O. Sterkers

Surgical treatment of the high jugular bulb in patients with Ménière's disease and pulsatile tinnitus.

Abstract The aim of this retrospective study was to evaluate the functional results of surgical lowering of the high jugular bulb in the treatment of patients with Ménière’s disease and pulsatile tinnitus. Fifteen patients with disabling Ménière’s disease associated with pulsatile tinnitus and a high and medial jugular bulb were included in this study. As treatment a complete mastoidectomy was performed, after which the jugular bulb was freed by an infralabyrinthine and subfacial approach. The bulb was then displaced downwards with surgical wax. Functional results of surgery were assessed by a questionnaire according to the 1995 guidelines of the United States American Academy Committee on Hearing and Equilibrium, audiometric and vestibular tests, and by magnetic resonance and computed tomographic imaging with vascular sequences. Surgical treatment was contraindicated in two cases: one had hypoplasia of the contralateral sigmoid sinus and the other a small petrous hemangioma located around the jugular bulb that was discovered peroperatively. Among the 13 patients treated by definitive surgery, attacks of vertigo were reported as disabling in 12 cases preoperatively (92%) versus 1 (8%) after surgical treatment. No significant change in hearing was observed after surgery. Tinnitus had been reported in all patients preoperatively and decreased in intensity in four (31%) and disappeared in three (23%) after surgery.

Temporal bone density measurements using CT in otosclerosis

Objective—To assess the bone density around the bony labyrinth in otosclerosis patients and to compare it to that of a control population. Material and Methods—This was a prospective case-control study. Ten patients with otosclerosis (mean age 42 years; range 24–55 years) and 33 control patients with vestibular schwannoma (mean age 46 years; range 20–71 years) were included. All patients underwent a clinical examination, audiometry and a CT scan comprising axial and coronal views of both temporal bones. In the otosclerosis group, audiometry showed unilateral involvement in six patients and bilateral hearing loss in four. The bone density was measured at the fissula ante fenestram (FAF) and at five other anatomical points on the bony labyrinth. Results—In the control group, the bone density was similar at the six anatomical points. In the otosclerosis patients, the mean bone density at the FAF was lower than that in control patients (1649±99.1 vs 2049±13.4 HU; p<0.01). For patients with FAF bone densities <2000 HU, a correlation was observed between hearing threshold and FAF bone density. Conclusion—FAF bone density appears to be a good indicator of disease progression, and could serve as a follow-up and prognostic parameter.

Diagnostic value of auditory brainstem responses in cerebellopontine angle tumours

Conclusion. Auditory brainstem responses (ABRs) associated with other audio-vestibular examinations and a thorough clinical examination should allow detection of the majority of cerebellopontine angle (CPA) lesions (99.2–100%). Objective. The increasing quality of MRI in the detection of CPA lesions, and the reports of false negative ABRs have raised issues concerning the value of ABR in the diagnosis and preoperative assessment of CPA lesions. The aim of this work was to assess the value of the ABR in the diagnosis of vestibular schwannomas (VS) and other CPA lesions. Patients and methods. This retrospective study included 676 solitary VS (548 operated on and 128 followed up) and 70 other CPA tumours (72% meningiomas, 11% cholesteatomas, 3% ependymomas, 15% miscellaneous) managed between 1990 and 2001. All patients underwent clinical examination, audiometry, ABR, vestibular caloric tests and MRI. Results. ABRs were normal in 4.8% of VS. Association of normal ABR, vestibular caloric tests and audiometry (AAO-HNS class A) represented only 0.7% of VS. In other CPA lesions, ABR were normal in 15% of cases and the association of the three above-mentioned examinations was encountered in 10%. However, in the latter cases the clinical examination showed an abnormality in all cases.

Anterior skull base osteoid osteoma: case report

Osteoid osteoma is a benign bone tumour which rarely occurs in the skull. A case of such a tumour in the posterior ethmoid region bulging into the anterior cranial fossa is reported in a 42-year-old woman who presented with intense frontal headaches. Excision of the tumour was performed through a subfrontal approach.

The effects of angiotensin II and the oxidative stress mediator 4-hydroxynonenal on human osteoblast-like cell growth : Possible relevance to otosclerosis

Otosclerosis is a complex disease characterized by an abnormal bone turnover of the otic capsule resulting in conductive hearing loss. Recent findings have shown that angiotensin II (Ang II), a major effector peptide of the renin-angiotensin system, plays an important role in the pathophysiology of otosclerosis, most likely by its proinflammatory effects on the bone cells. Because reactive oxygen species play a role both in inflammation and in the cellular signaling pathway of Ang II, the appearance of protein adducts of the second messenger of free radicals, the aldehyde 4-hydroxynonenal (HNE), in otosclerotic bone has been analyzed. Immunohistochemical analysis of HNE-modified proteins in tissue samples of the stapedial bones performed on 15 otosclerotic patients and 6 controls revealed regular HNE-protein adducts present in the subperiosteal parts of control bone specimens, whereas irregular areas of a pronounced HNE-protein adduct presence were found within stapedial bone in cases of otosclerosis. To study possible interference by HNE and Ang II in human bone cell proliferation, differentiation, and induction of apoptosis we used an in vitro model of osteoblast-like cells. HNE interacted with Ang II in a dose-dependent manner, both by forming HNE-Ang II adducts, as revealed by immunoblotting, and by modifying its effects on cultured cells. Namely, treatment with 0.1 nM Ang II and 2.5 μM HNE stimulated proliferation, whereas treatment with 10 μM HNE or in combination with Ang II (0.1, 0.5, and 1 nM) decreased cell proliferation. Moreover, 10 μM HNE alone and with Ang II (except if 1 nM Ang II was used) increased cellular differentiation and apoptosis. HNE at 5 μM did not affect differentiation nor significantly change apoptosis. On the other hand, when cells were treated with lower concentrations of HNE and Ang II we observed a decrease in cellular differentiation (combination of 1.0 or 2.5 μM HNE with 0.1 nM Ang II) and decrease in apoptosis (0.1 and 0.5 nM Ang II). Cellular necrosis was increased with 5 and 10 μM HNE if given alone or combined with Ang II, whereas 0.5 nM Ang II and combination of 1 μ M HNE with Ang II (0.1 and 0.5 nM) reduced necrosis. These results indicate that HNE and Ang II might act mutually dependently in the regulation of bone cell growth and in the pathophysiology of otosclerosis.

Effect of angiotensin II on inflammation pathways in human primary bone cell cultures in otosclerosis.

Introduction: The aim of this study was to assess the expression and production of inflammation mediators in basal condition and after angiotensin II (AngII) in otosclerosis. Materials and Methods: Human stapedial cell cultures (6 otosclerosis and 6 controls) were incubated with AngII (10–7M, 24 h) or vehicle. Cytokines and their mRNA expression were assessed by antibody and cDNA arrays. Results: In basal conditions, otosclerotic cultures produced higher amounts of interleukin (IL)-1β and interferon-inducible protein 10, and smaller amounts of tissue inhibitor of metalloproteinase 2. AngII promoted inflammation by increasing interferon γ and IL-10, and by decreasing macrophage inflammatory protein 1α and soluble tumor necrosis factor receptor II. Conclusions: Otosclerotic cultures produced higher proinflammatory cytokines in basal condition. AngII appeared to promote inflammation via these mediators in otosclerosis.

Posterior petrous bone meningiomas: surgical experience in 53 patients and literature review

Meningiomas of the posterior fossa represent a heterogeneous group of tumors regarding difficulty of resection and functional outcome. The aim of this review was to focus on tumors located mainly on the posterior surface of the petrous bone and threatening hearing and facial functions. An anatomical classification was used to evaluate surgical outcome depending on the relationship of the tumor to the internal auditory meatus. The authors performed a retrospective chart review of 53 consecutive patients operated on for a posterior petrous bone meningioma in a tertiary referral center and a literature review. Tumors were classified in four groups according to the modified Desgeorges and Sterkers classification: posterior petrous (P; 17 tumors), meatus and internal auditory canal (M; 12 tumors), petrous apex without invasion of the internal auditory canal (A; 9 tumors), and cerebellopontine angle with invasion of the internal auditory canal (AMP; 15 tumors). The facial function was preserved in 100% of P and A tumors, 75% of group M tumors, and 53% of AMP tumors. Hearing preservation was attempted only in P, A, and M groups where rates of serviceable hearing preservation were 82%, 80%, and 66%, respectively. The cumulative rate of hearing preservation for AMP tumors was 45% in our literature review. The increased facial morbidity associated with AMP tumors compared with other groups was also confirmed by the review of the literature. In conclusion, this study shows that among posterior petrous bone meningiomas, tumors invading the internal auditory canal present with increased postoperative functional morbidity in spite of a tailored approach regarding dural insertion.

From conception to application of a tele-operated assistance robot for middle ear surgery.

The authors’ goal was to design and evaluate a robot dedicated to middle ear surgery. Specifications for dimensions, forces, and kinematics were collected, based on the otosclerosis procedure. The robot structure has a compact geometry with 3 linear and 3 rotatory motors. It is remotely piloted via a robot–surgeon interface under operative microscope. Ability to reach anatomical targets, to perform stapedectomy, and to place prosthesis in a model of stapedotomy was evaluated by 6 surgeons. Multiple anatomical targets in the middle ear could be successfully reached without damaging surrounding structures. The robot could be used under operative microscope with minimal visual field impairment or jointly with a 4-mm endoscope through the external auditory canal to perform stapedectomy in temporal bone specimens. Prosthesis could be inserted in the stapedotomy model. The assistance robot is the first prototype with 6 degrees of freedom, a kinematic structure, and dimensions optimized for tele-operated middle ear surgery.

Meningioma of geniculate ganglion: case report and review of the literature

Abstract Although meningioma is a frequent intracranial tumor, it rarely affects the geniculate ganglion of the facial nerve. Facial palsy is the most common symptom. When hearing is preserved (class A or B, AAO-HNS), tumor is best removed through a middle cranial fossa approach. We report the case of a geniculate ganglion meningioma and present its clinical, radiological, and pathological features. Surgical management is discussed. A literature review revealed that only 17 previous cases have been reported during the last 50 years.

Mechanical Design and Optimization of a Microsurgical Robot

The tele-operated system with three arms for the microsurgery of the middle ear is composed of an operator console from where the surgeon tele-operates three robotized arms that hold surgery tools with a high level of accuracy. The main difference between these micromanipulators and the conventional minimal-invasive surgery robots is the increased field of vision capacity to carry out complex operational gestures without using dextral tool with intra-body mobility. The method used to design the micromanipulator tool holder is described. A first task consists of analyzing functional specifications. The next step is to define and select a kinematic structure adapted to the task. Finally, a dimensional optimization is carried out by using Pareto front method.