Headache resembling tension-type headache as the single manifestation of Lyme neuroborreliosis.

We present two patients with monosymptomatic headache resembling chronic tension-type headache as the first manifestation of Lyme neuroborreliosis. The headache developed over a few days in both cases and lasted for three months in the first case and for two and a half years in the second case before the diagnosis of Lyme neuroborreliosis was made. Neuroimaging and many laboratory investigations did not lead to the diagnosis, which was only established after lumbar puncture. The CSF in both cases showed high protein, lymphocytic pleocytosis and Borrelia burgdorferi-specific intrathecal antibody synthesis. The headache disappeared completely after treatment with penicillin G. In patients suffering from daily headaches which have developed subacutely, Lyme neuroborreliosis should be considered even in the absence of signs of meningeal irritation. A lumbar puncture should be performed more often than is presently customary and the CSF should be examined for pleocytosis as well as Borrelia burgdorferi-specific intrathecal antibody synthesis.