Differential Diagnosis for a 36-year-old Female with Arm Pain and Left-sided Weakness

The patient's presentation of arm pain followed by left-sided weakness, along with a history of recent massage and back pain, suggests a neurological issue. The differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis
  • Cervical Disc Herniation or Cervical Spondylosis: The recent massage could have exacerbated a pre-existing cervical spine condition, leading to disc herniation or worsening of spondylosis, which compresses spinal nerves or the spinal cord, causing arm pain and weakness. The back pain after the massage supports this possibility.
• Other Likely Diagnoses
  • Multiple Sclerosis (MS): Although less common, MS could present with weakness on one side of the body and bladder urgency. The absence of visual or speech issues does not rule out MS, as it can have varied presentations.
  • Spinal Cord Infarction or Arteriovenous Malformation (AVM): These conditions could cause sudden onset of weakness and bladder symptoms but are less likely without other specific risk factors or symptoms.
• Do Not Miss Diagnoses
  • Spinal Epidural Abscess or Hematoma: These are medical emergencies that can cause rapid neurological deterioration. Recent back pain and new neurological deficits make these conditions crucial not to miss, despite their lower likelihood.
  • Stroke: Although the patient's symptoms are more suggestive of a spinal issue, a stroke affecting the brainstem or a large cerebral vessel could present with unilateral weakness. The absence of speech or visual changes does not entirely rule out a stroke.
• Rare Diagnoses
  • Intramedullary Spinal Cord Tumors: These are rare and could present with gradual onset of neurological deficits, including weakness and bladder symptoms.
  • Vascularitis or Inflammatory Conditions (e.g., Transverse Myelitis): These conditions are less common and could present with a variety of neurological symptoms, including weakness and bladder urgency, often accompanied by other systemic symptoms.

Workup in the Emergency Department

Given the differential diagnoses, the workup should include:

• Imaging: Urgent MRI of the cervical spine to evaluate for disc herniation, spondylosis, spinal cord compression, or other spinal pathology. Consider a brain MRI if stroke is suspected.
• Neurological Examination: A thorough neurological exam to assess the extent of weakness, reflexes, and sensory deficits.
• Laboratory Tests: Complete blood count (CBC), blood chemistry, and erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) to evaluate for inflammatory conditions.
• Urgent Consultation: Neurology and/or neurosurgery consultation for further evaluation and management, especially if there are signs of spinal cord compression or other urgent conditions.

This approach ensures that both common and potentially life-threatening conditions are promptly identified and treated.