Influence of surgical technique on residual cholesteatoma location and prevalence

OBJECTIVE

Compared to canal wall up (CWU) tympanoplasty, canal wall reconstruction (CWR) allows better visualization of cholesteatoma extension. The canal wall up approach provides good functional outcomes, but with higher rates of residual cholesteatoma. The aim of this study was to compare residual cholesteatoma prevalence and location between the two approaches.

METHOD

Subjects were adult patients with residual cholesteatoma following CWU or CWR surgery between January 1, 2010 and December 31, 2015. During this period, 94 patients underwent CWU and 71 CWR; 22 presented with residual cholesteatoma: 16 after CWU (R-CWU group) and 6 after CWR (R-CWR group).

RESULTS

There was no significant inter-group difference in residual cholesteatoma prevalence: 17% after CWU, 8.4% after CWR. Locations comprised: 13 (81%) in the attic, 9 (56%) in the tympanic cavity and 4 (25%) in the mastoid in the R-CWU group, and 6 (100%) in the attic in the R-CWR group. There were significantly fewer tympanic cavity locations after CWR compared to CWU (P=0.046).

CONCLUSION

Residual cholesteatoma prevalence did not significantly differ between the CWU and CWR approaches. The most frequent location was the attic; significantly more locations were in the tympanic cavity with the CWU approach. These findings are important for surgeons and neuro-radiologists during follow-up.

Electrophysiological exploration of hearing

Electrophysiologic hearing tests have been developed since the 1960s to determine hearing thresholds objectively. They are now implemented in newborn hearing screening. While they determine thresholds, interpretation requires subjective pure-tone and speech audiometry to determine the type of hearing loss. Each examination tests a different anatomic region, enabling the auditory system to be explored from the organ of Corti to the auditory cortex. Thus, the various objective audiometric examinations are complementary.

Cancer of the external auditory canal

INTRODUCTION

Cancer of the external auditory canal is a rare tumour with an annual incidence of one per one million inhabitants. The objective of this study was to evaluate the 5-year overall survival and disease-free survival rates in a series of patients with carcinoma of the external auditory canal and to compare our results concerning the clinical presentation, management and survival with those of the literature.

PATIENTS AND METHOD

Ten patients were included in this retrospective, single-centre study over a 20-year period. Data concerning age, symptoms, imaging, TNM stage according to the Pittsburgh classification, histology, management, sequelae, recurrences and survival were recorded.

RESULTS

The mean age of the patients of this series was 60.7 years. Seven patients had a squamous cell carcinoma. The other histological types were undifferentiated carcinoma, adenoid cystic carcinoma and neuroendocrine carcinoma. Staging was based on the Pittsburgh classification with one stage I, one stage III and eight stage IV tumours. Five-year overall survival rates were 100%, 50% and 0%, respectively. The mean 5-year overall survival rate was 35% and the mean 5-year disease-free survival rate was 24%.

CONCLUSION

Carcinoma of the external auditory canal is a difficult diagnosis when the tumour does not present as a fungating mass protruding from the external auditory canal. The Pittsburgh classification was used for TNM staging of these tumours, allowing comparison of our results with those of the literature. The clinical findings and survival rates observed in this study are comparable to those reported in the literature. These tumours are associated with a poor prognosis on the basis of our results and published data.

Minimization of cochlear implant artifact in cortical auditory evoked potentials in children

OBJECTIVES

In congenitally deaf children fit with a cochlear implant, little is known about the maturation of the auditory cortex. Cortical auditory evoked potentials are a useful methodology to study the auditory cortical system of children with cochlear implants. Nevertheless, these recordings are contaminated by a cochlear implant artifact. The objective of this study was to use independent component analysis to minimize the artifact of the cochlear implant to study cortical auditory evoked potentials.

STUDY DESIGN

Prospective study.

METHOD

A total of 5 children ranging in age from 21 to 49 months who were fitted with a cochlear implant for at least 6 months were included in this study. The stimuli were pure tones (750 Hz, 200 ms duration, 70 dB SPL) presented with an irregular interstimulus interval (1000-2000 ms) via loud speakers. The cortical auditory evoked potentials were recorded from 17 Ag-AgCl electrodes referenced to the nose. The peak latency and amplitude of each deflection culminating at the fronto-central and temporal sites were analyzed.

MAIN OUTCOME MEASURES

The P100-N250 peak latencies and amplitudes of the cortical auditory evoked potentials recorded from children fitted with cochlear implants. Scalp map potentials distributions were done for each child for the N250 wave.

RESULTS

The use of independent component analysis permitted to minimize the cochlear implant artifact for the five children. Cortical auditory evoked potentials were recorded at fronto-central and temporal sites. Scalp map potentials distributions for the N2 wave showed activation of temporal generators contralateral at the CI for the five children.

CONCLUSION

This preliminary electrophysiological study confirms the value and the limits of independent component analysis. It could allow longitudinal studies in cochlear implant users to examine the maturation of auditory cortex. It could also be used to identify objective cortical electrophysiological measures to help the fitting of CIs in children.

Lipoleiomyosarcoma of the larynx

BACKGROUND

Lipoleiomyosarcoma is a rare tumor consisting of well-differentiated liposarcoma and leiomyosarcoma. The ear-nose-throat location of lipoleiomyosarcoma has not been previously described.

METHODS AND RESULTS

A 37-year-old man with a dysphagia had a dyspnea after an endoscopy. A large tumor was exteriorized from the man's mouth. The lesion was pedicled to the epiglottis. A histologic examination determined that the tumor was a lipoleiomyosarcoma. MDM2 and CDK4 gene amplification were positive. Due to the risk of recurrence, a second intervention was performed to complete the excision.

CONCLUSION

These tumors develop in cavities slowly and gradually. The treatment of this lesion is surgical with a sufficient resection margin.

Canal wall up tympanoplasty for middle ear cholesteatoma in adults: modeling cartilage

OBJECTIVES

The authors report their experience with a variant cartilage tympanoplasty technique in a canal wall up (CWU) procedure for middle ear cholesteatoma, comparing reliability with other techniques. Functional results are analyzed according to ossicular chain status.

MATERIALS AND METHODS

A retrospective study was performed in adults operated on with CWU tympanoplasty for middle ear cholesteatoma. The surgical technique of "modeling" cartilage is described.

RESULTS

One hundred and nine patients were included (113 procedures). There were four recurrences (3.5%). Mean follow-up was 48 months (range, 24-96 months). In case of normal ossicular chain, postoperative pure-tone average air-bone gap was always less than 20dB, and less than 20dB following myringostapedopexy in 60% of cases with incus destruction.

CONCLUSION

Modeling cartilage is a reliable reconstruction technique to prevent recurrent cholesteatoma, and contributes to the quality of functional results in ossiculoplasty.

[Use of inomeric cement: preliminary results in revision stapes surgery]

OBJECTIVES

Lonomeric cement can be used in revision of stapes surgery to extend the long process of the incus. Indeed, necrosis of the long process of the incus is the most common peroperative finding in this surgery. The objective in this study is to describe the technique and precautions of using SerenoCem, in the reconstruction of the long process of the incus in this indication.

TYPE OF STUDY

Prospective study.

PATIENTS AND METHODS

Consecutive patients with necrosis of the long process of the incus were included from September 2009 to October 2010. We analyzed peroperative findings and evaluated functional results by hearing tests before and three months after surgery.

RESULTS

Nine patients, were included. The preoperative air-bone gap was 29 dB (+/- 14) whereas postoperative air-bone gap was 16 dB (+/- 10). The rate of postoperative air-bone gap closure to within 10 dB was 55% (n = 5). No sensorineural hearing loss occured in this study. Results of revision surgery were more successful when the piston is directly attached to the incus remnant and stabilized with cement, compared to incus reconstruction followed by piston attachment.

CONCLUSION

Ionomeric cement permits reconstruction of the necrosis of the long process of the incus during revision surgery. Preliminary results reveal a significant hearing improvement, without complementary morbidity.

Residual cholesteatoma: prevalence and location. Follow-up strategy in adults

OBJECTIVES

To assess prevalence and location of residual cholesteatoma following closed "canal wall up" tympanoplasty (CWUT). The evolution of follow-up strategy is discussed.

PATIENTS AND METHODS

A retrospective study was run in adults operated on by CWUT for middle-ear cholesteatoma and who had undergone second look surgery and/or postoperative radiology (CT-scan, diffusion-weighted MRI).

RESULTS

One hundred and nine patients (113 ears) underwent the procedure. Mean follow-up was 48 months (range, 24-96 months). Twenty-nine residual cholesteatomas were found (25%), including 11 located in the anterior attic (38%). Follow-up included 77 second look operations (70%), and 71 radiological examinations (62 CT-scans and nine diffusion-weighted MRIs). Second look surgery was without benefit for the patient (no residual, no ossiculoplasty) in one third of cases.

CONCLUSION

Residual cholesteatoma in the anterior attic is a problem in CWUT. When postoperative auditory results are good, second look surgery should not be systematic but guided by high quality imaging.

A review of 89 revision stapes surgeries for otosclerosis

OBJECTIVES

The aim of this study was to identify the causes and the audiometric results of revision surgery following stapedotomies and stapedectomies.

PATIENTS AND METHODS

We retrospectively reviewed a series of 89 revisions after surgery for otosclerosis between 1993 and 2008. Intraoperative findings, causes of failure, and pre- and postoperative audiometric results were noted retrospectively.

RESULTS

The leading causes of failure found intraoperatively included dislocated prosthesis and necrosis of the long process of the incus. The average postoperative air-bone gap was 13 dB. Closure of the air-bone gap to within 10 dB was achieved in 52% of patients.

CONCLUSION

Stapes revisions had less satisfactory results compared with primary procedures in this series. However, certain precautions during initial surgery should decrease the number of stapes surgery revisions.

[Epidermoid cysts of the fourth ventricle mimicking benign paroxysmal positional vertigo]

OBJECTIVE

To report a case of atypical positional vertigo revealing a fourth ventricle epidermoid cyst.

MATERIAL AND METHODS

We report a case of a thirty-year-old woman suffering from positional vertigo with downbeat nystagmus. Except for these symptoms, the physical examination was normal, apart from intermittent headaches. On videonystagmography, a decrease in the average speed of beats and lowered benefits obtained by slow motion were noted. MRI revealed a fourth ventricle epidermoid cyst.

RESULTS

Physical examination may provide several signs that are likely to enable the examiner to distinguish between central nervous system or peripheral vertigos. Atypical symptoms such as a downbeat nystagmus, a lack of reversal in nystagmus beats when returning to the sitting position and a lack of a latency period in vertigo and nystagmus occurrence during the Dix-Hallpike maneuver suggest a central nervous system etiology.

CONCLUSION

With atypical symptoms noted when questioning the patient or during physical examination, a central nervous system etiology should be mentioned and explored with cerebral MRI.

Otosclerosis in children and adolescents: a clinical and CT-scan survey with review of the literature

OBJECTIVE

To assess the role of the CT-scan in the preoperative evaluation of juvenile otosclerosis and to study additional outcome data.

DESIGN AND SETTING

We performed a retrospective case series study from an academic referral hospital using data from 1992 to 2005.

PATIENTS AND METHODS

We selected patients younger than 18-year-old who had undergone primary stapedectomy for otosclerosis among the 10 stapedectomies performed over the study period and analyzed the patients' systematic pre- and post-operative audiograms and CT-scan findings.

RESULTS

For this survey, complete data was available for 7 children, totaling 10 primary stapedectomies for otosclerosis. Their ages at diagnosis ranged from 10 to 17 years. In 4 children, CT-scan demonstrated bilateral findings typical of otosclerosis: poorly calcified foci near the fissula ante fenestram, associated with a hypodense edging surrounding the labyrinthine capsule in 2 children. The youngest patient had no CT-scan abnormalities. Stapedectomy was performed in one case and laser stapedotomy in 9 cases. Seven children were immediately improved following surgery and no postoperative facial palsy or prolonged vertigo was reported. The mean (S.D.) postoperative ABG was 6.5dB (+/-3.7). The mean closure was 19dB (+/-11.2). The mean change in high-tone bone conduction level was 1.8dB (+/-7.5). Six children had a postoperative ABG less than 10dB while in one, the ABG was inferior to 20dB.

CONCLUSION

Preoperative CT-scan is useful for the preoperative diagnosis of otosclerosis in children. The images seen must be distinguished from other footplate pathologies or deformities of the ossicular chain which are often associated with poorer surgical results. This survey provides additional evidence that stapes surgery is an effective procedure for treating juvenile otosclerosis.

[Evolution of facial nerve prognosis in vestibular schwannoma surgery by translabyrinthine approach]

OBJECTIVES OF THE STUDY

To evaluate our results on the postoperative facial function, its pre and preoperative predictive factors, and the application of the surgical technique to lesions of decreasing size.

PATIENTS AND METHODS

A series of 248 patients operated of an unilateral vestibular schwannoma has been reviewed. We have compared the results gathered over two periods corresponding to the evolution of our surgical technique since 1998.

RESULTS

Immediate and 1 year postoperative facial function is significantly better among patients operated after 1998 (satisfactory in 75 and 88% respectively). This trend marked by the improvement of the results since 1998 has to be discussed according to other predictive factors. One of predictive factor is the decrease of the size of the lesion during the same period. The other factors are the hearing level, deafness duration, trigeminal nerve involved, vestibular status and ABR desynchronization.

CONCLUSION

The positive predictive factors are usually correlated with the size of the tumour This implies the necessity of an early diagnosis of the schwannomas. The second predictive factor of the facial function is the use of a soft surgical technique.

Neuro-endocrine adenoma of the middle ear: a case study

Neuroendocrine adenomas are rare tumors, which can appear in the middle ear. Approximately a hundred cases have been reported in the literature. We report the case of a 58-year-old man who consulted for an abnormal sensation of fullness in the right ear. The otoscopic examination showed a retrotympanic tumefaction. The CT scan and MRI of the middle ear demonstrated a well-defined tissue mass without any osteolysis. We performed surgical exeresis by transcanal procedure with a cartilage graft tympanoplasty. Microscopic examination and immunohistochemistry revealed an endocrine adenoma of the middle ear. Neuroendocrine adenomas can develop in a number of different sites. When they appear in the middle ear they usually produce hypoacousia. The otoscopic examination shows non-specific findings with only retrotympanic swelling. Surgical exeresis enables histologic and immunohistochemically analysis of the surgical specimen. The adenoma is composed of two cellular types: neuroendocrine (which closely resemble carcinoid tumors) and glandular. Regular clinical and radiologic follow-up is necessary since recurrence is possible. The formal diagnosis of neuroendocrine adenomas of the middle ear requires histologic and immunohistochemically confirmations since the clinical symptoms are non-specific. Surgical excision with removal of the ossicular chain is the treatment of choice in order to prevent recurrence.

[Intrapetrous cholesteatoma. A retrospective study of seven operated cases]

INTRODUCTION

Intrapetrous cholesteatoma can be recalled with regard of facial paralysis, mixed deafness, cholesteatoma visible under an otoscopy and some characteristic signs in imaging. Its treatment is a real dilemma between its complete exeresis and the preservation of the facial nerve.

METHODOLOGY

We studied the diagnostic and therapeutic aspects of the 7 operated cases from 1994 to 2004.

RESULTS

We noted 5 men and 2 women with an average age of 37.29 years. One case was primitive. We observed 6 translabyrinthic lesions, 5 supralabyrinthic lesions and 2 infralabyrinthic lesions. The surgical approach was: translabyrinthic (1 case), translabyrinthic and suprapetrous (2 cases), suprapetrous (1 case), suprapetrous and petrectomy (1 case), petrectomy (2 cases). The diversion of the facial nerve was often associated. After the surgical operation the activity of the facial nerve was conserved in 4 patients and improved in 2 patients. The facial nerve paralysis that appeared on a patient after being operated on, totally recovered after 7 months. In spite of the appropriate surgical approach, the residual lesions were not rare (2 cases). This situation imposes a clinical and radiological follow-up for life.

CONCLUSION

Intrapetrous cholesteatoma is rare. The X-ray confirmed the diagnosis. The new MRI techniques allow to detect recurrences and residues. A second surgical operation can be necessary.

[Acute mastoiditis in children: clinical and bacteriological study of 17 cases]

OBJECTIVE

Acute mastoiditis (AM) represents the most frequent complication of acute otitis media (AOM) in children. In the literature, its incidence is stable but with an impressive increase in pneumococci with reduced sensitivity to penicillin (PRSP). The aim of this study was to assess the incidence of AM in the area of Tours and the prevalence of PRSP.

METHOD

This was a retrospective study of children admitted to the regional paediatric centre in the Tours area, between January 1994 and May 2001. The coded AM files were analysed, excluding all the sub-acute forms or those complicating a cholesteatoma. The criteria studied concerned the clinical signs on admission, the imaging data and the bacteriological samples and the results of treatment.

RESULTS

Seventeen children (8 boys, 9 girls) were admitted for an AM during the study period. Their mean age was of 3.2 years (range: 6 months to 13 years). In 24% of cases, the mastoiditis existed on admission and in 59% of cases it complicated an AMO already treated with antibiotics. In 3 cases (18%), the AM was complicated on admission with peripheral facial paralysis in one case and thrombosis of the lateral sinus in 2 cases. The germ responsible was identified in 14 cases (82%) with a predominance of pneumococci (11 cases). Eight were PRSP-type. Scan of the pars petrosa identified a subperiosteal abscess in 13 cases. Fourteen mastoidectomies were performed and the mean duration of antibiotic therapy was of 23 days. The outcome was always good.

CONCLUSION

Over the past 7 years, the incidence of AM has been estimated at 1.2/100 000 children aged under 15 per year. The prevalence of PRSP is high but does not change the principles or the results of the treatment of AM.

Nocardia farcinica infection of a cochlear implant in an immunocompetent boy

The first case of an infection caused by Nocardia farcinica on a cochlear implant and its progression is described. As it is difficult to diagnose Nocardia spp., the identification was confirmed by phylogenetic analysis using 16S rDNA sequencing.

[Teratoma of the rhinopharynx and the infratemporal fossa in neonates: report of 3 cases]

Teratomas are tumors which develop in childhood or early adulthood, generally in the gonads. More rarely these tumors may be found in an axial localization, notably in cervicofacial forms. We report three cases of teratomas observed in rhinopharynx of three neonates operated at the Clocheville General Hospital. We present the main anatomoclinical features of these tumors, focusing on the cervicofacial forms in neonates. All three cases occurred in female neonates presenting acute dyspnea within the first hours of life, requiring intubation in two cases. The first two tumors invaded the infratemoral region and the third was a pediculated tumor of the velum exteriorized via the mouth. In one case antenatal ultrasound had suggested the diagnosis of a right temporomaxillary tumor. Rapid excision of the rhinopharngyeal component allow extubation for the two intubated infants and pathology diagnosis. In the first infant operated at 2 months, the lateral route was adapted to age, with mandibulotomy with section of the coronoid process but preserving the mandibular condyle. The second infant was operated at the age of 3 weeks using a wide frontotemporoperitonial approach then at the age of 3.5 months for recurrence extending to the floor of the temporal fossa and the middle ear. A type C infratemporal approach was used with lost-bone temporal craniectomy. Per-buccal excision was possible in the third infant with resection at the base of implantation. No recurrence has been observed in the first two cases at 3.5 and 2.5 months follow-up in the first two cases. The third infant was lost to follow-up.

[Otosclerosis surgery: a series of 227 cases. Introduction of CO2 laser]

OBJECTIVES

To evaluate the effects of the size of the footplate opening on the hearing results in surgical treatment of otosclerosis and the use of CO2 laser in this indication.

PATIENTS AND METHODS

190 patients with otosclerosis underwent 227 procedures between 1986 and 1995. Hearing results and symptoms were analyzed to compare the different procedures: 140 stapedectomies, 87 Fisch's stapedotomies, 35 of them with manual perforator, 52 of them with CO2 laser.

RESULTS

Air/bone gap closure within 10 dB was obtained in 87, 92 and 97 percent of stapedectomies and in 80, 84 et 90 percent of stapedotomies after 3 months, 1 and 3 years (NS). Bone conduction was improved in 81, 80 et 63 percent of stapedectomies and 87, 97, 60 percent of stapedotomies after the same time (NS). Air/bone gap closure within 10 dB was obtained in 75 and 80 percent of manual perforator stapedotomies and in 84 and 88 percent of CO2 laser stapedotomies after 3 months, and 1 year (NS). Bone conduction was improved in 78 and 96 percent of manual perforator stapedotomies and 95 and 100 percent of CO2 laser stapedotomies after the same time (NS). No facial palsy or prolonged vertigo occurred. There was one case of anucusis following a stapedectomy.

CONCLUSION

Although both stapedectomy and stapedotomy produced equivalent air/bone gap closure, reduction of inner ear trauma was noted with Fisch's stapedotomy. CO2 laser technique is a safe procedure, which optimizes the Fisch's stapedotomy.

[Results of vestibular neurotomy from a socio-professional point of view]

Vestibular neurotomy, in addition to the fact that it preserves the hearing, is considered to be the most effective form of treatment for incapacitating unilateral Menières disease which is resistant to medical treatment. The authors have carried out a retrospective study of 20 cases of vestibular neurotomy operated on between 1986 and 1996. They have evaluated the results of the suppression of vertigo and the improvement of quality of life. Each patient was given a questionnaire. The parameters studied were the quality of daily life, professional life and driving ability. The mean follow-up period was 3 years. This study confirms the good results obtained with vestibular neurotomy for vertigo: complete control of attacks of vertigo was obtained in 90% of cases according to the criteria laid down by the American Committee on Hearing and Balance, as modified in 1985 (AAO, 1985). This study has also confirmed that the quality of patients lives is greatly enhanced both for everyday activities, professional activities and driving.

Bilateral conductive deafness related to erosive lichen planus

A case of bilateral progressive stenosis of both external auditory canals with resultant conductive hearing loss is presented. The stenosis revealed multifocal erosive and synechiant lichen planus. To our knowledge, this is the first reported case of lichen planus involvement of the external ear.

[Is the afferent auditory message modulated by the cortex?]

An eventual modulation of the afferent auditory message by the cortex is the subject of this study. To test this hypothesis, clicks (10 Hz, 100 microseconds) of white noise of 40 and 70 dB Hl were sent alternatively into the ears of normally hearing volunteers, while the brainstem evoked potentials were recorded. The subjects were asked to focus or relax their attention on one or other ear. Thirty subjects aged less than 25 years (15 men and 15 women) with normal hearing level, were split into two groups. The first group was asked to focus first on the more strongly stimulated ear (70 dB), the second group on the more weakly stimulated one (40 dB). Each subject received (1) without any instruction about attention: 40 dB on the left ear (L), 70 dB on the right ear (R); 40 dB then 70 dB bilateral; (2) 2 runs with 40 dB on the L and 70 dB on the R focussing on the most or less strongly stimulated ear; (3) a run without instruction with 70 dB on the L and 40 dB on the R, and (4) two runs with 70 dB on the L and 40 dB on the R focussing enough on the more or less strongly stimulated ear. On the evoked potentials simultaneously recorded, amplitudes and latencies of the pikes were measured and compared. From these experiments, the following elements were obtained. (1) The measured potentials were always caused by ipsilateral stimuli. (2) Focussing on left or right ear was not equivalent. (3) A gender difference appeared in the brainstem auditory responses. (4) Preferential attention paid to the left ear was more efficient than to the right one. (5) Attention can alter the whole nervous pathway with considerable lengthening of O-I, O-III, O-V, III-V, I-V but not I-III latencies. The III wave amplitude generally decreased on the side where attention was focussed while V waves seemed not to vary. These first results indicate that a cortico-efferent pathway stimulated by the attention plays a role in the auditory responses modifying the afferent message. These effects were not the same among the side focussing attention and among sex.

Reliability of low-frequency auditory stimulation studies associated with technetium-99m hexamethylpropylene amine oxime single-photon emission tomography

Development of auditory stimulation tests associated with single-photon emission tomography (SPET) shows evidence of variations in perfusion related to the stimuli. Three brain SPET examinations with technetium-99m hexamethylpropylene amine oxime were performed on eight right-handed adults with normal hearing, the first one without stimulation and the other two associated with a 500-Hz/30-dB stimulation of the right ear. Temporal regions of interest covering auditory areas, as well as parietal ones (internal control), were drawn on three successive coronal slices. A cortico-cerebellar index R was calculated, and the variation in activity was defined for each subject using the ratio R poststimulation--R prestimulation/R prestimulation. A significant increase in the temporal cortex count occurred in all subjects. This increase was bilateral, except for one subject in whom it was not significant on the right side. This result recurred during the second stimulation study. Overall the response of the left temporal cortex was stronger, although the asymmetry was not significant. The asymmetry repeated itself after each stimulation. The perfusion response is globally reliable in our study. We must ascertain how sensitive this test is with regard to deaf adults and adults with normal hearing before extending its use to children.

Perfusion response during electrical stimulation of the auditory nerve in profoundly deaf patients: study with single photon emission computed tomography

Brain activation procedures associated with single photon emission computed tomography (SPECT) recently have been developed in healthy controls and in diseased patients to help in their diagnosis and treatment. We investigated the effects of an electrical stimulation of the auditory nerve on the cerebral distribution of 99mTc-HMPAO in seven profoundly deaf adults. The promontory test was positive (PT+) in six patients and negative (PT-) in one. A count increment of the temporal cortex was observed in all patients, and was higher in all patients with PT+ (right 20%, left 19%) than in the patient with PT- (right 9%, left 3%). These results led us to consider 99mTc-HMPAO brain SPECT imaging as a potential preoperative test for cochlear implant. It might be helpful for the evaluation of cortical perfusion response to an electrical stimulation. Sensitivity tests for the method are requested before this clinical application.

Cortical perfusion response to an electrical stimulation of the auditory nerve in profoundly deaf patients: study with technetium-99m hexamethylpropylene amine oxime single photon emission tomography

Brain activation procedures associated with single photon emission tomography (SPET) have recently been developed in healthy controls and diseased patients in order to help in their diagnosis and treatment. We investigated the effects of a promontory test (PT) on the cerebral distribution of technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) in 7 profoundly deaf patients, 6 PT+ and one PT-. The count variation in the temporal lobe was calculated on 6 coronal slices using the ratio (Rstimulation-Rdeprivation)/Rdeprivation where R = counts in the temporal lobe/whole-brain count. A count increase in the temporal lobe was observed in all patients and was higher in all patients with PT+ than in the patient with PT-. The problems of head positioning and resolution of the system were taken into account, and we considered that the maximal count increment was related to the auditory cortex response to the stimulus. Further clinical investigations with high-resolution systems have to be performed in order to validate this presurgery test in cochlear implant assessment.

Increment of brain temporal perfusion during auditory stimulation. Preliminary study with technetium-99m HMPAO SPET

A study on the dynamic exploration of the auditory pathway is presented, in which technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPET) was used in volunteers with normal hearing. Changes in 99mTc-HMPAO distribution were calculated using a region of interest/whole-brain count ratio. The results showed a temporal perfusion increment of 17% (right) and 19% (left) during tonal supraliminar stimulation, which was significantly different from the control ROI. Sensitivity tests for the method were requested before any clinical application.

Surgical treatment of Graves' disease

Seven men and 81 women were operated on for Graves' disease. Their median age was 33 years. Eleven patients underwent a bilateral subtotal lobectomy; 77 patients underwent a complete lobectomy with contralateral partial lobectomy. Forty-seven patients were treated before 1981. In these patients, the weight of the thyroid remnant was estimated empirically between 5 and 12 g. In the 41 patients treated since 1981, the remnant weight was estimated at 5 g by comparative weighing. There were no postoperative deaths. Functional results were established in 83 patients with an average follow-up of 50 months (range 12 to 156 months), with control of vocal cord mobility demonstrated by indirect laryngoscopy in 66 patients. Hormonal determinations were carried out in 74 patients. There were no cases of permanent hypoparathyroidism. Three patients (4.5 percent) had unilateral vocal cord dysfunction. Twelve patients (14.5 percent) had clinical and biologic hypothyroidism, which occurred within 1 year postoperatively in 11 cases. Seven patients (8.3 percent) had latent hypothyroidism only discovered by hormonal determinations. Fifteen patients (17.8 percent) had recurrent hyperthyroidism, 6 of whom were diagnosed by hormonal determinations. The actuarial recurrence rate increased progressively up to the sixth postoperative year. The only predictive factor for recurrence was the type of operation. Patients who underwent a bilateral subtotal lobectomy had more recurrences than patients who underwent a complete lobectomy with partial contralateral lobectomy (p less than 0.01). These results suggest that patients should be followed closely for many years and should undergo hormonal determinations regularly, as some recurrences can occur 5 years or more after operation with very few symptoms.

Choanal atresia and deafness

Nine cases of bilateral choanal atresia are reported. The association with other malformations and deafness is evaluated. The choanal atresia is associated with multiple malformation in two cases and bilateral deafness in 5 cases. Before discussing surgery, a complete evaluation has to be performed, deafness has to be evaluated with modern electrophysiological methods. The risks of the surgery should be considered in case of cardiac malformation and cerebral anoxia.

Auditory brain stem responses and cortical auditory-evoked potentials in difficult-to-test children

Brain-stem-evoked responses (BERs) and cortical auditory-evoked potentials (AEP) were recorded in 24 children showing severe behavioral disorders. BER testing always requires sedation if not general anesthesia. This allowed us to perform precise acoustic impedance measurements, and thus to find 3 glue ears. The electrophysiological tests revealed whether there was sensorineural deafness, which was cared for if necessary. Finally, when the BERs were normal, we evaluated the modifications in the cortical AEP, in relation to a clinical classification closely related to that of the DSM III of the American Academy of Psychiatry.