Search PubMed⌕ Search

Biomedical subjects

H Silverstein

Publications and source records attributed to H Silverstein.

At least 109 records · Page 6Linked to original sources
PubMed1985

Hearing preservation after acoustic neuroma surgery using intraoperative direct eighth cranial nerve monitoring.

Since the advent of brainstem auditory evoked response audiometry and computerized tomography, small acoustic neuromas are found more frequently. The patients often have serviceable hearing and wish to preserve it during complete tumor removal. Since 1978, we operated on thirteen patients with acoustic neuromas using the retrosigmoid suboccipital approach. Our goal in these cases was to preserve hearing. We began using intraoperative direct eighth nerve monitoring in 1983. This allowed us to rapidly assess cochlear nerve function during excision of small acoustic neuromas. Intraoperative monitoring was used in 5 of 13 cases, and in three patients, hearing was preserved. In the 8 cases where intraoperative monitoring was not used, hearing was preserved in only two patients. Our overall success rate of simultaneous total tumor removal hearing preservation was 38%. Tumor size varied from intracanalicular to one with a 3.0 cm protrusion medial to the porus acousticus. Hearing was preserved in 54% of cases where tumor size was less than 1.5 cm. We find continuous monitoring of direct eighth nerve evoked action potentials to be extremely valuable and a rapid indication of reversible cochlear nerve trauma.

Adult↗
PubMed1984

Streptomycin drug fever during treatment of bilateral Meniere's disease.

The use of intramuscular injections of streptomycin sulfate for the ablation of vestibular function in patients with bilateral Meniere's disease is well established. Although hypersensitivity reactions to streptomycin are documented, frank drug fevers are rare. Our patient, with no previous history of drug allergies, was treated with parenteral streptomycin for disabling bilateral Meniere's disease. The patient's hospital course was complicated by severe hypotension and spiking fevers, which were temporally related to the streptomycin injections, and which resolved on cessation of the drug therapy. A challenge dose of a new batch of streptomycin resulted in renewed rigors, fever, and hypotension. The necessity of early recognition of this uncommon, life-threatening drug fever with streptomycin is emphasized by our experience.

Drug Hypersensitivity↗
PubMed1984

Cochlear and vestibular gross and histologic anatomy (as seen from postauricular approach).

The otologic surgeon must have a clear understanding of the anatomy of the seventh and eighth cranial nerves from the labyrinth to the brain stem, as seen from the postauricular approach. The surgical anatomy of the seventh and eighth cranial nerves was studied in 64 transcochlear eighth-nerve sections and 33 retrolabyrinthine vestibular neurectomies. Analysis indicates the nerves rotate 90 degrees in their course from the ear to the brain. The key relationship is that the cochlear nerve is always the most inferior, rotating from anterior (medial) near the labyrinth to posterior (lateral) near the brain stem. The seventh (facial) nerve rotates from anterosuperior (medial superior) near the labyrinth to anteroinferior (medial inferior) near the brain stem. The seventh nerve is easily seen in the transcochlear approach and hidden from view in the retrolabyrinthine approach. Twenty-seven fixed nerve specimens were examined with an operating microscope before being prepared for sectioning. In 73% (19 of 26) a cleavage plane was seen on the lateral aspect of the eighth nerve (that portion of the nerve facing the surgeon in the retrolabyrinthine approach).

Brain Stem↗
PubMed1984

Analysis of surgical procedures in patients with vertigo.

The majority of patients with vertigo secondary to inner ear problems can be cured by surgery (80%). The results after neurectomy procedures such as cochleovestibular neurectomy or vestibular neurectomy appear to be much better (85%) than after the endolymphatic subarachnoid shunt procedure (70%). If hearing is worth saving, a conservative procedure should be used first in an effort to preserve the patient's hearing. If this fails, a cochleovestibular neurectomy will usually resolve the problem. At present we are using the retrolabyrinthine vestibular neurectomy as a primary procedure for Meniere's disease, reserving the cochleovestibular neurectomy for those in whom the vestibular neurectomy failed. In elderly patients it appears the Schuknecht cochleosacculotomy may have promise as a first procedure for control of vertigo.

Aged↗
PubMed1984

Use of streptomycin sulfate in the treatment of Meniere's disease.

Streptomycin sulfate has been known to be ototoxic since its use in the treatment of tuberculosis. This report describes 10 years of experience in the treatment of Meniere's disease with streptomycin. Streptomycin has been used in classical Schuknecht ablation of the vestibular system in bilateral Meniere's disease; classical Schuknecht ablation of the vestibular system in unilateral Meniere's disease in the only hearing ear; intratympanic streptomycin in the treatment of unilateral Meniere's disease; and low-dose intramuscular streptomycin as outpatient treatment in unilateral Meniere's disease. The results of bilateral vestibular ablation were similar to Schuknecht's and others. Patients developed profound ataxia with a wide-based gait and oscillopsia, which improved rapidly over a period of months. Approximately 30% experienced significant improvement in hearing, which usually deteriorated again after several months. All patients were relieved of vertigo. Patients with unilateral Meniere's disease in the only hearing ear responded as did the bilateral cases. Hearing in the only hearing ear was preserved in all cases. Low-dose subototoxic streptomycin as outpatient treatment offers promise in some cases for relieving attacks of Meniere's disease while improving hearing without producing the temporary disabling effects of ataxia and oscillopsia. Streptomycin and similar drugs that may reduce the production of endolymph may eventually be the treatment of choice in Meniere's disease.

Ataxia↗
PubMed1984

Retrolabyrinthine vestibular neurectomy with simultaneous monitoring of eighth nerve action potentials and electrocochleography.

Since November 1978, we have used retrolabyrinthine vestibular neurectomy in 29 of 42 cases as the primary procedure to relieve vertigo in Meniere's disease. The results indicate that 67% of patients had no vertigo postoperatively, while 21% were much improved. Hearing was maintained within 20 dB of the preoperative level in 78%. Simultaneous intraoperative electrocochleography and eighth nerve action potentials were used to monitor auditory function in the last fourteen cases using an Amplaid Mark V evoked potential signal processor. It appears that the intraoperative electrocochleography after vestibular neurectomy can be used as an indicator of postoperative auditory function. The retrolabyrinthine vestibular neurectomy has replaced the middle fossa vestibular neurectomy and the endolymphatic subarachnoid shunt in our practice.

Action Potentials↗
PubMed1981

Surgery for vertigo (you don't have to live with it).

Surgery for vertigo is recommended where there is objective evidence of a unilateral inner ear disorder, when medical therapy fails, and when the patient demands definitive therapy. Common surgical procedures are the endolymphatic subarachnoid shunt, retrolabyrinthine vestibular neurectomy, cochleovestibular neurectomy, and the post ampullary nerve section (singular neurectomy). Vertiginous disorders which can be surgically cured are Ménière's disease, vestibular neuronitis, chronic labyrinthitis, and benign positional vertigo. Due to the recent advances in microsurgery and the development of new surgical procedures in the past 20 years, it is possible to help the vertiginous patient who has been told he must live forever with his problem.

Cochlear Nerve↗
PubMed1981

Surgery of the facial nerve.

The diagnosis and management of facial nerve disorders are challenging aspects of neurotological practice. In Bell's palsy and Herpes Zoster oticus facial nerve decompression is indicated in approximately 10 per cent of cases within the first three weeks if 90-95 per cent degeneration has occurred. The presence of a dry eye determines whether the lesion is proximal to the geniculate ganglion and a middle fossa approach is necessary. Injury to the facial nerve occurs most commonly as a result of temporal bone fractures, from either blunt trauma or penetrating wounds. Occasionally iatrogenic injury occurs during ear surgery. Injury resulting in immediate and total facial paralysis with degeneration confirmed by appropriate electrical testing requires facial nerve exploration. In the presence of an injury proximal to the geniculate ganglion and hearing preservation, exploration of the nerve via middle fossa approach is indicated. If the hearing is lost then the translabyrinthine approach is appropriate. In the event the entire interosseous segment requires exposure, both mastoid and middle fossa exposures are required. If the traumatized facial nerve has not been divided it is decompressed proximal and distal to the injury site. In the event the nerve is divided, a direct anastomosis is the ideal treatment. Rerouting is necessary to achieve adequate length for the anastomosis. Nerve grafting is done when required.

Accidents, Traffic↗
PubMed1981

Vertigo.

Explore the source record for details and available documents.

Central Nervous System Diseases↗
PubMed1980

Species differences in inner ear fluids.

Inner ear fluids of guinea pigs and cats were analyzed for sodium, potassium, chloride, glucose, and total protein to determine species differences in chemical compositions. In the scala vestibuli perilymph and scala tympani perilymph, sodium potassium, and choride levels in the guinea pig were lower than in the cat. The protein levels in the scala vestibuli perilymph and scala tympani perilymph of the guinea pig were lower than those of the cat. The glucose levels in the guinea pig were higher in the scala vestibuli perilymph and scala tympani perilymph, as compared to findings in the cat. Regarding the utricular endolymph, there were significant differences between guinea pigs and cats in sodium and potassium concentrations; the concentration in the former being higher in sodium and lower in potassium. These findings are pertinent for the phylogenetic studies on inner ear fluid biochemistry.

Animals↗
PubMed1978

Chemical composition in various compartments of inner ear fluid.

Sodium, potassium, chloride, glucose and total protein were determined in samples of scala vestibuli perilymph, scala tympani perilymph, CSF, cochlear endolymph and utricular endolymph from normal cats. Small but significant differences were evident in the concentrations of sodium and potassium between the scala vestibuli and scala tympani perilymph. It was also apparent that each compartment of endolymph has different values for sodium and potassium concentrations. Compared with the endolymph, the perilymph was found to contain a higher concentration of glucose and total protein. These findings are discussed from the view point of biological significance.

Cerebrospinal Fluid↗
PubMed1978

The effect of the endolymphatic subarachnoid shunt operation on vestibular function.

Preoperative vestibular function was studied in 56 patients undergoing the endolymphatic subarachnoid shunt procedure for Ménière's disease by electronystagmographic recording of bithermal air caloric stimulation. Fifty-two percent had normal vestibular function while 48% had a reduced vestibular response on the affected side using 20% difference as being significant. Best results of surgery with relief of vertigo were found in the group of patients with normal preoperative vestibular function (82%) while the group with reduced vestibular response preoperatively showed 63% with a good result. Postoperatively, 81% had a reduced vestibular response in the operated-on ear with 62% obtaining relief of vertigo. In patients with normal vestibular function postoperatively excellent relief of vertigo was obtained. Of patients with normal vestibular function preoperatively, 69% developed a reduced vestibular response postoperatively with only 55% having relief of vertigo. The results of surgery could be predicted more accurately using the results of vestibular function tests than audiometric data. It appears that for best results the endolymphatic subarachnoid shunt procedure should be performed early in the course of Ménière's disease when hearing is fluctuating and vestibular function is normal.

Adolescent↗