Case History

A 10-year-old female presented to the audiology department at a large pediatric hospital. She recently failed a hearing screening in both ears at her pediatrician’s office. The patient reported she was unable to hear. She stated that sounds were muffled and she was unable to understand when spoken to. The audiologist attempted to converse with the patient; however, she responded inconsistently and frequently looked to her mother for clarification.

Reported medical history was significant for recent complaints of hip pain and intermittent vomiting. The parent conveyed that her daughter’s symptoms began approximately one month prior. At that time, she was also notably lethargic. The patient was receiving counseling to address emotional concerns that developed around the time of her parents’ recent divorce. 

Two to three weeks following the onset of hip pain, but prior to her audiological evaluation, the patient was taken to the emergency department. Radiographs of the hips and pelvis were completed and there were no abnormal findings. 

The parent reported that the patient visited her primary care physician a few days prior to the audiology evaluation due to continued hip pain. During this examination, a sore was identified on her upper leg which was subsequently cultured for Lyme disease. Results of this culture were still pending at the time of the audiological evaluation. 

Although not reported by the parent during the initial case history, a thorough review of the medical record at a later date revealed that the patient had returned to the emergency department the day after discharge with continued hip pain and more frequent vomiting. Her abdominal symptoms were reported to be exacerbated under stress and the patient was discharged again with the recommendation to follow up with her primary care physician. Continued counseling was also recommended as it was believed symptoms were likely related to her parents’ recent divorce. 

Audiometric Findings

  • Otoscopic examination confirmed ears were clear of debris.
  • Tympanometric measures were within normal limits, bilaterally.
  • Transient evoked-otoacoustic emissions (TEOAEs) screening was consistent with a pass result, bilaterally. 
  • Distortion product otoacoustic emissions (DPOAEs) were present for the frequency-regions tested, bilaterally. 
  • Behavioral threshold testing was attempted; however, no reliable results were obtained. The patient was unable to repeat spondees presented to each ear at various intensities up to 90 dB HL. The patient did not respond consistently to tones presented at various frequencies and intensities. Although the patient was repeatedly re-instructed, no reliable thresholds were obtained. 

What Would You Do?

At this time, testing was suspended. Questions arose about the possibility of Lyme disease causing a sudden onset neural hearing loss, an undiagnosed auditory neuropathy spectrum disorder exacerbated by Lyme disease, or a case of pseudohypacusis. After audiologist reflection and a discussion with the parent, it was decided to continue testing. 

  • Middle-ear muscle reflex (MEMR) testing was completed and revealed absent ipsilateral and contralateral acoustic reflexes at 110 dB HL for 1000 and 2000 Hz stimuli.
  • Natural-sleep auditory brainstem response (ABR) testing was attempted. No repeatable waveforms were identified using a 2000 Hz tone burst or a click stimulus. Waveform morphology was poor. The patient was not asleep for testing and although she was calm, artifact secondary to her wakefulness was present, preventing the majority of waveforms from being interpreted accurately.

What Does that Add to the Diagnostic Picture?

Although the natural-sleep ABR testing did not provide additional information regarding the patient’s hearing sensitivity, the absence of identifiable waves at high intensities (90 dB nHL), as well as absent MEMRs suggested abnormal auditory function. 

FIGURE 1. Results from audiometric evaluation completed three weeks after oncology plan was initiated.
FIGURE 1. Results from audiometric evaluation completed three weeks after oncology plan was initiated.

Course of Care

Atypical audiological (behavioral and physiological) as well as reported sudden onset hearing loss prompted an immediate evaluation with an otolaryngologist. This otolaryngologist recommended a consult to neurology and ordered an expedited magnetic resonance image (MRI) of the brain and internal auditory canals. The MRI was completed later that same day and revealed a lesion in the nasal cavity, thickening of multiple cranial nerves including the optic and vestibulo cochlear nerves, and increased cranial pressure. An MRI of the spine and pelvis completed the next day revealed additional abnormalities including masses and tumor infiltration concerning for lymphoma or leukemia. 

The patient was admitted to an inpatient unit where a plan for chemotherapy and radiation was initiated immediately to treat her diagnosis of B cell lymphoblastic lymphoma. Upon admission, her functional hearing ability decreased and she was unable to communicate. Her vision also became blurry and she began to have seizures. 

Approximately three weeks after the oncology treatment plan was initiated, both the patient and her parents reported a significant improvement in hearing. 

Follow-up Audiological Testing

MEMRs were retested and were present ipsilaterally at 85 dB HL for 1000 Hz stimuli in both ears. The patient was able to complete reliable behavioral audiological testing. Results were consistent with a mild sensorineural hearing loss in the right ear and a moderately severe rising sensorineural hearing loss in the left ear (FIGURE 1). 


FIGURE 2. Results from audiometric evaluation completed eight weeks after oncology plan was initiated.

Audiologic testing was completed again following another month of treatment. Hearing in the right ear returned to normal with the exception of a mild hearing loss at 250 Hz. A mild low-frequency sensorineural hearing loss was documented in the left ear (FIGURE 2). DPOAE testing was repeated and emissions were present for all frequency regions tested, bilaterally.

Ototoxicity Monitoring

The patient was treated with radiation approximately three times a week for two weeks. Although she also received chemotherapy, non-ototoxic agents were used. Nonetheless, audiologic testing using an ototoxicity monitoring protocol was recommended. As the dosage of radiation increases, the risk of hearing loss also increases. Additionally, hearing loss can appear up to 18 months after the completion of treatment (Hua et al, 2008). 

Discussion

This patient presented with many symptoms that upon the initial encounter were suspect for pseudohypacusis. Previous hearing screenings administered at school and at her pediatrician’s office were normal. Her parents reported that she seemed to hear at home. There were no academic concerns and her speech and language skills were age-appropriate. At times, she seemed to respond appropriately to questions from the audiologist. She was receiving counseling due to her parents’ recent divorce and was reported to exhibit other concerning social-emotional behaviors at home. Finally, OAE results were consistent with normal cochlear function. MEMR and ABR results eventually ruled out pseudohypacusis. 

Thinking critically and completing various cross-check measures led to a compilation of test results with atypical findings. These findings, along with reported audiological and medical history, led to urgent recommendations from other specialists which ultimately confirmed a life-threatening diagnosis. Previous symptoms including hip pain, vomiting, and lethargy, which had resulted in more than one visit to the emergency department, did not lead to a diagnosis. In the three days between audiologic testing and her inpatient admission, this patient experienced a dramatic decline including vision loss and seizures. With a diagnosis and appropriate treatment, her condition improved.

Dr. Theodore Woodward, professor at the University of Maryland, is often credited for coining the phrase, "When you hear hoofbeats, think of horses not zebras." This case highlights the fact that, although less likely, zebras do exist. Practicing with a questioning attitude with each patient allows you to consider the atypical, and in this case, mindful practice that was lifesaving.