A Rare Cause of Optic Neuropathy.

Lyme disease is a multisystem infection caused by Borrelia burgdorferi that mainly affects the joints, the heart, and the nervous system. Neurological complications usually manifest in untreated patients and present as meningitis, cranial neuropathies, and radiculoneuritis. The authors present the case of a 48-year-old male who developed loss of vision in the right eye over a period of two months. On physical examination a relative afferent pupillary defect of the right eye was noted. Visual evoked potential test revealed delayed P100 latency bilaterally, confirming a bilateral optic neuropathy. The analysis of the cerebrospinal fluid (CSF) showed a lymphocytic meningitis. After an extensive work-up, a diagnosis of Lyme neuroborreliosis with meningitis and optic neuritis was made. The patient was treated with antibiotics and showed gradual improvement. The follow-up brain MRI revealed a mild T2 hyperintensity on the right optic nerve with gliosis, sequelae of the inflammatory process. Lyme disease should always be considered in patients from endemic areas with nonspecific symptoms. The diagnosis of neuroborreliosis is challenging, but prompt identification and treatment can prevent the development of complications and sequelae.