Search for herpetic antibodies in the cerebrospinal fluid in senile dementia and mental retardation.

Complement-requiring neutralizing antibodies to herpes simplex type 1 virus (HSV 1) in titres from 2 to greater than 16 were detected in the cerebrospinal fluid (CSF) of 47% senile patients with various forms of dementia, but in none of mentally retarded adolescents and adults suffering from various neurologidal diseases. Also the incidence of HSV 1 serum antibodies in elevated titres (larger than or equal to 512) was increased in senile demented patients (61%) as compared with persons in normal senium (31%), normal adults (15%), mentally retarded adolescents (17%) and prisoned felons with low IQ (45-47%).