Presbyacusis

Presbyacusis

The labyrinth of presbycusis within chapter in the adult, ie in degenerative diseases of the inner ear. For presbycusis is defined as a sensorineural hearing loss frequently observed in both sexes, with greater frequency in males, older, more evident after 60 years of age, but which can already be observed in the early stages after 30 years (Alajmo1995 ).
Man is constantly affected by a progressive weakening of the organ and then the sense of hearing. Diseases such as diabetes mellitus, hypertension, smoking, alcoholism, atherosclerosis, stress, metabolic disorders (hypercholesterolemia) are causes that lead to an aging body. Among these is the significant role played by the NOISE: Significant differences exist between populations living in areas with high rate of industrialization in relation to the populations living in the countryside, as assessed in individuals of the same age. The noise is the cause of occupational disability for many industrial workers (noise of the living or SOCIOACUSIA).
The number of cells present at birth, constituting the organ of Corti, then progressively diminishing (Rossi, 1994). This decrease occurs after the birth of cells in the basal turn of the cochlea and is associated with a reduction of nerve fibers, resulting in a reduction in the audible tonal range after 10 years of age. This particular senescence comes from the fact that it is during waking than during sleep, the organ of Corti is under stress and the functional consequence is called presbycusis, and is the expression of an aging process that affects all sense organs.
The presbycusis is established and progresses slowly and is due to the interest of every sector of the hearing, the eardrum UP BY THE PRIMARY AND SECONDARY cortical areas of the temporal lobe (Brodman AREAS).
The aging process that characterizes the presbycusis involves various processes:
a) thickening of the tympanic membrane and degenerative joints ossiculari that result in increased impedance of the eardrum-ossicular system;
b) loss of elasticity of the basilar membrane of primitive thickening and formation of mineral deposits;
c) degeneration of the cells of the organ of Corti and the ganglion of Corti or associated with atrophy of the industry processes or vascular compression of the nerve fibers to the processes of hyperostosis of the walls of the internal auditory meatus;
d) reducing the number of cell nuclei of the central acoustic pathway;
e) reducing the number of cortical cells of primary and secondary acoustic areas.

The presbycusis is therefore an extremely complex phenomenon that slowly leads to a sensory deficit of quantitative and qualitative: the first related to the quantitative reduction of the structures that carry auditory information to areas of the cortex, the latter linked to the regressive phenomena dependent areas brain, which has the task to decode, analyze, process, interpret the information received. The quantitative deficit makes it difficult to perceive high-pitched sounds, the quality of the difficulty in understanding verbal messages, which can be understood only when the centers are working in optimal conditions, ie when the information is not contaminated by other information presented simultaneously (more people who speak make it difficult to selective hearing, so-called cocktail-party phenomenon: the presbycusis feel better in general, the low frequency, so the old man suffers a greater masking effect of environmental noise) or in the presence of other components (lip-reading ).
In terms of audiometric intentendendo refer to the techniques of tonal liminal audiometry and speech audiometry, the presbycusis may have four different profiles in relation to the prevalence of pathogenic elements that support it.
1) Presbyacusis Neurosensory: is the most common and distinctive and is characterized by regressive changes that affect all structures of the membranous cochlear duct from the base and proceed toward the elicotrema, with the corresponding disappearance of the spiral ganglion neurons (recruitment absent, tone decay test normal).
2) THE MECHANICS presbycusis: involves a stiffening of the basilar membrane or alteration of its mechanical retrogressive changes.
3) THE NEURAL presbycusis: compression of neural atrophy of the auditory nerve fibers to changes of hyperostotic modiolo, resulting in a decrease in the number of cells in the CNS, a process that begins early in youth.
4) THE METABOLIC presbycusis: changes to metabolic processes in the stria vascular load.
The presbycusis is often accompanied by tinnitus, a noise that is pitched with a receptive type of hearing loss on high-pitched sounds and is, in the neurosensory forms, a gradual descent curve, increasing the threshold for the higher frequencies first, and then for the intermediate and serious.
The selective deficits sec. Matshke refer initially to above 2000 Hz, for cell loss and external noise is more evident after 60 years of age, sec. Belal the presbycusis is not an event strongly correlated with age, old age and could exist a picture of normoacusia and it is important to investigate the diagnostic procedures relating to the forms that appear asymmetric sensorineural, could suggest disorders of the inner ear (cochlear otosclerosis, Meniere's disease or tumors of the acoustic nerve.
The healthy lifestyle and food, coupled with the concomitant reduction of the causes of senescence may be an effective way to reduce the aging process and delay the onset of hearing onset of senescence.
The only help the patient presbycusis is the hearing aid, preferably bilateral: the results are usually lower than in young subjects with similar hearing loss and the reason is the central acoustic deficit, which makes it difficult for the intelligibility of the spoken message. But if the denture is well made and correction is binaural and the subject is well trained, the advantages are obvious.
In conclusion we can say with Solomon, that the ability to communicate is fundamental for the autonomy of a person the opportunity to interact with the outside world and be happy.

Dr. Carmine Capasso
MD ENT