A 42-year-old male was seen for an initial audiological examination. He presented with a report of a gradual hearing loss, intermittent tinnitus, and aural fullness in the left ear. His hearing sensitivity has reportedly deteriorated slowly over the last 2 years. The patient has a history of unprotected noise exposure working as a club promoter for many years and recently has been exposed to machinery noise while working in construction. The patient denies otalgia, otorrhea, or dizziness.
An audiological examination revealed clear external canals bilaterally. Pure-tone thresholds (Fig. 3.1) indicated hearing within normal limits at 250 to 1000 Hz, a slight hearing loss at 2000 to 8000 Hz in the right ear, and a slight to moderate sensorineural hearing loss in the left ear at 250 to 4000 Hz with recovery to a mild sensorineural hearing loss at 8000 Hz. Speech recognition thresholds (SRTs) were at 15 dB HL in the right ear and 35 dB HL in the left ear indicating normal ability to receive speech in the right ear and a mild loss in the ability to receive speech in the left ear. The SRTs were considered to be in good agreement with pure-tone averages (PTAs) for the right ear but were slightly elevated for the left ear. Word recognition scores (WRSs) revealed normal ability to recognize words bilaterally at 40 dB sensation level (SL). Immittance audiometry revealed type Ad tympanograms bilaterally, indicative of hypercompliant tympanic membranes with normal middle ear pressure (daPa), normal ear canal volume (mL), and slightly elevated static admittance (mL). Contralateral acoustic reflex thresholds (ARTs) were within normal limits at 500 to 4000 Hz bilaterally. Contralateral reflex decay was negative in the right ear and positive in the left ear at 500 and 1000 Hz. Otoacoustic emissions were absent at 1500 to 6000 Hz bilaterally.
Based on the initial results of the audiological evaluation, what pathology would be most likely?
Audiological results indicate a unilateral sensorineural hearing loss. Left-sided aural fullness and tinnitus along with positive left ear contralateral reflex decay suggest possible retrocochlear pathology.
What recommendations should be made for this patient?
Due to suspected left-sided retrocochlear pathology, the patient should be referred to an otologist for further examination. The otologist may order auditory brainstem response (ABR) and/or image testing.
In that the patient presents with a hearing loss in the left ear, can amplification be recommended at this time?
Amplification may be an option in the future. Amplification, however, cannot be fit when a medical condition is suspected, unless a physician provides medical clearance.
How should the patient be counseled at this time?
The audiologist should explain the results of the audiological examination. Suspicion of problems past the cochlea should be discussed. The patient should be counseled to schedule an appointment with an otologist for further medical intervention. The possibility of amplification, pending medical clearance, should be discussed. Ear protection in the presence of loud noise should be recommended.
The patient was referred to an otologist. The otologist ordered an ABR test and magnetic resonance imaging (MRI) of the temporal area. The ABR test with a standard stimulus rate revealed normal peak and interpeak latencies in the right ear and delayed peak and interpeak latencies in the left ear. Increased stimulus rate revealed no adverse effects in the right ear and continued delayed peak latencies in the left ear. An MRI scan with and without contrast indicated a 4 × 3 × 2 mm left internal auditory canal lesion suggesting the presence of an acoustic neuroma.
Surgery was performed and a left acoustic neuroma was removed (Fig. 3.2). Fig. 3.2c reveals that the tumor was encapsulated and easily removed. A depression in the auditory nerve was present after the space-occupying lesion (tumor) was removed (Fig. 3.2d). The patient reported dizziness and left-sided facial weakness following surgery. He also experienced a decrease in hearing sensitivity in the left ear. Due to the lingering dizziness, the patient has been unable to continue in his profession as a construction worker. He has received counseling from Vocational Rehabilitation (VR) and is pursuing a new career. A postoperative audiological examination (Fig. 3.3) reveals a significant decrease in hearing sensitivity at 250 to 8000 Hz in the left ear, which has remained stable since surgery.