Time and geographic clustering of adult patients with unilateral idiopathic sudden sensorineural hearing loss

Temporospatial aggregation of three individuals with idiopathic sudden onset low-tone sensorineural hearing loss

OBJECTIVE

To report temporospatial aggregation of low-tone sudden onset sensorineural hearing loss (SSNHL) and provide plausible aetiological explanations.

DESIGN

Retrospective analysis of records of patients, including medical notes, clinic letters, audiology reports, blood test and imaging results after occurrence of low-tone SSNHL.

STUDY SAMPLE

Three patients working in the same department and presenting with low-frequency SSNHL between March and July 2019.

RESULTS

There was complete symptom resolution in two of the three cases, one treated with oral and one with intratympanic steroid administration, whereas low-tone SSNHL persisted in the third case. Probability of events occurring randomly was calculated and it was suggested that the three cases were highly unlikely to be independent events.

CONCLUSIONS

This is the first report of temporospatial aggregation of acute low-tone idiopathic SSNHL. Our findings support that an environmental or transmissible agent could underlie aetiology in at least a proportion of such cases.

COVID-19 and anosmia in Tehran, Iran

Patients with acute olfactory disorders typically present to the otolaryngologist with both acute hyposmia and less often with anosmia. With the onset of COVID-19 we have noticed an increase in the number of patients who have presented with new onset of complete smell loss to the senior author's practice in Tehran, Iran. This anosmia and the frequency with which patients present is highly unusual. Coronaviruses have been known to cause common cold symptoms. COVID-19 infections have been described as causing more severe respiratory infections and the symptoms reported by authors from Wuhan, China have not specifically included anosmia. We describe patients who have presented during a two-week period of the COVID-19 pandemic with complete loss of sense of smell. Most had either no symptoms or mild respiratory symptoms. Many had a normal otolaryngologic exam. A relationship between COVID-19 and anosmia should be considered during the pandemic. We hypothesize that the mechanism of injury is similar to that of other coronavirus infections that cause central and peripheral neurologic deficits.