Differential Diagnosis

The patient's symptoms of increased fatigue, daily nausea, feelings of instability and imbalance, and a history of chemotherapy with cisplatin for breast cancer, along with sudden onset of hearing loss and tinnitus, suggest a complex clinical picture. The differential diagnoses can be categorized as follows:

• Single Most Likely Diagnosis
  • Ototoxicity secondary to cisplatin chemotherapy: This is the most likely diagnosis given the patient's history of cisplatin treatment for breast cancer and the subsequent development of hearing loss, tinnitus, and balance issues. Cisplatin is known to cause ototoxicity, which can lead to permanent damage to the inner ear, resulting in hearing loss, tinnitus, and balance problems.
• Other Likely Diagnoses
  • Vestibular disorder: The patient's symptoms of dizziness, imbalance, and nausea could be indicative of a vestibular disorder, which affects the balance system in the inner ear.
  • Anemia or nutritional deficiency: The patient's fatigue and weight loss could be related to anemia or a nutritional deficiency, which may be contributing to her overall sense of fatigue and malaise.
  • Hypothyroidism: Fatigue, weight loss, and hearing loss can also be symptoms of hypothyroidism, although this would need to be confirmed with laboratory tests.
• Do Not Miss Diagnoses
  • Recurrence of breast cancer: Although the patient completed chemotherapy six years ago, it is essential to consider the possibility of cancer recurrence, which could be causing her symptoms.
  • Central nervous system disorder: The patient's symptoms of dizziness, imbalance, and nausea could also be indicative of a central nervous system disorder, such as a brain tumor or multiple sclerosis.
  • Medication side effects: The patient may be experiencing side effects from medications she is currently taking, which could be contributing to her symptoms.
• Rare Diagnoses
  • Autoimmune inner ear disease: This is a rare condition in which the immune system attacks the inner ear, leading to hearing loss, tinnitus, and balance problems.
  • Superior canal dehiscence syndrome: This is a rare condition in which there is an abnormal opening in the bone overlying the superior canal, leading to symptoms of vertigo, hearing loss, and sound-induced vertigo.