Abstract
Objective measures of neurologic function were used to assess response to treatment in patients with late Lyme borreliosis. Neurophysiologic evidence of peripheral neuropathy was present in 64 of 137 patients tested. Measures of distal axon function (sensory amplitude and conduction velocity, motor terminal latency) were most affected. Repeat studies following 60 patients receiving antimicrobial therapy demonstrated significant improvement in these values. Before and after therapy 17 patients with late Lyme borreliosis and prominent subjective cognitive dysfunction underwent neuropsychologic tests of memory, conceptual ability, concentration, psychomotor function, overlearned intellectual abilities, and mood. Significant abnormalities wereevident before treatment; all reversed with antimicrobial therapy. Many patients with this encephalopathy had specific abnormalities revealed by magnetic resonance imaging of the brain and had evidence of intrathecal synthesis of antibody to Borrelia. These findings indicate that late Lyme borreliosis commonly causes nervous system abnormalities that are reversible with appropriate antibiotic therapy.