[Case of diabetes mellitus associated with cervical pyogenic spondylitis and meningoencephalitis secondary to retropharyngeal abscess caused by Streptococcus pneumoniae].

A 63-year-old man with diabetes mellitus had undergone insulin therapy for 10 years. He developed symptoms of upper respiratory tract infection and neck pain. After 5 days, he suddenly experienced high fever and consciousness disturbance. Neurological examination detected drowsiness and neck stiffness. Cerebrospinal fluid (CSF) examination revealed pleocytosis with low glucose level. Gram staining and a latex agglutination test of his CSF revealed Streptococcus pneumoniae to be the causative organism of meningoencephalitis in the patient. Gadolinium-enhanced T1-weighted images obtained from a cervical spine MRI showed ring enhancement in the anterior clivus and thickening in the anterior dura matter with specific thickening at the dens of the axis. Based on the diagnosis of cervical pyogenic spondylitis and meningoencephalitis secondary to retropharyngeal abscess caused by Streptococcus pneumoniae, the patient was administered panipenem/betamipron and dexamethasone, following which his neurological symptoms and signs gradually improved. Diabetes mellitus is a factor that predisposes patients to invasive pneumococcal infection. Thus, we conclude that physicians need to be aware of the possible development of cervical pyogenic spondylitis and meningoencephalitis subsequent to Streptococcus pneumoniae infection, and symptoms such as fever and neck pain should be carefully examined.