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N L Cohen

Publications and source records attributed to N L Cohen.

At least 73 records · Page 4Linked to original sources
PubMed1993

A prospective, randomized study of cochlear implants. The Department of Veterans Affairs Cochlear Implant Study Group.

BACKGROUND: Cochlear implants restore some degree of hearing in patients with severe hearing impairment, but the efficacy of different implants has not been compared. We conducted a prospective trial to compare several cochlear implants. METHODS: We studied 82 patients who were randomly assigned to receive one of three cochlear implants: the Ineraid multichannel implant (implant 1), the Nucleus multichannel implant (implant 2), and the 3M/Vienna single-channel implant (implant 3). All the patients had profound deafness, and none had derived benefit from hearing aids. The assigned device was successfully implanted in 80 patients. Twenty-four hearing tests were used to assess the patients' performance before implantation and 12 and 24 months after implantation. The tests were grouped into five categories according to their content, and a weighted composite index was developed to provide a single numerical indicator of the overall auditory response. RESULTS: All the patients were able to hear with their implants. Nineteen of the 30 patients (63 percent) who received implant 2, 18 of the 30 patients (60 percent) who received implant 1, and 1 of the 20 patients (5 percent) who received implant 3 were able to distinguish some words and sentences. The scores for the composite index were similar in the patients who received implant 1 and those who received implant 2, and were higher in both these groups than in the patients who received implant 3 (P = 0.02). When 24 patients with implant 2 were given an improved speech processor, their composite index increased significantly within 3 months (P < 0.001); their score at that time was also significantly higher (P = 0.04) than the score of the patients with implant 1 at 24 months. Age at implantation, lip-reading ability, and IQ were prognostic indicators of the patients' performance with a cochlear implant. CONCLUSIONS: Multichannel cochlear implants are superior to single-channel implants, especially for understanding speech. Changes in speech processing can improve patients' performance.

Aged↗
PubMed1993

Hearing preservation in cerebellopontine angle tumor surgery: the NYU experience 1974-1991.

Between 1974 and 1991, hearing preservation surgery was attempted on 161 of 476 patients with a variety of cerebellopontine (CPA) tumors, at New York University School of Medicine. This included 146 unilateral acoustic neuromas, seven meningiomas, and six cases of neurofibromatosis. The suboccipital/retrosigmoid approach was used almost exclusively. The cochlear nerve was anatomically preserved in 131 cases, 32 percent of whom had successful hearing preservation. In the most successful group, hearing was preserved in 9 of 12 patients (75%). Success was defined as a postoperative pure-tone average (PTA) or speech reception threshold (SRT) of no more than 50 dB, and a speech discrimination score (SDS) of at least 50 percent. In those patients whose preoperative hearing was worse that this, success was based on a loss of no more than 10 dB in PTA or SRT, and 10 percent in SDS. Success was dependent mostly on extracanalicular (EC) tumor size, with the smallest tumors yielding the best results. When controlled for EC size, intracanalicular size and preoperative hearing were statistically significant variables. Origin from the superior vestibular nerve was also a favorable prognostic indicator. The character and duration of hearing loss, the patient's age, and the histology of the tumor did not have prognostic value. Auditory monitoring with either auditory brainstem response (ABR) or direct eighth nerve electrodes did not have a significant impact on success. Complications were somewhat increased by attempted hearing preservation. Facial nerve function was type I or II in 93 percent of patients. Cerebrospinal fluid leaks occurred in 15 percent of cases, but only 4 percent required surgical repair. There was one death, a patient with a 2.5-cm tumor. Early in the series, when a classic long vertical nuchal incision was used, headache and neck pain were common.

Adolescent↗
PubMed1993

Surgical complications of multichannel cochlear implants in North America.

By paying careful attention to the details of surgical technique, many of the complications which have occurred to date may be avoided. Some, such as late electrode and receiver/stimulator migration, device failures, and late flap necrosis due to excessive magnetic forces cannot be avoided by the surgeon, but may be prevented by further advances in implant designs. Although the incidence of life-threatening complications is minimal, and that of major complications is acceptable, every effort should be made by the surgeon, audiologist and manufacturer to further diminish these problems.

Adult↗
PubMed1993

The benefits of cochlear implantation in the geriatric population.

The deterioration of speech-understanding abilities in the aged that results from factors such as reduced speed and accuracy in processing has been well documented. The purpose of this study was to evaluate whether the geriatric population could benefit from a cochlear implant, despite the possibility of reduced processing abilities. Twenty patients, ages 65 to 85 years, with bilateral profound sensorineural hearing loss received the Nucleus multichannel cochlear prosthesis at NYU Medical Center. All patients underwent extensive preoperative medical and audiologic assessments to determine candidacy. The surgical procedure was well-tolerated by all patients. Mean postoperative test results revealed significant improvements in both auditory performance and quality of life as a result of implant usage. These data support the concept that although a reduction in the processing of sensory stimulation might exist, the elderly can process a new auditory code delivered by means of a cochlear implant.

Age Factors↗
PubMed1993

Petrous jugular malposition (diverticulum).

Jugular bulb anatomy is variable. A "high-riding" bulb extending into the tympanic cavity is a well-described anomaly. Petrous jugular malposition (diverticulum) (PJMD), however, is rare. The relationship between PJMD and clinical symptoms is questionable because the differentiation between PJMD as an anatomic variant and pathologic process is unproved. A literature review reveals 14 previously documented cases. We report an additional four cases. Diagnostic and management dilemmas are discussed, with the importance of high-resolution CT stressed.

Adult↗
PubMed1993

Surgical pitfalls in cochlear implantation.

Increasing experience with cochlear implantation has led to the identification of potential surgical pitfalls: improper patient selection, poor flap design and handling, facial nerve injury, improper electrode placement, and improper seating of the receiver stimulator. Each of these areas of potential difficulty are reviewed, emphasizing methods of avoidance and management of adverse outcome.

Cochlear Implants↗
PubMed1993

Partial insertion of the nucleus multichannel cochlear implant: technique and results.

The goal of cochlear implant surgery is to insert the entire electrode array into the scala tympani. Incomplete insertion is usually attributable to the presence of new bone formation as a result of meningitis. Surgical techniques for dealing with obstruction include various degrees of drilling of the cochlea or alternative placement of the electrode array. We evaluated the postoperative performance of eight such patients implanted with the Nucleus multichannel cochlear implant at NYU Medical Center as well as data from adults and children nationwide. Scores ranging from marginal closed-set speech discrimination to 40 percent on open-set speech recognition tests were obtained. Surgical procedure, placement, and number of electrodes as well as number of channels in use affect the ultimate performance of these patients.

Adolescent↗
PubMed1992

Onset and characteristics of the midcycle surge in bioactive and immunoactive luteinizing hormone secretion in normal women: influence of physiological variations in periovulatory ovarian steroid hormone secretion.

Limited studies in nonhuman primates suggest that the midcycle LH surge is characterized by distinctly different patterns of bioactive (LH-BIO) and immunoactive (LH-RIA) LH secretion. To further examine the patterns of midcycle LH-BIO and LH-RIA secretion and explore the influence of physiological variations in steroid hormone feedback on LH surge dimensions we studied seven normal ovulatory women over the periovulatory interval. In each, blood samples were obtained every 3 h and transvaginal ultrasonography was performed every 12 h over a 5-7 day interval at midcycle. Serum levels of LH-RIA, FSH, estradiol (E2), progesterone (P4), and 17-hydroxyprogesterone were determined by RIA; LH-BIO was estimated using a mouse leydig cell bioassay. Hormone data were standardized to the time of surge onset in LH-RIA (time zero), defined as a 100% increase above a 6-point running mean baseline value; surge cessation was defined as a decline to below baseline concentration. Mean LH-RIA surge duration was 54.0 +/- 4.0 h. LH-BIO surge onset was simultaneous with that of LH-RIA and coincident with the peak in E2 levels (mean data). Mean P4 and 17-hydroxyprogesterone rose in a parallel, phasic manner, an abrupt increase in slope occurred between -6 h and +30 h but an acute rise in P4 was not consistently observed among individuals. The surge onset to follicle rupture interval (mean 37.6 +/- 4.2 h) positively correlated with peak LH-RIA (r = 0.76, P less than 0.05), surge amplitude (r = 0.74, P less than 0.05) and surge onset to peak interval (r = 0.87, P less than 0.02), but not surge duration. There were no significant relationships between E2 or P4 (mean, peak, integrated, slope) and surge amplitude or duration (LH-RIA, FSH), peak value, or surge onset to peak interval (LH-RIA, LH-BIO, FSH). These data suggest that in women, 1) onset of the midcycle surge in LH-RIA and LH-BIO is simultaneous, and 2) surge characteristics are not influenced by physiological variations in steroid hormone secretion that occur beyond the thresholds required for surge initiation.

Adult↗
PubMed1992

Use of a multichannel cochlear implant in the congenitally and prelingually deaf population.

Fourteen children and three adults, each congenitally and prelinguistically deaf, received the Nucleus multichannel implant. All underwent extensive evaluations and rehabilitation. The surgery was uneventful, and no patients have been lost to follow-up. Results have shown a significant increase in auditory and speech reception and perception skills in all children. Some children have open-set speech recognition using the prosthesis alone. The adults have shown an increased awareness of sound along with minimal improvement in perceptual skills. This supports the concept that early implantation of congenitally and prelinguistically deaf individuals results in improved performance.

Adult↗
PubMed1992

Sensory aids in conjunction with cochlear implants.

The use of cochlear implants in profoundly hearing-impaired individuals can restore varying degrees of auditory capabilities. Although very little auditory information is transmitted to these patients through amplification systems, we hypothesized that some of the cues obtained from sensory aids might be helpful when used in conjunction with the cochlear implant postoperatively. Eight patients implanted at NYU Medical Center, Bellevue Hospital Center, have used some sensory aid in addition to the Nucleus multichannel cochlear prosthesis. All subjects were evaluated using standard auditory tests including pure-tone and speech audiometry, portions of the Minimal Auditory Capabilities (MAC), Speech Pattern Contrast Perception (SPAC), Iowa test batteries; and the Early Speech Perception (ESP), Word Intelligibility by Picture Identification (WIPI), and Glendonald Auditory Screening Procedure (GASP), where appropriate. Subjects were evaluated under three conditions: implant alone, implant plus sensory aid, and sensory aid alone. Results indicate that the interaction between a multichannel cochlear implant and a sensory aid can provide some improved performance for adult implanted patients (i.e., they do better under the dual condition than in the implant-alone condition). Variables such as thresholds in the nonimplanted ear and usage time can affect the outcome.

Adult↗
PubMed1992

Cochlear implants in the management of bilateral acoustic neuromas.

Multichannel cochlear implants currently provide the only modality for successful auditory rehabilitation of patients with bilateral profound sensorineural hearing loss who derive no benefit from amplification. We have developed a protocol for patients with neurofibromatosis and bilateral acoustic neuromas in which every effort is made to preserve hearing in at least one ear. Failing that, the cochlear nerve is spared, potentially allowing for the insertion of a cochlear implant. We present our data on one such patient whose auditory function was restored with a Nucleus mini 22-channel cochlear implant following removal of his acoustic neuroma.

Adult↗
PubMed1992

Spontaneous temporal bone cerebrospinal fluid leak.

Eight patients with spontaneous cerebrospinal fluid leak of temporal bone origin are presented. Pertinent history and surgical findings are reviewed and contrasted with 33 previously reported patients. Unilateral ear fullness and mild hearing loss are the most common presenting symptoms. Profuse clear otorrhea following myringotomy is virtually pathognomonic. Diagnostic methods including high-resolution computed tomography, magnetic resonance imaging, and contrast cisternography are discussed. The indications for transmastoid and combined transmastoid/middle fossa surgical repairs are compared. Both surgical approaches were found to be equally effective. We favor the transmastoid as the initial approach because of simplicity, safety, and the ability to visualize both the middle fossa and posterior fossa plates as well as the middle ear.

Adult↗
PubMed1992

Retrosigmoid approach for acoustic tumor removal.

The retrosigmoid technique has evolved from the traditional suboccipital operation and, when combined with removal of the posterior wall of the internal auditory canal, affords a wide exposure of the cerebellopontine angle. This approach may be used for acoustic neuromas of all sizes, from intracanalicular to more than 4 cm from the porus acusticus. Hearing preservation may be attempted and is generally successful in a substantial minority of cases. The facial nerve is readily visualized at the lateral end of the internal auditory canal and is at no greater risk than in the translabyrinthine operation. We use this approach for all hearing preservation surgery as well as for tumors of more than 3 cm, regardless of hearing.

Cerebellum↗
PubMed1991

Emergency psychiatric intervention on the street.

The development of outreach approaches to engage and provide services to the homeless mentally ill must account for the heterogeneity of the population. The homeless mentally ill as a group are symbols of the failure of a comprehensive and integrated system of community-based care to develop in conjunction with the widespread proliferation of deinstitutionalization policies over the past several decades. Life in a community is far more complex and less easily controlled than life in an institution. People are free to reject the label of patient and refuse all mental health services. An engagement strategy must therefore be devised from the knowledge of specific aspects of a person's life in that community, so that outreach and networking efforts can be sensitive to the total context of the problems experienced by that patient. A multidisciplinary team approach is essential to the effort to engage and monitor those chronically mentally ill individuals who are at risk for psychiatric and/or medical decompensation. A variety of skills are needed, and team members must be flexible about their roles on the team. The clinician, while maintaining expert psychiatric, diagnostic, and treatment skills, must at the same time be able to adapt to people in their own environments, provide them with necessary social and medical services, and interface with other agencies working with these persons. The work is very labor intensive. It may involve two or more clinicians spending entire days with one patient. During a crisis state, these patients will require even more intensive attention from multiple team members to prevent decompensation and rehospitalization. In conclusion, there is no one intervention style in the work of psychiatric outreach. While the type of intervention offered follows from the mission of the outreach program, all outreach teams must be able to address the totality of needs of people who are fragile and at risk for psychiatric and medical decompensation. Case management services cannot be segregated easily from the task of crisis intervention in the work with the seriously mentally ill. The failure to establish an accessible network of community-based services for those chronically disaffiliated populations of mentally ill gives the outreach team the critical role of brokering any available services needed to support the individual in the community. The flexibility required of the outreach team derives both from the scarcity of community-based resources and the heterogeneity of the population of chronically ill adults who will most need these services.(ABSTRACT TRUNCATED AT 400 WORDS)

Community Mental Health Services↗
PubMed1991

Medical treatment of endometriosis: a comparison of the suppressive effects of danazol and nafarelin on reproductive hormones.

OBJECTIVE: Patients with endometriosis were studied to investigate hormonal suppression by the gonadotropin-releasing hormone against nafarelin acetate compared with danazol. We hypothesized that the pattern, time course, and degree of gonadotropin and ovarian suppression would be different. DESIGN: The study included 16 patients who were randomized into one of three 6-month treatment protocols. SETTING: Patients were recruited from a university hospital setting. PATIENTS: Eligible candidates were 18 to 45 years of age, with regular menses and documented pelvic endometriosis. INTERVENTION: Six-month treatment protocols included nafarelin 800 or 400 micrograms/d, or danazol 800 mg/d. MAIN OUTCOME MEASURES: Serum estradiol (E2), progesterone (P), luteinizing hormone (LH), and follicle-stimulating hormone were determined before treatment and then monthly. Thirteen patients consented to a 12-hour hospital admission during the 5th and 6th month of treatment to determine LH pulse frequency and amplitude. RESULTS: Estradiol and P were suppressed in all groups, but E2 significantly more by nafarelin than danazol (P less than or equal to 0.01). Nafarelin, 800 micrograms, significantly depressed LH pulse amplitude compared with danazol (P less than or equal to 0.05). Two patients in the nafarelin group had the administration of their medication observed, and both demonstrated single, high-amplitude pulses immediately after administration. CONCLUSION: Nafarelin is a more potent LH and E2 suppressor than danazol, and the agonist effect of nafarelin may continue to provoke transient gonadotropin responses despite long-term therapeutic suppression.

Adult↗