Marco Manfrin

The effects of endolymphatic and perilymphatic pressure changes on resting and mechanically evoked responses were studied in isolated posterior semicircular canals of the frog. The results demonstrated that ampullar receptors are extremely sensitive to hydrostatic pressure changes (0.25 mm H2O were sufficient to produce distinct changes), being inhibited by endolymphatic pressure increases and facilitated by perilymphatic ones. Intracellular recordings from single afferent axons showed that the effects of hydrostatic pressure result from a modified transmitter release from the synaptic pole of the hair cells. Unlike resting activity, mechanically evoked activity was always depressed in the presence of a hydrostatic pressure. This indicates that the sensitivity of ampullar receptors to mechanical stimuli, i.e. the gain of the conversion process, is maximal when no pressure is present between the inner and the outer fluid. The possible action of hydrostatic pressure on vestibular receptors is discussed.

Background:The diagnosis of benign paroxysmal positional vertigo (BPPV) involving the lateral semicircular canal (LSC) is traditionally entrusted to the supine head roll test, also known as supine head yaw test (SHYT), which usually allows identification of the pathologic side and BPPV form (geotropic vs. apogeotropic). Nevertheless, SHYT may not always allow easy detection of the affected canal, resulting in similar responses on both sides and intense autonomic symptoms in patients with recent onset of vertigo. The newly introduced upright head roll test (UHRT) represents a diagnostic maneuver for LSC-BPPV, supplementing the already-known head pitch test (HPT) in the sitting position. The combination of these two tests should enable clinicians to determine the precise location of debris within LSC, avoiding disturbing symptoms related to supine positionings. Therefore, we proposed the upright BPPV protocol (UBP), a test battery exclusively performed in the upright position, includi...

Purposes To primarily evaluate MRI-induced effects for Ultra 3D cochlear implantation in human cadavers in terms of artifact generation and MR image quality. Methods Three human cadaveric heads were submitted to imaging after unilateral and bilateral cochlear implantation. The 1.5 T MR examination protocol was chosen in accordance with our institutional protocol for the assessment of brain pathology. The maximal signal void size was measured according to each sequence and plane. Two experienced neuro-radiologists and one experienced otoneurosurgeon independently evaluated the MR image quality findings. A 4-point scale was used to describe the diagnostic usefulness of 14 brain structures. Results Shape and size of the artifacts were found to be highly related to MRI sequences and acquisition planes. MRI sequences and processing algorithms affected the ability to assess anatomical visibility. Image quality appeared either high or assessable for diagnostic purposes in 9 out of 14 of th...

Il monitoraggio intraoperatorio e una tecnica che consente di controllare la funzionalita del nervo facciale e di ottenere informazioni in tempo reale sull’insorgenza di eventuali traumatismi nel corso di un intervento chirurgico, dove il chirurgo viene avvisato da un allarme sonoro. Dopo un breve accenno al percorso storico che ha portato a tale tecnica, questo lavoro vuole sottolinearne l’importanza ed i relativi vantaggi; vengono inoltre analizzate le caratteristiche tecniche, gli interventi in cui e indicato applicarlo ed i limiti presentati da questo tipo di metodica.

SUMMARY In recent years the increasing development of hearing devices has led to a critical analysis of the standard methods employed to evaluate hearing function. Being too far from reality, conventional investigation of hearing loss based on pure-tone threshold audiometry and on mono/disyllabic word lists, presented in quiet conditions, has been shown to be inadequate. A speech-in-noise test using a roving-level adaptive method employs target and competing signals varying in level in order to reproduce everyday life speaking conditions and explore a more complete sound range. Up to now, only few roving-level adaptive tests have been published in the literature. We conducted a rovinglevel adaptive test in healthy Italian adults to produce new normative data on a language of Latin origin.

Con questo lavoro si vuole presentare l’andamento clinico del paziente affetto dalla Sindrome di Alport, descrivendone la sintomatologia con particolare approfondimento all’ambito otorinolaringoiatrico. Inoltre si discute della terapia con l’intervento chirurgico di impianto cocleare, i benefici e l’utilita che si possono raggiungere anche con l’ausilio delle tecniche riabilitative. Per una miglior analisi viene presentato un caso della nostra Clinica Otorinolaringoiatrica, sottolineando il fatto che attualmente non sono presenti in letteratura studi clinici o singoli casi di impianto cocleare effettuato in pazienti affetti da Sindrome di Alport.

La Sindrome di Epstein e uno dei quadri clinici di quelle che vengono definite patologie correlate a deficit di MYH9, un gene che codifica per una miosina non muscolare. Le caratteristiche cliniche sono una macrotrombocitopenia severa dalla nascita, una glomerulonefrite progressiva fino all’insufficienza renale cronica e una sordita neurosensoriale cocleare sviluppata nell’adolescenza. Quest’ultima riguarda soprattutto le alte frequenze ed e di grado severo/profondo, per cui porta all’esclusione dal parlato. I pazienti affetti da questo tipo di sordita non possono trovare sufficiente beneficio nell’utilizzo delle protesi tradizionali, per cui devono ricorrere all’intervento chirurgico di impianto cocleare. Questo sistema pone una serie di elettrodi all’interno della coclea per stimolare in modo diretto il nervo acustico, ristabilendo cosi una percezione sonora che permette una riabilitazione uditiva. Con questo lavoro si vuole presentare il profilo clinico di questa rara patologia c...

SUMMARY Introduction The retrosigmoidal (RS) placement of the Bonebridge system (BB) has been advocated for cases of unfavourable anatomical or clinical conditions which contraindicate transmastoid-presigmoidal positioning. However, these disadvantageous conditions, combined with the considerable dimensions of the implant, may represent a challenge, especially for surgeons with no skull base experience. Moreover, the literature reports only limited experience concerning RS implantation of the BB system. Methods A multicentre, retrospective study was conducted to analyse the surgical and functional outcomes of a wide population of patients undergoing RS placement of the BB system by means of a surgical technique specifically developed to overcome the intraoperative issues related to this surgery. Twenty patients with conductive or mixed hearing loss and single sided deafness were submitted to RS implantation of the BB system. Results Audiological assessment concerning the measurement...

Speech in noise test is a new type of hearing test that simulates an everyday listening situation in a very realistic way: in order to achieve this goal sentences and masking noise are sent simultaneously to the patient. This makes it possible to obtain reliable information about the level of intelligibility of a patient, that must be considered to make the best choice, whether it is diagnostic or therapeutic. A clinical trial was conducted from June 2011 at our institution: 50 normoacusic volunteers were submitted to a Speech in noise test and it has been obtained a range of values indicative of the level of normoacusia regard to this new kind of test.

Isolated Eustachian tube osteomata are a very rare entity indeed, with the last case being reported in 1979. We describe a case of the otoscopic finding of a blue-yellowish eardrum and successive identification by computed tomography scan of an osteoma localized in the Eustachian tube. Clinical presentation and diagnostic and therapeutic phases in comparison with the literature will be discussed.

In response to passive high-acceleration head impulses, patients with low vestibulo-ocular reflex (VOR) gains often produce covert (executed while the head is still moving) corrective saccades in the direction of deficient slow phases. Here we examined 23 patients using passive, and 9 also active, head impulses with acute (< 10 days from onset) unilateral vestibular neuritis and low VOR gains. We found that when corrective saccades are larger than 10°, the slow-phase component of the VOR is inhibited, even though inhibition increases further the time to reacquire the fixation target. We also found that 1) saccades are faster and more accurate if the residual VOR gain is higher, 2) saccades also compensate for the head displacement that occurs during the saccade, and 3) the amplitude-peak velocity relationship of the larger corrective saccades deviates from that of head-fixed saccades of the same size. We propose a mathematical model to account for these findings hypothesizing tha...

Surgical management of Ménière's disease (MD) is recommended in case of medical and intratympanic treatment failures. Translabyrinthine vestibular nerve section has been considered the gold standard for denervation procedures in order to control vertigo attacks, although at the cost of sacrificing residual hearing. To the best of our knowledge, no work has been published with regard to a group of patients submitted to translabyrinthine vestibular neurectomy and simultaneous cochlear implant for MD. The aim of the present study was to assess the effectiveness of translabyrinthine vestibular nerve section and simultaneous cochlear implant in a prospective study. All adult patients (over 18 years of age) with a diagnosis of intractable unilateral definite MD and useless residual hearing function were enrolled after medical and intratympanic treatment failures. Pre- and postoperative otoneurological evaluation concerned: frequency of vertigo attacks, head impulse test and caloric testing, pure tone average and speech perception audiometry in quiet conditions, tinnitus handicap inventory test, functional level scale and rate of vertigo control, dizziness handicap inventory test, and MD patient-oriented severity index. At least 6 months of follow-up were needed to be enrolled in the study. Four patients were included in the study. Translabyrinthine vestibular nerve section and simultaneous cochlear implant seemed to considerably improve the disabling effects of MD, achieving a good control of vestibular symptoms (mean pre/postoperative vertigo attacks per month: 16.5/0), resolving hearing loss (mean pre/postoperative pure tone average in the affected ear: 86.2/32.5 dB), improving the tinnitus (mean pre/postoperative tinnitus handicap inventory test: 77.2/6), and finally increasing the overall quality-of-life parameters. In our preliminary report, translabyrinthine vestibular nerve section and simultaneous cochlear implant showed encouraging results in order to definitively control both vestibular and cochlear symptoms during the same therapeutic procedure.

The head impulse test (HIT) is nowadays recognized as the gold standard for clinical testing of the angular vestibulo-ocular reflex (VOR). By imposing unpredictable, abrupt head rotations in canal pairs' planes it aims at unveiling the dysfunction of the semicircular canal towards which the head is rotated based on Ewald's II law. Functional testing of the VOR aims at assessing the ability of the reflex to stabilize gaze in space and thus allow clear vision during head movements. The HIT device (HITD) approach exploits impulsive head rotations spawning a range of angular accelerations while requiring subjects to identify optotypes briefly displayed on a screen. Here we also recorded eye movements, so that the evaluation of the individual subject is based both on the VOR gain and on the percentage of correct answers with respect to a population of controls. Here we used the HITD to study 14 patients suffering from vestibular neuritis and 7 of those were re-tested after three ...

The effects of hypotonic and hypertonic solutions (the normal value was 240 mOsm) on posterior canal resting and evoked discharge were studied in isolated labyrinth preparations. Hypotonic solutions (60-180 mOsm) were obtained by reducing the perilymphatic NaCl content. Hypertonic solutions (300-420 mOsm) were obtained by adding to normal perilymphatic solutions suitable amounts of NaCl, glucose, sucrose, glycerol, mannitol and urea. The results demonstrated that any kind of receptor activity was inhibited by hypotonic solutions. On the contrary, hypertonic solutions produced different effects on resting and evoked activity. The resting discharge was, with the exception of urea, constantly increased whereas the evoked responses were constantly decreased by all the hypertonic solutions tested. The possible effects of media with changed osmolarity in Meniere's patients is also discussed.

La vertigine e l’instabilità sono sintomi molto comuni nella popolazione la cui prevalenza è stimata tra il 20 e il 56%. L’obiettivo del nostro lavoro è stato quello di determinare la prevalenza di questi sintomi in una popolazione di 2672 soggetti. È stato somministrato loro loro un questionario; nella prima parte sono stati richiesti i dati demografici e se avessero mai sofferto di vertigine o instabilità nella loro vita. L’età media del campione è stata di 48,3 ± 15 anni, il 46,7% erano maschi. Sul totale della popolazione 1077 (40,3%) hanno riferito di aver sofferto di vertigine o instabilità nella loro vita, con un primo episodio occorso all’età di 39,2 ± 15,4 anni. Nella seconda parte del questionario sono state indagate le caratteristiche delle vertigini (età del primo episodio, il tipo di vertigine, presenza di più episodi, esacerbazione posizionale della vertigine, presenza di sintomi cocleari infine la presenza di cefalea da moderata o severa nel corso della vita e le sue ...