Disorders of taste and smell commonly present diagnostic dilemmas to the medical profession. This may be secondary to the lack of knowledge and understanding of these conditions. There seems to be a low level of interest in the disorders, when compared with disruption of the other senses such as sight and hearing. Nevertheless, impairment of these senses are common and may be life threatening, especially when they involve the elderly patient. The aetiology of the conditions is widespread, and extend beyond the content of this article. This article will relate only to how the ageing process may contribute to sensory dysfunction. It will focus on how the ageing process changes the normal anatomy and physiology of the senses, how this effects the person's quality of life, and the current management of these conditions.

There are a number of pathophysiological processes underlying age related changes in the auditory system. The effects of hearing loss can have consequences beyond the immediate loss of hearing, and may have profound effects on the functioning of the person. While a deficit in hearing can be corrected to some degree by a hearing aid, auditory rehabilitation requires much more than simply amplifying external sound. It is important that those dealing with elderly people are aware of all the issues involved in age related hearing loss.

Forty-six patients who had undergone a radical neck dissection more than six months previously were assessed to determine the degree of handicap that results from division of the accessory nerve. Employment problems, amount of pain, and social and recreational difficulties were assessed. Forty-six per cent of those in employment prior to their operation gave up their work specifically because of problems with their shoulder; this affected more manual than non-manual workers (11 out of 20 manual compared with zero out of four non-manual). Thirty per cent complained of moderately severe or severe pain related to the shoulder. The amount of pain could not be correlated with age, sex, side of operation in relation to handedness, physical build of the patient, or whether the patient had been treated with radiotherapy. Although this is the largest study to address this question since that of Ewing and Martin in 1952, the small numbers involved mean that if any such correlation exists then it may not have become apparent. In view of this incidence of pain and occupational handicap, we feel that efforts should be made to preserve accessory nerve function in cases where surgical clearance of the tumour field is not compromised as a result.

Different strains of mice provide a valuable research tool for studying both hereditary and acquired forms of deafness. The cd/1 strain has been found to demonstrate hereditary cochlear pathology. The characteristics of hearing loss in cd/1 mice have not previously been reported. In this investigation auditory thresholds were obtained by measuring evoked brain stem responses in subjects of three different ages: 3 weeks, 10 weeks and 6 months. The results were compared with thresholds obtained from CBA/Ca mice (which have normal hearing) and C57BL/6 mice (which are known to have a genetically determined pre-senile progressive cochlear hearing loss). A significant hearing loss was observed which progressed from high to low frequencies, and with age. Extensive degeneration was observed throughout the organ of Corti. cd/1 mice may provide a useful model for studying genetically determined deafness.

The effect of noise exposure on auditory sensitivity and inner ear morphology was compared in aged and young mature mice. Hearing thresholds were obtained by auditory evoked brain stem responses (ABR) before and after noise exposure, and hair cell loss was quantified. The study was done in two parts: first to assess the effect of noise exposure on subjects with presbycusis, and second to assess its effect on aged subjects without measurable presbycusis. In the first experiment C57BL/6 mice, with an age-related hearing loss, were used as a model for presbycusis. C57BL/6 mice exhibiting presbycusis were more susceptible to noise injury than age-matched CBA/Ca mice. In the second experiment CBA/Ca mice were used. These mice retain normal hearing even with advancing age. The aged CBA/Ca mice had the same susceptibility to noise injury as young CBA/Ca mice.