Differential Diagnosis for Migraine vs. Radiologically Isolated Syndrome (RIS)

Given the brain MRI findings of multiple periventricular and juxtacortical lesions without intratentorial lesions or contrast agent enhancement, and fulfilling the McDonald criteria for dissemination in space, the differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis

  • Radiologically Isolated Syndrome (RIS): The presence of multiple periventricular and juxtacortical lesions on MRI, which fulfill the McDonald criteria for dissemination in space, strongly suggests a demyelinating process, making RIS the most likely diagnosis. RIS is characterized by the presence of lesions suggestive of multiple sclerosis (MS) on imaging in individuals without a clinical history of neurological symptoms.

• Other Likely Diagnoses

  • Migraine: Although migraine can sometimes present with white matter lesions on MRI, the pattern and distribution of lesions described, along with the fulfillment of McDonald criteria, make it less likely than RIS. However, migraine should still be considered, especially if the patient has a history of migraine headaches.
  • Other Demyelinating Diseases: Conditions like acute disseminated encephalomyelitis (ADEM) or neuromyelitis optica spectrum disorder (NMOSD) could be considered, although the lack of clinical symptoms and specific lesion patterns makes them less likely.

• Do Not Miss Diagnoses

  • Multiple Sclerosis (MS): Although the patient does not have a clinical history of MS, the MRI findings are highly suggestive of MS. It is crucial not to miss this diagnosis, as early treatment can significantly impact the disease course.
  • Vasculitis or Vasculopathy: Conditions like cerebral vasculitis or vasculopathy (e.g., moyamoya disease) can present with white matter lesions and should be considered to avoid missing a potentially treatable condition.
  • Infections (e.g., Lyme Disease, Neurosyphilis): Certain infections can cause white matter lesions and should be ruled out, especially if there are risk factors or exposure history.

• Rare Diagnoses

  • Leukodystrophies: A group of rare, genetic disorders characterized by the progressive degeneration of the white matter in the brain. They could present with similar MRI findings but are much less common.
  • Mitochondrial Encephalomyopathies: Conditions like MELAS (Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like episodes) can have white matter changes on MRI, although they typically present with additional systemic and neurological symptoms.