This is certainly a tough case. There is considerable overlap in presentation between much of the differential, but a characteristic feature in this patient provides a clue to diagnosis. But first, let’s narrow down the differential of high basal ganglia T1 signal:

• Leigh syndrome is primarily seen in children
• osmotic demyelination syndrome is T2 hyperintense, and usually in putamen and external capsule
• Wilson disease can be distinguished based on the current disease trajectory
  • if copper predominating, T1 hyperintense, T2 hypointense
  • if gliosis predominates, T1 hypointense, T2 hyperintense
• hypoxic ischemic injury is more common in globus pallidus, but can affect all deep nuclei

The likely diagnosis is Creutzfeldt-Jakob disease (CJD).