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Biomedical subjects

S G Harner

Publications and source records attributed to S G Harner.

At least 55 records · Page 3Linked to original sources
PubMed1986

Acoustic neuromas with normal pure tone hearing levels.

From 1966 through 1983, 408 patients underwent primary removal of an acoustic neuroma at the Mayo Clinic. Of these, 21 had preoperative pure tone hearing levels of 25 dB hearing loss or better at 500, 1000, and 2000 Hz, which for this study was defined as normal pure tone hearing. Fourteen patients (67%) had dysequilibrium and 13 (62%) had subjective hearing impairment. Nystagmus was the most common physical finding. Five patients (23%) had completely symmetric pure tone hearing levels through all frequencies tested. The mean speech discrimination score was 90%. Mean tumor size was 2.4 cm. Brain stem evoked response audiometry was the most helpful of the special tests in the evaluation of these patients with normal pure tone hearing levels. Our results suggest that 5% of patients with acoustic neuromas have normal pure tone hearing levels. A careful history, a thorough physical examination, and an appropriate selection of tests will identify these patients.

Adult↗
PubMed1986

The effect of butyl 2-cyanoacrylate on the middle and inner ear of the chinchilla.

Butyl 2-cyanoacrylate was placed on the oval and round window of the ear of the chinchilla and was also used as an adhesive for myringoplasty with autogenous muscle fascia. Butyl 2-cyanoacrylate was found to be difficult to manipulate and moderately toxic to the middle ear; there were occasional significant reactions in the inner ear.

Animals↗
PubMed1986

Electrophysiologic monitoring of facial nerve during temporal bone surgery.

Monitoring of peripheral nerves during surgical procedures decreases trauma to the nerve, which may preserve function. During 1984, electrophysiologic monitoring of the facial nerve was used during 32 operative procedures in and around the temporal bone. The largest group were for cerebellopontine angle tumors. Clinically, monitoring appeared to be helpful by providing objective evidence of trauma to the facial nerve and a method of demonstrating integrity of the nerve. However, review of this series did not reveal objective evidence of improved facial nerve preservation compared to results in a similar group of patients operated on without monitoring. We think that the monitoring is best done by personnel experienced with the technique.

Action Potentials↗
PubMed1985

Meningiomas of the cerebellopontine angle.

The majority of cerebellopontine angle tumors are acoustic neurinomas; however, 10% to 15% are meningiomas. Meningiomas are benign lesions that must be removed but may require surgical approaches different from those used for acoustic neurinomas. To determine if meningiomas could be distinguished from acoustic neurinomas clinically, findings in 20 patients who underwent removal of a meningioma were compared to those in 131 patients who had an acoustic neurinoma removed during the same period. We found that in patients with meningiomas the tumors frequently are large at presentation, the otologic symptoms and audiometric findings are less dramatic, and roentgenograms of the skull and tomograms of the petrous apex rarely show erosion of the internal auditory canal. Computerized tomography is the most useful method for differentiating a meningioma from a neurinoma: when a meningioma is present the characteristic finding is a broad-based mass aligned with the petrous ridge, not centered over the internal auditory canal.

Adolescent↗
PubMed1985

Management of acoustic neuromas, 1978-1983.

The surgical aspects of 162 consecutive procedures for removal of acoustic neuromas, performed from 1978 through 1983, are reviewed. Nearly all of the procedures were done through a retrosigmoid suboccipital craniectomy. Most used the combined skills of a neurosurgeon and an otological surgeon. Total tumor removal was accomplished in 98% of cases. There have been two recurrences and one postoperative death. The facial nerve was preserved in 81% of procedures. Facial function returned in nearly all of these patients, but the degree of return was variable. The cochlear nerve was preserved in 55 patients, but hearing was present in only 14. The most common complication was cerebrospinal fluid otorhinorrhea (12%); about half of these patients required a secondary procedure. Other complications were meningitis (5%), aspiration (3%), and hemorrhage (2%). During the period reviewed, several changes occurred in management of this disorder. These procedures are now being done by a surgical team. The neurosurgeon performs the intracranial work and the otological surgeon accomplishes the temporal bone dissection. Most patients undergo the operation in the supine rather than the sitting position. During the operation, the facial nerve is monitored continuously by electromyography with intermittent bipolar stimulation. There appears to be continuing improvement in the management of these patients.

Adolescent↗
PubMed1984

Roentgenographic diagnosis of acoustic neurinoma.

This article reviews the roentgenographic studies performed in 131 patients who had surgically confirmed acoustic neurinomas. In this 5-year study (1978-1982), all patients had computed tomography (CT) and 82% had petrous apex tomography. Approximately 18% of patients underwent angiography, and 18% had positive contrast rhombencephalography. The diagnostic capability with CT scanning has improved remarkably. There were no false-negative results for scans obtained in 1981 and 1982. At the same time the accuracy of other radiographic and audiometric tests was decreasing. The proportion of small tumors diagnosed has increased 200%, with a corresponding decrease in medium and large tumors. Tumors can be diagnosed at an earlier stage; and, because of this, surgical results have improved. No surgical mortality occurred in this series, preservation of the facial nerve was excellent, and in some patients cochlear function was maintained.

Angiography↗
PubMed1984

Hearing preservation after removal of acoustic neurinoma.

Between January 1, 1978, and July 1, 1983, 149 patients underwent acoustic neurinoma removal (151 procedures). Of these, 119 ears (118 patients) had had some degree of hearing on the affected side preoperatively, and in all of them the tumors had been removed by a posterior cranial fossa approach. Fourteen (12%) had measurable hearing preserved postoperatively--serviceable in eight ears and poor in six. The patients with preserved hearing had had their hearing loss for a shorter period, slightly better preoperative hearing levels, and a smaller tumor. The complications, morbidity, and mortality in this group were comparable to those in other series. It is concluded that preservation of hearing is a worthwhile goal that can be achieved without increased risk.

Female↗
PubMed1983

Lymphoma of the nose and paranasal sinuses.

The records of 37 patients with lymphoma of the nose and paranasal sinuses in an 18-year period were studied. The symptoms were divided into three categories: (1) local symptoms: obstruction, bleeding, and rhinorrhea; (2) symptoms of invasion of adjacent structures: facial pain and ear fullness; and (3) systemic symptoms: fever, weight loss, and nocturnal sweating. The presence of an intranasal mass was the most common physical finding. Conventional tomography and computed tomography were helpful for diagnosis. Abnormalities were usually disclosed on biopsy specimens from the nose or mouth. As a rule, several sites in the nose and sinuses were involved. An early diagnosis of sinonasal lymphoma and other malignant neoplasms generally allows effective treatment; therefore, the otorhinolaryngologist should be alert for such disease and, if the clinical picture warrants, should add tomography to the diagnostic workup.

Adolescent↗
PubMed1983

Cochlear function in chronic otitis media.

Otologic symptoms, audiometric data, and operative findings were reviewed in 200 consecutive patients who had surgically treated unilateral chronic otitis media. Bone conduction thresholds were analyzed in relation to extent of perforation, frequency of otorrhea, duration of disease, and extent of pathologic change. Median bone conduction threshold differences between diseased and uninvolved ears were within 5 dB at all frequencies. The mean speech discrimination score between affected and unaffected ears was equal. Patients with prolonged disease and more extensive pathologic alterations were more likely to experience cochlear changes and hence sensorineural hearing loss, though not to the extent others have described. Our findings indicate that chronic otitis media has little effect on cochlear function in the majority of patients.

Adolescent↗
PubMed1983

Ophthalmic manifestations of acoustic neurinoma.

Acoustic neurinomas comprise 8% of all primary intracranial neoplasms. The authors reviewed 100 cases of pathologically confirmed acoustic neurinomas and compared tumor size, based on observations at operation, with findings on history and physical examination. Of the 100 patients, 36 had a decreased corneal reflex, 36 had nystagmus, and 8 had papilledema. Ninety-two percent of the patients with nystagmus had brainstem compression from tumor, and unilateral nystagmus when present was predominantly on gaze toward the side of the tumor. A positive correlation was found between tumor size and the presence of signs and symptoms. Tumors causing nystagmus were at least 2 cm in greatest dimension; those causing a diminished corneal reflex were at least 2.5 cm; and those causing subjective symptoms and papilledema were at least 4.0 and 4.5 cm, respectively.

Adolescent↗
PubMed1983

Clinical findings in patients with acoustic neurinoma.

Herein we review the symptoms, physical findings, and test results in 131 patients with acoustic neurinoma. The earliest symptoms are unilateral hearing loss, tinnitus, and dysequilibrium. As the disease progresses, facial numbness, facial weakness, and headaches become more prominent. Physical findings other than hearing loss are uncommon; the most frequently observed are a decreased corneal reflex, nystagmus, and facial hypoesthesia. Routine audiometry provides objective information about the hearing loss. Some degree of asymmetry is found in the pure-tone tests. In addition, the speech discrimination scores are frequently lower than expected. Special audiometric tests should be performed on those patients with residual hearing; at the present time, acoustic reflex tests and the brainstem-evoked response yield the most information. Computed tomography with dye enhancement with or without the use of air contrast has become the most accurate roentgenographic test. Our goal is to identify acoustic neurinomas sufficiently early so that surgical removal is safe and leaves minimal deficit.

Adolescent↗
PubMed1983

Auditory brain-stem response and acoustic reflex test.

Auditory brain-stem response (ABR) and acoustic reflex test (ART) results were reviewed for 30 patients with cerebellopontile angle tumors and for 30 patients without tumor. Patients included in the nontumor group were selected to match the audiometric configurations for individual patients in the tumor group. The ABR waveforms were abnormal for all but one of the patients with tumor and for seven of the patients without tumor. The ART results were abnormal for 25 of the patients with tumor and two of the patients without tumor. Patients without tumor yielding abnormal ABR results usually had more severe hearing losses than the patients without tumor who demonstrated normal ABR waveforms. The ABR and ART merit continued use in the audiologic examination of patients suspected of having retrocochlear lesions, but obviously, degree of hearing loss and other medical information must be considered also when retrocochlear lesions are suspected.

Adolescent↗
PubMed1982

Adenocarcinoma and adenoma of the middle ear.

Primary middle ear glandular tumors of the adenocarcinoma and adenoma types are rare. The terminology used in describing them is quite varied. Some investigators presume that a distinct recognizable group of these tumors are benign, but because of the rarity of the lesions, such conclusions have been difficult to verify. We review the literature of these lesions and report 11 additional cases. The course was documented in 25 cases in the literature; 20 of these were reported to be benign over periods of follow-up from 1 month to 10 years, and 5 were fatal. Among our patients, 5 had a benign course, 3 died of causes related to the tumor, and 3 had persistence of their lesion and substantial consequent morbidity. We emphasize the slow growth and elusive nature of these lesions. Histologic evidence of mitoses, roentgenologic evidence of bony destruction, and cranial nerve involvement were factors consistent with a poor prognosis. The origin of these tumors may vary. A similarity to paragangliomas is noted. The ultimate course of these tumors cannot always be predicted from the histologic appearance. Early surgical removal appears to be the most successful therapy. Three of the 4 types of glandular tumors of the external ear canal described by Wetli, et al, can be found in the middle ear: adenoma, adenocarcinoma, and adenoid cystic carcinoma. In addition, several other types of glandular lesions can occur in the middle ear--the "choristomas," mucoepidermoid carcinomas, and what we believe to be a variant of paragangliomas. The adenoid cystic tumors are well described in the literature and will not be discussed here. We reviewed cases of the adenoma and adenocarcinoma types, some of which bore a resemblance to the paragangliomas.

Adenocarcinoma↗
PubMed1982

Translabyrinthine repair for cerebrospinal fluid otorhinorrhea.

Cerebrospinal fluid (CSF) otorhinorrhea may occur as a complication of surgery for removal of acoustic neurinomas. The CSF leak usually appears within the first 2 weeks after surgery, and the diagnosis is obvious. The fistulous site is frequently inaccessible and may be difficult to repair by reexploring the suboccipital craniectomy. Successful closure of the fistula is accomplished by obliterating the space between the posterior fossa dura and the eustachian tube orifice with homograft muscle, using a radical translabyrinthine approach.

Cerebrospinal Fluid Otorrhea↗
PubMed1981

Posterior fossa approach for removal of acoustic neurinomas.

Herein we review our experience with surgical removal of acoustic neurinomas in 74 patients from January 1978 through December 1980. The surgical approach was through the posterior fossa. Total removal was accomplished in 73 of 74 patients, and there were no surgical or postoperative deaths. The facial nerve was preserved in 54 patients, and hearing was preserved in five (21% of patients with small tumors). We believe that this approach to acoustic neurinomas has the advantages of being universally applicable, having a low complication rate, and possessing the potential of saving both facial and cochlear function.

Adolescent↗
PubMed1981

Diagnosis of acoustic neurinoma.

Seventy-six patients underwent the primary removal of an acoustic neurinoma at the Mayo Clinic from 1978 through 1980. Hearing loss was present in 97% of the patients, and tinnitus and dysequilibrium occurred in 70% of the patients. The most common signs were a decreased corneal reflex, nystagmus, and facial hypesthesia. In these patients, pure tone and speech audiometry are used to define the hearing loss. When hearing is still present, the speech discrimination is often disproportionately low. Acoustic reflex testing and brain stem evoked response are used to determine whether the hearing loss is cochlear or retrocochlear. When these tests could be performed in this series of patients, they were accurate in 85 to 95%. The vestibular response to caloric testing is expected to be decreased or absent in about 90% of patients, and this was so in 86% of our patients. Radiographic studies are the most important tests currently used for the diagnosis of acoustic neurinoma. Tomography of the internal auditory canal shows abnormalities in 80% of patients. Computed tomography with contrast enhancement demonstrates abnormalities in 90% of patients. The computed tomographic (CT) scan may reveal the location, the size, and often the consistency of the tumor. In cases still questionable after CT scanning, positive contrast rhombencephalography is used for clarification. In this series, no single symptom, sign, abnormal audiometric test result, or abnormal radiographic finding was present in all patients; therefore, the most important factor in diagnosis is an alert physician.

Adolescent↗