Abstract
In a 29-y-old male with neuroborreliosis, partially responsive to ceftriaxone, myasthenia gravis with acetylcholine-receptor antibodies elevated almost 1000 times the upper reference limit was diagnosed. Pyridostigmine resolved all remaining neurological deficits. During a 1-y follow-up the patient remained symptom free, despite persistently high acetylcholine-receptor antibodies. They were attributed to epitope homology of the acetylcholine receptors and Borrelia surface antigens.