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Biomedical subjects

D E Brackmann

Publications and source records attributed to D E Brackmann.

At least 37 records · Page 2Linked to original sources
PubMed1999

Report of 190 consecutive cases of large acoustic tumors (vestibular schwannoma) removed via the translabyrinthine approach.

OBJECT: The choice of approach for surgical removal of large acoustic neuromas is still controversial. The authors reviewed the results in a series of patients who underwent removal of large tumors via the translabyrinthine approach. METHODS: The authors conducted a database analysis of 190 patients (89 men and 101 women) with acoustic neuromas 3 cm or greater in size. The mean age of these patients was 46.1+/-15.6 years. One hundred seventy-eight patients underwent primary translabyrinthine surgical removal and 12 underwent surgery for residual tumor. Total tumor removal was accomplished in 183 cases (96.3%). The tumor was adherent to the facial nerve to some degree in 64% of the cases, but the facial nerve was preserved anatomically in 178 (93.7%) of the patients. Divided nerves were repaired by primary attachment or cable graft. Facial nerve function was assessed immediately after surgery, at the time of discharge, and at 3 to 4 weeks and 1 year after discharge. Excellent function (House-Brackmann facial nerve Grade I or II) was present in 55%, 33.9%, 38.8%, and 52.6% of the patients for each time interval, respectively, with acceptable function (Grades I-IV) in 81% at 1 year. Cerebrospinal fluid leakage that required surgical repair occurred in only 1.1% of the patients and meningitis in 3.7%. There were no deaths. CONCLUSIONS: Use of the translabyrinthine approach for removal of large tumors resulted in good anatomical and functional preservation of the facial nerve, with minimum incidence of morbidity and no incidence of mortality. The authors continue to recommend use of this approach for acoustic tumors larger than 3 cm and for smaller tumors when hearing preservation is not an issue.

Adolescent↗
PubMed1999

Establishment of primary vestibular schwannoma cultures from neurofibromatosis type-2 patients.

Primary cultures were established from vestibular schwannomas of NF2 patients. The cultured tumor cells were selectively amplified by growth factor supplemented medium and characterized by immunocytochemistry. NF2 cDNA was amplified by RT-PCR and mutations were detected by both the non-isotopic RNase cleavage assay and direct DNA sequencing, no detectable wild-type NF2 transcript was found in cDNA from the cultured cells. Distinguishable morphology and growth rate differences have been observed in different passages of the primary cells. The data suggest that a pure schwannoma primary culture can be established and could be very useful in vitro model for further understanding the NF2 gene function in Schwann cells.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1999

Intraoperative corticosteroids in acoustic tumor surgery.

BACKGROUND: Corticosteroids are frequently used for the prevention and treatment of neural edema. Although perioperative steroid therapy has been used in patients undergoing acoustic neuroma removal, the efficacy of such therapy has not been previously documented. METHODS: A retrospective review of 169 patients who underwent acoustic neuroma surgery with (n = 75) or without (n = 94) a single dose of intraoperative corticosteroids was performed. Tumor size ranged from 0.4 cm to 6 cm (mean, 2.1; SD, 1.0) The translabyrinthine approach was used in 85% of the patients, and the middle cranial fossa approach was used in 13%. Data were analyzed for differences in postoperative facial function and complication rates. RESULTS: After controlling for differences in tumor size, no significant effects of steroid therapy were found for any of the outcome variables. CONCLUSIONS: This retrospective study showed no apparent benefit from intraoperative steroid use in acoustic neuroma surgery. A prospective, randomized, placebo-controlled trial should be performed to confirm these findings.

Anti-Inflammatory Agents↗
PubMed1999

Acoustic tumor growth: implications for treatment choices.

BACKGROUND: Knowledge of acoustic neuroma (AN) growth is essential for treatment planning. METHODS: A retrospective analysis of 119 patients with AN (mean age, 65 years; range, 37-84 years) followed with interval magnetic resonance imagings (MRIs) was performed. Change in maximum tumor dimension as a function of follow-up period was analyzed. RESULTS: Overall, maximum tumor dimension increased >2 mm in only 30% of patients. Of those that grew, the mean growth rate was 3.8 mm/year (maximum, 25 mm/year). Age, gender, and laterality did not predict growth. Most tumors that grew (86.1 %) were <20 mm at presentation. However, tumors >20 mm were statistically more likely to grow (71%, p =0.028). CONCLUSIONS: Most ANs followed with periodic MRIs do not grow. Available clinical information usually cannot predict growth. Serial MRIs are advocated for all patients treated with observation.

Adult↗
PubMed1998

Auditory-nerve integrity after middle-fossa acoustic-tumor removal.

We sought to investigate the functional integrity of the auditory nerve in patients with postoperative hearing loss after middle cranial fossa acoustic-tumor removal in a case-series descriptive study. The study setting was a tertiary referral center, a private otologic practice. The study population comprised seven patients who underwent a middle-cranial-fossa approach for unilateral acoustic-tumor resection and sustained postoperative anacusis with an anatomically intact auditory nerve. Four were men and three women; they ranged in age from 30 to 60 years; all underwent surgery between 1990 and 1994 and agreed to return to the center to participate in the study during 1995. Diagnostic electrical promontory stimulation was used to determine the functional integrity of the auditory nerve. Our main outcome measures were the presence or absence of discrete tone perception, electrical threshold, maximum acceptable level and dynamic range, gap detection and temporal difference limen during electrical promontory stimulation. Three of the seven patients demonstrated positive responses to electrical promontory testing (e.g., discrete tone perception). All three were able to perform the gap-detection and temporal difference limen tests. None of the preoperative characteristics was related to performance on promontory stimulation testing. We conclude that the middle cranial fossa approach permits anatomic--and, in some cases, functional auditory-nerve preservation. These data suggest that auditory rehabilitation in some patients who sustain anacusis after the middle cranial fossa approach to acoustic tumors, as in neurofibromatosis 2, may be provided with cochlear implantation.

Adult↗
PubMed1998

Germline screening of the NF-2 gene in families with unilateral vestibular schwannoma.

Vestibular schwannoma may present clinically in two forms: sporadic unilateral or hereditary bilateral. Familial transmission of vestibular schwannoma is known to occur only in neurofibromatosis type II (NF-2). We have previously described the clinical characteristics of unilateral vestibular schwannoma presenting in families, in the absence of ther criteria necessary for the diagnosis of NF-2. Polymerase chain reaction-single strand chain polymorphism was used to screen for germline NF-2 gene mutations in six families with unilateral vestibular schwannoma. Direct sequencing of DNA from blood was done in affected subjects from three families. No germline mutations were identified. Because NF-2 gene mutations are detected in only 33% of patients with NF-2, hereditary transmission of mutations cannot be entirely excluded. However, in the absence of germline mutations in the NF-2 gene, familial occurrence of unilateral vestibular schwannoma more likely represents either a chance somatic NF-2 gene mutation or originates from a separate genetic loci.

Case-Control Studies↗
PubMed1998

The multichannel auditory brain stem implant: performance in twenty patients.

The auditory brain stem implant has been used effectively to provide hearing sensations to individuals deafened by bilateral auditory nerve tumors (neurofibromatosis type 2). During tumor removal, the auditory brain stem implant is implanted into the lateral recess of the fourth ventricle by a translabyrinthine approach and is intended to stimulate auditory neurons of the cochlear nucleus complex. A new eight-electrode multichannel auditory brain stem implant was developed and evaluated in 20 patients who had at least 3 months' experience with the device. Mild nonauditory sensations (primarily tingling in the head or torso) were encountered in some instances but could be managed by changing the stimulus characteristics or excluding electrodes. Testing of perceptual performance indicated significant benefit from the device for communication purposes, including sound-only sentence recognition scores in three patients ranging from 49% to 58% and ability to converse on the telephone. These results indicate that significant auditory benefit can be derived from direct multichannel electrical stimulation of the auditory portion of the human brain stem.

Acoustics↗
PubMed1998

Primary lymphoma of the internal auditory canal. Case report and review of the literature.

We report a rare case of a primary intracranial B cell lymphoma originating in the internal auditory canal. The clinical manifestations were indistinguishable from those of other, more common tumors of the same region. We achieved total gross tumor removal with preservation of the facial nerve. A detailed histologic examination and a systemic workup confirmed the primary nature of this tumor. To our knowledge, this is the second case reported in the literature of a primary malignant lymphoma originating in the internal auditory canal. This is the first instance that includes immunohistochemical and cytometric studies of fresh tissue. We discuss the management of primary lymphomas of the central nervous system, with special emphasis on their association with acquired immunodeficiency syndrome and other immune system diseases. Awareness of primary central nervous system lymphomas is important, since a greater occurrence of these rare tumors in the cerebellopontine angle is probable in the future.

Ear Canal↗
PubMed1998

Hearing preservation in neurofibromatosis type 2.

OBJECTIVE: The aim of the study was to provide a clinical review of the middle fossa approach for hearing preservation in patients with neurofibromatosis type 2 (NF2). STUDY DESIGN: The study design was a prospective case review. SETTING: The study was conducted at a private practice tertiary neurotologic referral center. PATIENTS: Eighteen patients diagnosed with NF2 underwent 23 middle fossa procedures between 1992 and 1996 for removal of an acoustic neuroma. The nine males and nine females ranged in age from 11-73 years with a mean age of 28 years. Tumor size ranged from 0.5-2.5 cm with a mean of 1.1 cm. MAIN OUTCOME MEASURES: House-Brackmann facial nerve grade was measured. In addition, hearing level was classified both by the American Academy of Otolaryngology-Head and Neck Surgery criteria for reporting results of hearing preservation surgery and by comparison with preoperative level (15 dB/15%). RESULTS: Measurable hearing was preserved in 65%, 48% within 15 dB of preoperative pure-tone average (PTA) and within 15% of preoperative speech discrimination. Bilateral hearing preservation occurred in five patients. Excellent facial nerve function (House-Brackmann grades I-II) was obtained in all patients with normal preoperative facial nerve function. CONCLUSIONS: In this series of patients with NF2, outcomes in hearing and preservation of preoperative facial nerve function are similar to results seen in patients suffering a sporadic unilateral acoustic neuroma. However, early intervention is crucial in obtaining such favorable outcomes.

Adolescent↗
PubMed1997

Management of the contracted mastoid in the translabyrinthine removal of acoustic neuroma.

Several approaches to the internal auditory canal and cerebellopontine angle for acoustic neuroma removal have been described. We prefer the translabyrinthine approach in patients with tumors larger than 2 cm or poor preoperative hearing, since both factors predict poor hearing preservation. Many surgeons perceive this approach as confining and consider it contraindicated in large tumors or contracted mastoids. We have recently described the utility of the translabyrinthine approach for the removal of large (> 4 cm) acoustic neuromas. In more than 5000 tumor excisions performed by the senior author (W.E.H.), no cases required a modification of the approach because of anatomic constraints within the mastoid. We describe our techniques for the management of the low-lying tegmen, the anterior sigmoid sinus, and the high jugular bulb, alone or in combination, during translabyrinthine removal of acoustic neuromas.

Cerebellopontine Angle↗
PubMed1997

Particulate matter in the posterior semicircular canal.

The pathoetiology of benign paroxysmal positional vertigo (BPPV) is controversial. Particulate matter within the posterior semicircular canal has been identified intraoperatively in patients with BPPV but has also been reported in non-BPPV patients at the time of translabyrinthine surgery (Parnes LS, McClure JA. Free-floating endolymphatic particles: a new operative finding during posterior semicircular canal occlusion. Laryngoscope 1992;102:988-92; Schuknecht HF, Ruby RRF. Cupulolithiasis. Adv Otorhinolaryngol 1973;20: 434-43; Kveton JF, Kashgarian M. Particulate matter within the membranous labyrinth: pathologic or normal? Am J Otol 1994;15:173-6). The nature of the particulate matter remains unknown. The purpose of this study was to prospectively examine the posterior semicircular canal of patients with and without a clinical history of BPPV for the presence of particulate matter. Seventy-three patients without BPPV symptoms undergoing labyrinthine surgery (vestibular schwannoma excision or labyrinthectomy) and 26 patients with BPPV undergoing the posterior semicircular canal occlusion procedure were compared. Additionally, 70 archived temporal bones without a history of BPPV were examined microscopically for the presence of particulate matter within the lumen of the membranous labyrinth. No particles were observed intraoperatively in any of the 73 patients without a history of BPPV. Particulate matter was observed in 8 of 26 patients at the time of the posterior semicircular canal occlusion procedure for intractable BPPV. Of the 70 temporal bones examined, 31 did not show significant postmortem changes and also did not demonstrate cupulolithiasis or canalithiasis. Particulate matter from within the membranous posterior semicircular canal was removed from one patient at the time of posterior semicircular canal occlusion for intractable BPPV symptoms and was examined by scanning electron microscopy. The particulate matter appeared morphologically consistent with degenerating otoconia. These data show a statistically significant association between the presence of particles within the posterior semicircular canal in this study and the symptom complex of BPPV.

Ear, Inner↗
PubMed1997

Familial occurrence of unilateral vestibular schwannoma.

Vestibular schwannoma (VS) may present clinically in one of two forms: sporadic unilateral or hereditary bilateral. Almost all cases of familial transmission have been associated with the diagnosis of neurofibromatosis type II (NF-2). In this report, we describe nine families (18 individuals) presenting with unilateral VS without evidence of NF-2. In four of the nine families, the affected individuals were of parent-offspring relationship, in three families they were cousin-cousin, and in the remaining two families, they were sibling-sibling and aunt-nephew. No other members of the families were diagnosed with NF-2. There was no evidence for gender predilection or genomic imprinting among affected individuals. This study suggests that familial occurrence of unilateral VS may be genetically inherited as it occurs more commonly than would be estimated by chance alone. Future genetic studies will elucidate whether occurrence of unilateral VS in these families represents a variable expression of NF-2, chance occurrence of unilateral VS in families, or a new genetic disorder.

Adult↗
PubMed1997

Meningiomas intrinsic to the geniculate ganglion.

OBJECTIVE: To present the clinical, surgical and histopathological manifestations of meningioma intrinsic to the geniculate ganglion. STUDY DESIGN: Retrospective study of outcome. SETTING: Three private tertiary and one university (otology/neurotology) referral centers. PATIENTS: Six patients with cranial nerve VII paresis underwent magnetic resonance imaging and/or high-resolution computed tomography for subsequently histologically proven intrinsic meningioma of the geniculate ganglion. An additional six cases were identified in the literature. Most patients were female and ranged in age from 5 to 40 years. INTERVENTION: Total tumor removal via middle fossa and mastoid exposures followed by cable graft VII-VII neuroanastomosis. MAIN OUTCOME MEASURE: Meningioma can occur intrinsic to the geniculate ganglion and produces gradual VIIth nerve paresis as its first symptom. Other sites of predilection may occur extrinsically within the temporal bone or along intracranial venous sinuses at sites of arachnoid villi. RESULTS: Hearing was maintained in each patient, and postoperative House-Brackmann grade III-V facial nerve function was achieved. CONCLUSIONS: Intrinsic meningiomas of the geniculate ganglion rarely occur. However, this entity should be included in the differential diagnosis of a slowly progressive VIIth nerve paresis, especially in young females. Surgical removal and cable graft VII-VII neuroanastomosis is the treatment of choice. Long-term follow-up should be maintained because of the potential for von Recklinghausen's disease.

Adolescent↗
PubMed1997

Preoperative electroneuronography and facial nerve outcome in acoustic neuroma surgery.

OBJECTIVE: To determine whether preoperative electroneuronography (ENoG) predicts facial nerve outcome in patients undergoing acoustic neuroma surgery. STUDY DESIGN: Prospective, consecutive patients undergoing surgery for acoustic neuroma. SETTING: A private tertiary otology and neurotology practice. PATIENTS: One hundred consecutive patients presented for surgical removal of an acoustic neuroma between May 1992 and September 1993. The mean patient age was 49 years (range 17-77). Forty-three percent were male and 57% were female. The mean tumor size was 1.77 cm (range 3 mm to 5 cm). The tumors were removed by a translabyrinthine approach in 59% of patients, via the middle fossa in 40%, and retrosigmoid in 1%. The facial nerve was anatomically intact at the conclusion of the operation in all but one patient. INTERVENTION: Preoperative ENoG in all patients undergoing surgical removal of their acoustic neuromas. MAIN OUTCOME MEASURES: Facial nerve outcome was measured using the House-Brackmann scale immediately after the operation. 5-7 days after surgery, and > 1 year after surgical resection. RESULTS: Preoperative ENoG had no predictive value in determining immediate or eventual facial nerve outcome. CONCLUSIONS: ENoG has no value in predicting the facial nerve outcome in acoustic neuroma patients. The results of this study are similar to reports with smaller series in the literature. Preoperative ENoG has proven useful, in another study from this institution, in predicting the possible presence of a facial nerve neuroma. This test may be helpful in determining the possible etiology of an intracanalicular mass.

Adolescent↗
PubMed1997

Middle fossa approach for hearing preservation with acoustic neuromas.

OBJECTIVE: This study aimed to provide a clinical review of middle fossa approach for hearing preservation in acoustic neuroma surgery. STUDY DESIGN: This was a prospective case review. SETTING: The study was performed in a tertiary referral center of a private otologic practice. PATIENTS: One hundred fifty-one consecutive middle fossa approaches for removal of acoustic neuroma were used. The 91 males and 60 females ranged in age from 10-72 years with a mean age of 48 years. Tumor size ranged from 0.5-2.5 cm, with a mean of 1.2 cm. MAIN OUTCOME MEASURES: House-Brackmann facial nerve grade and hearing level classified both by the American Academy of Otolaryngology-Head and Neck Surgery criteria for reporting results of hearing preservation surgery and by comparison with preoperative level (15 dB/15%) were the main outcome measures. RESULT: Measurable hearing was preservation in 68%, with 52% within 15 dB and 15% discrimination. Excellent facial function (House-Brackmann grade I-II) was obtained in 95% of patients. CONCLUSION: The middle fossa craniotomy approach for acoustic neuroma is a reliable approach with a good hearing preservation rate and excellent facial nerve function outcome. Complications are minimal in this group of patients.

Adolescent↗