Lyme disease as a possible underlying factor in sudden sensorineural hearing loss – what do the clinical data show?
Sudden sensorineural hearing loss (SSNHL) is an acute condition that develops within 72 hours and involves a hearing loss of at least 30 dB in three consecutive frequencies. The condition requires urgent investigation and treatment, as early therapy can significantly influence the prognosis.
In the vast majority of cases (approximately 80–90%), SSNHL is idiopathic, meaning that the cause cannot be clearly identified. Possible aetiological factors include vascular circulation disorders, viral infections, autoimmune processes and other inflammatory mechanisms. In recent years, the possible role of Lyme disease, or more precisely Borrelia burgdorferi infection, has also been suggested in some cases.
Aim of the study
The clinical study referred to set out to investigate the prevalence of antibodies against Borrelia burgdorferi in patients with sudden sensorineural hearing loss and whether the presence of Lyme infection influences the outcome of treatment.
The study was conducted at a university ear, nose and throat clinic, where patients diagnosed with SSNHL underwent routine audiological and laboratory testing. ELISA was used to detect Lyme infection, followed by Western blot testing for confirmation.
What was the rate of Lyme positivity?
Of the 86 patients included, 9 (10.5%) had positive serological results suggestive of Borrelia burgdorferi infection.
This rate is not clinically insignificant, but it is important to emphasise that
- in the vast majority of patients, no specific aetiological factor could be identified,
- seropositivity alone does not prove the existence of an active infection,
- positive findings must always be evaluated in conjunction with the clinical picture.
Did antibiotic treatment affect hearing?
Some of the Lyme-positive patients received antibiotic treatment (e.g. doxycycline or ceftriaxone). According to the authors’ report, partial or complete hearing improvement was observed in these patients, especially in cases where standard (steroid-based) therapy alone did not produce satisfactory results.
However, the study was not a randomised, controlled clinical trial, so a causal relationship cannot be clearly established. The improvement may have been due to spontaneous regeneration or the effect of the combined treatment.
Possible pathomechanism
Lyme infection can affect multiple organ systems, including the nervous and vascular systems. Theoretically, the following mechanisms may contribute to the development of SSNHL:
- release of inflammatory mediators in the structures of the inner ear,
- microvascular circulatory disturbance,
- immune-mediated nerve damage.
These processes are consistent with other proposed pathophysiological models of SSNHL.
Clinical conclusions
Based on the study, the following professional conclusions can be drawn:
- Lyme infection cannot be considered a common cause of sudden sensorineural hearing loss, but it may play a role in certain cases.
- In endemic areas or in cases of clinical suspicion, testing for Lyme disease may be warranted.
- Positive results should always be evaluated in a complex clinical context.
- Antibiotic treatment may result in improvement in some cases, but further studies with larger sample sizes are needed to clearly confirm the therapeutic benefit.
What does this mean in practice?
Based on current evidence, Lyme disease screening cannot be considered a routine mandatory test for all patients with SSNHL, but it may be justified from a differential diagnostic point of view:
- in younger patients,
- those living in endemic areas,
- in atypical or treatment-resistant cases,
- or in patients who also have other symptoms suggestive of Lyme disease.
The study contributes to a better understanding of the possible otoneurological manifestations of Lyme infection, but does not support the claim that Lyme disease is a common or primary cause of sudden hearing loss.
(C) Lyme Borreliosis Foundation
