Abstract
Herpes simplex virus (HSV) involvement has been clarified as the cause of Bell's palsy by molecular biological techniques. To clarify the direct relationship between virus reactivation and paralysis development, both detection of the virus genome by DNA-diagnostic and quantitative analysis of its time-course change are needed. Using polimerase chain reaction (PCR) method and microplate-hybridization combined, we detected the virus genome in small amount of specimens from patients with Bell's palsy, quantified its number of copies, and examined timecourse changes. We attempted to type of HSV in positive specimens. Subjects were 16 patients with Bell's palsy positive for serum anti-HSV IgG antibody (enzyme immunoassay) who visited the outpatient clinic of Department of Otorhinolaryngology, Itabashi Hospital, Nihon University School of Medicine, within 14 days after onset without having any treatment. Tears and saliva from the parotid gland and the submaxillary gland were separately collected from the affected side and healthy side twice or more. A total of 244 specimens was subjected to DNA extraction, PCR, and microplate-hybridization, and HSV DNA was detected in 38 specimens (11.8%) from 5 patients (31%). From sampling time, the highest detection (28.5%) was obtained within 2 weeks after onset. Detection at 3 weeks and later (2.8%) was significantly lower (p<0.05). DNA was also found on the healthy side, but in comparison between sides, detection on the healthy side (18.9%) was significantly lower than that on the affected side (83.8%) (p<0.01). In quantitative determination of the virus genome, the amount (number of copies) was large on the affected side and largest early after onset regardless of the clinical course. Positive specimens underwent HSV-typing, and HSV-1 was found in all of them, suggesting that HSV-1 reactivation is a cause of Bell's palsy.
