Recognize tumefactive demyelination as neurological manifestation of acute Q fever.

This case report documents a previously healthy 35-year-old male without farm exposure, who consumes queso fresca. He presented with one-week increasing confusion and dysdiadokinesia with studies revealing basal ganglia perivascular demyelination in the setting of acute Q fever.

MRI brain demonstrated multiple ring-enhancing lesions within the basal ganglia (largest 2.1 by 1.1 cm) with surrounding T2/FLAIR hyperintensities and heterogenous internal enhancement, diffusion restriction, and hemosiderin. Since lumbar puncture was unremarkable for infection and confusion persisted despite empiric antibiotics, the right basal ganglia lesion was biopsied, revealing only reactive gliosis and perivascular histiocyte infiltration. Based on epidemiological risk factors and one AFB-positive sputum culture, antituberculosis therapy (RIPE) and dexamethasone were empirically started for possible tuberculoma. Mental and physical symptoms improved post-discharge, even after discontinuing RIPE once cultures speciated to Mycobacteria stomatepiae. Serum studies collected 2.5 weeks after presentation returned positive for Coxiella burnetii (phase II IgG 1:64). Repeat titers collected 6 weeks later demonstrated a four-fold increase (phase II IgG 1:256), consistent with acute Q fever, and doxycycline was initiated. 

This case describes a previously unreported association between Q fever and tumefactive ADEM-like demyelination. This presentation of multiple ring-enhancing lesions initially raised concern for primary infection, septic emboli, or lymphoma. However, without infection or atypical lymphocytes on pathology, observed histiocytes and suggested perivascular demyelination supported secondary tumefactive ADEM-like pathology, which clinically responded to steroids. Follow-up MRI is planned, pending insurance authorization. Given reports describing encephalomyelitis and demyelinating polyneuropathy with acute Q fever, Coxiella burnetii testing should be considered in tumefactive demyelination.