‘Eiffel-by-Night’: A New MR Sign Demonstrating Reactivation in Idiopathic Hypertrophic Pachymeningitis

A forty- seven-year-old man presented with chronic headache with lower cranial nerve palsies of ten year duration with recent aggravation of symptoms. MRI revealed hypointensity - predominantly of the posterior falx cerebri and the tentorium cerebelli - on all sequences with intense peripheral contrast enhancement on CE SE T1, which on coronal images mimicked the illuminated Eiffel tower by night.