[Spectrum analysis of vestibular nystagmus]

Area of Science:

• Otolaryngology
• Neuroscience
• Vestibular System Analysis

Background:

• Cochleovestibular pathologies present complex diagnostic challenges.
• Understanding vestibular nystagmus patterns is crucial for accurate diagnosis.

Purpose of the Study:

• To develop a spectral analysis procedure for nystagmograms.
• To identify characteristic changes in vestibular nystagmus associated with cochleovestibular diseases.
• To correlate specific harmonic components with peripheral and central vestibular function.

Main Methods:

• Rotary stimulation at 180 degrees/s for 20 seconds.
• Acquisition and computer-aided spectral analysis (EC-1022) of nystagmograms.
• Calculation of periodograms using fast Fourier transform and smoothing techniques.

Main Results:

• Absence of the third harmonic was observed in Ménière's disease during labyrinth stimulation.
• Absence of the third or fifth harmonic was noted in cases of acoustic nerve neurites.
• Distinct spectral patterns differentiate between specific cochleovestibular pathologies.

Conclusions:

• The third harmonic may indicate the status of the peripheral vestibular analyzer.
• The fifth harmonic might reflect the state of the central vestibular analyzer.
• Spectral analysis of nystagmograms offers a valuable tool for diagnosing vestibular disorders.