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Updated: Feb 18, 2026
A Method for Tracking the Time Evolution of Steady-State Evoked Potentials
Published on: May 25, 2019
Effect of Mild Cognitive Impairment and Alzheimer Disease on Auditory Steady-State Responses
Elaheh Shahmiri1, Zahra Jafari2, Maryam Noroozian3
1Department of Neurosciences and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Introduction:
Mild Cognitive Impairment (MCI), a disorder of the elderly people, is difficult to diagnose and often progresses to Alzheimer Disease (AD). Temporal region is one of the initial areas, which gets impaired in the early stage of AD. Therefore, auditory cortical evoked potential could be a valuable neuromarker for detecting MCI and AD.
Methods:
In this study, the thresholds of Auditory Steady-State Response (ASSR) to 40 Hz and 80 Hz were compared between Alzheimer Disease (AD), MCI, and control groups. A total of 42 patients (12 with AD, 15 with MCI, and 15 elderly normal controls) were tested for ASSR. Hearing thresholds at 500, 1000, and 2000 Hz in both ears with modulation rates of 40 and 80 Hz were obtained.
Results:
Significant differences in normal subjects were observed in estimated ASSR thresholds with 2 modulation rates in 3 frequencies in both ears. However, the difference was significant only in 500 Hz in the MCI group, and no significant differences were observed in the AD group. In addition, significant differences were observed between the normal subjects and AD patients with regard to the estimated ASSR thresholds with 2 modulation rates and 3 frequencies in both ears. A significant difference was observed between the normal and MCI groups at 2000 Hz, too. An increase in estimated 40 Hz ASSR thresholds in patients with AD and MCI suggests neural changes in auditory cortex compared to that in normal ageing.
Conclusion:
Auditory threshold estimation with low and high modulation rates by ASSR test could be a potentially helpful test for detecting cognitive impairment.
Insights
The Auditory Steady-State Response (ASSR) test shows potential for detecting cognitive impairment. Increased auditory thresholds in Alzheimer Disease (AD) and Mild Cognitive Impairment (MCI) patients suggest neural changes in the auditory cortex.
Area of Science:
- Neuroscience
- Audiology
- Gerontology
Background:
- Mild Cognitive Impairment (MCI) is a precursor to Alzheimer Disease (AD), often affecting the temporal lobe early.
- Early detection of MCI and AD is crucial for timely intervention and management.
- Auditory cortical evoked potentials offer a potential non-invasive biomarker for cognitive decline.
Purpose of the Study:
- To compare Auditory Steady-State Response (ASSR) thresholds at 40 Hz and 80 Hz in patients with AD, MCI, and healthy elderly controls.
- To investigate the utility of ASSR as a diagnostic tool for identifying cognitive impairment.
- To explore neural changes in the auditory cortex associated with aging and cognitive disorders.
Main Methods:
- ASSR thresholds were measured at 500, 1000, and 2000 Hz using 40 Hz and 80 Hz modulation rates in both ears.
- Participants included 12 AD patients, 15 MCI patients, and 15 elderly normal controls.
- Statistical analyses compared ASSR thresholds across the three groups.
Main Results:
- Significant differences in ASSR thresholds were found in normal subjects across frequencies and modulation rates.
- MCI patients showed significant differences only at 500 Hz, while AD patients did not show significant differences.
- Both AD and MCI groups exhibited increased estimated 40 Hz ASSR thresholds compared to controls, indicating auditory cortex alterations.
Conclusions:
- ASSR testing, using varying modulation rates, may serve as a valuable tool for detecting cognitive impairment.
- The findings suggest that auditory pathway changes are associated with cognitive decline in aging.
- Further research is warranted to validate ASSR's role in early AD and MCI diagnosis.
