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Electrocochleography (ECochG) Report

Patient: Mr. Chander Singh Rawat

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Test Overview

• SP (Summating Potential) - reflects the hair cell (outer and inner) response to sustained sound stimulation. An enlarged SP can indicate endolymphatic hydrops (as seen in Meniere's disease).
• AP (Action Potential) - also referred to as Wave I of the ABR; represents the synchronous firing of the auditory nerve (Compound Action Potential - CAP).
• SP/AP Amplitude Ratio - the most clinically significant measure. A ratio > 0.45-0.50 is typically considered abnormal and suggestive of endolymphatic hydrops.

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Stimulus Parameters

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Waveform Results - By Ear

Right Ear (RE) - File: 51RE88A.1

Left Ear (LE) - File: 51LE88A.2

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Area Measurements (from Acquisition Page)

Note: Area ratios > 1.0 indicate SP area exceeds AP area, which is associated with endolymphatic hydrops.

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Clinical Interpretation

Right Ear

• SP/AP ratio = 0.31 - this is within normal limits (< 0.45).
• AP amplitude (0.13 µV) is relatively small with an SNR of 0.40; the residual noise (RN = 0.560) is higher, suggesting the right ear response is less reliable/noisier.
• The waveform morphology is discernible but of lower amplitude overall.

Left Ear

• SP/AP ratio = 0.42 - this is borderline / approaching abnormal (normal < 0.45; some labs use < 0.40 as their cutoff).
• AP amplitude (0.23 µV) is larger and the RN (0.264) is lower, indicating a more reliable, cleaner recording.
• The left ear SP is notably larger relative to AP, which warrants clinical attention.

Area Ratios

• Both area ratios (1.48 and 1.68) are elevated above 1.0, indicating the SP area dominates over the AP area. This pattern is a known indicator of endolymphatic hydrops.

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Summary & Clinical Significance

1. The left ear shows a borderline-elevated SP/AP ratio (0.42) and elevated area ratios, which may suggest early or subclinical endolymphatic hydrops in the left ear. This is consistent with early Meniere's disease or hydrops secondary to other causes.
2. The right ear SP/AP ratio (0.31) is within normal limits, though the recording quality is lower (higher RN, lower SNR), and the right ear area ratios are also elevated.
3. The area ratios (1.48, 1.68) being >1.0 are a supportive finding for endolymphatic hydrops.

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Recommendations

• Correlate clinically with symptoms: fluctuating sensorineural hearing loss, episodic vertigo, tinnitus, and aural fullness (classic Meniere's triad).
• Repeat testing of the right ear with more sweeps to improve SNR and reduce residual noise for a more reliable result.
• Consider audiogram and VEMP (Vestibular Evoked Myogenic Potentials) testing to further characterize the vestibular and cochlear function.
• ENT/Otologist referral is advisable given the borderline ECochG findings, especially if the patient reports any of the above symptoms.
• Serial ECochG monitoring may be useful if Meniere's disease is suspected.

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This report is based on objective electrophysiological data. Clinical correlation with the patient's history, symptoms, and other audiological findings is essential for a definitive diagnosis.