정신건강의학과 환자 중 인지 및 기억 장애 지표로서 MMN의 임상적 유용성 연구 = The clinical Usefulness of Mismatch negativity (MMN) as an index of cognitive and memory impairment in neuropsychiatric disorder

국문 초록 (Abstract)

배경(Background): Memory deficit or cognitive impairment is an inclusive term to describe any characteristic that acts as a barrier to the cognition process. This study provides a non-invasive tool for evaluating patients with cognitive dysfunctions. The mistmatch negativity (MMN) component of event-related brain potentials (ERPs) has become a very popular tool to study auditory functions. The MMN measurement enables one to gain insights into neurobiological substrate of central auditory processing, particularly auditory memory, as well as various attention-related processes of controlling the access of auditory input into conscious perception and higher forms of memory. Moreover, MMN amplitude reduction to duration deviant tones was found to be related to the neuropsychological (working memory and verbal domains) and psychosocial functional outcomes. The present study focused on the relationship between MMN, and cognitive and memory impairment in patients with neuropsychiatric disorders. 방법(Methods): Twenty-six memory & cognitive deficit patients and 16 healthy controls underwent scalp EEG recordings during the delivery of a two-tone passive auditory paradigm (Pure tones; 85% standards [1 kHz, 80 dB], 15% frequency deviants [1.2 kHz, 80 dB]), and an electro-neuropsychological examination. Patients were assessed in regard to clinical symptoms. We measured N1, P2 latency and amplitude (deviant, standard sound response and difference value) at Midline (Fz, FCz, Cz, CPz, Pz) among ERP-MMN. 결과(Results): ERP-MMN waveforms makes it feasible to identify central auditory processing changes and cognitive, speech, and working memory impairment in patients with neuropsychiatric disorders. Compared to those of healthy controls, patients showed significantly reduced MMN amplitudes and shortened latency; impaired memory and cognitive function; and poorer tone matching performance. Cognitive deficits may be congenital or acquired secondarily by brain injuries, mental illness, or other neurological disorders. The MMN may be useful for understanding components of cognition in 고찰(Discussion): various disorders. Our study demonstrated decreased MMN amplitude and shortened latency their association with positive symptoms in patients with memory and cognitive impairment. These findings confirm and extend previous studies regarding impaired basic sensory processing in neurophysiological disorders and explain early sensory processing dysfunction in cognitive impairments. However, further investigation on larger scale is needed to ensure the statistical significance. In addition, future study should consider the use of more diverse paradigms to allow a more detailed understanding of sensory deficit.