Hearing restoration with auditory brainstem implants after radiosurgery for neurofibromatosis type 2.

The auditory brainstem implant (ABI) is designed to restore useful auditory sensations in patients with neurofibromatosis Type 2 (NF2). The implantation is usually performed at the time of tumor removal in patients who do not undergo radiation treatment. The authors evaluated the performance of ABIs in three patients with NF2 in whom vestibular schwannoma continued to grow after radiation treatment. These three patients with NF2 received a 21-channel ABI; a translabyrinthine approach was used for both the tumor removal and the ABI placement. The interval between radiosurgery and the tumor removal plus device implantation ranged from 2 to 11 years. In all cases, the tumor was growing and the patients presented with total deafness. The mean number of active electrodes in these three patients was equivalent to the average results reported in other patients who received ABIs. The patients in this study used the ABI regularly for everyday life and obtained useful levels of environmental sound recognition. It is concluded that hearing function can be rehabilitated using ABIs in patients with NF2, even if radiosurgery fails to control the tumor growth.

Extensive intratemporal cholesteatoma: surgical strategy.

OBJECTIVE: To evaluate the decisional elements in the surgical strategy for extensive intratemporal cholesteatomas. STUDY DESIGN: A retrospective review of cases followed up between 1985 and 1996. SETTING: Tertiary referral center. PATIENTS: Nineteen patients with temporal bone cholesteatoma extending beyond the middle ear limits and surgically treated were included. Preoperative imaging distinguished apical (8), infralabyrinthine (3), supralabyrinthine (3), retrolabyrinthine (1), and translabyrinthine (4) cholesteatomas. INTERVENTION: Apical and supralabyrinthine lesions were treated through a middle fossa approach. Infralabyrinthine and translabyrinthine locations were exposed through a subtotal petrosectomy or a transotic route, depending on the preoperative audiovestibular status and labyrinthine destruction on computed tomography. The retrolabyrinthine lesion was approached through a retrolabyrinthine route. MAIN OUTCOME MEASURES: Patients were assessed for postoperative audiologic and facial functions and for recurrence of tumor. RESULTS: The facial nerve was neither rerouted nor interrupted during surgery. Among the 12 patients with preoperative facial palsy (FP), 5 cases of improvement (42%), 6 cases of stable function (50%), and 1 case of mild deterioration (8%) were observed postoperatively. In patients without preoperative FP, facial function remained unchanged postoperatively. The labyrinth could be preserved in three patients (16%), with postoperative stable hearing function in two (11%), and a 40-dB mean auditory deterioration in one (5%). Complete macroscopic resection was obtained in all patients. Two cases (11%) of postoperative recurrence were observed. CONCLUSION: The surgical strategy, principally based on cholesteatoma location and preoperative auditory function, yielded a high rate of local disease control and facial function preservation.

No evidence of measles virus in stapes samples from patients with otosclerosis.

Otosclerosis is a localized bone dystrophy of unknown etiology mainly involving the stapes. The hypothesis of a persistent infection by the measles virus was based on the inconstant detection of the virus by various methods, including reverse transcription-PCR (RT-PCR) of patients' stapes samples. The aim of this work was to investigate the presence of the measles virus in stapedial otosclerosis foci by different sensitive methods. Pathologic stapes samples were obtained from 35 patients suffering from otosclerosis. Measles virus detection was performed by (i) cocultures of Vero cells and primary cell cultures of bone samples (n = 7), (ii) immunofluorescence study of these cocultures (n = 3), and (iii) RT-PCR on RNA directly obtained from fresh frozen samples (n = 28) and on RNA extracted from the primary cell cultures (n = 2). Viral genomic regions coding for N (nucleoprotein) and M (matrix) proteins were separately amplified. PCR sensitivity was optimized on the measles virus Edmonston strain. Glyceraldehyde-3-phosphate dehydrogenase mRNA was used as a marker of total RNA recovery. PCR products were tested by Southern blot hybridization technique to improve sensitivity and specificity. PCRs amplifying the M and the N protein genes were able to detect the control measles virus RNA at titers as low as 0.1 and 0.01 50% tissue culture infective dose, respectively. With these highly sensitive methods, we could not evidence the presence of the measles virus in any of our bone samples or primary bone cell cultures. Our results do not confirm the hypothesis of persistent measles virus infection in otosclerosis.

Parathyroid hormone-parathyroid hormone-related peptide receptor expression and function in otosclerosis.

The aim of this study was to investigate the possibility that an abnormality related to parathyroid hormone (PTH) action is involved in the increased bone turnover observed in otosclerosis. To do so, expression and function of the PTH-PTH-related peptide (PTHrP) receptor were studied in the involved tissue (stapes) and compared with that in control bone sample obtained from the external auditory canal (EAC) in the same patient in 10 cases of otosclerosis and in 1 case of osteogenesis imperfecta. PTH-PTHrP receptor expression was studied by RT-PCR of RNA prepared from cultured cells in three patients and RNA directly extracted from bone samples in four patients. PTH-PTHrP receptor function was assessed by measuring the stimulation of cAMP production by 0.8, 8, and 80 nM PTH in bone cell cultures in seven cases. Results showed that PTH-PTHrP receptor mRNA expression in the otosclerotic stapes was lower than that in EAC samples (P < 0.05), whereas it was higher in stapes than that in EAC in the case of osteogenesis imperfecta. cAMP production after PTH stimulation was lower in bone cells cultured from otosclerotic stapes compared with that in cells cultured from EAC (range of increase in stimulation: 0.8-4.5 and 1.5-7 in stapes and EAC bone cells, respectively, P < 0.05). In contrast, the stimulation of cAMP production by forskolin was not significantly different in otosclerotic stapes and EAC bone cells (range of increase in stimulation: 20.7-83.1 and 4.9-99.8 in stapes and EAC, respectively, P > 0.05). These results show a lower stimulation of cAMP production in response to PTH associated with a lower PTH-PTHrP receptor mRNA expression in pathological stapes from patients with otosclerosis compared with that in control EAC samples. This difference supports the hypothesis that an abnormal cellular response to PTH contributes to the abnormal bone turnover in otosclerosis.

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

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.

Tuberculoma of the cavernous sinus: case report.

OBJECTIVE AND IMPORTANCE: The cavernous sinus is an exceptional location for intracranial tuberculomas. A rapid diagnosis, based on pathological findings, improves the prognosis. CLINICAL PRESENTATION: A case of left cavernous sinus tuberculoma, revealed by frontal headaches and ipsilateral palsies of Cranial Nerves III and V, in a 48-year-old patient is reported. The lesion mimicked an aggressive meningioma in radiological examinations. INTERVENTION: The lesion was excised through a subtemporal approach. The diagnosis was based on the pathological examination of the mass. Postoperative antituberculous chemotherapy completed the treatment. Neurological symptoms regressed rapidly. CONCLUSION: Although the incidence of intracranial tuberculomas is decreasing in developed countries, a high index of suspicion must be maintained for the diagnosis of intracranial masses in the presence of risk factors for tuberculosis.

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.