability of specific brain cortical region. We hypothesize that MMN deficit of schizophrenia is related to inferior frontal gyrus (IFG) hypofunction, and this deficit can be improved by using rTMS to enhance IFG function. It is a randomized, double-blinded, sham-controlled clinical trial. Forty-eight schizophrenia patients with MMN deficits (mean amplitude at FCz > -0.7 ㎶) will be recruited and then randomized at a 1:1 ratio to rTMS group and sham-stimulation group. Subjects in rTMS group will receive high frequency rTMS over IFG, while in the other group subjects will receive sham stimulation at IFG. Frameless stereotaxy navigation will be used to guide the rTMS coil to IFG. The primary outcome is the change of MMN mean amplitude at FCz after stimulation. We hypothesize that the change of MMN mean amplitude is significantly larger in rTMS group than in sham-stimulation group. Their cognitive function and clinical condition will be evaluated carefully before and after experiments.