Neuroborreliosis.

Appropriate, critical application of evidence-based diagnostic criteria enables both a clear definition of what constitutes neuroborreliosis-nervous system infection with Borrelia burgdorferi sensu stricto in the US, B garinii and less commonly B. afzelii and other species in Europe-and recognition that this disorder is quite similar in Europe and the US. Most commonly evidenced by lymphocytic meningitis and/or multifocal inflammation of the peripheral (common; cranial neuropathy, radiculopathy, mononeuropathy multiplex) or central (rare) nervous system, it is readily diagnosed and highly antibiotic responsive. Encephalopathy-altered cognition or memory-can occur as part of the systemic infection and inflammatory state, but is not evidence of neuroborreliosis. Post treatment Lyme disease syndrome-persistent neurobehavioral symptoms 6 months or more after usually curative antibiotic treatment-if real and not simply an example of anchoring bias-is unrelated to neuroborreliosis. The pathophysiology of neuroborreliosis remains unclear, but appears to involve both a requirement for viable micro-organisms and significant immune amplification.