We report a 70-year-old man who presented symptoms resembling those of 
meningoencephalitis and who was subsequently diagnosed as having a crowned dens 
syndrome. The patient exhibited severe neck pains, headache, high fever and a 
pain in his knee joints together with symptoms of the central nervous system. 
The patient's cerebrospinal fluid was almost clear and showed no sign of viral 
infection. An analysis of the synovial fluid in the right knee joint revealed 
typical calcium pyrophosphate dehydrate crystal deposition and a diagnosis of 
pseudogout was therefore made. A tomographic examination of the neck showed 
periodontoid calcification. The patient was first treated with non-steroidal 
anti-inflammatory drug, but its effect was only minimal. On the other hand, the 
administration of corticosteroid resulted in a dramatic improvement in his 
condition.