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Biomedical subjects

J M Sterkers

Publications and source records attributed to J M Sterkers.

At least 19 recordsLinked to original sources
PubMed2004

Facial nerve outcome in non-vestibular schwannoma tumour surgery.

PROBLEMS/OBJECTIVES: Tumour size, intra-operative electrophysiologic thresholds and postoperative facial nerve function have been demonstrated to be important predictors of ultimate facial nerve function after vestibular schwannoma surgery. In general little attention has been given to the prediction of outcome of facial nerve function in non-vestibular schwannoma tumour surgery of the cerebellopontine angle (CPA). METHODOLOGY: A prospective study was performed to assess the predictive value of patient, tumour histology and electrophysiologic factors in the estimation of ultimate facial nerve outcome after this form of surgery. RESULTS: Sixteen patients satisfied the requirements of the study. Poor long-term facial nerve outcome was associated with abnormal pre-operative facial nerve function, facial nerve schwannomas, premeatal meningiomas and electrophysiologic stimulation thresholds of greater than 0.1 mA. CONCLUSIONS: It is concluded that tumour histology and pre-operative facial nerve function are additional factors that must be considered in the prediction of facial nerve function after non-vestibular schwannoma surgery of the CPA.

Aged↗
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↗
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↗
PubMed1999

Bilateral facial nerve schwannomas.

Facial nerve schwannoma is an uncommon tumor and bilateral facial nerve tumors are extremely rare. A case is presented in which neuromas affecting the intra-canalicular and labyrinthine portions of both facial nerves occurred. Radiologic assessment demonstrated the origin of these tumors. Eventual tumor involvement of the sole functioning cochlea resulted in the development of total hearing loss. Management entailed symptomatic care and surgical resection. Auditory rehabilitation was attempted using cochlear implantation, but results have not been satisfactory. Genetic screening identified a mutation in the NF2 gene. It is proposed that this patient's condition should be considered a variant of neurofibromatosis 2 and that bilateral facial neuromas should be included in the clinical criteria for this condition.

Adult↗
PubMed1998

Slow-growing labyrinthine masses: contribution of MRI to diagnosis, follow-up and treatment.

We report the use of MRI in the diagnosis, follow-up and therapeutic management of three cases of intralabyrinthine Schwannoma. The diagnosis was based on the history and initial and follow-up MRI findings. The main feature suggesting the diagnosis was a nodular intralabyrinthine mass of low signal intensity on T2-weighted images, and high or isointense signal on T1-weighted images (relative to cerebrospinal fluid), which showed contrast enhancement. Follow-up imaging showed growth of the tumour in one patient. One patient underwent surgery for severe tinnitus. To detect these lesions, MRI should be focussed on the inner ear, using thin-section T2-weighted and T1-weighted images before and after contrast medium. MRI allowed informed surgical planning.

Adult↗
PubMed1996

Unusual presentations of acoustic tumours.

A series of 238 consecutive patients with acoustic neuromas, operated on in Paris has been studied to identify unusual presentations and varied symptomatology. The most common history was that of a progressive unilateral hearing loss (in 68.1%), with tinnitus (in 49.1%) or disequilibrium (in 49.1%) or both. Sudden hearing loss (in 14.7%) or fluctuating hearing loss (in 6.3%), and a single or repeated episodes of acute vertigo (in 8.8%) were seen less commonly. Headaches occurred as an associated symptom in 10.5%, tinnitus was the sole symptom in 2.8% and other uncommon symptoms included otalgia, facial nerve palsy, facial or ocular pain, altered sensation in the face or eye, or tingling of the tongue. Some 11.3% of patients presented with normal pure tone auditory thresholds and a 100% speech discrimination score and of these patients acoustic reflex thresholds were normal in 53% and brainstem auditory evoked responses were suggestive of the retro-cochlear abnormality in only 76.2%. Amongst the less common presentations, the initial symptoms mimicked such diagnoses as Meniére's disease, benign positional vertigo, vertebro-basilar migraine, vertebro-basilar insufficiency, Bell's palsy and Trigeminal neuralgia. Overall, 20.6% of patients had unusual initial presenting symptoms, 36.5% of the symptoms were unusual and these were found in isolation in 11.8% of patients. An awareness of the spectrum of more subtle symptoms of acoustic tumours may lead to the correct diagnosis at an earlier stage.

Aged↗
PubMed1996

[Hemangioma of the facial nerve].

In this retrospective study the respective values of MRI and CT in the location and nature diagnoses of facial nerve haemangiomas were evaluated. The four male patients examined were 31, 44, 56 and 62 years old; they presented with facial nerve pals and/or cochlear-vestibular dysfunction. The haemangiomas were located in the internal auditory canal, the geniculate ganglion, the tympanic segment of the facial nerve and the petrous bone apex. MRI revealed a tumoral process, while CT showed intratumoral calcifications and provided a diagnosis of mass nature in two cases. In the other cases the pre-operative diagnosis was neurinoma of the VIIIth or VIIth cranial nerve. Histology ascertained the diagnosis. MRI is the method of choice in cases of facial paralysis or cochlear-vestibular dysfunction if a tumoral cause is suspected. Haemangioma is an uncommon tumour without specific image, except for calcifications and neighbouring osseous reactions. It must also be considered on the basis of clinical and topographical findings revealed by CT and MRI imaging.

Adult↗
PubMed1995

Screening for germ-line mutations in the NF2 gene.

Neurofibromatosis type 2 (NF2) is a monogenic dominantly inherited disease that predisposes to the development of tumors of the nervous system, particularly meningiomas and schwannomas. The gene which, when altered, causes NF2, is localized on chromosome 22 and has recently been identified. The NF2 gene is also the site of somatic mutation in tumors, suggesting that it might have a tumor suppressor activity. We here report a screening method for the detection of point mutations in NF2 which takes advantage of denaturing gradient gel electrophoresis (DGGE). This method efficiently screens 95% of the coding sequence and 90% of intron/exon junctions. When applied to 91 unrelated NF2 patients, it enabled the identification of 32 germ-line mutations. Since mutations are found in only one third of the patients, it is expected that mutations or deletions affecting the promoter and/or intronic regions of the NF2 gene occur frequently. The characterized mutations are preferentially located within the 5' half of the gene. Most of them are predicted to lead to the synthesis of a truncated protein. A search for genotype/phenotype correlations showed that, at least in this series of patients, mild manifestations of the disease were associated with mutations which preserve the C-terminal end of the protein.

Base Sequence↗
PubMed1995

[Surgery for meningioma of the posterior skull base. 135 cases. Choice of approach and results].

One hundred and thirty-five patients with posterior skull base meningiomas were seen and treated by a neurosurgical-neurotological team over the last 12 years. Ten tumors were "true" clival meningiomas and 125 were posterior petrous meningiomas: 25 were located anterior to the internal auditory meatus (IAM) (zone A); 29 were located around the IAM (zone M) and 18 were posterior to the IAM (zone P). 53 tumors had a larger zone of implantation and are accordingly called AM (31 cases), MP (15 cases), AMP (7 cases). The choice of routes was guided by a radiological anatomy classification system (17). Transpetrous approaches, alone or in combination with subtemporal transtentorial or retrosigmoid approaches were the surgical routes of choice for posterior petrous meningiomas, making it possible to reach the tumoral osteodural implantation, reduce the tumoral mass and perform a subarachnoidal dissection of the tumor poles. A retrolabyrinthine (RL) approach allows access to zone P and a translabyrinthine approach to zone MP. Zones A, M and P can be reached via the anterior extended translabyrinthine (AETL) approach. Anterolateral transclival approaches with apex petrectomy were used to reach the clival meningiomas with a wide implantation zone. Standard microsurgical techniques were used in 32 cases and 103 procedures included the use of a microscope-guided laser. Complete tumor removal was accomplished in 88% of cases (120/135). Overall mortality was 3.7% (2 cases at 30 days and 3 cases between 31 days and 1 year).

Aged↗
PubMed1994

Preservation of facial, cochlear, and other nerve functions in acoustic neuroma treatment.

Between March 1966 and September 1992, 1400 acoustic neuromas were treated in Paris, France, by surgical excision. The findings over the last 7 years are presented. The translabyrinthine approach has been used in more than 85% of cases. Where hearing preservation is attempted, the middle fossa approach has been adapted for intracanilicular tumors and the retrosigmoid approach for small tumors extending into the cerebellopontine angle, in which the fundus of the internal meatus is free of tumor. The main goal is to achieve a grade I or II result in facial function within 1 month of surgery. Results improved during 1991 after the introduction of continuous facial nerve monitoring and the use of the Beaver mini-blade for dissection of tumor from nerve. With these techniques, facial function of grade I or II at 1 month improved from 20% to 52% for large tumors (larger than 3 cm), from 42% to 81% for medium tumors (2 to 3 cm). and from 70% to 92% for small tumors (up to and including 2 cm extracanalicular). The facial nerve was at greater risk using the retrosigmoid or middle fossa approaches than by the translabyrinthine route. Since 1985, success in hearing preservation has changed little, with useful hearing being preserved in 38.2% of cases operated on by means of the retrosigmoid route and a 36.4% of cases after the middle fossa approach. In older patients with good hearing and small tumors, observation with periodic MRI scanning is recommended. Despite earlier diagnosis, the number of patients suitable for hearing preservation surgery remains very limited and careful selection is required. Trigeminal nerve signs were present in 20% of cases preoperatively, in 10% postoperatively, and recovered spontaneously. Palsies of the other cranial nerves after surgery were much rarer and were as follows: sixth nerve (abducens), 0.5%; ninth nerve (glossopharyngeal), 1.4%; and tenth nerve (vagus), 0.7%. The importance of preservation of function of the nervus intermedius of Wrisberg is stressed. These results emphasize the advantages of the translabyrinthine approach, offering greater security to the facial nerve and lower morbidity.

Adolescent↗
PubMed1993

[Acoustic neuroma].

The progress of the diagnostic and treatment of the acoustic tumors have begin in the years 1960. From this time, radio imaging, surgical and anasthesic techniques have improved in such a way that the lethality of the surgery is almost equal to 0% and the preservation of the facial mimic have reached a point that was never attained before. It must be emphasized that this surgery requires a surgical staff well trained and an appropriate structure. The preservation of hearing remains and will remain possible in some exceptional cases, as we know how fragile is this function in most of the cases.

Diagnostic Imaging↗
PubMed1992

Magnetic resonance imaging of acoustic neuromas: pitfalls and differential diagnosis.

A total of 162 patients with suspected acoustic neuromas underwent MR imaging at 1.5 T. All patients were injected with Gd DTPA or DOTA. In 72 patients, uni- or bilateral acoustic neuromas were detected. 18 cases were equivocal: In 9 cases, contrast enhancement was due to other tumors (5 meningiomas, 2 metastases, 1 hemangioma). In 1 case, misinterpretation resulted from partial volume effects with the petrous bone marrow. In one patient, previously operated on, increased signal was due to postoperative fat graft. Four hypersignals were due to intracanalicular venous or meningeal enhancement. Three cases are still equivocal. Most of the diagnostic problems may be obviated by precontrast MR imaging, multidimensional 3-mm sections, and fast imaging.

Contrast Media↗
PubMed1991

[Unusual circumstances of disclosure of acoustic neurinoma].

While progressive unilateral deafness remains the most typical symptom of the development of acoustic neuroma, the study of at least 1,200 cases operated since 1966 shows that in at least 16.5% of all cases, the triggering signal to seek medical advice was either otologic but atypical, or non-otologic but including symptoms in another pair of cranial nerves, or without any apparent relationship with the area showing a tumor of the eight pair, or even occurring under etiological circumstances that were misleading at first.

Adolescent↗