title: An investigation of hearing impairment in de-novo Parkinson's disease patients: A preliminary study.
abstract: OBJECTIVE
  To investigate the peripheral auditory pathway in Parkinson's disease (PD) by using objective, quantitative and non-invasive audiological techniques, transient-evoked (TEOAE) and distortion product (DPOAE) otoacoustic emissions, in order to detect subclinical alterations of cochlear functioning and possible changes after dopaminergic stimulation.
  
  
  METHODS
  We enrolled 11 untreated de-novo PD patients and 11 age and sex-matched healthy controls. Subjects underwent a routine audiological evaluation and otoacoustic emission recordings. The patients were then slowly-titrated to a stable dose of 100 mg levodopa four times in a day. A post-treatment assessment was made in order to detect significant changes in audiological responses. Finally, possible associations between clinical data and hearing results were also evaluated.
  
  
  RESULTS
  At pure-tone audiometry, higher auditory threshold levels were observed in PD when compared to the controls. Moreover, DPOAE responses in PD patients were found low at almost all tested frequencies, suggesting subclinical cochlear damage. Interestingly, after dopaminergic treatment, a significant increase in DPOAE responses was detected. Notably, DPOAE dysfunction correlated with clinical severity, whereas high hearing thresholds appeared positively related with more prolonged disease duration.
  
  
  CONCLUSIONS
  Our findings demonstrate that otoacoustic emission recording and pure-tone audiometry reveal levodopa-sensitive cochlear dysfunction and hearing loss in PD. A parallel improvement in subjective motor symptoms and DPOAE objective responses could help clinicians in monitoring therapeutic responses and dynamic changes during the course of the disease.
authors.affiliation: Department of Clinical Sciences and Translational Medicine, University of Rome "Tor Vergata", Rome, Italy; I.R.C.C.S. "Santa Lucia" Foundation, Rome, Italy. Electronic address: valerio.pisani@uniroma2.it.
authors.forename: Valerio
authors.initials: V
authors.lastname: Pisani
authors.affiliation: INAIL Research, Monteporzio Catone, Rome, Italy.
authors.forename: Renata
authors.initials: R
authors.lastname: Sisto
authors.affiliation: Department of Physics, University of Rome "Tor Vergata", Rome, Italy.
authors.forename: Arturo
authors.initials: A
authors.lastname: Moleti
authors.affiliation: Department of Otolaryngology, University of Rome "Tor Vergata", Rome, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Di Mauro
authors.affiliation: I.R.C.C.S. "Santa Lucia" Foundation, Rome, Italy; Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Pisani
authors.affiliation: Neurology Unit, "Sant'Eugenio" Hospital, Rome, Italy.
authors.forename: Livia
authors.initials: L
authors.lastname: Brusa
authors.affiliation: Neurology Unit, A.C.O. "San Filippo Neri", Rome, Italy.
authors.forename: Maria Concetta
authors.initials: MC
authors.lastname: Altavista
authors.affiliation: Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Stanzione
authors.affiliation: Department of Otolaryngology, University of Rome "Tor Vergata", Rome, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Di Girolamo
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001301:Audiometry, Pure-Tone; D001306:Auditory Pathways / Q000187:drug effects / Q000503:physiopathology*; D001309:Auditory Threshold / Q000187:drug effects / Q000502:physiology*; D003051:Cochlea / Q000187:drug effects / Q000503:physiopathology*; D005260:Female; D034381:Hearing Loss / Q000175:diagnosis* / Q000209:etiology; D006320:Hearing Tests; D006801:Humans; D007980:Levodopa / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D017084:Otoacoustic Emissions, Spontaneous / Q000187:drug effects / Q000502:physiology*; D010300:Parkinson Disease / Q000150:complications / Q000188:drug therapy*
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa
keywords: Cochlea; Hearing; Levodopa; Otoacoustic emission; Parkinson's disease