I was in my fellowship training when I signed up for a “Tough Mudder” race in rural Texas. I had a blast crawling through mud and tackling obstacles, but in hindsight, I should have worn earplugs. About two weeks later, I noticed a foul-smelling discharge from my right ear—known as otorrhea (“oto-” means ear, and “-rrhea” means discharge).
After seeing a few primary care doctors, I was diagnosed with myringitis, an infection of the eardrum likely from mud exposure. Luckily, the discharge cleared up, but I developed pulsatile tinnitus, meaning I could hear my heartbeat in my ear all day. When I started struggling to hear through my stethoscope, I asked friends if they noticed. They laughed and said, “Girl, you really can’t hear anything!” Fun fact: pulsatile tinnitus can sometimes signal serious issues like an arteriovenous malformation (AVM), so off to ENT I went.
CT scan ruled out an AVM but revealed a cholesteatoma, an abnormal growth of skin cells and debris in the middle ear. These can be serious as they grow in a tight space, potentially causing hearing loss, facial paralysis, or even brain infections. Pre-op testing showed I had hearing loss in both ears, which puzzled me since only one ear was affected. I mentioned my family history of hearing loss and asked if I might have otosclerosis, even though no on in my family actually carried that diagnosis. My ENT reviewed the CT again and confirmed I was right.
Otosclerosis causes abnormal bone growth in the ear, preventing the stapes (stirrup bone) from moving, which impairs sound transmission. It’s one of the few surgically treatable types of hearing loss. The procedure involves replacing the stapes with a metal prosthesis. While usually successful, the risks include complete hearing loss, nerve injury, and dizziness due to the middle and inner ear’s complex anatomy and all of the vital functions that are housed there.
While I addressed the cholesteatoma with two surgeries (one to remove it and another to reconstruct my eardrum after a failed graft), I put the otosclerosis on hold as I also wasn’t sure if I believed my own discovery.
At first, I was content with hearing aids and an amplified stethoscope. But when the stethoscope stopped meeting my needs, I decided to proceed with surgery on one side. I had the procedure last week. It’s too soon to tell if it worked, and I’m currently dealing with vertigo, but I’m hopeful it will improve as I heal.
How is this related to childhood cancer?
Well, it isn’t directly to be honest, it just got me thinking about hearing loss. When a child is diagnosed with cancer, the first goal that we have is to save the child’s life and to treat the cancer. However, buried in there is weighing all of the risks and benefits of therapy. We do cause a lot of toxicity to patients in the pursuit of eradicating the cancer, and one of them is ototoxicity (damage to the ears/hearing).
Chemotherapy-induced ototoxicity occurs when certain chemotherapy drugs damage the structures and functions of the inner ear, leading to hearing loss, tinnitus (ringing in the ears), or balance issues. This side effect can range from mild to severe and may be temporary or permanent.
The highest risk chemotherapy medications that cause hearing loss that I use are the heavy metals like cisplatin and carboplatin, with cisplatin having the highest risk. There are likely several mechanisms (see below) that lead to hearing loss from cisplatin, but we know that younger children and older adults are more at risk to develop hearing loss from chemotherapy and this is critically important for young children who are still developing speech.
Younger children and older adults are more at risk to develop hearing loss from chemotherapy. Share on X- Cochlear Cell Damage: Drugs like cisplatin harm hair cells in the cochlea, which are vital for detecting and amplifying sound.
- Oxidative Stress: Chemotherapy increases harmful reactive oxygen species (ROS), damaging cochlear cells and leading to their death.
- Stria Vascularis Impairment: Damage to this structure disrupts the electrochemical balance needed for normal hearing.
- Inflammation: Chemotherapy triggers inflammation in the inner ear, worsening damage.
- DNA Damage: Drugs like cisplatin directly damage DNA in ear cells, leading to their destruction.
Recent data has shown that for patients with localized cancer, sodium thiosulfate (SDS) administered shortly after cisplatin therapy can reduce the damage to the cochlear cells and lessen or prevent the hearing loss associated with cisplatin. There are some more nuances to this data that would need to be addressed by the treating physician, but we have now entered an era where we can at least have the conversation of mitigation of this toxicity.
