Varicella zoster virus: beyond facial paralysis.

J. Ramsay Hunt's hypothesis that herpes zoster oticus results from a reactivation of the herpes zoster virus in the geniculate ganglion, has been supported by the demonstration of varicella zoster viral DNA in the geniculate ganglion of the side with facial paralysis in patients with Ramsay Hunt syndrome, with the use of the polymerase chain reaction. Similarly, DNA of the varicella zoster virus has been identified in the spiral and vestibular ganglion as well. We report on three patients with cochleovestibular symptoms as the first manifestations of Ramsay Hunt syndrome. A 64-year old woman and a 72-year old man presented with vertigo and an auricular herpetiform eruption. Only the woman developed later on a mild facial paralysis. A 58-year old man presented with an acute cochleovestibular syndrome, serologically proven to be a varicella zoster viral reactivation, which was followed three weeks later by the typical cutaneous recrudescence. We believe that these cases result from reactivation of latent varicella zoster virus in the spiral and/or vestibular ganglion. As the varicella zoster virus is dormant in the non-neuronal satellite cells, the facial symptoms in our patients as well as the high incidence of cochleovestibular symptoms in classical Ramsay Hunt syndrome can be explained by viral transmission across the nerves inside the internal auditory canal. Therefore, we think there are grounds to recommend a prompt treatment with an antiviral and a corticosteroid agent, not only in case of an acute facial paralysis but also when confronted with an acute cochleovestibular syndrome.

Detection of varicella-zoster virus DNA in human geniculate ganglia by polymerase chain reaction.

Latent varicella-zoster virus (VZV) has been demonstrated in the human trigeminal and thoracic ganglia by means of nucleic acid hybridization. However, the human geniculate ganglia in VZV latency have not been examined. Tissue DNA extracted from the trigeminal and geniculate ganglia of a newborn and 7 adults was examined by polymerase chain reaction with a pair of VZV-specific primers. None had symptoms of recent infection with VZV (chickenpox or shingles). VZV DNA was detected in 11 (79%) of 14 trigeminal ganglia and in 9 (69%) of 13 geniculate ganglia of the adults. VZV DNA was not detected in either type of ganglion from the newborn or from 1 adult who was seronegative for VZV antibodies. These findings indicate that VZV becomes latent in human geniculate ganglia after primary infection and suggest the possibility that reactivation of the virus from the geniculate ganglia may cause Ramsay Hunt syndrome.

Detection of latent herpes simplex virus DNA and RNA in human geniculate ganglia by the polymerase chain reaction.

By using the polymerase chain reaction (PCR) we detected latent herpes simplex virus type 1 (HSV-1) in human geniculate and trigeminal ganglia obtained from autopsy cases. A pair of primers which were specific for a part of the HSV-1 thymidine kinase domain were used for detection of HSV DNA. We also examined the latency-associated transcript (LAT), known as latency-specific RNA, by means of reverse transcription-PCR with a pair of LAT-specific primers. HSV-1 DNA was detected in 16 of 17 (94%) trigeminal ganglia and in 15 to 17 (88%) geniculate ganglia of adults. We also demonstrated HSV-1 RNA derived from the LAT in both types of ganglia. These findings suggest that HSV-1 latently infects the majority of geniculate and trigeminal ganglia of adults, and that PCR and reverse transcription-PCR are useful tools for analysis of HSV latency.

Latent herpes simplex virus type 1 in human geniculate ganglia.

Viral infection, especially by reactivation of herpes simplex virus (HSV) has been considered to be a possible explanation for the pathogenesis of idiopathic peripheral facial nerve palsy (Bell's palsy). We investigated whether the geniculate ganglia of man contain latent HSV type 1 (HSV-1), and compared the frequency of HSV-infected ganglia and that of latently infected neurons in human geniculate ganglia and in trigeminal ganglia. From autopsy specimens of eight adults 15 geniculate ganglia and 16 trigeminal ganglia were examined by means of in situ hybridization and immunohistochemical staining. The HSV-1 genome was detected in 11 of the 15 (71%) geniculate ganglia and in 13 of the 16 (81%) trigeminal ganglia. No HSV antigen was noted in any of the ganglia. The incidence of latently infected neurons was 0.9% in the trigeminal ganglia and 5.3% in the geniculate ganglia. The difference in percentages between the two types of ganglia was significant. Our results suggest that reactivation of latent HSV in the geniculate ganglia is a probable cause of some cases of herpetic stomatitis and of idiopathic peripheral facial nerve palsy.

Attempts to isolate virus from human trigeminal and facial ganglions.

Herpes virus hominis type 1 was isolated from the trigeminal ganglion (ganglion semilunare, gasservian) in three out of 20 randomly selected autopsies. Two of the three patients had been treated with immunosuppressive or cytostatic agents. Clinical signs of herpes infection were not observed during the previous 6 months. No virus was isolated from the facial ganglion (geniculate ganglion) in the same 20 cases. The findings are discussed in relation to the viral etiology of acute peripheral facial palsy.

Viral culture and electron microscopy of ganglion cells in Meniere's disease and Bell's palsy.

Specimens of Scarpa's ganglion during vestibular neurectomy were obtained in 6 cases of Meniere's disease and specimens of geniculate ganglion in 2 cases of total facial nerve decompression and studied by tissue culture methods for detection of possible herpes and cytomegalovirus infection. In electron microscopy inclusions in the form of interwoven yarn-like structures, coarse aggregates of chromatin and light nuclear bodies were found in several vestibular ganglion cells. No typical herpes virus virions could be demonstrated. The culture for viruses all proved finally negative. At present there is no proof that viruses are present in Scarpa's or geniculate ganglions but the possibility remains that the inclusion bodies observed might be viruses inactivated inside the ganglion cells.