In the risk group, inhabiting endemic areas, even non-specific symptoms should alert the physician to the possibility of infection caused by the spirochete. The invasion of central nervous system (neuroborreliosis) may be the cause for persisting, irreversible intellectual impairment and memory deficits. Brain lesions are the result of misdiagnosis and delayed antibiotic treatment. This paper describes a case of neuroborreliosis with atypical beginning and diagnostic difficulties.