Facebook
Twitter
LinkedIn
Email
 |
Checking for direct PDF access through Ovid | |
Excerpt
Recent advancement in molecular methods of in situnhybridization and polymerase chain reaction revealed the existence of HSV-1 genomes in the involved human facial nerve. In addition, animal experiments have shown that HSV-1 could induce facial paralysis. These events provide the evidence that latently infected HSV-1 causes Bell's palsy when it reactivates.
Methods
PCR and serological analyses were carried out in Bell's patients and Ramsay Hunt patients. The effect of combination treatment with acyclovir-prednisone on facial nerve recovery was analyzed retrospectively in 69 Bell's patients. The number of patients receiving the decompression operation in each 5-year period from 1976 to 1997 was examined.
Results
In a previous PCR study, we detected HSV-1 genomes from endoneurial fluid of the facial nerve in 11 of 14 Bell's patients. The genomes were also detected from the posterior auricle muscle in 8 of Bell's patients. The prevalence of antibodies to HSV in Bell's patients (88.9%) is significantly higher than that of Ramsay Hunt patients (60.0%) and controls (50.0%). With use of acyclovirprednisone, full recovery was achieved for 66 of 69 patients (95.7%), whereas with prednisone alone, recovery was achieved in 342 of 386 patients (88.6%). A significant difference in facial nerve recovery was found between two groups. After introduction of the combination treatment with acyclovir-prednisone, the number of patients receiving the decompression operation markedly declined in recent years.
Conclusions
The existence of HSV-1 genomes in the involved facial nerve, high prevalence of anti HSV antibody and the effectiveness of antiviral agent on facial nerve recovery have strongly suggested that HSV-1 is a cause of Bell's palsy. Consequently, it has been suggested that whether we should continue using the term “Bell's palsy” to mean “idiopathic facial paralysis” or whether we should now recognize Bell's palsy as “herpetic facial paralysis”. However, currently, we have no reliable, widely available clinical test for early identification of HSV-1 infection in Bell's palsy. Methodological breakthrough will be resolve this problem and data accumulation will determine the percentage of patients with Bell's palsy in whom HSV-1 is the etiological agent.
