Isolated trochlear palsy secondary to Lyme neuroborreliosis.

The objective of the study is to report the first case of isolated trochlear palsy secondary to Lyme neuroborreliosis in an adult. A 22-year-old male presented with history of flu-like illness and headache, accompanied by vertical binocular diplopia, worse on downgaze and better in upgaze and right head tilt. Physical examination revealed trochlear palsy on the left side with a compensatory head tilt to the opposite side. A subsequent workup for trochlear palsy was conducted, including hematological and cerebral spinal fluid serum studies, and magnetic resonance imaging of the brain. Immunoglobulin (Ig)M and IgG antibodies against Borrelia burgdorferi were positive in serum and cerebral spinal fluid (CSF). Symptoms of double vision completely resolved after 3 weeks of antibiotic treatment with intravenous ceftriaxone. CSF studies, in addition to clinical symptoms of vertical double vision and a positive Parks 3-step test, are a good diagnostic tool for B. burgdorferi. Resolution of symptoms was noted after a complete course of intravenous ceftriaxone.