Gap-induced reductions of evoked potentials in the auditory cortex: a possible objective marker for the presence of tinnitus.

Gap-induced reductions of evoked potentials in the auditory cortex: a possible objective marker for the presence of tinnitus. Brain Res. 2017 Nov 27;: Authors: Berger JI, Owen W, Wilson CA, Hockley A, Coomber B, Palmer AR, Wallace MN Abstract Animal models of tinnitus are essential for determining the underlying mechanisms and testing pharmacotherapies. However, there is doubt over the validity of current behavioural methods for detecting tinnitus. Here, we applied a stimulus paradigm widely used in a behavioural test (gap-induced inhibition of the acoustic startle reflex GPIAS) while recording from the auditory cortex, and showed neural response changes that mirror those found in the behavioural tests. We implanted guinea pigs (GPs) with electrocorticographic (ECoG) arrays and recorded baseline auditory cortical responses to a startling stimulus. When a gap was inserted in otherwise continuous background noise prior to the startling stimulus, there was a clear reduction in the subsequent evoked response (termed gap-induced reductions in evoked potentials; GIREP), suggestive of a neural analogue of the GPIAS test. We then unilaterally exposed guinea pigs to narrowband noise (left ear; 8-10 kHz; 1 hour) at one of two different sound levels - either 105 dB SPL or 120 dB SPL - and recorded the same responses seven-to-ten weeks following the noise exposure. Significant deficits in GIREP were observed for all areas of the auditory cortex (AC) in the 120 dB-ex...
Source: Brain Research - Category: Neurology Authors: Tags: Brain Res Source Type: research

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We describe a case of intravestibular ILS in which we included the ocular vestibular evoked myogenic potentials (oVEMPs) test in the diagnostic workup. The oVEMPs test is a relatively new neurophysiologic diagnostic modality that evaluates the superior vestibular pathway and the ascending contralateral pathway through the vestibulo-ocular reflex. In our case, a 65-year-old man presented with progressive right-sided sensorineural hearing loss, dizziness, and tinnitus and fullness in his right ear. Audiovestibular examination and MRI detected an intravestibular ILS on the right. We found that oVEMPs were absent on the contra...
Source: Ear, Nose and Throat Journal - Category: ENT & OMF Authors: Tags: Ear Nose Throat J Source Type: research
AbstractThe aim of this study was to investigate the possible role of cochlear outer hair cell function with TEOAE and DPOAE tests in patients with normal hearing and tinnitus. 25 tinnitus patients with normal hearing sensitivity selected as study group. Control group consist of 50 normal hearing subjects without tinnitus. All subjects had thresholds below 25 dBHL at frequencies 250 –8,000 Hz, tympanogram type A and normal acoustic reflex thresholds. TEOAE were recorded with click stimulus at 80 dB SPL at 1,000, 2,000, 3,000 and 4000 Hz. DPOAE were measured at frequencies 1,000–8,000 Hz and inten...
Source: Indian Journal of Otolaryngology and Head and Neck Surgery - Category: ENT & OMF Source Type: research
At the University of Michigan, scientists have developed a non-invasive technology to treat tinnitus, in most sufferers, by training the brain to “desynchronize” and to begin responding properly to real sounds. Their approach involves sti...
Source: Medgadget - Category: Medical Devices Authors: Tags: ENT Neurology Source Type: blogs
We report a severe adverse event occurring in the course of a cohort study (ISRCTN13784335) aimed at measuring the efficacy and safety of venous stenting in the treatment of patients with medically refractory idiopathic intracranial hypertension (IIH). The patient was a 41-year-old woman who was not overweight, who presented with severe headache, grade 1 bilateral papilledema and transient tinnitus, refractory to medical treatment. Right transverse sinus stenting was successfully performed. Following surgery, the patient's state of consciousness decreased acutely with rapid and progressive loss of brainstem reflex. CT scan...
Source: Interventional Neuroradiology - Category: Radiology Tags: Interv Neuroradiol Source Type: research
The objective is to describe a large cohort of patients presenting with patulous Eustachian tube (pET) dysfunction. Study Design: Retrospective patient series. Setting: Tertiary referral center. Patients: All outpatient visits (2004–2016) that were assigned ICD9 code (381.7-Patulous Eustachian tube) were screened. Only patients with observed tympanic membrane movements during ipsilateral nasal breathing or acoustic reflex decay testing demonstrating transmitted nasal breathing were included (n = 190, n = 239 ears). Main Outcome Measures: Demographics and nasopharyngoscopy/otomicroscopy findings by comorbi...
Source: Otology and Neurotology - Category: ENT & OMF Tags: Medical Neurotology Source Type: research
ConclusionsDeep brain stimulation of the caudate nucleus can modulate tinnitus in a rat model of tinnitus. Level of EvidenceNA. Laryngoscope, 2017
Source: The Laryngoscope - Category: ENT & OMF Authors: Tags: Otology/Neurotology Source Type: research
Conclusion Titration methods or multiple injections on a daily basis can be preferred if the patients have profound or non-serviceable hearing, since these methods have significant incidence of hearing loss. Treatment protocols with a frequency of injection not shorter than once a week, or those with injections on a monthly basis as “needed” provide the same level of vertigo control with better preservation of hearing. Caloric testing is not an ideal tool to analyze the correlation between vertigo control and the effect of gentamicin as compared with gain asymmetry of the vestibulo-ocular reflex. Vestibula...
Source: International Archives of Otorhinolaryngology - Category: ENT & OMF Authors: Tags: Update Article Source Type: research
We report about a patient, who in 2005, as a 37-year-old, experienced a sudden, mild to moderate, mid-frequency sensorineural hearing loss in the right ear, along with tinnitus and mild dizziness. MRI of the temporal bone revealed a very small (1 mm) enhancing lesion in the second turn of the right cochlea after injection of contrast medium. Hearing gradually deteriorated, with complete hearing loss in 2015. At this time, an MRI scan showed a lesion completely filling the cochlea.The tumor was removed through a subtotal cochleoectomy. The cochlea was partially reconstructed with cartila...
Source: HNO - Category: ENT & OMF Tags: HNO Source Type: research
We report about a patient who in 2005, aged 37 years, experienced sudden mild to moderate, mid-frequency sensorineural hearing loss in the right ear along with tinnitus and mild dizziness. MRI of the temporal bone revealed a very small (1 mm) contrast-enhancing lesion in the second turn of the right cochlea. Hearing gradually deteriorated with complete hearing loss in 2015. At this time, an MRI scan showed a lesion completely filling the cochlea.The tumor was removed via transmeatal subtotal cochleostomy. The cochlea was partially reconstructed with cartilage and fascia. A cochlea implant dummy electrode was in...
Source: HNO - Category: ENT & OMF Tags: HNO Source Type: research
Abstract Animal models have demonstrated that tinnitus is a pathology of dysfunctional excitability in the central auditory system, in particular in the dorsal cochlear nucleus (DCN) of the brainstem. We used a murine model and studied whether acoustic over-exposure leading to hearing loss and tinnitus, affects long-term potentiation (LTP) at DCN multisensory synapses. Whole cell and field potential recordings were used to study the effects on release probability and synaptic plasticity, respectively in brainstem slices. Shifts in hearing threshold were quantified by auditory brainstem recordings, and gap-induced ...
Source: Experimental Neurology - Category: Neurology Authors: Tags: Exp Neurol Source Type: research
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