Herpes virus reactivation and gadolinium-enhanced magnetic resonance imaging in patients with facial palsy

The ratio of facial nerve to facial canal as an indicator of entrapment in Bell's palsy: A study by CT and MRI

OBJECTIVES

To find out if the ratio of facial nerve to facial canal diameter plays any role in the etiopathogenesis and grade of Bell's palsy.

PATIENTS AND METHODS

Twenty-nine consecutive patients (16 females, 13 males) diagnosed with unilateral Bell's palsy were enrolled into the study. At admission, 5 patients were grade V, 11 were grade IV, 11 were grade III and 2 were grade II. The grade of Bell's palsy was documented by House-Brackmann facial nerve grading system at admission, 15th day, 1st month and 3th month. Temporal MRI and CT scans were obtained at the time of diagnosis. Diameter of facial nerve and facial canal at the middle of five different segments were measured equidistantly at the same workstation. Both sides of every patient (affected and unaffected) were measured by one radiologist who was not informed about the side of the paralysis. MRI and CT values of each segment were compared between affected and unaffected sides. In addition, FN/FC ratio of affected and non-affected sides was calculated and compared for each segment. We also analyzed if a relationship exists between above-mentioned measurements and the House-Brackmann grade.

RESULTS

Considering MRI values; statistically significant thickening of facial nerve between affected and unaffected sides was found at labyrinthine (p = 0.012), tympanic (p = 0.023) and geniculate parts (p = 0.04). Considering CT values; statistically significant difference between affected and unaffected sides was not found at any segment. Comparison of FN/FC ratio of both sides revealed statistically significant increment of the affected side at labyrinthine segment (p = 0.015) and geniculate ganglion (p = 0.032). We determined positive correlation between diameter of FN and HB grade at labyrinthine segment (p = 0.03, R = 0.531). On the other hand, we determined negative correlation between diameter of FC and HB grade at labyrinthine segment (p < 0.001, R = -318). A positive correlation between HB grade and FN/FC ratio was found only at the labyrinthine segment (p = 0.003, R = 0.673).

CONCLUSION

FN/FC ratio of labyrinthine segment and geniculate ganglion was found to be increased in patients with Bell's palsy. In addition, a positive correlation was determined between this ratio and grade of Bell's palsy particularly at labyrinthine segment. Basing the current study, if FN decompression is recommended in Bell's palsy patients with objective findings of bad prognosis, conservative surgery targeting the labyrinthine segment and geniculate ganglion alone might be safer.

Ramsay Hunt syndrome with pontine lesion: A case report

RATIONALE

The coexistence of Ramsay Hunt syndrome (RHS) and varicella-zoster virus (VZV) encephalitis is rare. A patient who developed RHS after being infected with VZV, along with a pontine lesion, is reported in the present study.

PATIENT CONCERNS

A 41-year-old male patient presented with his mouth askew for 7 days, and dizziness, accompanied by hearing loss for 3 days.

DIAGNOSES

The patient was initially diagnosed with RHS. Brainstem encephalitis was confirmed by lumbar puncture and cerebrospinal fluid. Brain magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) revealed how VZV entered the intracranial space along the vestibulocochlear nerve and facial nerve in the acute period.

INTERVENTIONS

Intravenous acyclovir, IV, immunoglobulins (IVIg) and methylprednisolone were administered.

OUTCOMES

The herpes was cleared up and left facial nerve palsy was improved, but hearing loss in the left ear did not improve.

LESSONS

An MRI was necessary for some VZV infections limited to the cranial nerve, although there was no evidence of brain stem injury. DWI provided evidence, showing how VZV entered the brain in the early stage. This allowed the doctor to judge the necessity of a lumbar puncture.

Typical or Atypical Ramsay-Hunt Syndrome in Delayed Facial Palsy After Stapedectomy?

OBJECTIVES

The aim of this study was to define the typical pattern for varicella zoster virus (VZV) reactivation in delayed facial palsy (DFP) after stapedectomy for otosclerosis.

MATERIALS AND METHODS

Review of the relevant literature, personal casistics, and case-report.

RESULTS

In total, 48 cases of DFP after stapes surgery have been described so far, including the reported case with exclusive manifestation of atypical Ramsay Hunt syndrome (RH); in the personal series of 1253 stapedectomies, DFP occurred in only one case (0.08%). Complete DFP (House-Brackmann grade VI) rapidly developed 12 days after surgery; RH appeared 2 days later, confirming the role of VZV. The DFP started improving after 8 weeks and completely recovered 6 months later.

CONCLUSION

Acute otalgia prior to DFP should raise the suspicion of VZV reactivation. Atypical RH is the most frequent pattern that occurs in DFP after stapedectomy.

Clinical value of 4-hour delayed gadolinium-Enhanced 3D FLAIR MR Images in Acute Vestibular Neuritis

OBJECTIVE

To investigate the clinical significance of 4-hour delayed-enhanced 3.0 Tesla three-dimensional (3D) fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) imaging in acute vestibular neuritis.

STUDY DESIGN

A prospective observational study.

METHODS

Twenty-nine vestibular neuritis patients were enrolled between January 2017 and June 2017. Vestibular function tests, comprising the caloric and video head impulse tests and vestibular-evoked myogenic potential measurements, were performed. Precontrast, 10-minute, and 4-hour delayed-enhanced 3D-FLAIR MR images using double-dose IV gadolinium were obtained. After laterality and extent of inner ear enhancement were defined, the patients were divided into groups based on the patterns of enhancement, and clinical parameters were analyzed according to the groups.

RESULTS

Twenty patients (20 of 29, 69.0%) had obviously asymmetric enhancement of the affected inner ear structures on 4-hour delayed images, whereas only three patients (10.3%) had marked enhancement on 10-minute delayed images. The duration of spontaneous nystagmus (DurSN) was significantly longer in the patients with enhancement, especially with enhancement of the whole inner ear, including the vestibule and semicircular canals (P < 0.033). Spontaneous nystagmus resolved within 12 days in patients without laterality of enhancement, and within 16 days in ipsilesional enhancement confined to the inner auditory canal and fundus. Other results of vestibular function tests did not reveal any significant associations with MR enhancement.

CONCLUSIONS

Contrast enhancement of the vestibular nerve and inner ear structures can be identified on 4-hour delayed-enhanced 3T 3D-FLAIR MR images in acute vestibular neuritis. The extent of inner ear enhancement may be associated with the DurSN.

LEVEL OF EVIDENCE

4. Laryngoscope, 1946-1951, 2018.

A case of Ramsay Hunt syndrome diagnosed after kidney transplantation

We report the first case of Ramsay Hunt syndrome (RHS) diagnosed after kidney transplantation in Korea. RHS is a disease caused by latent varicella-zoster characterized to involve geniculate ganglion of the seventh cranial nerve. Patients who have undergone kidney transplantation can be easily affected by viral infections because of their immune-compromised status. A 35-year-old man with hypertensive end-stage renal disease underwent kidney transplantation. Two months after surgery, the recipient was diagnosed with RHS and treated with antivirals and steroids. However, after using the antiviral agents for the recommended duration, facial paralysis occurred as a new presentation and he required further treatment. Otalgia and periauricular vesicles improved, but the facial palsy remained.

Treatment of Bell's Palsy Using Monochromatic Infrared Energy: A Report of 2 Cases

OBJECTIVE

The purpose of the study is to describe the use of monochromatic infrared energy (MIRE) therapy in the management of 2 patients with Bell's palsy.

CLINICAL FEATURES

Two patients presented to a chiropractic clinic with Bell's palsy that was diagnosed by a medical physician. Both patients were treated using MIRE. The acute patient was a 32-year-old male. He presented with left facial palsy 1 day before the consultation. He was unable to puff the left cheek and close the left eyelid. He had difficulty raising the left eyebrow. The chronic case was a 46-year-old lady. Prior to the first consultation, she was treated with corticosteroid and electro-acupuncture for one and a half years, with incomplete recovery. When first seen, the left corner of mouth drooped and she had difficulty raising her left eyebrow.

INTERVENTION AND OUTCOME

Monochromatic infrared energy therapy, emitting 890 nm infrared light, was placed on the post-auricular area, pre-auricular area, the temple and mandibular area of the affected side. Each treatment lasted 30 minutes. Photographs were taken every week to document changes. The acute case received 19 treatments in 6 weeks. He reported an improvement of 95%. The chronic case received a total of 45 treatments in 9 months. She rated an improvement of 50%. At the conclusion of treatment, she was able to close her left eyelid and puff her left cheek but still could not raise her left eyebrow.

CONCLUSION

These 2 patients seemed to respond to a different degree to the MIRE therapy. As 71% of patients with Bell's palsy recover uneventfully without any treatment, the present study describes the course of care but cannot confirm the effectiveness of MIRE therapy in the management of Bell's palsy.

Vestibular and cochlear neuritis in patients with Ramsay Hunt syndrome: a Gd-enhanced MRI study

CONCLUSION

It is suggested that vertigo in patients with Ramsay Hunt syndrome is mostly induced by superior vestibular neuritis consecutive to the reactivation of varicella-zoster virus (VZV) infection from the geniculate ganglion through the faciovestibular anastomosis. Refractory hearing loss in patients with Ramsay Hunt syndrome may be due to cochlear neuritis following the spread of VZV.

OBJECTIVES

An attempt was made to selectively identify vestibulocochlear nerves in the internal auditory canal (IAC) on gadolinium (Gd)-enhanced MRI in patients with Ramsay Hunt syndrome.

METHODS

Fourteen patients with Ramsay Hunt syndrome presenting with facial palsy, herpes zoster oticus, vertigo, and/or sensorineural hearing loss were scanned on 1.5 T MRI enhanced with Gd. Perpendicular section images of the IAC were reconstructed to identify the facial, superior, and inferior vestibular nerves and the cochlear nerves separately.

RESULTS

All except one of the patients with Ramsay Hunt syndrome with vertigo showed both canal paresis on the caloric test and Gd enhancement of the superior vestibular nerve in the IAC on MRI. Among 10 patients with hearing loss, 3 patients with severe to moderate sensorineural hearing loss showed Gd enhancement of the cochlear nerve in the IAC on MRI.

A cell culture model of facial palsy resulting from reactivation of latent herpes simplex type 1

HYPOTHESIS

Reactivation of herpes simplex virus type 1 (HSV-1) in geniculate ganglion neurons (GGNs) is an etiologic mechanism of Bell's palsy (BP) and delayed facial palsy (DFP) after otologic surgery.

BACKGROUND

Several clinical studies, including temporal bone studies, antibody, titers, and intraoperative studies, suggest that reactivation of HSV-1 from latently infected GGNs may lead to both BP and DFP. However, it is difficult to study these processes in humans or live animals.

METHODS

Primary cultures of GGNs were latently infected with Patton strain HSV-1 expressing a green fluorescent protein-late lytic gene chimera. Four days later, these cultures were treated with trichostatin A (TSA), a known chemical reactivator of HSV-1 in other neurons. Cultures were monitored daily by fluorescent microscopy. Titers of media from lytic, latent, and latent/TSA treated GGN cultures were obtained using plaque assays on Vero cells. RNA was harvested from latently infected GGN cultures and examined for the presence of viral transcripts using reverse transcription-polymerase chain reaction.

RESULTS

Latently infected GGN cultures displayed latency-associated transcripts only, whereas lytically infected and reactivated latent cultures produced other viral transcripts, as well. The GGN cultures displayed a reactivation rate of 65% after treatment with TSA. Media from latently infected cultures contained no detectable infectious HSV-1, whereas infectious virus was observed in both lytically and latently infected/TSA-treated culture media.

CONCLUSION

We have shown that cultured GGNs can be latently infected with HSV-1, and HSV-1 in these latently infected neurons can be reactivated using TSA, yielding infectious virus. These results have implications for the cause of both BP and DFP.

Varicella-zoster virus reactivation from multiple ganglia: a case report

Introduction

Simultaneous involvements of multiple cranial nerve ganglia (geniculate ganglion and peripheral ganglia of cranial nerves VIII, IX and X) by varicella-zoster virus and its subsequent activation may result in the characteristic eruptions of herpes zoster cephalicus. Coexistence of facial palsy and involvement of upper cervical dermatomes by varicella-zoster virus is quite rare.

Case presentation

Here, we report a 71-year-old Iranian man with involvement of multiple sensory ganglia (geniculate ganglion and upper dorsal root ganglia) by varicella-zoster virus. He presented with right-sided facial weakness along with vesicular eruptions on the right side of his neck, and second and third cervical dermatomes.

Conclusion

The present case is an example of herpes zoster cephalicus with cervical nerve involvement. Although resembling Ramsay Hunt syndrome with presence of facial nerve paralysis and accompanying vesicles, involvement of cervical dermatomes is not a feature of the classic Ramsay Hunt syndrome.

A case of Varicella zoster virus polyneuropathy: involvement of the glossopharyngeal and vagus nerves mimicking a tumor

A 36-year-old woman presented with glossopharyngeal and vagus nerve palsy, which proved to be herpes zoster based on the high titers of Varicella zoster virus antibody in her serum. Thin-section T1-weighted images with contrast media demonstrated swelling and distinct contrast enhancement of the glossopharyngeal and vagus complex, mimicking a tumor. Following MR imaging, the size of the nerve complex returned to normal; however, the contrast enhancement remained longer than the symptoms.

Imaging the cranial nerves: Part I: methodology, infectious and inflammatory, traumatic and congenital lesions

Many disease processes manifest either primarily or secondarily by cranial nerve deficits. Neurologists, ENT surgeons, ophthalmologists and maxillo-facial surgeons are often confronted with patients with symptoms and signs of cranial nerve dysfunction. Seeking the cause of this dysfunction is a common indication for imaging. In recent decades we have witnessed an unprecedented improvement in imaging techniques, allowing direct visualization of increasingly small anatomic structures. The emergence of volumetric CT scanners, higher field MR scanners in clinical practice and higher resolution MR sequences has made a tremendous contribution to the development of cranial nerve imaging. The use of surface coils and parallel imaging allows sub-millimetric visualization of nerve branches and volumetric 3D imaging. Both with CT and MR, multiplanar and curved reconstructions can follow the entire course of a cranial nerve or branch, improving tremendously our diagnostic yield of neural pathology. This review article will focus on the contribution of current imaging techniques in the depiction of normal anatomy and on infectious and inflammatory, traumatic and congenital pathology affecting the cranial nerves. A detailed discussion of individual cranial nerves lesions is beyond the scope of this article.

Viral diseases of the central nervous system

Viral diseases of the central nervous system encompass a wide range of different processes, mainly inflammation affecting the brain (encephalitis), the meninges (meningitis), or a combined meningoencephalitis. The spinal cord can be affected as well (myelitis). Another group of viral-related disorders, sometimes without a clear pathophysiological mechanism disclosed, include post-viral illnesses. All of these groups of diseases are discussed in this article, with an emphasis on their imaging presentation, using magnetic resonance imaging.

Trigeminal neuralgia and facial nerve paralysis

The trigeminal nerve is the largest of the cranial nerves. It provides sensory input from the face and motor innervation to the muscles of mastication. The facial nerve is the cranial nerve with the longest extracranial course, and its main functions include motor innervation to the muscles of facial expression, sensory control of lacrimation and salivation, control of the stapedial reflex and to carry taste sensation from the anterior two-thirds of the tongue. In order to be able adequately to image and follow the course of these cranial nerves and their main branches, a detailed knowledge of neuroanatomy is required. As we are dealing with very small anatomic structures, high resolution dedicated imaging studies are required to pick up normal and pathologic nerves. Whereas CT is best suited to demonstrate bony neurovascular foramina and canals, MRI is preferred to directly visualize the nerve. It is also the single technique able to detect pathologic processes afflicting the nerve without causing considerable expansion such as is usually the case in certain inflammatory/infectious conditions, perineural spread of malignancies and in very small intrinsic tumours. Because a long course from the brainstem nuclei to the peripheral branches is seen, it is useful to subdivide the nerve in several segments and then tailor the imaging modality and the imaging study to that specific segment. This is particularly true in cases where topographic diagnosis can be used to locate a lesion in the course of these nerves.

Vertigo from herpes zoster oticus: superior or inferior vestibular nerve origin?

OBJECTIVE/HYPOTHESIS

This study aims to analyze which division of vestibular nerve in the internal auditory canal is responsible for inducing vertigo in patients with herpes zoster oticus (HZO).

METHODS

Eight patients (three men and five women) suffered from auricular vesicles, otalgia, and facial palsy, and five of them also had vertigo. Each patient received a battery of tests, including neurological examination, blood examination, audiometry, caloric test, electronystagmography, and vestibular evoked myogenic potential (VEMP) test.

RESULTS

All five HZO patients with vertigo had facial palsy on the lesioned side and spontaneous nystagmus beating toward the healthy side. Absent VEMPs were noted in five patients, absent caloric response was noted in four, and sensorineural HL was noted in three. Compared to another three HZO patients without vertigo, all revealed normal responses in both the caloric test and the VEMP test. On MRI scan, two out of four had abnormal gadolinium enhancement along the nerve segments within the internal auditory canal. Six months after treatment, a follow-up caloric test and VEMP test in these eight patients did not alter the results compared with before treatment.

CONCLUSION

The nerve trunks within the internal auditory canal are widely affected in HZO patients with vertigo. Both superior division and inferior division of the vestibular nerve attribute to the vertiginous attack. Further, large numbers of HZO patients undergoing caloric testing and VEMP testing are required to support this tentative conclusion.