The effects of dexamethasone and acyclovir on a cell culture model of delayed facial palsy.
Publication/Presentation Date
4-1-2014
Abstract
HYPOTHESIS: Pretreatment with antiherpetic medications and steroids decreases likelihood of development of delayed facial paralysis (DFP) after otologic surgery.
BACKGROUND: Heat-induced reactivation of herpes simplex virus type 1 (HSV1) in geniculate ganglion neurons (GGNs) is thought to cause of DFP after otologic surgery. Antiherpetic medications and dexamethasone are used to treat DFP. Pretreatment with these medications has been proposed to prevent development of DFP.
METHODS: Rat GGN cultures were latently infected with HSV1 expressing a lytic protein-GFP chimera. Cultures were divided into pretreatment groups receiving acyclovir (ACV), acyclovir-plus-dexamethasone (ACV + DEX), dexamethasone alone (DEX), or untreated media (control). After pretreatment, all cultures were heated 43°C for 2 hours. Cultures were monitored daily for reactivation with fluorescent microscopy. Viral titers were determined from culture media.
RESULTS: Heating cultures to 43°C for 2 hours leads to HSV1 reactivation and production of infectious virus particles (59 ± 6.8%); heating cultures to 41°C showed a more variable frequency of reactivation (60 ± 40%), compared with baseline rates of 14.4 ± 5%. Cultures pretreated with ACV showed lower reactivation rates (ACV = 3.7%, ACV + DEX = 1.04%) compared with 44% for DEX alone. Viral titers were lowest for cultures treated with ACV or ACV + DEX.
CONCLUSION: GGN cultures harboring latent HSV1 infection reactivate when exposed to increased temperatures that can occur during otologic surgery. Pretreatment with ACV before heat provides prophylaxis against heat-induced HSV reactivation, whereas DEX alone is associated with higher viral reactivation rates. This study provides evidence supporting the use of prophylactic antivirals for otologic surgeries associated with high rates of DFP.
Volume
35
Issue
4
First Page
712
Last Page
718
ISSN
1537-4505
Published In/Presented At
Turner, M. T., Nayak, S., Kuhn, M., & Roehm, P. C. (2014). The effects of dexamethasone and acyclovir on a cell culture model of delayed facial palsy. Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology, 35(4), 712–718. https://doi.org/10.1097/MAO.0000000000000231
Disciplines
Medicine and Health Sciences
PubMedID
24622026
Department(s)
Department of Surgery
Document Type
Article