Differential Diagnosis

The patient's presentation of recurrent strokes in the right deep MCA territory and initial left MCA deep watershed territory, along with multiple areas of narrowing in the intracranial circulation and concentric enhancement within the bilateral middle cerebral arteries on MRI vessel wall imaging, suggests a complex vascular pathology. The following differentials are considered:

• Single most likely diagnosis
  • Primary Angiitis of the Central Nervous System (PACNS): This condition is characterized by inflammation of the blood vessels within the brain, leading to stroke-like symptoms. The presence of high-grade narrowing in multiple arteries, concentric enhancement on MRI vessel wall imaging, and the absence of systemic symptoms or abnormal serum cholesterol panel support this diagnosis. The patient's history of Hodgkin's lymphoma could potentially increase the risk for autoimmune or inflammatory conditions.
• Other Likely diagnoses
  • Atherosclerosis: Although the serum cholesterol panel is normal, atherosclerosis cannot be entirely ruled out, especially given the patient's history of hypertension. However, the pattern of short segmental stenosis and concentric enhancement is less typical for atherosclerosis.
  • Vasculitis (systemic): Conditions like giant cell arteritis or other forms of systemic vasculitis could potentially cause the observed vascular changes. However, the lack of systemic symptoms, normal CSF except for a mild increase in lymphocytes, and the specific pattern of vascular involvement make this less likely.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Reversible Cerebral Vasoconstriction Syndrome (RCVS): Although RCVS typically presents with thunderclap headaches and is more common in women, it can cause strokes and should be considered due to its potential for severe outcomes if not recognized and treated appropriately.
  • Moyamoya Disease: This rare condition causes narrowing or blockage of the internal carotid artery and its branches, leading to stroke. It could be considered, especially with the pattern of stenosis, but the absence of the typical "puff of smoke" appearance on angiography and the patient's age make it less likely.
• Rare diagnoses
  • Susac Syndrome: A rare condition characterized by microangiopathy of the brain, retina, and inner ear. It could be considered due to the patient's stroke-like symptoms, but the lack of visual or auditory symptoms and the specific vascular changes make it less likely.
  • Cerebral Amyloid Angiopathy: Although this condition can cause lobar hemorrhages and is associated with Alzheimer's disease pathology, it is less likely given the patient's presentation with ischemic strokes and the pattern of vascular narrowing.

Each of these diagnoses requires careful consideration of the patient's clinical presentation, imaging findings, and laboratory results to determine the most appropriate diagnostic and therapeutic approach.