Francesca Ravecca

Progressive sensorineural hearing loss in childhood

Prevalence of progressive sensorineural hearing loss in childhood seems to be extremely variable, as percentages reported range from 4 to 30%. Differences in the criteria employed for identifying the deterioration, in the groups of patients, and the age range, could explain this wide range of reported figures. The etiology of the progressive sensorineural hearing loss in infants can be hereditary or acquired. Hereditary causes are divided into syndromic and non-syndromic, whereas the acquired causes include congenital or acquired infection (syphilis, cytomegalovirus, rubella virus and toxoplasma infections, bacterial meningitis and acquired viral infections) and congenital inner ear anomalies (Mondinis dysplasia, large vestibular aqueduct, large cochlear aqueduct). Other acquired causes such as disorders of the metabolism, chronic use of ototoxic drugs, autoimmune diseases, perilymphatic fistula and head or acoustic trauma are less common. The age of onset of deterioration shows a great variability because even the congenital hearing losses may occur late after birth. The progressive evolution seems to be binaural in most patients, but more commonly it presents interaural differences, and when the hearing deficit is initially asymmetrical the deterioration is usually greater in the ear which appeared least affected in the first audiogram. Furthermore, at the different frequencies, there is a tendency to a greater deterioration at the frequencies initially least affected, but some authors are not in agreement because they report a uniform pattern of progression in the range of 0.5 to 4 kHz with no modification of the audiometric shape in most of the examined patients.

Acoustic neuroma: correlations between morphology and otoneurological manifestations

Forty-two patients with acoustic neuroma (AN) were studied to determine whether different types of neuroma could be correlated with specific signs and symptoms of the disease. Based on gadolinium-enhanced TI-weighted MRI sequences, the 42 cases of AN could be divided into three groups, either by size (small: 11.9%, medium: 50%, and large: 38.1%) or by site of origin of the tumour (lateral: 16.7%, intermediate: 69%, and medial: 14.3%). Relations were found between the size and the site of origin of the neuromas and certain clinical, audiological and vestibular findings. The clinical presentation seemed to vary with the site of origin and the size of the tumour: patients with lateral neuromas generally had small tumours, sometimes only located in the internal auditory canal (IAC), and presented early subjective hearing loss while patients with medial neuromas had larger tumours which grew without causing significant audiological symptoms. Normal hearing function was seen only in the patients with medial ANs; however, a significant relation between the size or the site of origin of the AN and the average hearing threshold was not demonstrated. The sensitivity of the stapedial reflex test (SR) was higher for lateral ANs. Anomalies in the brainstem auditory evoked potentials (BAEPs) did not seem to be related to either the size or the site of origin of the AN. The vestibular tests demonstrated a higher frequency of central vestibular involvement in the large tumours, while normal function was more frequent in the lateral tumours. In the group studied the combination of BAEPs and vestibular tests allowed us to identify all the ANs with an optimal level of sensitivity.

Distal renal tubular acidosis associated with isolated large vestibular aqueduct and sensorineural hearing loss.

Distal renal tubular acidosis (dRTA) is characterized by a defect in urinary acidification with various degrees of metabolic acidosis; it can be inherited either as an autosomal dominant trait or as a recessive trait. The recessive form is associated in about one third of cases with progressive sensorineural hearing loss (SNHL). We performed a neuroradiological study in 3 consecutive unrelated pediatric patients affected with sporadic dRTA and progressive SNHL that disclosed an enlarged vestibular aqueduct (VA) and endolymphatic sac (ES) in each. The presence of an enlarged VA in our patients with dRTA and SNHL could contribute to the development, or at least the progression, of the hearing impairment. We suppose that the same molecular defect present in both the kidney and the inner ear could be the cause of dRTA and of the development of the enlarged VA and ES.

Progressive sensorineural hearing impairment in systemic vasculitides.

OBJECTIVES A large series of patients with various forms of systemic vasculitis were evaluated to analyze the prevalence of progressive sensorineural hearing loss (PSNHL), its characteristics and evolution, and the effects of different therapies. METHODS A total of 673 patients were questioned about the presence of subjective audiovestibular disturbances. Of those, 80 subjects complained of subjective audiological disturbances and underwent oto-rhino-laryngological and audiovestibular evaluation. Those patients with progressive hearing impairment were selected and studied carefully. RESULTS A PSNHL was observed in 14 patients. The hearing loss was bilateral and asymmetrical in most subjects. It was usually sensorineural, with a cochlear lesion. Unsteadiness was the most frequent vestibular symptom and canal paresis or palsy was noted in most patients. Systemic corticosteroids and cyclophosphamide were useful treatments; in unresponsive patients, satisfactory results were obtained with methotrexate and plasma exchange. CONCLUSIONS PSNHL is a rare complication of systemic vasculitis, but occasionally is one of the presenting symptoms. Its clinical evolution is variable, but timely clinical assessment and treatment can positively affect prognosis.

Imaging Evaluation in Otosclerosis: Single Photon Emission Computed Tomography and Computed Tomography

Objectives: The aim of our study was to demonstrate the utility of diphosphonate bone single photon emission computed tomography (SPECT) in diagnosing otosclerosis and to correlate the findings from SPECT with age, gender, and sensorineural hearing loss. We also evaluated the ability of high-resolution computed tomography (HR-CT) in detecting otospongiotic and otosclerotic foci and correlated the HR-CT findings with the SPECT results. Methods: Seventy-three subjects with surgically confirmed otosclerosis underwent SPECT, and 45 of the 73 patients also underwent HR-CT of the petrous bones. Results: In the patient sample examined in this study, SPECT demonstrated a sensitivity of 95.2% and a specificity of about 96.7%. By correlating the SPECT findings, we found an inverse relationship between bone radioactivity and age (ie, greater disease activity in younger patients) and a direct relationship between bone radioactivity and the severity of sensorineural impairment in younger patients. In the 45 patients who also underwent HR-CT, the sensitivity of HR-CT (58%) was lower than that of SPECT, and the comparison between SPECT activity and the HR-CT findings (fenestral or retrofenestral type) demonstrated a statistically significant correlation between the morphological finding of bone demineralization (pericochlear foci) and a high uptake index. Conclusions: The use of SPECT seems to be highly effective in differentiating normal from pathological petrous bone. It also provides a quantitative evaluation of disease activity and shows a significant correlation with bone demineralization revealed by HR-CT.

Far advanced otosclerosis: stapes surgery or cochlear implantation?

OBJECTIVE Nowadays, two surgical alternatives are to be considered in patients with far advanced otosclerosis: stapedectomy and cochlear implantation. The aim of this study was to analyze and compare the hearing and communicative results obtained in two groups of patients affected with far advanced otosclerosis, who were treated with the two different surgical procedures, to assess the proper surgical approach for these patients. DESIGN Retrospective study. SETTINGS University hospital and referral audiologic centre. METHODS We submitted 11 adult patients, affected by far advanced otosclerosis and exhibiting unsatisfactory communicative abilities with hearing aids, to two different procedures: 5 to cochlear implantation, and 6 to stapedotomy followed by hearing aid fitting. The benefits afforded by the two procedures were assessed by means of pure-tone audiometry and speech audiometry in an open field and by means of a speech perception test. MAIN OUTCOME MEASURES Hearing and communicative outcomes, measured 1 year after intervention. RESULTS The results achieved in the patients subjected to stapedotomy were unpredictable and variable: very good in some cases but unsatisfactory in others, whereas those who had cochlear implantation all achieved satisfactory results with regard to speech recognition. CONCLUSIONS Patients who underwent cochlear implantation achieved better hearing and communicative results than those who underwent stapedotomy. Even if the number of patients reported in this study is too small to provide definitive results, and despite the reportedly better results afforded by cochlear implantation, in our opinion, correction of far advanced otosclerosis should first be attempted via stapedotomy, and cochlear implantation should instead be reserved for cases in which stapedotomy is unsuccessful or for which imaging techniques unequivocally reveal a fenestral or cochlear obstruction.

LARGE VESTIBULAR AQUEDUCT IN DISTAL RENAL TUBULAR ACIDOSIS: High-resolution MR in three cases

High-resolution MR of the inner ear performed in 3 consecutive pediatric patients affected by distal renal tubular acidosis (dRTA) and progressive sensorineural hearing loss (SNHL) revealed enlarged vestibular aqueducts (LVA) (bilateral in 1 case and unilateral in 2). LVA is associated to sporadic, progressive SNHL, often secondary to minor head trauma and activities involving the Valsalva maneuver. We believe that the presence of LVA may have contributed to the onset of SNHL and its progression in our patients, and therefore want to stress the importance of morphological studies of the inner ear in patients affected by dRTA and SNHL.

Single photon emission computed tomography in otosclerosis: Diagnostic accuracy and correlation with age, sex, and sensorineural involvement

Objective To evaluate the accuracy of single photon emission computed tomography (SPECT) in detecting otospongiotic foci of the labyrinthine capsule in otosclerotic patients and to correlate the metabolic patterns detected by SPECT with age, sex, and sensorineural hearing loss. Patients and Methods Thirty-six patients with surgically confirmed otosclerosis and a control group of 12 subjects with normal hearing; each subject underwent SPECT study of the skull with 99mtechnetium-diphosphonate (99mTc-medronate). Statistical analysis of the results was performed by use of the Mann-Whitney U test. Results SPECT seemed to be very sensitive in differentiating otospongiotic bone from normal bone; in the affected group, only 2 of 72 ears yielded false-negative results (sensitivity 97.2%). Moreover, in the otosclerotic patients, the mean petrosa uptake value was higher than in the control group, a difference that was statistically significant (p < 0.0001). Main Outcome Measures Regarding uptake in relation to patient age, an inverse relationship was observed between increased metabolic activity and age: the mean uptake index in the younger patients was significantly higher than that in the older patients (p < 0.0001). By contrast, no statistically significant differences were found between men and women (p = 0.1519). Comparison of SPECT alterations with bone conduction thresholds revealed a statistically significant correlation (p = 0.0002 and p = 0.0010) between increased metabolic bone activity and sensorineural involvement only in the younger group of otosclerotic patients. Conclusions Diphosphonate bone SPECT is the only functional method that allows in vivo evaluation of disease activity, and it was highly sensitive in detecting otosclerosis. SPECT can be considered useful in the diagnosis of otosclerosis that is difficult to recognize, such as cochlear otosclerosis and far-advanced otosclerosis, and it could also find a place in evaluating the efficacy of medical therapy for otosclerosis.

Correlations Between Virtual Endoscopy and Otoendoscopy of the Retrotympanum

The aim of this study was to examine the anatomical landmarks of the retrotympanum using two different techniques, virtual endoscopy (VE) and fiberoptic endoscopy, and to correlate the results furnished by the two methods. Ten otosclerotic patients who were due to undergo stapedectomy were scanned using high-resolution spiral CT. Selected CT datasets were processed with Navigator 2.0 software to obtain virtual endoscopic views of the retrotympanum. Subsequently, during the surgical procedure, fiberoptic endoscopy was performed with 2.7-mm 0° and 30° rigid endoscopes. The ability of the two imaging methods to identify specific anatomical structures was then compared. In all cases the pyramidal eminence, pyramidal crest and sinus tympani were clearly identified in both VE images and otoendoscopy recordings, while fiberoptic endoscopy seemed to be less satisfactory than VE for studying the facial sinus, sinus of Proctor and fossula of Grivot. The two techniques proved to be equally sensitive for visualizing the ponticulus and subiculum, while the stapedius tendon could be visualized only by means of fiberoptic endoscopy. Overall, VE imaging appears promising for rendering important anatomical details of the retrotympanum, allowing identification of osseous landmarks and exploring recesses that are difficult to visualize via otoendoscopy.