Thesis (Ph.D.) - Cairo University - Faculty of Medicine - Department of E.N.T

Introduction: Seniors often have more difficulty understanding speech than younger adults, particularly in noisy environments. Literature findings in Speech Auditory Brainstem response indicate that Cognitive Impairment coincides with changes in the neural representation of speech at multiple levels of the nervous system especially in the subcortical brainstem. Aims of work: Correlate objective auditory evoked potentials in form of Complex Auditory Brainstem Response with Cognitive Dysfunction. Subjects & Methods: The Study group comprised of fifty one patients having Cognitive Impairment (diagnosed according Diagnostic and Statistical Manual of Mental disorders, fifth edition 2013 (DSM-V)) while the Control group comprised of twenty healthy age & gender matched subjects. Both groups were subjected to 1) Full history taking &Otologic examination, 2) Full Neurological examination, 3) Full Audiologic evaluation, 4) Cognitive assessment, 5) Behavioural Central Auditory Processing battery and finally 6) Electrophysiologic Assessment (Complex Auditory brainstem response (cABR). Results: A statistical significant difference was found between both groups in Stimulus to response correlation (SR-r), Envelope (F0), and Response RMS but Fine temporal structure (F1) was non-significantly different. Conclusions: The key features of the Cognitively impaired elderly in the cABR are: a) Reduced phase locking in form of reduced consistency of cABR waves, b) delayed V, A, O latencies, c) abnormal temporal processing, d) Reduced F0 amp (pitch encoding) & e) Normal F1 amp (Fine temporal structure). Also, reduced Root Mean Square amplitude (RMS amp) & reduced Stimulus-Response correlation (S-R r) were more pronounced in the cognitively impaired elderly as analyzed by MATLAB

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