Patient case (clinical description): A 47-year-old woman comes to the clinic complaining of dizziness.  She also has occasional nausea and ringing in her right ear.  The patient also has difficulty hearing while holding her phone to the left ear, although hearing in her right ear is normal.  The dizziness improves spontaneously, and she feels fine between episodes.  Past medical history is notable for hypothyroidism and low vit D level, for which she is using Levothyroxine and Vit D pearl.  She does not use tobacco or drink alcohol. Physical examination shows sensorineural hearing loss in the left ear. She has only one-man sexual partner and menopaused 2 years ago.

Patient's own account: The other day, I had to go to the clinic due to severe dizziness. I'm 47 years old, and I've been suffering from nausea and ringing in my right ear. I also have difficulty hearing in my left ear while I hold my phone, even if my hearing in my right ear is normal. The dizziness just gets me all of a sudden but I don't have any symptoms in between 2 episodes. I suffer from hypothyroidism and low vitamin D levels. So I take Levothyrox and vitamin D pearl. I don't smoke or drink. They conducted a physical exam and said I had hearing loss in my left ear. My only partner is my husband, and I'm menopause for 2 years now.

Clinical trial: Cochlear Implantation for Treatment of Single-sided Deafness

Eligibility criteria:
Inclusion Criteria:

          -  18 years of age or older with the ability to provide informed consent

          -  English as the primary language

          -  Medically and psychologically suitable

          -  Willing to receive/have received meningitis vaccinations

          -  Able to pay for all care received through the study, either through the subject's
             insurance company or through self-pay

          -  Able to comply with study requirements, including travel to the investigational sites

          -  Severe to profound sensorineural hearing loss (≥70 dB HL (decibel hearing level)
             thresholds between 500 and 4000 Hz) in the worse ear with ≤ 20%
             Consonant-Nucleus-Consonant (CNC) word scores

          -  Duration of single-sided deafness ≥ one year

          -  Tinnitus localized to the affected ear, both ears, or in the head localized to the
             affected ear, both ears, or in the head

               -  Expected subjects include those with:

          -  Unilateral hearing loss secondary to viral or bacterial infection, such as meningitis
             or labyrinthitis

          -  Ménière's disease

          -  Sudden sensorineural hearing loss

          -  Vascular disease affecting the inner ear

          -  A combination of any number of the above conditions

        Exclusion Criteria:

          -  Duration of single-sided deafness ≥ ten years

          -  Pure tone thresholds ≥ 35 dB HL at 500, 1000, 2000, and 4000 Hz in the better ear

          -  Consonant-Nucleus-Consonant (CNC) word scores ≤ 70% in the better ear

          -  Chronic otitis media in either ear

          -  Inner ear malformation in either ear

          -  Autoimmune inner ear disease (fluctuation sensorineural hearing loss in either ear)

          -  Evidence of retrocochlear pathology, including vestibular schwannoma

          -  Unilateral tinnitus in the unaffected ear

          -  Cochlear ossification

          -  Demonstrated cognitive and/or developmental challenges

          -  Major depression or anxiety; post-traumatic stress disorder; substance abuse

          -  Medical or psychological conditions that serve as contraindication to surgery

          -  Additional handicaps that would prevent or limit participation in evaluations

          -  Unrealistic patient or family expectations regarding the benefits, risks, and
             limitations inherent to the procedure and the prosthetic device

          -  Pregnant women: The investigators will specifically ask all women of childbearing age
             if there is a possibility they are pregnant or trying to become pregnant at the
             initial clinic visit; any women who are pregnant or actively trying to become pregnant
             will be excluded. In cases that are questionable on the day of planned surgery, a
             pregnancy test will be performed as per current Massachusetts Eye & Ear Infirmary
             anesthesia pre-operative protocols.
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 18 Years old.


Eligibility (NLI label): Contradiction