Essential tremor (ET) is the most common adult movement disorder, characterized by several motor and increasingly well recognized non-motor symptoms. Sensory deficits, such as hearing impairment and olfactory dysfunction, are amongst them. This review analyzes the available evidence of these sensory deficits and their possible mechanistic basis in patients with ET.
A PubMed literature search on the topic was performed in the May 2019 database.
Nineteen articles on hearing impairment and olfactory dysfunction in ET patients were identified. The prevalence of hearing impairment is higher in ET patients than healthy controls or Parkinson disease. Cochlear pathologies are suggested as the underlying cause, but there is still a lack of information about retrocochlear pathologies and central auditory processing. Reports on olfactory dysfunction have conflicting results. The presence of mild olfactory dysfunction in ET was suggested. Conflicting results may be due to the lack of consideration of the disease\'s heterogeneity, but according to recent data, most studies do not find prominent evidence of olfactory loss in ET.
Although there is increasing interest in studies on non-motor symptoms in ET, there are few studies on sensory deficits, which are of particularly high prevalence. More studies are needed on to investigate the basis of non-motor symptoms, including sensory deficits.

The objective of this study is to review the scientific literature to determine if a set of stimulus parameters can be described to elicit distortion product otoacoustic emissions (DPOAEs) of higher absolute level and/or greater reliability in healthy adult humans and higher sensitivity and specificity in adults with cochlear lesions.
Systematic review.
Searches of four electronic databases yielded 47 studies that had used different parameters to elicit DPOAEs from within or between-groups of adult humans.
The wide range of stimulus parameters used in the reviewed studies saw a wide range of reported values for DPOAE level, reliability, and sensitivity and specificity to cochlear lesions.
The most commonly used stimulus parameters for eliciting DPOAEs from adult humans have included frequency ratios for the two primary tones (f2/f1) of between 1.04 and 1.4 and levels (L1/L2) of 65/55 dB SPL. The most commonly used parameters for eliciting DPOAEs of higher level in healthy adults appear to be linked to f2/f1 values between 1.20 and 1.22 and L1/L2 levels of 75/75 dB SPL. The stimulus parameters for eliciting DPOAEs of greater reliability in healthy adults and higher sensitivity and specificity in adults with cochlear lesions have yet to be clearly determined.

BACKGROUND: The study of tinnitus mechanisms has increased tenfold in the last decade. The common denominator for all of these studies is the goal of elucidating the underlying neural mechanisms of tinnitus with the ultimate purpose of finding a cure. While these basic science findings may not be immediately applicable to the clinician who works directly with patients to assist them in managing their reactions to tinnitus, a clear understanding of these findings is needed to develop the most effective procedures for alleviating tinnitus.
OBJECTIVE: The goal of this review is to provide audiologists and other health-care professionals with a basic understanding of the neurophysiological changes in the auditory system likely to be responsible for tinnitus.
RESULTS: It is increasingly clear that tinnitus is a pathology involving neuroplastic changes in central auditory structures that take place when the brain is deprived of its normal input by pathology in the cochlea. Cochlear pathology is not always expressed in the audiogram but may be detected by more sensitive measures. Neural changes can occur at the level of synapses between inner hair cells and the auditory nerve and within multiple levels of the central auditory pathway. Long-term maintenance of tinnitus is likely a function of a complex network of structures involving central auditory and nonauditory systems.
CONCLUSIONS: Patients often have expectations that a treatment exists to cure their tinnitus. They should be made aware that research is increasing to discover such a cure and that their reactions to tinnitus can be mitigated through the use of evidence-based behavioral interventions.

BACKGROUND: Cisplatin is an effective chemotherapeutic agent commonly used in the treatment of malignant tumours, but ototoxicity is a significant side effect.
OBJECTIVE: To discuss the mechanisms of cisplatin ototoxicity and subsequent cell death, and to present the results of experimental studies.
METHODS: We conducted a systematic search for data published in national and international journals and books, using the Medline, SciELO, Bireme, LILACS and PubMed databases.
RESULTS: The nicotinamide adenine dinucleotide phosphate oxidase 3 isoform (also termed NOX3) seems to be the main source of reactive oxygen species in the cochlea. These reactive oxygen species react with other molecules and trigger processes such as lipid peroxidation of the plasma membrane and increases in expression of the transient vanilloid receptor potential 1 ion channel.
CONCLUSIONS: Cisplatin ototoxicity proceeds via the formation of reactive oxygen species in cochlear tissue, with apoptotic cell death as a consequence.

OBJECTIVE: The purpose of this study was to give a brief review of the effectiveness of otoacoustic emissions for getting frequency-specific information about a hearing-loss problem in newborns after hearing screening. Especially, the advantages of distortion-product otoacoustic emissions (DPOAE) over transiently evoked otoacoustic emissions (TEOAEs) are described.
METHODS: Approximately 186 ears of 104 children aged between 76 days and 15 years and 436 ears of adults with normal hearing and sensory hearing loss.
METHODS: Extrapolated DPOAE I/O-functions at frequencies between 1.5 and 6 kHz were obtained in the children for assessing the hearing loss and for differentiating between a transitory sound-conductive hearing loss and a persisting cochlear hearing loss. For getting information on the test time needed, measurements were performed in the adult patients.
RESULTS: DPOAE thresholds derived from extrapolated DPOAE I/O-functions (DPOAE audiograms) are closely related to behavior audiometric thresholds and can be used for determining characteristic quantities of the cochlear-impaired ear. A DPOAE audiogram can be obtained in a couple of minutes. DPOAE audiograms are able to reveal a transitory sound-conductive hearing loss because of Eustachian tube dysfunction and/or amniotic fluid in the tympanic cavity or to confirm a persisting cochlear hearing loss because of outer hair cell impairment in babies with a reference result in newborn hearing screening.
CONCLUSIONS: DPOAE audiograms provide a tool for a fast automated frequency-specific and quantitative evaluation of a mild or moderate hearing in follow-up diagnosis.

Multiple semicircular canal dehiscences are clinical entities characterised by vestibular and cochlear symptoms induced by enhanced sensitivity of labyrinthine receptors due to a multiple bone defect of the otic capsule. The case is presented of a 38-year-old male with bilateral posterior semicircular canal dehiscence associated with unilateral (right) superior semicircular canal dehiscence. The man suffered from vestibular (recurrent Tullio Phenomenon or sound-induced vertigo) and cochlear symptoms (persistent aural fullness associated with mixed hearing loss and disabling tinnitus).

CONCLUSIONS: Our data represent the experience of the largest cochlear implant program in Austria. In conclusion, cochlear implantation is a safe procedure, associated with a low rate of intra- and postoperative complications. Nevertheless, patients should be informed about possible problems and especially about the risk of a reoperation due to device failure.
OBJECTIVE: To evaluate the cause of deafness, the intraoperative findings and the complication rate for all cochlear implant operations performed consecutively between 1994 and 2003 at Vienna General Hospital.
METHODS: Including all surgeries for bilateral implantation and revision, a series of 342 operations performed on 164 adults (age range 14.5-81 years; mean age 50.79 years) and 128 children (age range 0.75-14 years; mean age 5.00 years) was retrospectively analyzed.
RESULTS: The etiology of deafness was predominantly congenital or progressive (66.89%). The routine mastoidectomy approach was chosen in 300 patients (87.72%) and the suprameatal approach in 42 (12.28%). Intraoperatively, 4 children (2.53%) had a cerebrospinal fluid fistula and 35 patients (10.23%) showed cochlear ossification. Three adults (1.63%) and two children (1.27%) had facial nerves with an aberrant course. The overall complication rate was 12.2%, the rate of major complications was 4.97% and the rate of minor complications was 4.09%. There were no cases of either postoperative meningitis or facial nerve palsy. Both flap necrosis and electrode dislocation occurred in one adult patient (0.54%), but in none of the children. Formation of cholesteatoma was found in one adult (0.54%) and one child (0.63%). The rate of device failure was 7.07% for adults and 13.92% for children.

Cochlear implants (CI) represent the current treatment for patients affected by profound sensorineural hearing loss (SNHL). Initially only deaf adult patients were considered to be candidates for a CI; however, the development of technology and matured experience have expanded the indications for cochlear implantation. Today, CIs are implanted in adults and children and broader indications are followed. There are, however, a number of patients who do not completely fulfill the current indications and who are potential candidates for CI. The duration of deafness and residual hearing represent prognostic indicators for CI performance; however, the candidacy of children with residual hearing and prelingually deafened adults are still under debate. Anatomical variants such as cochlear ossification, cochlear malformation and chronic otitis media represented and still represent for some surgeons a contraindication to CI. The otological experience of CI surgeons and the advent of auditory brainstem implants have changed the approach to these patients, who may still benefit from hearing rehabilitation. This paper briefly analyses and reviews the results obtained in these groups of patients, who were not, at least initially, considered to be candidates for cochlear implantation.

We report a single case of Susac syndrome (microangiopathy of the brain, retina, and cochlea). A 26-year-old woman developed branch retinal artery occlusion in the right eye, associated with bilateral hearing loss that mostly involved low frequencies. MRI of the brain revealed small multifocal hyperintensities in the white matter of the cerebrum on T2-weighted images with gadolium enhancement. The treatment consisted of anticoagulation and antiplatelet drugs. Seventy-one cases of Susac syndrome have been reported in the literature. The Susac syndrome is more frequent in females and its etiology remains unknown. However, immune inflammatory disorders, vasospastic phenomena, and coagulopathy could be involved in its pathophysiology. Treatment options are not standardized, ranging from antithrombotic drugs to immunomodulatory therapy. The course of the disease is self-limited after an initial fluctuating active phase. The prognosis of Susac syndrome is good in most cases.

Recently, there have been many reports describing the efficacy of intratympanic aminoglycoside injection for the treatment of intractable vertigo in patients with Ménière\'s disease. However, the number of injections and the amount of drug injected varies, with concomitant variation in the side-effect of hearing deterioration. To identify drugs that are more selectively vestibulotoxic, we have reviewed the ototoxicity of aminoglycosides, focusing on differences between vestibulo- and cochleotoxicity. At present, the basis for the different effects of each drug is unknown. The mechanisms of vestibulo- and cochleotoxicity are deemed worthy of further study.