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O Sterkers

Publications and source records attributed to O Sterkers.

At least 19 recordsLinked to original sources
PubMed2003

[Spontaneous otogenic pneumocephalus].

Otogenic pneumocephalus is uncommon. Typical causes include trauma, tumor, infection, and nasosinusal or mastoid surgery but spontaneous otogenic pneumocephalus is very exceptional. We report a case of spontaneous otogenic pneumocephalus located in the left temporal lobe revealed by sudden onset aphasia. The temporal pneumatocele was cured through an epidural subtemporal approach with needle puncture of the aeroma and duroplasty. Two years after surgery, no recurrence was observed and the patient remained symptom free.

Aphasia↗
PubMed2003

[Results of fine needle aspiration biopsy, frozen section diagnosis and definite histological results in thyroid pathology. Report of 163 cases].

INTRODUCTION: In thyroid diseases, the place of fine needle aspiration biopsy still continues to be discussed: the sensibility and specificity vary greatly in the literature. Frozen section diagnosis is necessary to form a diagnostic strategy. The objective of this study was compare the results of fine needle aspiration biopsy, frozen section diagnosis, and definitive histologic results in a population of 163 patients and to draw conclusions about treatment. MATERIAL AND METHOD: From 1994 to 1999, 163 patients (132 females and, 31 males) undergoing thyroid surgery were included in this retrospective study, after a standard preoperative work-up. Those with a single palpable nodule and hypofixation on scintigraphy underwent fine needle aspiration before surgery. These results were compared with the definitive histologic results. RESULTS: A loboisthmectomy was performed in 88 cases (54%), a subtotal thyroidectomy in 34 cases (21%), and a total thyrodectomy in 41 cases (25%). In the latter group, an associated neck dissection was performed in 18 cases (11%); a frozen section diagnosis was obtained in all cases of thyroid nodules. This study demonstrated a single nodule in 97 cases (60%), multiple nodules in 27 cases (17%), multinodular goitre in 34 cases (21%), and 5 Basedow diseases (3%). Sixty-two cases (38%) of thyroid nodules underwent fine needle aspiration before surgery. In 25 cases (15%), definitive pathology showed a malignant lesion. The frozen section diagnosis had a sensitivity of 73% and a specificity of 99%, and the fine needle aspiration biopsy had a sensitivity of 40% and a specificity of 100%. CONCLUSION: The authors propose fine needle aspiration biopsy in the following cases: a single palpable nodule and hypofixation on scintigraphy or a surgical contra indication; and direct surgery in symptomatic thyroid disease or if there are one or several full nodules > 2 cm. In near future, these indications will be modified with the increasing reliability of fine needle aspiration biopsy.

Adolescent↗
PubMed2002

Local administration of antioxidants to the inner ear. Kinetics and distribution(1).

Round window (r.w.) administration of drugs involves the delivery of medication directly into the inner ear via the r.w. membrane, avoiding a systemic effect of the therapy. Earlier experimental studies suggest that a number of antioxidants and scavengers hold promise for ameliorating the tissue damaging capacity of reactive oxygen species in some acquired cochlear disorders. D-Methionine and thiourea are two small sulfur-containing molecules with an antioxidative and scavenging effect. The passage through the r.w. of radioactive D-methionine and thiourea administered by 1 h infusion to the r.w. was studied in a rat model. Levels of the tracers were measured in scala tympani perilymph (PLT) 17-254 min after r.w. administration. Both tracers pass the r.w. membrane readily. Peak levels were found in the earliest taken samples after the administration. The radioactivity in PLT of the basal turn reached a peak to about 1.5-1.9% of the irrigating medium radioactivity. Following the r.w. administration, the concentration of radioactive D-methionine and thiourea declined with a terminal half-life of 0.57 and 0.77 h, respectively. The distribution of the tracers at the cellular level was analyzed by autoradiography. The most intense expression was found in the lateral wall of the cochlea. It can be postulated that local delivery to the cochlea of D-methionine and thiourea via the r.w. gives high local concentrations of the substances in PLT in the basal turn.

Animals↗
PubMed2002

Predictive factors of long-term facial nerve function after vestibular schwannoma surgery.

OBJECTIVE: To assess predictive factors of long-term facial nerve function in a series of patients undergoing vestibular schwannoma surgery and to evaluate the reproducibility of the relevant parameters. STUDY DESIGN: Prospective. SETTING: Three tertiary referral neurotology units in two separate countries. PATIENTS: A total of 67 patients, with normal preoperative facial function and an anatomically intact facial nerve postoperatively, undergoing vestibular schwannoma surgery during a sequential 18-month period. INTERVENTIONS: Recording of intraoperative stimulus amplitudes (minimum intensity medial to the tumor after excision) and postoperative facial nerve function up to 2 years after surgery. MAIN OUTCOME MEASURES: Long-term facial nerve function related to tumor size, early postoperative facial nerve function, and intraoperative electrophysiologic intensities. RESULTS: Multivariate logistic regression model identified tumor size and the minimum intensity required to provoke a stimulus threshold event medial to the tumor after excision as independent predictors of a favorable initial outcome. Immediate facial nerve function was the only independent predictor of long-term normal function. The sensitivity of this predictor was 95% (95% confidence interval [CI], 89-100%); specificity, 83% (95% CI, 62-100%); positive predictive accuracy, 96% (95% CI, 91-100%); and negative predictive accuracy, 77% (95% CI, 54-100%). CONCLUSION: The combination of electrophysiologic intensities and tumor size are reproducible and better predictors of initial facial nerve function than any individual parameter, but long-term facial nerve function is more likely to have a better outcome if the nerve is left intact and a per-operative graft repair is not performed. The study suggests that although the best available predictor of overall long-term facial nerve outcome is the level of early postoperative function, this factor is not useful in surgical rehabilitation decision making.

Adolescent↗
PubMed2002

[Na transport in the cochlea of mammals].

Endolymph, the fluid that bathes the apical side of the inner ear sensory cells, is a K-rich and Na-poor fluid. In the cochlea, various epithelial transport systems involved in the transport of Na from the apical endolymphatic to the basolateral perilymphatic compartments have been identified: basolateral Na+, K(+)-ATPase, apical non selective cationic channels, Na+/H+ exchanger, and ENaC epithelial Na channel. These transporters may be involved in physiological and pathological processes in which endolymph Na concentration is high.

Animals↗
PubMed2002

[Otosclerosis surgical techniques and results in 150 patients].

OBJECTIVES: To analyze outcome after otosclerosis surgery with stamedeotomy with blood clot sealing. PATIENTS AND METHODS: Otosclerosis surgery was performed in 150 adult patients between 1997 and 1999 by five surgical teams (70% of the procedures were performed by senior surgeons) and followed for 18 months. Stapedotomy was carried out under general anesthesia with an intrameatal approach in 96% of the cases. Stapedotomy (n=120, 80%) was performed with a drill in 141 cases and by laser in 9 (6%). Ninety percent of the Teflon prostheses had a 0.4 mm diameter and a 4.5 mm length. The footplate opening was sealed with blood clots. Venous interposition (n=30, 20%) was performed in the event of partial or total stapedectomy which occurred in spite of an initial stapedotomy attempt. RESULTS: The preoperative air-bone gap (ABG) was 32 +/- 10.3 dB. The gain in air conduction was 25 +/- 11.7 dB with 75% of the patients having more than 15 dB gain. The ABG was 10 +/- 5.4 dB with 73% of the patients having less than 5 dB gain. The interaural difference was 0.5 +/- 14.1 dB and the bone conduction (BC) variation was 1 +/- 7.5 dB. Functional failures were related to significant intralabyrinthine bleeding and revision procedure. The following factors had not effect on outcome: i) stapedotomy versus partial or total stapedectomy, footplate opening sealed by clots or vein, ii) diameter of the stapedotomy and/or the prosthesis, iii) surgical procedure performed by a junior surgeon. CONCLUSION: Sealing the stapedotomy opening with blood clots appears to provide reliable and reproducible functional outcome that remains stable over time. In this study, changing from partial to total stapedectomy with vein interposition did not modify the functional outcome.

Adult↗
PubMed2002

[Middle ear adenoma: report of two cases and review of the literature].

INTRODUCTION: Middle ear adenoma is an uncommon tumor. We report two cases and review the relevant literature concerning this rare entity. MATERIAL AND METHODS: Two patients with a middle ear adenoma were operated on in our department. Pre- and postoperative data concerning clinical examination, audiometry, and radiology were obtained. Information concerning intraoperative observations and the pathological examination were also gathered. RESULTS AND DISCUSSION: The diagnosis of middle ear adenomas is based on clinical, radiological, and pathological confrontation. The microscopic examination should be combined with histochemical and immuno-histochemical methods in order to evidence the glandular and neuroendocrin components of these lesions. CONCLUSION: Today, classified as a benign epithelial tumor, the middle ear adenoma is associated with an excellent prognosis provided total excision.

Adenoma↗
PubMed2002

[Acoustic neuromas and serviceable hearing: choosing the surgical approach].

The principal objectives of acoustic neuroma surgery in the order of priority are absence of mortality and neurological morbidity, total removal of the lesion, preservation of facial function, and preservation of hearing. The aim of this work was to evaluate the selection criteria and the therapeutic strategy for hearing preservation in acoustic neuroma management. This retrospective study included 436 consecutive patients referred to our department for an acoustic neuroma. The population comprised 365 patients (84%) treated surgically, 66 patients (15%) managed conservatively, and 5 irradiated patients (1%). The mean age was 54 years (range: 13-87). The mean follow-up period was 24 months (range: 1-120). The surgical approaches were translabyrinthine in 294 (81%), retrosigmoid in 37 (10%), and through the middle fossa in 34 cases (9%). Approaches preserving the labyrinth were employed in patients aged less than 60 years with lesions measuring or=50%). A serviceable hearing was preserved in 53% of the cases with a serviceable hearing in 44% of the cases. Postoperative normal or subnormal facial function was obtained in 72 to 98% of cases depending on tumor size. Two cases (0.5%) of recurrence were reported. In conclusion, our surgical strategy based on age, tumor size and pre-operative hearing function permitted hearing preservation in 50% of selected cases, a high rate of facial function preservation and a low risk of recurrence.

Adolescent↗
PubMed2001

MRI of unusual lesions in the internal auditory canal.

We report the MRI findings of six unusual lesions of the internal auditory canal: three haemangiomas, one lipoma, one metastasis and one traumatic neuroma. We compare the findings to those of 20 intracanalicular schwannomas. We noted the site and size of the tumour, its signal intensity, borders and the homogeneity of enhancement were studied on T1-weighted images before and after intravenous contrast medium and T2-weighted images. Most schwannomas were homogeneous lesions, isointense on T1- and T2-weighted images, and strongly enhancing. Spontaneous high signal on T1-weighted images, heterogeneous contrast enhancement and extranodular enhancement were helpful for recognising lesions other then schwannomas; site, size and signal on T2-weighted images were not. All the haemangiomas had a specific pattern of contrast enhancement, with an anterior core intensely enhancing portion and a posterior portion which enhanced moderately or not at all.

Adult↗
PubMed2001

Hemangioma of the porus acusticus. Impact of imaging studies: case reports.

Hemangiomas are tumors. Hemangiomas near the geniculate ganglion or in the internal acoustic meatus are well known but rare. We present two cases of hemangiomas located at the porus acusticus, an even more rare site. MRI showed a millimeter-sized tumor, located in the porus acusticus, developing perpendicular to the axis of the acoustico-facial nerves, surrounding them. They were hyperintense on T1-weighted images, strongly hyperintense on T2-weighted images with a characteristic progressive and marked enhancement after injection of gadolinium DTPA. Similar signal abnormalities were present in the adjacent temporal bone, and CT scan demonstrated a honeycomb appearance with intratumoral bony spicules. These imaging criteria allows differentiation between hemangioma and neurinoma. We hypothesize that this location is related to the presence of a rich vascular plexus of the dura mater in this area.

Adult↗
PubMed2001

Effects of acute and chronic hypertension on the labyrinthine barriers in rat.

Hearing loss, vertigo, and tinnitus have been related to arterial hypertension. The aim of the present work was to study the permeability of the blood-perilymph and of the labyrinthine barrier, between endolymph and perilymph, to small molecules during chronic and acute hypertension. Experiments were performed in normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Acute hypertension was induced by phenylephrine. Perilymph was sampled from the first turn of the scala vestibuli and the Na, K, urea, and radioactive concentrations ((14)C-urea and (3)H-mannitol) were measured. In another experimental set, the endocochlear potential was recorded from the basal turn of scala media, before and after phenylephrine injection. The composition of the perilymph and the kinetic constants for (14)C-urea and (3)H-mannitol were similar in WKY and SHR, and not modified after acute hypertension. In endolymph, the endocochlear potential in SHR (+80+/-2.7 mV, n=24) was lower (P<0.001) than in WKY (+98+/-1.5 mV, n=29). The endocochlear potential was decreased by 40 mV during acute hypertensive peak in seven out of 19 WKY but not in SHR rats (n=13). In conclusion, chronic or acute hypertension did not severely alter the permeability to small molecules of the blood-perilymph barrier. The relationship between the low endocochlear potential and hypertension in SHR remains to be evaluated. After acute hypertensive peak, the presence of vascular protective mechanisms in the cochlea could account for the stable endocochlear potential recorded in SHR and 60% of normotensive rats.

Acute Disease↗
PubMed2001

Delayed facial palsy after vestibular schwannoma surgery.

OBJECTIVE: there is a lack of uniformity in the literature of the definition of delayed facial palsy (DFP) after vestibular schwannoma surgery. The aim of this study was to attempt to provide a clear definition of this clinical entity. METHODS: a prospective study was undertaken of all patients, with an intact facial nerve postoperatively, undergoing vestibular schwannoma surgery during a 16-month period. Delayed facial palsy was defined as any worsening of facial function after the initial assessment of postoperative function. RESULTS: a total of 67 patients, operated on between February 1994 and June 1995 satisfied the requirements of the study. Eight of the 67 patients developed a worsening of facial function after the first postoperative day. There were three males and five females with an age range of 29-73 years (mean, 53 years). CONCLUSION: DFP should be defined as any deterioration of facial function after vestibular schwannoma surgery.

Adult↗
PubMed2001

Surgical management of intratemporal lesions.

In order to evaluate the decisional elements in the surgical strategy of deep-seated and/or extensive intratemporal lesions, a retrospective review of cases followed up between 1985 and 1996 in our department was undertaken. Eighty-one adult patients presenting temporal bone lesions located or extending beyond the middle ear limits excluding vestibular schwannomas and surgically treated were included. The population comprised 38 men and 43 women (mean age: 43 years, range: 17-81). Pre-, intra- and postoperative data were collected from medical files. The principal factors influencing the choice of the surgical approach were the location of the lesion and its presumed aggressiveness, the tumour involvement of the internal carotid artery and the labyrinth on preoperative imaging, and the preoperative hearing loss. A coherent algorithm based on these factors can be proposed for the surgical management of intratemporal lesions. High quality preoperative imaging is mandatory for the surgical planning.

Adolescent↗
PubMed2001

H+,K+-ATPase is not involved in endolymph pH homeostasis.

In endolymph, the calculated electrochemical gradients suggest the presence of active transport of H+ and K+. The presence of H+,K+-ATPase, an active transporter that mediates the exchange of intracellular H+ for extracellular K+, was investigated using reverse transcription-polymerase chain reaction on rat microdissected inner ear tissues. Distal colon and kidney were used as positive controls. The two H+,K+-ATPase colonic or gastric isoforms were not detected in the rat cochlea and endolymphatic sac. This result suggests that H+,K+-ATPase is not involved in H+ and K+ endolymph homeostasis.

Acid-Base Equilibrium↗
PubMed2001

A multicenter study of the Vibrant Soundbridge middle ear implant: early clinical results and experience.

OBJECTIVE: The Vibrant Soundbridge (VBS; Symphonix Devices, Inc., San Jose, CA, U.S.A.) is an active, semi-implantable, middle ear hearing device that directly drives the ossicular chain and is used in the treatment of patients with mild to severe sensorineural hearing loss. The benefits of the VBS and the effects of surgery were examined and compared with the preoperative aided condition in 25 patients with implants. STUDY DESIGN: Single-subject repeated-measures evaluations were performed with each patient acting as his or her own control. Objective audiologic measures and subjective questionnaires also were used. SETTING: Five tertiary referral and teaching hospitals. SUBJECTS: Adult patients had bilateral sensorineural hearing loss (average hearing loss, 56 dB; range, 33-80 dB). Twenty-one patients had worn a conventional hearing aid before surgery (11 binaurally, 10 monaurally). Four patients had not used a conventional hearing aid before surgery. INTERVENTION: Rehabilitative. RESULTS: No significant change in residual hearing after surgery was observed. Functional gain was significantly superior with the VBS. No significant differences were observed for aided speech recognition in quiet. A significant improvement in communication in various listening conditions was reported with the VBS as compared with conventional hearing aids. CONCLUSION: The VBS surgical implantation procedure does not affect the residual hearing level in the implanted ear, nor does it present any unacceptable risk. Measurable benefit from the VBS in comparison with conventional amplification was demonstrated with regard to the provision of superior usable amplification and greater ease in communication in daily listening environments for the majority of patients.

Acoustic Stimulation↗
PubMed2001

Location and function of the epithelial Na channel in the cochlea.

In the cochlea, endolymph is a K-rich and Na-poor fluid. The purpose of the present study was to check the presence and to assess the role of epithelial Na channel (ENaC) in this organ. alpha-, beta-, and gamma-ENaC subunit mRNA, and proteins were detected in rat cochlea by RT-PCR and Western blot. alpha-ENaC subunit mRNA was localized by in situ hybridization in both epithelial (stria vascularis, spiral prominence, spiral limbus) and nonepithelial structures (spiral ligament, spiral ganglion). The alpha-ENaC-positive tissues were also positive for beta-subunit mRNA (except spiral ganglion) or for gamma-subunit mRNA (spiral limbus, spiral ligament, and spiral ganglion), but the signals of beta- and gamma-subunits were weaker than those observed for alpha-subunit. In vivo, the endocochlear potential was recorded in guinea pigs under normoxic and hypoxic conditions after endolymphatic perfusion of ENaC inhibitors (amiloride, benzamil) dissolved either in K-rich or Na-rich solutions. ENaC inhibitors altered the endocochlear potential when Na-rich but not when K-rich solutions were perfused. In conclusion, ENaC subunits are expressed in epithelial and nonepithelial cochlear structures. One of its functions is probably to maintain the low concentration of Na in endolymph.

Action Potentials↗
PubMed2001

Hypertrophic neuropathy of the facial nerve.

Hypertrophic neuropathy is a peripheral nerve lesion that is histologically characterized by onion bulb formations around axons. This histologic picture, which is usually seen in generalized hypertrophic neuropathies, can occasionally be observed in single nerves as localized hypertrophic neuropathy. Cranial involvement of such localized hypertrophic neuropathy represents a very rare entity; only a few cases have been reported in the literature. We report the history of a progressive facial paralysis with a tumorous enlargement of the seventh cranial nerve that was clinically suspected of being a schwannoma. Pathological examination permitted the diagnosis of hypertrophic neuropathy.

Adult↗