Cognitive functioning in late Lyme borreliosis.

Lyme borreliosis, a tick-borne multisystem disease, may cause a variety of neurologic complications, including meningoencephalitis and encephalopathy. To evaluate neurobehavioral function following treated Lyme borreliosis, 15 patients with Lyme disease and complaints of persistent cognitive difficulty a mean of 6.7 months following antibiotic treatment underwent neuropsychological evaluation and were compared with 10 healthy controls, matched in aggregate for age and education, who underwent the identical neuropsychological assessment. Compared with controls, patients with Lyme disease exhibited marked impairment on memory tests and particularly on selective reminding measures of memory retrieval. The memory impairment did not correlate with serum or cerebrospinal fluid anti-Borrelia burgdorferi antibody titers and was not explained by magnetic resonance imaging findings or depression. The cause of this encephalopathy is currently unknown; however, indirect effects of systemic infection or other toxic-metabolic factors may be partly responsible.