I. Goals of the cochlear implant

The cochlear implant partially restores hearing to the totally deaf. It has helped greatly in the primitive and warning levels of hearing and is of benefit in lip reading and the symbolic levels of hearing.     

Electrical promontory testing in differential diagnosis of sensori-neural hearing impairment

The possibility of rehabilitation of sensory deafness by a peripherally implantable prosthesis makes it very important to differentiate sensory from neural hearing impairment. We do this by a technique which we call electrical promontory testing, which includes measuring the electrical potentials generated in the auditory system and stimulating the inner ear electrically. Types of Sensori-Neural Hearing Impairment. There are four or more types of sensori-neural hearing impairment which in the past have collectively been termed sensori-neural. They are: 1. sensory loss — deficiency in the hair cells; 2. neural loss — auditory nerve deficit; 3. brain stem loss — nuclear deficiency; and 4. central loss — auditory cortex defect. Method of Testing. Recording of the potentials evoked in the auditory system by the techniques of electrocochleography, brain stem audiometry and cortical evoked response audiometry is an important objective means of study of the auditory system. Characteristics of the potentials obtained such as wave form, latency, and amplitude help greatly in classifying types of partial hearing loss. In severe hearing loss no potentials are obtained from the auditory system. In these cases, a low-voltage, low-frequency electrical current is applied to the promontory. If the patient perceives an auditory sensation as a result of this stimulation, we believe that this demonstrates the presence of auditory neurons and the loss is classified as sensory. If an auditory sensation is not evoked, the deafness is classified as a neural or more central loss.     

Human reproductive technologies and the law: a select committee report

The House of Commons Science & Technology Committee has reviewed the Human Fertilisation and Embryology Act. It considered a) the balance between legislation, regulation and reproductive freedom; b) the role of Parliament in human reproductive technologies; and c) the foundation, adequacy and appropriateness of the ethical framework for legislation. It also considered the Act itself and the workings of the Human Fertilisation and Embryology Authority. Its report is written from a very liberal perspective, but is a very thorough overview of current issues and debate in the field. There follow, slightly abridged, the conclusions and recommendations of the 200-page report.     

Psychiatric manifestations of autoimmune disorders

Opinion statement Psychiatric symptoms are common to many autoimmune disorders. Patients often will have mood disorders, anxiety, cognitive deficits, delirium, and psychosis. These symptoms may reflect the direct or indirect effect of the autoimmune disorder on the central nervous system, may be related to medications used to treat the disorder, or may be a direct psychologic impact from suffering with the autoimmune disorder. Accurately recognizing the psychiatric component and generating a differential diagnosis is a complex task for the treating physician. Treatment of the psychiatric component to the disorder often will include addressing steroid induced side effects, psychotropic medications, psychotherapy, patient and family education, and a strong physician-patient relationship.     

Recovery of viruses from three transport media incorporated into culturettes

A double-blind prospective study was carried out to compare the rates of recovery of viruses from the upper respiratory tracts of children, using three different transport media. Stuart's, Hanks', and Leibovitz-Emory (LEM) media were packaged in the ampules of Culturettes and labeled in code by the manufacturer. Three swabs (one each from culturettes containing different media) were inserted simultaneously into the oropharynx or pressed onto unroofed dermal lesions, transported to the laboratory, and inoculated into MRC (Medical Research Council)-5 and primary monkey kidney-cell cultures. Eighty isolates were obtained from 200 specimens (40%) collected during all four seasons of the year. Parainfluenza virus, enterovirus, adenovirus, and herpes simplex virus accounted for 79% of the isolates. Of 80 isolates, 72 (90%) were recovered in Hanks', 64 (80%) in Stuart's, and 63 (79%) in LEM. The differences were not significant.