Hypertrophic cranial pachymeningitis and orbital apex syndrome secondary to infection of the eye: illustrative case

BACKGROUND Hypertrophic cranial pachymeningitis is a rare inflammatory disorder characterized by thickening of the dura mater and multiple cranial neuropathies. Although an infectious etiology may be present, often no specific cause is discovered. OBSERVATIONS The authors described a 71-year-old man with progressive right eye vision loss, ptosis, and complete ophthalmoplegia with imaging findings suggestive of hypertrophic cranial pachymeningitis. Extensive studies, including cerebrospinal fluid studies, showed negative results. Blood serum, cell-free evaluation, and paraffin-embedded dural tissue testing had positive results for Pseudomonas aeruginosa, which allowed treatment tailored to the organism and a salutary clinical outcome. LESSONS The constellation of neurological and radiological findings may make a diagnosis difficult in an inflammatory setting. The most precise methodology for establishing a diagnosis involves sampling the dura and testing it for infectious pathology. However, if results are inconclusive, further cell-free serum sampling with next-generation sequencing is a viable option for identifying pathogens with infectious concerns. This case highlighted the importance of multimodality studies for identifying a targetable pathogen.