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Biomedical subjects

V Colletti

Publications and source records attributed to V Colletti.

16 recordsLinked to original sources

Reduced active protection to the cochlea during physical exercise.

The present investigation was designed to evaluate whether dynamic physical exercise is able to modify stapedius reflex (SR) activity and, as a consequence, to influence the amount of temporary threshold shift (TTS). Experimental subjects were 10 normal-hearing male volunteers, aged 27-34 years (mean 30.8). SR parameters in the time-domain were assessed before, during and after submaximal exercise test, performed for 10 min on an ergometer cycle at 50% of maximum work capacity. The same parameters were also investigated in the absence of exercise, at time-matched intervals. In addition, the combined effect of noise and exercise was studied. The outcome of the investigation indicates that dynamic physical exercise depresses the SR and potentiates noise-induced TTS. The mechanisms underlying the present findings are discussed.

Adult

Surgery vs. natural course of chronic otitis media. Long-term hearing evaluation.

The present paper investigates the hearing function in chronic otitis media vs. tympanoplasty in 41 patients with bilateral chronic otitis media, operated on unilaterally. The auditory evaluation was performed immediately before surgery and at a follow-up time varying from 1 to 14 years (mean = 5 years). Results were expressed in terms of relative gain (in respect to preoperative hearing levels) and total gain (in comparison with the contralateral ear). A progressive reduction of the hearing threshold as a function of time was observed both in non-operated and operated ears. The comparison of the threshold shifts between the two ears indicated that the long-term functional results of tympanoplasty can be considered quite satisfactory.

Adult

Effect of sodium fluoride on early stages of otosclerosis.

The present investigation evaluates the effectiveness of NaF treatment in modifying the natural course of subclinical otosclerosis, as monitored by the stapedius reflex. The study was carried out on 128 relatives of patients suffering from surgically confirmed footplate otosclerosis. The diagnosis of subclinical otosclerosis was made on the basis of presence of the on-off effect. One group of subjects was treated with NaF in doses ranging from 6 to 16 mg according to age. The treatment lasted 2 years. A second group served as a control. Changes in stapedius reflex morphology were evaluated at 1, 2, and 5 years from the onset of treatment. The investigation demonstrated that NaF has a stabilizing effect on early otosclerosis. This drug, in fact, arrests the disease process in more than 60 percent of ears at the 2-year follow-up and in more than 50 percent at 5 years. A program of secondary prevention of otosclerosis by NaF is suggested.

Adolescent

NaCl deposition in the vestibule: a simple, safe, and effective method of cochleovestibular deafferentation.

Chemical cochleovestibular deafferentation was performed on 21 individuals suffering from disabling vertigo caused by unilateral Menière's disease. Patients ranged in age from 31 to 60 years, with a mean age of 47.4. The duration of the disease spanned 3 to 14 years, mean duration being 5.8 years. Subjects displayed pure-tone thresholds higher than 50 dB HL in the affected ear and better than 25 dB HL in the contralateral ear. The frequency of vertigo, evaluated during the 6 months before surgery, ranged from 1 crisis a month to 2 a week; mean duration of crises was 1 to 6 hours. Medical treatment had failed in all cases. The surgical procedure consisted of stapedectomy, deposition of several crystals of NaCl in the vestibule, and sealing of the oval window with a vein graft. Postoperative recovery was rapid, allowing patients to be discharged 4 to 6 days after surgery. All subjects reported complete relief of vertigo. Tinnitus disappeared in 47.6% of the subjects, was reduced in 33.3% and unchanged in 19.1%. Most patients complaining of aural fullness preoperatively reported relief of this symptom after surgery. The outcomes of the present study indicate that NaCl deposition into the vestibule is a simple, safe, and effective technique of cochleovestibular deafferentation.

Adult

Investigation of the long-term effects of unilateral hearing loss in adults.

The recent audiological literature has put forward the hypothesis that children with unilateral hearing loss (UHL) show delays in educational achievement and academic progress and some behavioural difficulties. This motivated us to investigate the long-term effects of monaural auditory deprivation in a group of adults who had suffered from UHL since childhood. A group of subjects, ranging in age from 30 to 55 years, suffering from sensorineural UHL since early childhood, has been examined for psychosocial and psychoacoustical effects and statistically compared with a control group matched for age and sex. We prepared a questionnaire directed to provide some objective and subjective indices of psychosocial disability and handicap. Some questions were directed towards specific aspects of auditory function; others assessed the degree of education and the type of working performed. The results of the investigation confirmed the superiority of binaural v. monaural hearing. This was clearly demonstrated in psycho-acoustical performance in sound localisation, speech recognition in noise, together with the appreciation of music. On the other hand, the parameters concerned with educational, social and employment achievement did not support the existence of any significant difference between binaurally and monaurally hearing subjects. The data obtained in the present study thus do not support the existence of non-auditory, long-term effects of monaural hearing loss.

Achievement

Stapedotomy with and without stapedius tendon preservation versus stapedectomy: long-term results.

Stapedectomy and stapedotomy are presently the techniques utilized in the surgical treatment of otosclerosis. The technique of choice at the ENT Department of the University of Verona has changed from stapedectomy to stapedotomy with and without stapedius tendon preservation. From January 1975 to December 1985, 805 ears were operated on for otosclerosis at our department. A statistical analysis has been performed on three groups of patients (stapedectomy, stapedotomy without and with stapedius tendon preservation) at short and long term. The results suggest that stapedotomy with stapedius tendon preservation should be the preferred surgery in the treatment of otosclerosis.

Adolescent

Minisculptured ossicle grafts versus implants: long-term results.

The present study deals with 832 ossicular chain reconstruction procedures performed in 655 patients from January 1975 to December 1985. Homograft and autograft ossicles, intraoperatively minisculptured according to personal or traditional techniques, were used in 626 ears (75.2%). In the remaining 206 ears Plastipore or Proplast total or partial ossicular replacement prostheses were employed. The functional hearing results are evaluated as a function of length of follow-up, techniques used, and preoperative diagnosis. Short-term hearing gain is satisfactory and very similar for both ossicles and implants. Long-term observation however, shows, a progressive and systematic reduction of the postoperative hearing gain for both treatments. The long-term deterioration of hearing levels in ears receiving implants is more evident and dramatic than that observed in ears with ossicles. The difference is statistically significant. The causes of failure are evaluated based on both clinical data and findings at revision surgery.

Adolescent

Tympanomety from 200 to 2000 Hz probe tone.

Previous investigations have shown that the probe tone frequency is the main factor in determing the shape of the tympanogram. These had, however, been limited up to 800 Hz. In the present paper, a multifrequency investigation (from 200 to 2000 Hz) has been performed on 72 ears with different pathophysiological conditions of the middle ear. From the analysis of the result some new critical aspects of tympanometry emerge. The multifrequency tympanometric investigation proves to be, according to our experience, a far more sensitive method for checking small changes in the transmission characteristics of the tympano-ossicular system than the monofrequency traditional analysis. In this connection, the technique seems to furnish a simple and reliable method for discriminating between stiffness versus mass-controlled systems.

Audiometry

Methodologic observations on tympanometry with regard to the probe tone frequency.

Changes in the tympanogram shape in the frequency range from 200 to 2000 Hz have been investigated. The tympanogram undergoes, as the probe tone frequency rises, characteristic morphologic modifications which are consistently observed both in normals and in some middle ear disorders. The only exception to this regular behavior is the pathological picture in which the structure or the dynamic of the tympano-ossicular system is remarkably anomalous (cholesteatoma and otitis media) where there are flat tympanograms. It is suggested that the frequency interval at which one of the characteristic tympanometric configurations appears in the element capable of furnishing a diagnostic tool for differentiating pathophysiologic conditions of the middle ear.

Air Pressure

An experimental study of inner ear pathology due to NaCl on the round window.

An animal experiment was performed to evaluate structural and ultrastructural changes to the inner ear as a result of placing 3-4 crystals of reagent grade sodium chloride (NaCl) on the round window membrane. Chinchillas were sacrificed at 8 and 24 hours after treatment and the cochlear and vestibular tissues were examined by light microscopy and scanning electron microscopy. Inner ear pathology consisted of destruction of both sensory and supporting cells in the basal turn of the organ of Corti, atrophy of the stria vascularis and alterations to the otoconia and the maculae and ampullae of the vestibular system. This study demonstrates that NaCl in the middle ear does not provide a model for Meniere's disease as previously suggested by Arslan. It may, however, be utilized in the destructive treatment of selected inner ear disorders.

Animals

Experimental cochleo-vestibular deafferentation with NaCl.

An animal experiment was performed to evaluate structural and ultrastructural changes in the inner ear as a result of placing 10-12 crystals of reagent grade sodium chloride (NaCl) in the vestibule. Chinchillas were sacrificed 8 and 24 hours after treatment and the cochlear and vestibular tissues were examined by light microscopy and scanning electron microscopy. Inner ear pathology consisted of extensive degenerative changes in morphology of all sensory structures of the inner ear. The extent of these pathological changes supports the idea of eventual total deafferentation of the inner ear.

Afferent Pathways

Chemical labyrinthectomy with NaCl. Menière's disease treatment with deposition of NaCl in the vestibule.

Thirteen individuals with unilateral Menière's disease were chosen for experimental chemical labyrinthectomy. All subjects suffered from frequent attacks of disabling vertigo and had mean pure-tone thresholds greater than 50 dB in the affected ear. The surgical procedure was similar to stapedectomy; after removal of the stapes, several crystals of NaCl were placed in the vestibule which was then covered with a vein graft. Postoperative recovery was rapid, allowing patients to be discharged 4-6 days after surgery. Of the 13 subjects, all reported complete relief from vertigo. Tinnitus was cured in 7 subjects, greatly improved in 4 and unchanged in 2. Most patients complaining of aural fullness preoperatively reported relief from this symptom following surgery. To date (up to 4 years post-surgery) none of the subjects has shown any significant alteration in audiologic or vestibular function in the contralateral ear. The ease and safety of this procedure make it an attractive method when cochleovestibular deafferentation is indicated.

Adult

Stapedius reflex abnormalities in multiple sclerosis.

Thirteen patients suffering from multiple sclerosis were analyzed by a Madsen ZO 70 electroacoustic bridge connected to an electronystagmograph through an impedance adaptor. Threshold, amplitude, decay and difference limen of intensity (DLI) of the stapedius reflex were examined for the frequencies 500, 1 000, 2 000 and 4 000 Hz. The difference between standard audiometric results and stapedius reflex data stresses the value of reflex measurements in assessing brain stem pathology.

Acoustic Stimulation

Multifrequency tympanometry.

The tympanogram shape has been investigated in 290 patients as a function of probe tone frequency (from 200 to 2000 Hz). As the frequency of the probe tone rises, the tympanogram undergoes characteristic modifications which have been grouped, according to their morphologic similarities, in three classes: V, W and inverted-V shape. These three tympanometric configurations are consistently observed both in normals and in some patients with middle ear disorders. Exceptions to this regular behaviour are the pathological pictures of the middle ear in which the structure or the dynamics of the tympano-ossicular system are significantly altered (massive tympanosclerosis, glue ear and cholesteatoma). The frequency interval at which the characteristic tympanometric configurations appear is the most important factor for differentiating pathophysiologic conditions of the middle ear.

Audiometry

Stapedius reflex in the monitoring of NaF treatment of subclinical otosclerosis.

Stapedius reflex testing was utilized to monitor the progression of subclinical otosclerosis and evaluate the efficacy of NaF treatment in stabilizing the disease process. The investigation was performed on 93 relatives of patients suffering with surgically confirmed otosclerosis. Subjects were divided into two groups. The first group was treated with NaF in doses ranging from 6 to 16 mg in relation to age. The treatment lasted two years. The second group served as control subjects. Before entering the research, all subjects presented reflex abnormalities represented by a partial or complete on-off effect in one or both ears. Changes in stapedius reflex morphology (from partial to complete on-off and from complete on-off to absence of the reflex) were evaluated at 1 and 2 years. The groups had not developed significant differences at 1 year. At 2 years, the incidence of stable stapedius reflex findings was 91.5% in the treated ears and 77% in the control group. The difference is significant (p less than 0.05) and indicates a stabilizing effect of NaF on the disease process.

Acoustic Impedance Tests