Differential Diagnosis for Right Arm Weakness and MS
- Single most likely diagnosis
- Multiple Sclerosis (MS) with a relapse: This is the most likely diagnosis given the patient's history of MS. MS is a chronic autoimmune disease that affects the central nervous system, and relapses can cause new or worsening symptoms, including weakness in one arm.
- Other Likely diagnoses
- Stroke or Transient Ischemic Attack (TIA): Although less likely than an MS relapse, a stroke or TIA could cause sudden weakness in one arm. The patient's history of MS may increase the risk of stroke.
- Radiculopathy or peripheral neuropathy: Nerve damage or compression could cause arm weakness, and MS patients may be more susceptible to these conditions.
- Spinal cord injury or compression: Trauma or degenerative changes in the spine could compress the spinal cord, leading to arm weakness.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Acute spinal cord compression (e.g., from a tumor or abscess): This is a medical emergency that requires prompt treatment to prevent permanent damage.
- Cervical artery dissection: A tear in the lining of the cervical artery could lead to a stroke or TIA, and MS patients may be at increased risk.
- Infections (e.g., meningitis, encephalitis): Infections can cause sudden weakness and may be more severe in patients with MS.
- Rare diagnoses
- Amyotrophic Lateral Sclerosis (ALS): Although rare, ALS is a progressive neurological disease that can cause arm weakness and may be considered in patients with MS-like symptoms.
- Neuromyelitis optica spectrum disorder (NMOSD): This rare autoimmune disease can cause optic neuritis, transverse myelitis, and other symptoms that may resemble MS.
- Mitochondrial myopathies: These rare genetic disorders can cause muscle weakness and may be considered in patients with MS-like symptoms and a family history of similar conditions.