Meningitis in the Guise of Dementia: Lyme-Induced Normal Pressure Hydrocephalus.

While the cause of altered mentation in the elderly may be multifactorial, infectious etiologies may be missed. This case report aims to detail an account of a patient with dementia, found to have Lyme meningitis in the setting of a normal pressure hydrocephalus (NPH). The patient smelled of urine and presented with ambulatory dysfunction, fitting the "wet, wacky, and wobbly" triad of NPH while also having subjective chills and leukocytosis. Non-contrast brain CT scan showed dilated ventricles. Cerebrospinal fluid (CSF) studies suggested aseptic meningitis. Serum studies using a modified two-tiered algorithm confirmed the diagnosis of Lyme disease. Treatment of the underlying condition with a prolonged course of doxycycline improved symptoms and clinical course. Review of the literature on the association between Lyme meningitis and NPH reveals that few cases of Lyme-related NPH have been reported worldwide and further research into the pathophysiology, diagnostic approach, treatment modalities, and management of NPH secondary to Lyme meningitis may be warranted.