Three cases of acute central nervous system disease occurring subsequent to infection with M pneumoniae are reported from University College, Institute of Child Health, and Great Ormond Street Hospital, London, UK. Patients were 8, 11, and 17 years of age. The 8-year old developed fever and cough 3 days before admission. He had diffuse crepitations in the lungs, reduced consciousness, loss of speech, and signs of encephalopathy. Serum anti-M pneumoniae immunoglobulin M titers were elevated, and cold agglutinins were positive. MRI of brain was normal. EEG showed diffuse slowing. Following acyclovir, cefotaxime, and erythromycin treatment, he became more responsive but developed visual hallucinations, and impaired visual acuity. Pupils were dilated and unresponsive to light. Funduscopic examination was normal, and VEPs were abnormal. Findings were compatible with optic neuritis. Rapid recovery followed IV methylprednisolone, and convalescent M pneumoniae immunoglobulin M titer was reduced. CSF polymerase chain reaction for M pneumoniae was negative in all 3 patients. The 11-year-old had an upper respiratory infection, transverse myelitis, and elevated M pneumoniae titer, and the 17-year-old presented with a convulsion and pneumonia and a diagnosis of M pneumoniae meningoencephalitis. Both patients recovered following treatment with steroids and antibiotics. A review of the literature concerning post-M pneumoniae neurologic dysfunction revealed several references, some with direct invasion of the CNS (M pneumoniae detected in the CSF), and others with immune-mediated “para-infectious” disease (M pneumoniae undetected in CSF). The distinction between these processes is essential in selection of appropriate antibiotic and immunomodulatory therapies. 
COMMENT. Neurologic complications of infection with M pneumoniae include encephalopathy, optic neuritis, transverse myelitis, seizures, and meningoencephalitis. Also, stroke, striatal necrosis, acute disseminated encephalomyelitis, cerebellitis, brainstem syndrome, dystonia, and focal cortical lesions have been reported. In some, direct invasion of the CNS is confirmed by CSF polymerase chain reaction and culture, and in others, a postinfectious immune-mediated ’para-infectious disease process is suggested. Full recovery followed treatment with steroids and antibiotics in the 3 cases reported here.
Restless Legs Syndrome is associated with Mycoplasma or Streptococcal Infection in a report of 3 cases from Saga University, Japan, and Johns Hopkins University, Baltimore, MD. . One had elevated antibodies against caudate nucleus and putamen.