A 50-year-old man sought medical attention in China for a year of progressive headaches and nausea. Physical examination revealed neck muscle rigidity and dysmetria (failure to perform a finger-to-nose test) in both hands. A lumbar puncture revealed an increase in cerebrospinal fluid pressure to 310 mm H2O (normal range: 70–200 mm H2O), as well as elevated protein levels and immunoglobulin index. Contrast-enhanced MRI showed a thickened dura mater with central hypointensity and peripheral enhancement in the posterior falx cerebri and tentorium cerebelli, a pattern known as the Eiffel Tower sign. Kundian Guo and Zhen Hong of Sichuan University Hospital shared their case in The New England Journal of Medicine.
This finding is considered pathognomonic for acute inflammation in chronic pachymeningitis, which may be inflammatory, autoimmune, neoplastic, or vascular in origin. Dura mater biopsy showed lymphoplasmacytic infiltration with IgG4-positive plasma cells, and the level of antibodies of this class was elevated in the blood. Whole-body MRI did not reveal involvement of other organs. Based on the findings, the patient was diagnosed with IgG4-associated hypertrophic pachymeningitis. He was given pulse therapy with methylprednisolone for five days, followed by a transition to oral glucocorticoids with a gradual reduction in dose. After two months, MRI showed improvement, and after six months, the headaches disappeared while taking a maintenance dose of drugs.