Journal of Nature and Science (JNSCI), Vol.1, No.3, e48, 2015

Neuroscience | Case Report

 

Hearing Impairment in Pineal Tumors

 

Bader N. Kashlan, Jordan Chick, Osama N. Kashlan, Suresh Ramnath

 

Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA


Background: Patients with pineal tumors commonly present with symptoms due to increased intracranial pressure and tectal deformation. However, hearing loss and tinnitus are likely under-represented, underestimated symptoms caused by pineal tumors. Case description: A 32-year-old male presented with symptoms of acute lethargy, confusion, headaches, nausea, vomiting, and slurred speech in addition to subacute visual and hearing impairment.  Prior to his acute presentation, both an audiogram and a brainstem auditory evoked response (BAER) test were performed and found to be normal. He was found to have a large pineal germinoma, which was debulked.  His subjective hearing impairment improved postoperatively with the rest of his symptoms. Conclusions: The case presented demonstrates the importance of proceeding with intracranial imaging in patients with subjective auditory symptoms, even with normal audiologic testing, and serves as a reminder for the clinician to keep pineal tumors in the differential diagnosis for hearing loss/tinnitus. Journal of Nature and Science, 1(3):e48, 2015.

 

Brainstem auditory evoked response test | germinoma | hearing loss | pineal tumor | speech audiometry

 

Introduction

Pineal region tumors comprise 1-2% of primary intracranial tumors in adults and 3-8% in children [1]. Neuro-ophthalmologic findings, classically Parinaud syndrome, are common. Hearing loss and tinnitus have also been described in patients presenting with pineal tumors. These symptoms are explained by the proximity of the pineal region to the auditory pathways in midbrain, upper brainstem, and diencephalon.

Hearing problems in patients with pineal tumors occur more commonly than expected, with some case series showing a prevalence of up to 20% [2-7]. We present a case that highlights the importance of keeping pineal tumors in the differential diagnosis of patients with subjective hearing loss, even those with normal auditory testing.  A literature review follows that demonstrates the heterogeneity of audiometric and brainstem auditory evoked response (BAER) tests in these patients and the various trajectories of improvement seen after the lesions are treated.

 

Figure 1. Non-contrast head CT demonstrating calcified mass in the pineal region with resultant obstructive hydrocephalus.

Case description

History

A 32-year-old, right-handed male presented to the Emergency Department for symptoms of lethargy, confusion, headaches, nausea, vomiting, and slurred speech. He had been complaining of decreased hearing for 3-4 months, and had been treated for recurrent ear infections during that time. Nineteen days prior he had a normal audiogram. One week before admission a BAER test was performed and was also completely normal.

 

Examination

On examination, the patient was lethargic but easily aroused. Cranial nerve examination was significant for Parinaud syndrome. Speech was dysarthric, and his responses were often inappropriate, with difficulty following commands. Unenhanced head CT showed a moderately dense mass in the pineal gland region, with central calcification (Figure 1). The mass obliterated the posterior third ventricle with resultant moderately enlarged lateral ventricles. MRI showed the mass to be densely enhancing (Figure 2).

 

Figure 2. Axial (A), coronal (B), and sagittal (C) T1-contrast MRIs of brain showing extent of tumor.

 

Operation

An external ventricular drain was placed; drainage resulted in immediate improvement in lethargy, but his other symptoms did not resolve. He then underwent surgery via supracerebellar infratentorial approach to debulk the mass.  Histologic diagnosis was germinoma.

 

Postoperative Course

Postoperatively, the patient’s preoperative symptoms resolved and his hearing returned to normal. He underwent a course of radiation therapy after healing from his operation. Audiogram performed 1 year postoperatively continued to be normal.                                                                     

 

 

 


Table 1.  Results of literature review for patients with pineal tumors and hearing test results

 

 

Reference

Auditory Symptoms at Presentation

 

Initial Audiogram Results

 

 

Initial BAER

 

 

Operation/Intervention

Postoperative Improvement in Auditory Symptoms

Post-Intervention Hearing Test Results

 

Starr & Hamilton [8]

None

None

Prolonged latency in waves II and III; small IV-V wave at prolonged latency

Ventriculoatrial shunt placement

N/A

N/A (patient expired)

 

Missori et al.[9]

Tinnitus

Severe bilateral neurosensory hypoacusia on medium-acute waves

Normal

Craniotomy

Yes; complete resolution of tinnitus

Unchanged audiometric examination

 

 

Not stated

Bilateral impairment of acoustic sensation

Normal

Craniotomy; previously fitted with ventriculoatrial shunt

Not stated

N/A (tests refused)

 

 

None

Slight impairment of acoustic sensation

None performed

Craniotomy

No change; no preoperative auditory symptoms

Normal audiometric testing

 

Gaspar et al.[7]

None initially; complete hearing loss after shunt placement

Profound bilateral perceptive hearing loss, no speech recognition or detection

Normal

Unsuccessful ventriculocisternostomy followed by placement of ventriculoperitoneal shunt and chemoradiation

Yes; return to normal function

Normal audiometric testing 4 months from start of chemoradiation

 

Woo et al. [10]

Bilateral hearing impairment

Significant left high-frequency hearing impairment with bilateral speech discrimination impairment

Bilateral increased interpeak latency of waves III-V

Cyst aspiration via Rickham reservoir followed by craniotomy.  Previous history of pineal region ganglioglioma with repeated excisions, adjuvant radiotherapy, and ventriculoperitoneal shunting

Transient dramatic improvement after cyst aspiration; continued improvement after craniotomy

Improvement in audiometric testing and BAER after cyst aspiration

 

DeMonte et al. [11]

Difficulty hearing

Near normal pure tone definition; significantly disturbed speech discrimination

Increased latency of wave V bilaterally and slight increased latency of wave III on right

Craniotomy

Improvement in hearing

-“Impressive” improvement in speech discrimination scores

- No change in BAER

 

Toshniwal et al. [12]

Progressive hearing loss and tinnitus; complete deafness

Profound bilateral sensorineural hearing loss

No response

Ventriculoperitoneal shunt followed by craniotomy and radiation

Continued hearing impairment

BAER absent

 

Kashlan et al.

Decreased hearing

Normal

Normal

External ventricular drain followed by craniotomy

Improved to normal

Normal audiometric testing

BAER = brainstem auditory evoked response

Discussion

The true incidence of hearing problems in pineal tumors is difficult to determine, mainly due to the lack of routine preoperative and postoperative auditory testing performed in these patients.  Moreover, hearing impairment is rarely the predominant presenting symptom and is more likely overshadowed by the more typical complaints caused by pineal tumors.  Hearing impairment associated with pineal tumors is most likely explained by the pineal gland’s location near the lateral lemniscus, inferior colliculus, and medial geniculate nucleus of the thalamus, all structures important in transfer of information from the cochlea to the primary auditory cortex. Another possible explanation includes the ability of increased intracranial pressure to also be a false-localizing sign of hearing loss [7]. However, the former theory is likely more valid, as the patient described by Gaspar et al. developed hearing problems after his intracranial pressure was normalized by placement of a ventriculoperitoneal shunt while awaiting chemoradiation [7].

Interestingly, there is a paucity of information regarding the effect of pineal tumors on audiometric and BAER tests. We performed a literature review for reports of pineal tumors causing hearing loss that included associated hearing test results (Table 1) [7-12].  Six of the 7 patients who underwent audiogram had significant abnormality. The other patient did not have auditory complaints and therefore only had slight impairment of acoustic sensation on audiometric testing. Three of 7 patients who underwent audiograms had disturbed speech recognition. Our patient had a completely normal audiogram preoperatively.  With regard to BAER results, 3 of 7 patients who underwent BAER testing had a normal examination similar to our patient. Three others had abnormalities in waves III-V, which is expected for the location of a pineal lesion. Previous results show that audiometric testing is likely more sensitive in characterizing hearing loss due to pineal tumors than BAER testing.  Moreover, it demonstrates the importance of keeping a central cause of hearing loss in the differential diagnosis for a patient with subjective auditory symptoms, even with normal audiometric or BAER testing.

Regarding postoperative improvement in symptoms, with the exception of the patient who presented with subacute complete deafness, all patients had improvement in auditory symptoms much like our patient did. In the 5 patients with post-intervention audiometric testing, 4 had concurrent improvement in their results, while 1 had an unchanged examination, even with improved preoperative symptoms.  In contrast, in the 3 patients with post-intervention BAER testing, 1 had improvement while 2 others had no change.   One of these 2 patients presented with complete deafness that did not improve postoperatively. These results demonstrate the ability to use audiologic and BAER testing as a correlate to improvement of functional hearing after an intervention is performed.

 

Conclusions

In summary, our case serves as a reminder to clinicians to keep pineal tumors in the differential diagnosis for patients presenting with hearing loss.  Moreover, it also demonstrates that hearing loss can be occult to detection on hearing tests, therefore making it important to proceed with cranial imaging in a patient with continued auditory complaints and normal audiograms and/or BAER tests.

 

Acknowledgments

The authors would like to thank Holly Wagner for critical review and assistance with submission of the manuscript.


 

 

 



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Conflict of interest: No conflicts declared.

Correspondence author: Suresh Ramnath, MBBS, FRCSC. Department of Neurosurgery, University of Michigan, 1500 E. Medical Center Dr., Room 3552 TC, Ann Arbor, MI 48109-5338. Telephone: 734-615-4486; Fax: 734-936-9294. Email: ramnaths@med.umich.edu.

© 2015 by the Journal of Nature and Science (JNSCI).