Ototoxicity

  What is it?

  Ototoxicity is damage to the inner ear caused by drugs or chemicals. Two areas can
  be damaged or destroyed through ototoxicity, the hair cells within the inner ear and
  the vestibulocochlear nerve that runs from the inner ear to the brain. When damage
  occurs, any degree and combination of hearing loss and balance disruption are possible
  depending upon the part(s) affected and how much information is getting through
  to the brain.

  Hair cells are located in both the cochlea and the vestibular areas of the inner ear.
  They are composed of a cell body with things looking like hair sticking up from one
  side. When these "hairs" are bent, they send electrical signals to the brain that
  result in hearing or balance function. In ototoxicity these hairs can be damaged
  to the point that they no longer stand up, and the usual number of signals can't be
  sent to the brain.

  When an individual has peripheral neuropathy, nerves of the PNS have been damaged.
  Certain nerve cell adons, such as the ones in the PNS, are covered with a substance

  What toxins can causes it?

Antibiotics Diuretics Environmental Chemicals Anti-Cancer Drugs
  • Amikacin (Amikin)
  • Acetazolamide (Diamox)
  • Tin
  • Cisplatin (Platinol AQ)
  • Streptomycin
  • Furosemide (Lasix)
  • Lead
  • Bleomycin (Blenoxane)
  • Neomycin
  • Bumetanide (Bumex)
  • Mercury
  • Vincristine (Oncovin)
  • Gentamicin (Garamycin)
  • Ethacrynic Acid (Edecrine)
  • Carbon monoxide
  • Erythromycin
    (E-Mycin, Eryc)
  
  • Carbon disulfide
  • Kanamycin (Kantrex)
  • Tobramycin (Nebcin)
  • Netilmycin (Netromycin)
  • Vancomycin (Vancocin)

  *NOTE:This is not a complete list. Many other drugs and chemicals may cause inner ear
   problems.

  What are the symptoms?

  Symptoms vary considerably from drug to drug and person to person. They range from
  mild imbalance to total incapacitation and from tinnitus to total hearing loss. Possible
  symptoms include:

  • Vertigo
  • Feeling of imbalance/unsteadiness
  • Wide-based gait
  • Vomiting
  • Bouncing/blurring of vision
  • Difficulty walking in the dark
  • Nystagmus
  • Inability to tolerate head movement
  • Severe fatigue
  • Feeling of ear fullness
  • Dizziness or lightheadedness
  • Headache

  What is the treatment?

  At present there are no treatments that can reverse the damage. Currently available
  treatments are aimed at reducing the effect of the damage and rehabilitating function.
  However, individuals with hearing loss may be helped with hearing aids, and those with
  profound bilateral (two-sided) losses have benefited from cochlear implants.

  In the case of lost balance function, Balance Retraining Therapy can be of great value
  for many individuals. The aim of this form of physical therapy is to help the brain become
  accustomed to the changed information from the inner ear and to assist the individual in
  developing other ways to maintain balance. Greater use of vision and muscle sense
  information (proprioception) can be developed through formal physical therapy and a
  program of general physical conditioning and exercise.

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