DOI: 10.36347/sjams.2017.v5i08.033

Pages: 3132-3140

Alzheimer’s disease (AD) is the most common cause of dementia worldwide and its prevalence increases steadily with age. The present study was undertaken to appreciate neural dynamics in Alzheimer’s Disease in terms of amplitude and latency of event related potentials (ERPs) giving an insight into working of neuronal pools sub-serving P300, an endogenous cognitive component of ERP. The results of present study define the role of P300 as an early predictor of conversion of Mild Cognitive Impairment to AD, wherein the component P300 could become a potential non-invasive, and economical, diagnostic and prognostic tool. The study was conducted in Departments of Physiology and Neurology at S.M.S. Medical College and Attached Hospitals, Jaipur. The age range of the study population was 55-70 years that was categorized into three groups namely, Alzheimer’s disease (AD) group, Mild Cognitive Impairment (MCI) group and Healthy Control group using Mini-Mental State Examination (MMSE) score as per Diagnostic and Statistical Manual (DSM)-V criteria. The sample consisted of 5 patients with mild to moderate AD, 30 patients with MCI, and 30 were healthy controls. ERP was recorded at Fz, Pz and Oz electrode sites using visual oddball paradigm, in which the subject was presented with a series of 100 visual stimuli, each consisting of a string containing eleven “S” alphabets out of which 80 stimuli consisted of all blue coloured “S” alphabets and the remaining 20 stimuli consisted of all red coloured “S” alphabets presented in the background of white colour. The amplitude of P300 displayed a significant difference across the three groups at Fz electrode site while the latency of P300 was significantly increased at Fz in AD group as compared to that observed in healthy controls.The time-locked feature of Fronto-Occipital Neuronal Pool and (space) amplitude-locked feature of Fronto-Parietal Neuronal Pool elicit the limiting neural mechanisms underlying neurocognitive processes that are