Differential Diagnosis for the 60-year-old Male Patient

The patient's presentation of sudden weakness, persistent pain, imbalance, and unsteadiness after a fall warrants a thorough differential diagnosis. The following categories outline potential diagnoses:

• Single Most Likely Diagnosis

  • Cervical Radiculopathy or Brachial Plexus Injury: The patient's symptoms of right-sided upper and lower extremity pain, weakness, and the incident of falling onto his right arm suggest a possible injury to the cervical spine or brachial plexus. The absence of cervical pain does not rule out this diagnosis, as the pain can be referred.

• Other Likely Diagnoses

  • Peripheral Nerve Injury: Direct trauma to the nerves of the right arm during the fall could result in persistent pain and weakness.
  • Musculoskeletal Injury: The fall could have caused a musculoskeletal injury, such as a fracture or severe sprain, contributing to the patient's pain and mobility issues.
  • Stroke or Transient Ischemic Attack (TIA): Although the patient denies typical symptoms of a stroke, such as headache, visual changes, or loss of consciousness, a small vessel stroke or TIA could present with focal weakness and should be considered.

• Do Not Miss Diagnoses

  • Spinal Cord Injury or Compression: Any injury to the spinal cord could lead to severe and permanent neurological deficits. The patient's symptoms of imbalance and unsteadiness, even without cervical pain, necessitate consideration of this diagnosis.
  • Epidural Hematoma: A fall onto the arm could potentially cause a traumatic injury leading to an epidural hematoma, which is a medical emergency requiring immediate intervention.
  • Osteoporotic Fracture: Given the patient's age and the mechanism of injury, an osteoporotic fracture should be considered, especially if the patient has risk factors for osteoporosis.

• Rare Diagnoses

  • Multiple Myeloma or Bone Metastasis: Although less likely, these conditions could predispose the patient to pathological fractures or could be the underlying cause of the patient's weakness and pain, especially if there are other systemic symptoms.
  • Amyotrophic Lateral Sclerosis (ALS): This is a rare condition that could present with focal weakness, but it would be unusual for it to be precipitated by a fall and to cause such immediate and noticeable imbalance and unsteadiness.
  • Vascular Malformations or Aneurysms: These could potentially cause neurological symptoms due to compression or rupture, but they would be less likely given the patient's presentation and the absence of other symptoms such as headache or visual changes.