Herpes simplex virus 2-induced aseptic meningitis presenting with sudden deafness: A case report

Abstract

BACKGROUND

Aseptic meningitis is defined as meningeal inflammation caused by various etiologies with negative cerebrospinal fluid (CSF) bacterial culture. The most common etiologies are viruses [enteroviruses, arboviruses, and herpes simplex virus type 2 (HSV-2)]. Aseptic meningitis can have various presentations, including sensorineural deafness. While sensorineural deafness from mumps meningoencephalitis has been reported, cases of HSV-2-induced hearing loss are rare. Herein, we report a case of HSV-2-induced meningitis that presented with sudden deafness.

CASE SUMMARY

A 68-year-old man experienced a profound sudden onset of left-sided hearing loss for one day. Pure-tone audiograms demonstrated sudden left-sided sensorineural hearing loss (thresholds 80-90 dB). After treatment with high-dose steroids for 1 week, he experienced an acute consciousness change with left hemiparesis. The laboratory data showed no significant abnormalities. Brain computed tomography without contrast and magnetic resonance imaging revealed no intracranial hemorrhage or obvious brain lesion. The CSF analysis and the Multiplex PCR panels showed HSV-2 positivity. Hence, under the diagnosis of herpes meningoencephalitis, acyclovir was prescribed and his symptoms gradually resolved.

CONCLUSION

This case report further demonstrates that a viral infection could be a cause of sudden sensorineural hearing loss.

Key Words: Aseptic meningitis; Type 2 herpes simplex; Sudden sensorineural hearing loss; Immunocompromised; Cerebrospinal fluid; Case report

Core Tip: We report a case of herpes simplex virus type 2 (HSV-2)-induced meningitis presenting with sudden deafness. A 68-year-old man experienced sudden left-sided hearing loss for one day. Pure-tone audiograms showed left-sided sensorineural hearing loss with an average threshold of 80 dB. After one week of high-dose steroids, the patient experienced acute changes in consciousness with left hemiparesis. Laboratory data showed no significant abnormalities. Brain computed tomography and magnetic resonance imaging revealed no intracranial hemorrhage or lesions. Cerebrospinal fluid analysis and multiplex PCR confirmed HSV-2. Acyclovir was prescribed for herpes meningoencephalitis, and symptoms gradually resolved.

INTRODUCTION

Sudden sensorineural hearing loss (SSNHL) is defined as a hearing loss of 30 dB or more across at least three contiguous frequencies that occurs within 72 hours. Idiopathic SSNHL may sometimes be accompanied by symptoms such as vertigo, nausea, and vomiting; however, these symptoms are also found in patients with identifiable causes of SSNHL.

A previous study reported that the most common causes of SSNHL are infection (13%), followed by otologic (5%), traumatic (4%), vascular or hematologic (3%), neoplastic (2%), and other causes (2%)[1]. Herpes simplex virus (HSV) types 1 and 2 are recognized etiologies of SSNHL, and idiopathic SSNHL can be the initial sign of various infections, warranting careful monitoring. According to the American Academy of Otolaryngology-Head and Neck Surgery guidelines[2], routine laboratory tests are discouraged to avoid false positives and unnecessary costs.

However, immunocompromised patients, such as those with diabetes, history of transplantation, or cancer, are more susceptible to viral and bacterial infections. Misdiagnosing idiopathic SSNHL and prescribing high-dose steroids alone may lead to severe complications. Here, we present a case of HSV type 2 (HSV-2)-induced aseptic meningitis with sudden hearing loss.

CASE PRESENTATION

Chief complaints

A 68-year-old man presented with sudden onset of profound left-sided hearing loss accompanied by aural fullness that had persisted for 1 day.

History of present illness

The patient reported that symptoms began the day before presentation, characterized by a sudden onset of profound left-sided hearing loss and aural fullness.

History of past illness

He reported no recent history of upper respiratory tract infection, use of ototoxic medications, or trauma.

Personal and family history

The patient had a history of type 2 diabetes mellitus, hypertension, and end-stage renal disease (ESRD) following renal transplantation in 2013. He was on regular medication, including tacrolimus. There was no relevant family history or related condition.

Physical examination

Otoscopy revealed a normal external auditory canal and tympanic membrane.

Laboratory examinations

A pure-tone audiogram (PTA) demonstrated sudden left-sided sensorineural hearing loss with thresholds of 80-90 dB and normal hearing function in the right ear. White blood cell count was 5850/µL, and renal and liver function test results were within normal limits. No hyperlipidemia was noted.

Imaging examinations

No imaging was initially arranged. Brain computed tomography (CT) and magnetic resonance imaging (MRI) conducted over two weeks revealed no intracerebral hemorrhage or brain lesions, despite the patient experiencing acute changes in consciousness, left hemiparesis, four-limb tremors, left-sided gaze deviation, and incoherent speech.

FINAL DIAGNOSIS

The final diagnosis was HSV-2-induced hearing loss secondary to aseptic meningitis.

TREATMENT

Upon admission to the otolaryngology department, high-dose steroid therapy with methylprednisolone (80 mg/day) and dextran 40 (500 mL/day) was initiated. However, on day 6, the PTA showed only mild improvement in left-sided hearing, with a threshold of 72 dB. Due to the limited response and steroid side effects, the patient was discharged and followed up with intratympanic steroid injections as an outpatient.

Two weeks post-discharge, the patient experienced an acute change in consciousness, left hemiparesis, four-limb tremor, left-sided gaze, and incoherent speech. His blood glucose was 457 mg/dL, and blood pressure was 255/217 mmHg, both of which were controlled with medication. Other tests were unremarkable. Chest radiography showed an underinflated lung without infection. Brain CT and MRI revealed no intracerebral hemorrhage or brain lesions. Hyperglycemic hyperosmolar syndrome was suspected, and the patient was admitted to the intensive care unit (ICU).

In the ICU, the patient gradually regained consciousness and clear orientation, with symmetric limb strength, although intermittent lower limb fasciculations persisted. Labetalol and levetiracetam were administered to manage hypertension and seizures, respectively. A cerebrospinal fluid (CSF) test was performed due to suspected meningitis. The CSF analysis showed HSV-2 positivity, prompting the administration of acyclovir, after which limb fasciculations and seizures gradually resolved.

OUTCOME AND FOLLOW-UP

The patient was discharged without sequelae two weeks after admission.

DISCUSSION

Identifiable causes of SSNHL account for 7%-45% of cases, with the most common identifiable cause being infection (13%)[3].

Almost all cases of SSNHL caused by viruses are unilateral, while bilateral SSNHL cases are rare[3]. HSV-1 and HSV-2 are known causes of hearing loss. However, HSV infection can lead to various symptoms, including hearing loss, painful blisters, fever, herpes keratitis, herpes esophagitis, and herpes viral meningitis. In the present case, the patient had a history of type 2 diabetes mellitus and ESRD following renal transplantation in 2013, with regular medication and tacrolimus use. Both of these conditions can contribute to an immunocompromised state.

The prevalence of HSV-induced meningitis is 0.5%-3.9% in immunocompromised patients[4-6]. Additionally, diabetes mellitus is a known risk factor for SSNHL[7].

To assess the potential risk of severe complications in immunocompromised patients with viral infections, serological tests should be routinely performed in select cases to help prevent severe comorbidities.

CONCLUSION

SSNHL can be caused by infections like HSV, especially in immunocompromised patients. Routine serological testing in high-risk patients may prevent complications, as misdiagnosis and steroid treatment alone can be risky.