Differential Diagnosis

The patient's complex presentation of optic neuritis, muscle spasms, dystonia, fatigue, and swallowing difficulties, along with the history of working in an oncology clinic, necessitates a broad differential diagnosis. The following categories outline potential diagnoses:

• Single Most Likely Diagnosis
  • Multiple Sclerosis (MS): The history of recurrent optic neuritis, muscle spasms, dystonia, and fatigue, despite initially clean MRIs, points towards MS, especially given the neurologist's attribution of symptoms to this condition. The presence of scars on the optic nerves and the patient's response to treatments like Copaxone (though discontinued due to side effects) support this diagnosis.
• Other Likely Diagnoses
  • Neuromyelitis Optica Spectrum Disorder (NMOSD): Although the NMO IgG test was negative, clinical presentation, particularly the history of optic neuritis and the involvement of the optic nerve up to the chiasm, could still suggest NMOSD, considering that not all patients test positive for NMO IgG.
  • Vitamin Deficiency: Given the patient's symptoms of fatigue, muscle cramps, and spasms, a deficiency in vitamins such as B12 or other nutrients could be contributing, despite the patient taking vitamin D, magnesium glycinate, and biotin.
• Do Not Miss Diagnoses
  • Lyme Disease: Neurological manifestations can include optic neuritis, muscle spasms, and fatigue. Given the potential for exposure and the severity of untreated disease, Lyme disease should be considered.
  • Syphilis: Neurosyphilis can present with a wide range of neurological symptoms, including optic neuritis and muscle spasms. The patient's occupation in healthcare might increase the risk of exposure.
  • Toxic Exposure: Working in an oncology clinic, there's a potential for exposure to toxic substances that could cause neurological symptoms. This includes chemotherapy agents, which can have neurotoxic effects.
• Rare Diagnoses
  • Mitochondrial Myopathies: Conditions like Kearns-Sayre Syndrome or Chronic Progressive External Ophthalmoplegia could explain some of the patient's symptoms, including muscle weakness and fatigue, though these are less common.
  • Leber's Hereditary Optic Neuropathy (LHON): A mitochondrial inherited disorder that predominantly affects young adult males but can affect females. It primarily causes optic neuritis and vision loss, but given the patient's history of optic neuritis, it's worth considering, especially if there's a family history.
  • Hashimoto's Encephalopathy: An autoimmune condition associated with Hashimoto's thyroiditis, which can cause neurological symptoms including seizures, tremors, and myoclonus. Though rare, it's treatable and thus important to consider.

Each of these diagnoses requires careful consideration of the patient's history, physical examination, and potentially additional diagnostic testing to determine the most appropriate diagnosis and treatment plan.