Hearing impairment in Parkinson's disease: Expanding the nonmotor phenotype

Abstract

The objective of this study was to evaluate hearing impairment in patients affected by Parkinson's disease compared with hearing scores observed in normal age- and sex-matched controls. One hundred eighteen consecutive patients with a clinical diagnosis of Parkinson's disease were screened. Severity of motor symptoms and staging were measured with the Unified Parkinson's Disease Rating Scale (section III) and the Hoehn and Yahr scale. Audiometric evaluation consisted of a comprehensive audiologic case history and questionnaire, visual otoscopic examination, acoustic immittance measures (tympanogram and acoustic reflexes), pure tone audiometry, and measurement of brain stem auditory-evoked potentials. Healthy age- and sex-matched subjects were selected as the control group. One hundred six of 118 patients were enrolled. Pure tone audiometry revealed age-dependent high-frequency hearing loss in patients with Parkinson's disease compared with both normative values and values for healthy age- and sex-matched controls (75/106 [71%], χ(2) = 5.959, P = .02; 92/106 [86.8%] vs 60/106 [56.6%], χ(2) = 23.804, P < .001, respectively). Pure tone audiometry scores correlated with Hoehn and Yahr scale scores (P < .05). Brain stem auditory-evoked potentials were normal in all patients. Our patients with Parkinson's disease showed age-dependent peripheral, unilateral, or bilateral hearing impairment. Whether these auditory deficits are intrinsic to Parkinson's disease or secondary to a more complex impaired processing of sensorial inputs occurring over the course of illness remains to be determined. Because α-synuclein is located predominately in the efferent neuronal system within the inner ear, it could affect susceptibility to noise-induced hearing loss or presbycusis. It is feasible that the natural aging process combined with neurodegenerative changes intrinsic to Parkinson's disease might interfere with cochlear transduction mechanisms, thus anticipating presbycusis.

Assessment of Hearing Impairment in Parkinson's Disease: Implications for Differential Diagnosis and Disease Progression

“…Four PD patients and one ART were not included in our data analysis because of middle ear disease revealed by the acoustic impedance test The PD group, by history, showed a mean disease duration of 8.7 ± 1.1 years and, on clinical examination, a mean UPDRS III score of 9.64 ± 5.6 (range, [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19], H&Y staging ranged from 1.5 to 3 (mean 2.4 ± 1.2).…”

“…Hearing impairment frequently occurs in PD patients, and may therefore be considered in the wide spectrum of NMS [4]. Several lines of evidence suggest that hearing impairment may not only be due to the physiological presbycusis that occurs with aging, but could instead originate from a damage involving either the cochlea or the MOC, with a consequent impairment between dopaminergic and glutamatergic neurotransmission below the inner hair cells (IHC) [14].…”

“…However, a better comprehension of the underling mechanisms is crucial to conceive novel therapeutic options for patients. Recent evidence included hearing loss into the wide spectrum of PD NMS [4]. The origin of hearing loss in PD has not been clarified yet; indeed it may be related to the physiological hypoacusis of aging, reaching 62% of population at the age of 85 [5].…”

Aging of perennial cells and organ parts according to the programmed aging paradigm

“…The incidence of PD was shown to be 1.77 times more likely in patients with hearing loss than in those without nonhearing loss (Lai et al 2014), and hearing impairment is a common feature in idiopathic PD (Vitale et al 2012). …”

Evoked potential changes in patients with Parkinson's disease

“…The measurement of the evoked potential (EP) is a widely used noninvasive technique for studying the functional changes in neural conductive pathway of PD. Some studies demonstrated VEP or BAEP in patients with PD, but the results were inconsistent (Deng, Deng, Zhao, Yan, & Chen, 2006; Li, 2004; Venhovens, Meulstee, Bloem, & Verhagen, 2016; Vitale et al., 2012; Yylmaz et al., 2009). So our study explored whether the impairment of brainstem auditory and visual passageway exists in patients with PD using VEP and BAEP.…”