Abstract

Many disorders with various clinical manifestations are observed in COVID-19 coronavirus infection, including dam-age to the cardiovascular, central nervous systems and other organs and systems of the human body. The functions of sensory systems and higher nervous activity may also be affected by COVID-19. However, the issue is not sufficiently understood at the moment.

The purpose of the study is to assess the state of the sensory systems – auditory, taste and olfactory analysers in people with COVID-19 based on the analysis of complaints and anamnesis data, taking into account the severity of its course.

Materials and methods: We analysed survey data, anamnesis and complaints of 122 patients with COVID-19. All sub-jects were divided into two groups according to the clinical course of the disease: group 1 included patients with mild COVID-19 – 63 patients, and group 2 – 59 patients with moderate infection.

Results and discussion: In the more severe COVID-19, complaints of hearing, smell, voice, and vestibular function disorders are more frequent. At the same time, the manifestations of such sensory system disorders were more pronounced in patients in group 2. Patients in group 1 complained of hearing impairment in 41.3%, voice impairment in 26.9%, vestibular function in 33.3%, and general complaints from the central nervous system in 77.7%. In group 2, the following complaints were observed in a higher percentage of cases: hearing impairment 57.6%, voice impairment 33.9%, vestibular function 45.7%, and general CNS complaints 91.5%.

In general, 49.2% of the surveyed complained of hearing impairment in the form of decreased hearing sensitivity, changes in speech intelligibility, and tinnitus. After COVID-19 infection, even in mild form, 36.5% of patients often complained of hearing loss. The number of moderate cases was 42.4%. Patients also noted a deterioration in speech intelligibility (Group 1 – 14.3%, Group 2 – 16.9%) and tinnitus (Group 1 – 38.1%, Group 2 – 55.9%. In 36.9% of the examined patients, hearing impairment was present before COVID-19, and the disease led to the progression of HNP. In group 1, 33.3% of such cases were in group 2, and 40.7% in group 3.

The number of patients complaining of olfactory impairment in the first group was 65.1%, and in the second group – 69.4%. In all patients with olfactory disorders, such disorders occurred during the disease and, in most cases, disappeared after recovery, but in 4.8% of cases in group 1 and 16.9% in group 2, persistent olfactory disorders occurred that persisted for a long time, mainly in the form of anosmia and hyposmia.

When analysing the duration of some complaints, significant differences were found between the groups both during illness and long after recovery. The presence of long-term sensory systems and CNS disorders after COVID-19 is of the most significant interest. In group 2, persistent olfactory disorders in the form of anosmia (16.9%) and hyposomia (6.8%), hearing impairment (27.1%), subjective tinnitus (33,9%), ear congestion (16.9%), headache (45.7%), memory and attention disorders (44.1%), sleep disorders (45.7%), fatigue, general weakness (69.4%).

Thus, patients with COVID-19 often complain of impaired hearing, smell, taste, voice, vestibular function, and general CNS complaints. Moreover, there are often persistent disorders of sensory functions that persist for a long time after the dis-ease.

Conclusions:

1. Patients with COVID-19 often have symptoms of sensory impairment – hearing, voice, smell, taste and vestibular function, as well as CNS conditions. These symptoms occur either during the disease or overtime after recovery and occur in both mild and moderate cases.
2. The more severe COVID-19, the more frequent are complaints of sensory system disorders, and such manifestations are usually more pronounced and prolonged.
3. In the mild form of COVID-19, the following symptoms of sensory system disorders were most commonly observed: decreased and distorted taste, decreased, distorted or exacerbated sense of smell, voice fatigue, dizziness, weakness, headaches, ear congestion, poor tolerance to loud sounds, which mostly resolve after recovery. The following sensory disorders were more common in moderate COVID-19 cases: prolonged hearing impairment (mainly prolonged secretory otitis media and sensorineural hearing loss), decreased or absent olfactory function, hoarseness, and vestibular disorders that persist long after recovery.
4. Complaints of central nervous system disorders and hearing impairment occur even with mild COVID-19. Taste disorders are almost independent of the severity of the disease. Voice and smell disorders are more likely to be persistent after severe COVID-19.

Key words: COVID-19, auditory disorders, olfactory disorders.