What are the gaps in literature regarding sudden sensorineural hearing loss (SSNHL)?

From the Guidelines

The literature on sudden sensorineural hearing loss (SSNHL) is marked by significant gaps, particularly in defining the condition, understanding its incidence, and establishing effective treatment protocols, as highlighted in the 2019 clinical practice guideline update 1. The gaps in literature can be broadly categorized into several areas, including:

• Definition and incidence: There is a need for a standardized and evidence-based definition of SSNHL, as well as determination of its actual incidence in the United States 1.
• Treatment protocols: The effectiveness of systemic corticosteroid treatment versus a placebo, and the benefit of hyperbaric oxygen therapy (HBOT) are still uncertain and require further investigation 1.
• Outcome measures: Standardized outcome criteria are needed to aid in the comparison of clinical studies, and the development of criteria to determine at what level of hearing recovery intratympanic (IT) steroids would be offered as salvage therapy is necessary 1.
• Combined therapy: The use of combined therapy, such as oral and IT steroids, in patients with SSNHL needs to be investigated further 1.
• Long-term follow-up: Long-term follow-up protocols for patients with SSNHL are lacking, and the evaluation of therapies with standardized definitions and treatment protocols across studies is necessary 1.
• Diagnostic protocols: The development of a protocol with stacked auditory brainstem response (ABR) to better detect small retrocochlear lesions is needed, as well as the investigation of targeted laboratory assessment in determining the etiology of SSNHL 1.
• Prognostic factors: Reliable predictors of recovery are lacking, making it difficult to provide accurate prognoses to patients, and the association of SSNHL with other risk factors, such as stroke and coagulopathies, needs to be investigated 1.
• New treatments: The investigation of new agents for the treatment of SSNHL is necessary to improve patient outcomes 1.

From the Research

Gaps in Literature Regarding Sudden Sensorineural Hearing Loss (SSNHL)

• The exact pathophysiology of SSNHL remains unclear, with an underlying cause identified in only 10-15% of cases 2.
• There is a lack of conclusive evidence on the efficacy of various treatment agents, resulting in the propagation of consensus-based treatment protocols 2.
• The management of idiopathic SSNHL is empirical, and the availability of conflicting outcomes has led to controversy in treatment approaches 2.
• Further high-quality research is required to improve outcomes for patients with SSNHL, particularly in regards to the use of corticosteroid treatment and other interventions 3.
• There is insufficient evidence to support the routine use of antiviral therapy, hyperbaric oxygen therapy, and vasodilator and vasoactive agents in the treatment of SSNHL 3, 4.
• The role of emerging therapies, such as intratympanic steroid administration, in augmenting standard treatment approaches is not yet fully understood 4.