Lyme Neuroborreliosis Presenting as Acute Meningoencephalitis in a Post-Splenectomy Patient: A Diagnostic Challenge

Abstract

Lyme disease, caused by Borrelia burgdorferi, is an emerging but under-recognized infection in India and can occasionally involve the central nervous system, presenting as Lyme neuroborreliosis. Its clinical manifestations often overlap with several tropical infections, making diagnosis challenging. We report a case of a young adult post-splenectomy patient who presented with acute meningoencephalitis characterized by fever, headache, neck pain, and behavioural changes. Initial investigations revealed lymphocytic meningitis, nonspecific MRI abnormalities, and isolated Brucella IgM seropositivity, raising suspicion for neurobrucellosis. However, the patient lacked systemic features of brucellosis, and cerebrospinal fluid cultures were negative. Subsequent testing showed Borrelia burgdorferi IgM positivity, and the constellation of clinical, CSF, and radiological findings strongly supported Lyme neuroborreliosis. The patient improved significantly with ceftriaxone, doxycycline, and rifampicin therapy. This case emphasizes the importance of cautious interpretation of Brucella serology, particularly isolated IgM, and highlights Lyme disease as an important differential diagnosis in patients presenting with subacute meningitis in endemic regions.