Vestibular Issues with Chemotherapy
While undergoing cancer treatments, patients may come into contact with various therapeutic medications that can damage the inner ear. Most of the drugs used to fight cancer can cause “Ototoxicity”, a term referring to inner ear damage or poisoning caused by these drugs.
The Hearing Professionals: Doctors of Audiology found “Ototoxicity can result in temporary or permanent auditory and/or vestibular (balance) dysfunction as these cancer fighting drugs negatively affect the inner ear. The reported prevalence of hearing loss associated with chemotherapeutic agents ranges from as high as 91% to as low as 9%”.
The Hearing Professionals: Doctors of Audiology note the following side effects from ototoxicity may include:
Tinnitus (ringing, roaring, clicking, banging, buzzing sound in the ear)
Hyperacusis (a perception of abnormality of loudness)
Aural fullness
Distorted hearing
Auditory hallucinations or phantom sounds
Hearing loss
The Cancer Treatment Centers of America note Vestibular side effects may include:
Dizziness
Vertigo (spinning)
Nystagmus
Loss of balance/disequilibrium disorder
Oscillopsia (bouncing vision)
The Hearing Professionals: Doctors of Audiology note the “only way to detect ototoxicity is by assessing auditory and vestibular function directly. The optimal monitoring program may include a baseline audiological and/or vestibular evaluation prior to the initial chemotherapy/radiation treatment, as well as subsequent testing throughout each patient's treatment regimen”.
While initial ototoxic drug exposure typically affects cochlear regions coding the high frequencies, continued exposure can result in a spread of damage to progressively lower frequencies.
The Hearing Professionals: Doctors of Audiology note “early identification and monitoring of ototoxic hearing loss also provides audiologists the opportunity to provide appropriate rehabilitation during and after treatment”. If you are experiencing any of the aforementioned side effects, contact a hearing health care professional and/or your doctor to further discuss your symptoms.
The Cancer Treatment Centers of America note the “result of ototoxicity negatively affecting the vestibular system creates further complications for patients, as damage to the vestibular system will affect the patient's balance”.
Balance is defined as the body’s ability to remain stable while standing, sitting or moving about, and it is important in preventing injuries from falls or missteps.
The vestibular system of the inner ear is critical to good balance, as is the cerebellum (the rear part of the brainstem) that controls and regulates muscle movement. Chemotherapy drugs, pain medications, and other interventions, as well as cancers of the head, neck or nervous system, may affect the vestibular system or the cerebellum.
Chemotherapy-induced peripheral neuropathy may also result in the following balance issues The Mayo Clinic: Chemotherapy and The Hearing Professionals: Doctors of Audiology report the following possibilities:
An altered pace or irregular step
The need for canes or other aids to support a steady gait or stance
Erratic or slow steps, or unusual clumsiness
Falls
Lethargy or tired feeling that prevents the ability to perform everyday tasks
Dizziness or light-headedness, especially while standing
Vertigo, an extreme form of dizziness that causes the feeling of movement, as if the room is spinning
If you or a loved one is about to start any of the above treatments, it may be worth having baseline testing completed prior to the commencement of treatments.
Alternatively, if you or a loved one is already within a treatment regime, it will be important to know and understand that balance may be an issue. Clearing your home of tripping hazards, making sure each room has adequate lighting, and wearing supportive indoor footwear may help prevent a fall/trip/or slip during this time.
References
Cancer Treatment Centers of America
The Hearing Professionals: Doctors of Audiology