Herpes Simplex Virus Type 1 in Saliva of Patients With Vestibular Neuronitis: A Preliminary Study

Vestibular function is associated with immune inflammatory response

Association between vestibular function and immune inflammatory response has garnered increasing interest. Immune responses can lead to anatomical or functional alterations of the vestibular system, and inflammatory reactions may impair hearing and balance. Vestibular disorders comprise a variety of conditions, such as vestibular neuritis, benign paroxysmal positional vertigo, Meniere's disease, vestibular migraine, posterior circulation ischemia, and bilateral vestibular disease. Moreover, some patients with autoimmune diseases develop vestibulocochlear symptom. This paper offers an overview of prevalent vestibular diseases and discusses associations between vestibular dysfunction and immune diseases.

Cellular Processes Induced by HSV-1 Infections in Vestibular Neuritis

Herpesvirus is a prevalent pathogen that primarily infects human epithelial cells and has the ability to reside in neurons. In the field of otolaryngology, herpesvirus infection primarily leads to hearing loss and vestibular neuritis and is considered the primary hypothesis regarding the pathogenesis of vestibular neuritis. In this review, we provide a summary of the effects of the herpes virus on cellular processes in both host cells and immune cells, with a focus on HSV-1 as illustrative examples.

Comparison of Herpes Simplex Virus Reactivation Frequency in Acute Idiopathic Cranial Mononeuropathy and Normal Population by Serological Assay

Background: Herpes simplex virus (HSV) is a neurotropic DNA virus with a high prevalence. Following primary infection, HSV remains dormant in the neural ganglia. Secondary infection can emerge after the reactivation of latent infection, presenting as neurological manifestations. Previous studies have demonstrated the relationship between HSV reactivation and selective involvement of cranial nerves. Depending on the affected nerve, cranial mononeuropathies can present with symptoms, including diplopia, blurred vision, vertigo, unilateral facial palsy, speech impairment, swallowing difficulties, and hoarseness. Objectives: This study used a serological assay to compare HSV reactivation frequency between patients with recent idiopathic cranial mononeuropathies and normal individuals. Methods: Plasma samples from 35 idiopathic cranial mononeuropathy cases (57.2% women, mean age 58.37 years) and 35 age and sex-matched healthy controls were analyzed for anti-HSV immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies by enzyme-linked immunosorbent assay (ELISA). Results: Anti-HSV IgG antibody was positive in 91.4% of patients and 88.6% of controls. The mean serum anti-HSV IgG antibody level was significantly higher in patients (146.78 ± 60 RU/mL) than in the controls (130.61 ± 52.99 RU/mL) (P-value = 0.037). Anti-HSV IgM antibody was positive in 37.1% of patients and 14.3% of controls (P = 0.042). Conclusions: The frequency of HSV reactivation was significantly higher in patients with acute idiopathic cranial mononeuropathy than in the healthy controls, indicating the possible role of HSV as an etiology of cranial mononeuropathy.

White Matter Hyperintensities (WMH) and clinical outcome after vestibular neuritis

OBJECTIVES

Identification of patients at high risk for chronic dizziness after Vestibular Neuritis (VN) would allow these patients to be the target of focused therapies. However, there is a discrepancy between studies with regard to which factors best predict symptom recovery. The present study provides a comprehensive evaluation of Vestibular Neuritis and the major predictors for the development of chronic vestibular insufficiency.

METHODS

All subjects (n = 54) with acute vestibular neuritis admitted to the Department of Neurology of Beijing Luhe Hospital affiliated to Capital Medical University from 2018 to 2020 were retrospectively identified . Forty-three subjects who received a 4-test battery as well as 3.0T brain MRI, were included in the study. Patients were divided into two groups: Group 1 with complete recovery and Group 2 without recovery, as determined by symptoms 3 months after the VN episode. In addition, we recruited 21 healthy subjects to characterize the profiles of acute VN .

RESULTS

The total WMH score negatively correlated with a clinical recovery (Phi coefficient = -0.808, p value = 0.000). Statistical regression for predicting the outcome of clinical recovery using cerebral white matter changes as an independent variable was significant (p = 0.004). However, clinical recovery was not associated with the nerve divisions (Phi coefficient = 0.108, p = 0.492), age (p = 0.247) and the grade of nystagmus (p = 0.797)   .

CONCLUSIONS

A 4-test battery provides essential information to identify vestibular nerve dysfunction. Cerebral white matter change on MRI was predictive of chronic vestibular insufficiency after vestibular neuritis.

About the pathophysiology of acute unilateral vestibular deficit - vestibular neuritis (VN) or peripheral vestibulopathy (PVP)?

OBJECTIVE

To determine whether patients with acute unilateral peripheral vestibulopathy (PVP), often called "vestibular neuritis/neuronitis or neuropathy" (VN) have a vestibular lesion pattern consistent with the distribution of the neurological afferents.

BACKGROUND

Much is known about the clinical nature of PVP, however less so about its etiology and pathogenesis. Due to the frequency with which VN is used to describe the syndrome, an inflammation of the vestibular nerve or of one of its branches is often assumed to be the cause of PVP, though there is insufficient data so far to support this assumption.

METHODS

We conducted a retrospective study of 25 patients who had presented to our clinic with PVP and had all vestibular receptor organs tested shortly after start of symptoms. We analysed their vestibular lesion patterns in order to determine whether they were consistent with the neuritis hypothesis (NH).

RESULTS

The lesion patterns varied conspicuously. 76% did not follow an innervation pattern, thereby contradicting the NH and only 24% had a lesion pattern that either definitely (16%) or probably (8%) supported the NH.

CONCLUSION

These results should remind us to be careful before jumping to quick conclusions about the pathogenetic nature of PVP. With any reason to question VN as the only cause of PVP, we should reconsider the treatment approach to PVP. If the cause probably or even possibly lies inside the vestibular labyrinth, an intratympanic steroid injection might prove to be a more effective measure, even in first-line treatment. If the etiology is unsure, a combination of systemic and intratympanic steroid treatment may be adequate.

Clinical application of viral cerebrospinal fluid PCR testing for diagnosis of central nervous system disorders: a retrospective 11-year experience

The cerebrospinal fluid (CSF) polymerase chain reaction (PCR) is the gold standard to detect cerebral viral activity. As positive findings do not prove an impact on the neurological disorder, data interpretation is difficult. To better assess the impact of positive CSF PCR findings in different neurological diseases and to identify coherences facilitating CSF PCR data interpretation, we performed this retrospective analysis of CSF PCR data of 481 pediatric and 2604 adult patients, including herpes simplex virus (HSV), varicella zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6), and enteroviruses (EV). Nucleic acid of EBV was detected in 1.6% (39/2449), of VZV in 1.3% (34/2624), of HSV in 1.24% (37/2994), of EV in 0.4% (10/2364), of HHV-6 in 0.17% (4/2417), and of CMV in 0.2% (5/2514) of the patients. Newborns and elderly people showed highest infection rates. HSV, VZV, and EV prevailed in typical infectious central nervous system (CNS) diseases; EBV, in further inflammatory neurological diseases; HSV and EBV, in immunocompromised patients; and EBV, HSV, and HHV-6, in further non-inflammatory neurological diseases. Analysis of successive PCR studies revealed delayed viral detection for EBV (6/147) and HSV (1/217), respectively. Rapid viral clearance was typical for HSV, VZV, CMV, and EV infections, although the maximum duration of viral detection was 15days for HSV and 12days for VZV, respectively. This suggests that the detection of HSV, VZV, CMV, and EV strongly indicates symptomatic viral CNS disease. Secondary viral reactivation mostly underlies positive EBV and HHV-6 findings. Their detection does not rule out clinical impact but recommends searching for additional underlying conditions.