Audição e aspectos cognitivos em pacientes com Doença de Parkinson: uma análise comparativa

Abstract

Introduction: Parkinson's disease (PD) is the second most common neurodegenerative disease, affecting more than 1% of individuals over 65 years of age. It occurs as a consequence of the intense decrease in the production of dopamine, an important neurotransmitter, concentrated in the midbrain region that acts in the conduction of information in the central nervous system. In the literature, there are reports of early PD and the occurrence of non-motor symptoms, such as depression, anosmia and, more recently, hearing loss. The objectives of the present study were to evaluate whether hearing loss is more common in individuals with PD than in individuals without PD, and to evaluate hearing and cognitive aspects in individuals with PD and healthy individuals. Methods: In the first article, a systematic review was carried out, searches were conducted in March and April 2024, in the electronic databases PubMed, SciELO, LILACS, Web of Science and Scopus. Articles published between 2019 and 2024, in Portuguese or English, that mentioned the frequency of hearing loss in Parkinson's disease were selected. The studies were evaluated by two independent evaluators. In the second article, a comparative cross-sectional study was carried out. Individuals with depression, cognitive impairment and conductive hearing loss were excluded, screened respectively by the Geriatric Depression Scale (GDS), Mini Mental State Examination (MMSE) and immittance testing. The quality of life of patients with PD was assessed using the PDQ-39 and all participants underwent hearing assessment using pure tone audiometry and cognitive aspects using the P300. Results: In the first study, seven articles met the proposed selection criteria and were included in the review. The main hearing tests performed were pure tone audiometry, otoacoustic emissions (OAE) and brainstem auditory evoked potential (BAEP). The data indicate that 60% of the selected articles reported a higher frequency of hearing loss in individuals with PD compared to the control group (Odds Ratio ranged from 1.14 to 1.67). In the second article, 56 participants were included, 28 individuals with PD and 28 without PD. The PD group had a male predominance (15 individuals), mean age of 65 years, mean education of 6 years and median disease time of 8 years, while the group without PD had a mean age of 64 years and 8 years of education. Quality of life, measured by the PDQ-39, revealed a mean score of 48 points, with the discomfort domain being the most affected (68 points). The comparison between the groups indicated differences with statistical relevance in the auditory frequencies of 4 kHz and 8 kHz in both ears (p<0.005), and in 3 kHz and 6 kHz in the left ear (p<0.005). There were no statistically significant differences for SRT (OD, p = 0.594; OE, p = 0.516) and IPRF (OD, p = 0.172; OE, p = 0.219). Individuals with PD had a higher prevalence of hearing loss compared to the CG (p = 0.006). In the analysis of long-latency auditory evoked potentials (P300), statistical differences were observed in the latencies of P300 (p=0.021), N2 (p=0.003), P2 (p=0.007) and N1 (p=0.008). There was no difference in the amplitude comparison. Discussion: The results of the systematic review reveal a relationship between PD and hearing loss, reflecting the complexity and multifactorial nature of the disease manifestations. The data indicate that 60% of the selected articles reported a higher frequency of hearing loss in individuals with PD compared to the control group. This finding reinforces the hypothesis that hearing loss may be a non-motor manifestation of PD, possibly related to neurological and sensory changes that occur with the progression of the disease. In the second study, the mean age was 64-65 years, with most participants being male and having incomplete elementary school education. In the hearing evaluation, there were no significant differences between the groups when comparing low frequencies (250 to 2000 Hz), but there was a difference at higher frequencies (3000 to 8000 Hz), with the group with PD showing worse performance, especially in the left ear. This suggests that PD affects hearing more at high frequencies. Hearing loss was more prevalent in the group with PD, corroborating previous studies. The P300 test revealed longer latencies in the PD group, indicating slower cognitive processing. This reflects the frequency of cognitive changes associated with PD, which can affect quality of life. The prevalence of cognitive changes in PD can reach 90% as the disease progresses. The study also highlighted the importance of assessing quality of life, given the presence of auditory and cognitive deficits. Caution is advised when generalizing the results, with more research needed, especially at early ages (<55 years) and at higher frequencies, to better understand the impact of PD on hearing and cognition. Conclusion: The systematic review of the literature demonstrated that hearing loss is a more common symptom in individuals with Parkinson's disease when compared to individuals without the disease in the same age group, and that therefore, patients affected by this neurological disease require a complete audiological evaluation to verify its frequency and relationship. And the second article demonstrated that changes in hearing and cognitive aspects are more prevalent in individuals with PD compared to individuals without PD.