From the Guidelines
For a 31-year-old male with non-pulsatile tinnitus and no hearing loss, I recommend a comprehensive workup starting with a detailed history and physical examination, focusing on potential causes such as noise exposure, ototoxic medications, and temporomandibular joint dysfunction, as suggested by the American Academy of Otolaryngology and Head and Neck Surgery Foundation guidelines 1. The initial evaluation should include a complete audiological assessment with pure tone audiometry, speech audiometry, tympanometry, and otoacoustic emissions to confirm normal hearing and rule out subtle auditory abnormalities. Some key points to consider in the workup include:
- Laboratory tests should include complete blood count, thyroid function tests, lipid profile, and fasting blood glucose to identify metabolic causes.
- Imaging studies are not routinely needed for non-pulsatile tinnitus with normal hearing but may include MRI of the brain and internal auditory canals if neurological symptoms are present or if tinnitus is unilateral and persistent, as recommended by the ACR Appropriateness Criteria 1.
- Referral to otolaryngology is appropriate for specialized assessment. Management typically involves addressing any identified underlying causes, counseling about tinnitus, sound therapy with white noise generators or hearing aids if beneficial, and cognitive behavioral therapy for coping strategies, as recommended by the American Academy of Otolaryngology and Head and Neck Surgery Foundation guidelines 1. Tinnitus often results from neural hyperactivity in auditory pathways despite normal peripheral hearing, which explains why patients can experience tinnitus even with normal audiograms. Given the most recent evidence from 2023, imaging studies such as MRI of the brain and internal auditory canals should only be considered if there are neurological symptoms or if the tinnitus is unilateral and persistent 1. It is essential to follow the guidelines and recommendations from reputable sources, such as the American Academy of Otolaryngology and Head and Neck Surgery Foundation and the American College of Radiology, to ensure the best possible outcome for the patient 1.
From the Research
Workup for Non-Pulsatile Tinnitus with No Hearing Loss
- A standard workup for tinnitus begins with a targeted history and physical examination to identify treatable causes and associated symptoms that may improve with treatment 2.
- Less common but potentially dangerous causes such as vascular tumors and vestibular schwannoma should be ruled out 2.
- A comprehensive audiologic evaluation is not necessarily required for patients with non-pulsatile tinnitus and no hearing loss, unless the tinnitus is unilateral, has been present for six months or longer, or is accompanied by other symptoms 2.
- Neuroimaging is not part of the standard workup for non-pulsatile tinnitus with no hearing loss, unless there are other symptoms such as focal neurologic abnormalities or asymmetric hearing loss 2, 3.
Consideration of Venous Origin
- Non-pulsatile subjective tinnitus without hearing loss may be caused by undetectable sounds originating from the venous system of the brain 4.
- The dural-jugular system is dominant only in the horizontal body position, and jugular flow is at maximum during this position, possibly making any noise generated within the dural-jugular system louder 4.
- If a vascular pathology causes a non-pulsatile complaint that cannot be heard by the examiner or cannot be detected clinically or radiologically, it is bound to be misdiagnosed as central tinnitus 4.
Imaging Studies
- Imaging studies should only be performed after a careful clinical examination and otoscopy 5.
- The choice of imaging study should be guided by the type of hearing loss and additional physical examination findings 3.
- Magnetic resonance imaging of the internal auditory meatus is the definitive investigation in the detection of vestibular schwannomas, but the detection rate of vestibular schwannoma in patients with unilateral non-pulsatile tinnitus without asymmetrical hearing loss is low 6.