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Biomedical subjects

E M Monsell

Publications and source records attributed to E M Monsell.

17 recordsLinked to original sources
PubMed1992

Labyrinthotomy with streptomycin infusion: early results of a multicenter study. The LSI Multicenter Study Group.

Early results for hearing and vertigo are reported for 47 labyrinthotomies with streptomycin infusion (LSI) by 13 coinvestigator-surgeons. Sixty-eight percent of patients had worse hearing after surgery (10 dB or 15% word recognition). Patients with a preoperative pure-tone average better than or equal to 40 dB appeared to suffer less postoperative hearing loss than those with a greater preoperative deficit. Severe to profound postoperative hearing loss was experienced by 27 patients (57%), all of whom had preoperative pure-tone averages worse than 40 dB. Opening the endolymphatic space was associated with a deleterious effect on hearing. Because of persistent vertigo, 17 percent of patients required a secondary procedure during the period of observation. These early results indicate that LSI is associated with a significant risk of postoperative hearing loss. Of the 13 coinvestigator-surgeons, four have stopped using LSI, while one considers his results satisfactory. The remaining surgeons have taken an intermediate position and feel it is useful in selected cases. Longer follow-up is required to judge the efficacy of LSI for controlling vertigo. We are currently studying these long-term results.

Adult↗
PubMed1990

Estrogen and progesterone binding by acoustic neuroma tissue.

Tissue samples from 37 acoustic neuromas were assayed for estrogen and progesterone hormone receptor binding by radioimmunoassay using a dextran-coated charcoal method and Scatchard plot analysis. Twenty-one of the samples were from men, and 16 of the samples were from women. Seven of 37 samples (19%) were positive for estrogen receptor and six of 36 samples (17%) were positive for progesterone receptor. Three of 37 samples (8%) were positive for both receptors. There was no correlation of estrogen receptor positivity with the sex of the patient. These results indicate that estrogen or progesterone receptor binding activity or both are present in a small subset of acoustic tumors. Evidence is lacking, however, that binding of estrogen to the receptor results in growth changes in the tumor. The empirical use of antiestrogen treatment in acoustic neuroma does not appear to be justified at the present time.

Adult↗
PubMed1990

Diagnosis and treatment of arachnoid cysts of the posterior fossa.

Arachnoid cysts of the posterior fossa are rare. When arachnoid cysts are encountered, the presenting symptoms are frequently otologic, with hearing loss and imbalance occurring commonly. Three cases are presented with a previously unreported otologic symptom, that of bilateral hearing loss, which in one case was fluctuant. None of the patients had the common symptoms of unilateral hearing loss and headache. With the advent of computed tomography and magnetic resonance imaging, these cysts may be readily identified, usually with diagnostic imaging alone. Unfortunately there is often a delay in diagnosis because of the vague and fleeting nature of the symptoms. Because no single diagnostic symptom pattern is able to characterize all cases, it is believed computed tomography or magnetic resonance imaging or both are indicated in patients with long-standing otologic complaints--even in the absence of unilateral symptoms. Treatment of posterior fossa arachnoid cysts primarily consists of surgical procedures designed to decompress the cyst. In this series, treatment with diuretics alone resulted in improvement of symptoms during several years of followup, with no evidence of enlargement of the cysts.

Adult↗
PubMed1990

Sensorineural hearing loss and the diagnosis of acoustic neuroma.

Sensorineural hearing loss and tinnitus are gradually receiving more attention in medicine due to advances in diagnosis and treatment. Acoustic neuromas can now be detected when they are small, and early microsurgical removal results in the lowest overall morbidity. We examine the historical development of acoustic neuroma management, discuss current diagnosis and treatment, and present illustrative cases from our recent experience. Complaints of tinnitus and hearing loss, especially when unilateral, require appropriate medical evaluation.

Adolescent↗
PubMed1989

Age considerations in acoustic neuroma surgery: the horns of a dilemma.

Experience has shown that early removal of acoustic tumors results in less morbidity because the rate of surgical complications increases with tumor size. Nevertheless, acoustic tumors are benign and grow slowly--facts that support conservatism in elderly patients. We managed 21 patients with acoustic tumors over the age of 65. Eleven patients underwent immediate surgical excision. Ten patients were monitored clinically and with serial magnetic resonance imaging (MRI) or computed tomographic (CT) scans. To date, two of these patients have required surgical excision because of continued tumor growth. Our experience managing these patients both surgically and with "watchful waiting" is the subject of this report.

Adolescent↗
PubMed1988

Why do vestibular destructive procedures sometimes fail?

Vestibular nerve specimens and one temporal bone, from patients with vestibular symptoms after destructive surgery on the vestibular system, were studied by light microscopy. Surviving nerve axons in three specimens that followed retrolabyrinthine vestibular nerve section (RLVNS) were counted and compared to normative data. Results are consistent with persistence of the central processes of primary vestibular neurons in three specimens from patients who had persistent symptoms and ice-water caloric responses after RLVNS. Incomplete neurectomy probably results from anatomic variations in the plane of separation of the vestibular and cochlear portions of the eighth nerve in the posterior fossa. Regeneration neuromas were found in the vestibule after a complete transmastoid labyrinthectomy and a Fick sacculotomy; this indicates that wide degrees of injury to the labyrinth may provoke this response. Disabling unsteadiness after labyrinthectomy may or may not respond to revision surgery (translabyrinthine vestibular nerve section). The indications for revision surgery are discussed. The excision of Scarpa's ganglion by the translabyrinthine route offers the best chance to ensure complete removal of peripheral vestibular tissue, minimize postoperative unsteadiness, and prevent neuroma formation.

Adult↗
PubMed1988

Endolymphatic sac surgery in congenital malformations of the inner ear.

A retrospective analysis of 40 patients (49 ears) with congenital progressive sensorineural hearing loss who underwent endolymphatic sac surgery was performed. The inner ears were radiographically abnormal in 57% of operated ears. In the remaining cases, subtle malformations beyond the resolving power of radiographic studies were suspected. Early postsurgical hearing loss (defined as a loss greater than 10 dB in three-tone average or greater than 15% in speech discrimination score) was found in 29% of operated ears (14/49). However, only two of these patients lost all of their residual hearing postoperatively (2/49 or 4%). An enlarged endolymphatic sac was noted at surgery in 50% of those with significant postoperative hearing losses. Longer-term stability of hearing was assessed in 22 patients with bilateral inner-ear pathology who underwent surgery on one side only. A comparison of the hearing fate of the operated and nonoperated ears suggested no benefit from the surgical intervention when compared to the natural history of the disease. Based upon this experience, endolymphatic sac surgery for the purpose of hearing stabilization in patients with congenital malformations of the inner ear is no longer recommended.

Adolescent↗
PubMed1988

Surgical treatment of vertigo with retrolabyrinthine vestibular neurectomy.

Results for control of vertigo and preservation of hearing in patients who have had a retrolabyrinthine vestibular neurectomy (RVN) by our group were analyzed retrospectively. This procedure consists of selective section of the vestibular nerve in the posterior cranial fossa. Vertigo was completely controlled in all but two of 31 patients, one of whom required revision surgery to control attacks. Analysis of these two cases suggests that the cause of persistent vertigo is incomplete neurectomy. With our current surgical technique in patients with Meniere's disease, hearing results were not statistically different from our results with surgery of the endolymphatic sac. Control of vertigo was much more successful with the RVN than endolymphatic sac surgery.

Adult↗
PubMed1988

Endolymphatic sac surgery: methods of study and results.

Surgery of the endolymphatic sac (ELS) in classical Meniere's disease has fallen under attack and has been abandoned by some surgeons. We studied our results for vertigo and hearing in 83 patients undergoing surgery of the ELS for intractable classical Meniere's disease. Half of the patients were completely free of definitive attacks at 2 years; another quarter experienced substantial control. Three fourths noted an improvement in their level of disability. Results for vertigo were sustained at longer follow-up intervals. Nineteen percent had revision surgery (usually retrolabyrinthine vestibular neurectomy) for intractable vertigo within 2 years of the sac operation. The 1985 reporting method of the American Academy of Otolaryngology--Head and Neck Surgery was found superior to previous methods because it specified a meaningful follow-up interval, used a graded scale accounting for partial success in treatment, and separated results for vertigo and hearing. Nevertheless, optimal use of the method in the future will require prospective reporting and a concerted effort to avoid confusion between definitive attacks of true vertigo and adjunctive vestibular symptoms. Even though the mechanism of the beneficial effect of sac surgery is unknown, we have found it useful in the control of disabling vertigo.

Cost-Benefit Analysis↗
PubMed1987

Congenital malformations of the inner ear: histologic findings in five temporal bones.

The histopathologic findings in five temporal bones from three patients with congenital malformation of the inner ear are described. The external contour of the cochlea was deformed in two temporal bones, while the internal architecture was abnormal in all five temporal bones. Intracochlear abnormalities included defects in the interscalar septum, deficiencies in the modiolus, and a paucity of neural elements. Spiral ganglion cell populations varied, but were substantially diminished in all five temporal bones. Enlargement of the vestibule and semicircular canals (lateral and posterior) was seen in two temporal bones. A large vestibular aqueduct and saccular hydrops were found in one temporal bone each. An attempt was made to relate the histologic patterns of deformity to the proposed clinical classification of inner ear malformations. Radiographic abnormality of the cochlea would have been detectable in two bones (incomplete partition pattern), while two other bones would have appeared as vestibule-semicircular canal syndromes. One bone would have been radiographically normal.

Chromosomes, Human, Pair 13↗
PubMed1987

Brain herniation and space-occupying lesions eroding the tegmen tympani.

Technological advances in neuroradiology and the development of skull base surgery in neurotology have improved diagnosis and management of lesions eroding the tegmen tympani. The diagnosis of brain hernia is to be suspected in patients with a history of complicated chronic ear surgery and a slowly developing pulsatile mass with CSF leak. Patients are best evaluated in the upright position, with an otomicroscope and by magnetic resonance imaging (MRI). Over 6 years, our group has treated seven patients with eight space-occupying lesions eroding the tegmen. Five of the lesions were repaired with a temporalis muscle flap, 2 with fascia and bone, and 1 with Marlex. A review of new technology in the diagnosis of brain hernia and a modification of previous techniques is given.

Adolescent↗
PubMed1987

Surgical approaches to the human cochlear nuclear complex.

Patients with bilateral neural deafness may be candidates for rehabilitation with a device that provides direct electrical stimulation of the central nervous system. The cochlear nuclear complex at the pons-medulla junction is a logical site to implant because it is in the surgical field exposed for acoustic tumor surgery. In this study we compared four surgical approaches commonly used to reach the cerebellopontine angle for ease of access to the cochlear nuclear complex. We found the translabyrinthine approach to be the most satisfactory because the anterior approach facilitates identification of key landmarks, such as the tenia of the choroid plexus and the lateral recess of the fourth ventricle. The suboccipital, or retrosigmoid, approach would be satisfactory after removal of a large acoutic tumor; however, the amount of cerebellar retraction necessary may preclude its use in nontumor cases.

Cochlea↗
PubMed1986

Organization of the motor neuron components of the pallial nerve in octopus.

Following horseradish peroxidase (HRP) and cobalt (CO2+) application to the pallial nerve of two species of octopus, neurons that control various aspects of mantle behaviors were located in several lobes of the three main regions of the central brain. In the subesophageal region, cells were labeled in the anterior chromatophore, posterior chromatophore, palliovisceral, pedal and vasomotor lobes; in the superior buccal lobe of the supraesophageal region; and in the magnocellular lobe of the periesophageal region. Localization of labeled cells in and around both the anterior and posterior chromatophore lobes suggests a modification of the idea that a single functional area is solely located in an anatomically defined brain lobe of a cephalopod.

Animals↗
PubMed1985

Hearing and balance disorders. How to recognize, when to refer.

Nearly one in ten Americans has some degree of hearing loss. The primary care physician is frequently the first to examine patients with hearing and balance disorders. Examination begins with a thorough history and examination and may also include specific tests performed in the office. In many cases, the primary care physician can diagnose and treat disorders successfully. In other cases, referral to a specialist is necessary.

Aminoglycosides↗
PubMedDate not supplied

Superselective embolization of glomus jugulare tumors.

The purpose of this report is to introduce the technique of superselective embolization (SSE) and to review our experience in surgically treating glomus jugulare tumors with and without preoperative SSE. Retrospective chart review was performed to determine estimated blood loss and operative time, and illustrative case reports are presented. The technique of preoperative SSE represents an important advance in the surgical management of glomus jugulare tumors. In our experience, surgical ligation of tumor-feeding vessels or nonselective embolization of the external carotid system is unsatisfactory. Inadequate devascularization and excessive risk of complications have caused us and others to abandon these procedures. However, SSE performed by an experienced neuroradiologist can produce effective and safer tumor devascularization. Preoperative SSE results in shrinkage of tumor size and significantly decreases blood loss. The advantages to the surgeon include improved visualization and ease of dissection as well as increased confidence that complete tumor excision has been achieved.

Adult↗