Is electronystagmography of diagnostic value in the elderly?

We aimed to determine the diagnostic value of electronystagmography (ENG) in a community-based sample of dizzy subjects over 65 years old. A total of 96 asymptomatic controls and 149 dizzy subjects underwent ENG. Clinical diagnoses were made on standardized criteria. ENG results were classed as normal or abnormal, according to reference ranges derived from the controls. Rates of ENG abnormality in different diagnostic categories, sensitivities, specificities and predictive values were calculated. Central vascular disease was common (105 out of 149 subjects); peripheral vestibular disease was not (14). Spontaneous nystagmus had a positive predictive value of 95% for central vascular disease, but was only 18%-sensitive, and was usually detectable clinically. ENG had no other significant diagnostic value. ENG failed to discriminate dizzy subjects from controls and failed to differentiate various dizziness syndromes. ENG was of no practical value in this community-derived sample of dizzy elderly subjects.

Re-evaluation of normative electronystagmography data in healthy ageing.

Previous work by our group questions the validity of existing electronystagmography (ENG) reference ranges in the elderly. We aim to establish valid reference ranges for ENG in people over 65 on the Nicolet Nystar Plus system. Ninety-six healthy asymptomatic subjects over 65 underwent ENG, including spontaneous and positional nystagmus, saccades, smooth pursuit, optokinetic nystagmus and bithermal calorics; 95% reference ranges with confidence intervals were calculated. The newly determined reference ranges were far wider than those provided by the ENG equipment manufacturer for eight out of 11 parameters (all P < 0.001). Vestibular function is known to deteriorate and become more variable with age. The failure to reflect this change in currently used reference ranges may have contributed to the high rates of vestibular disease reported in some series of dizzy elderly patients. Clinical interpretation of ENG depends on valid reference ranges.

Evaluation of investigations to diagnose the cause of dizziness in elderly people: a community based controlled study.

OBJECTIVE: To compare the findings in dizzy elderly people with those in controls of a similar age to identify which investigations differentiate dizzy from non-dizzy patients and to design an investigational algorithm. DESIGN: Community based study of clinical and laboratory findings in dizzy and control elderly people. SETTING: Research outpatient clinic at a teaching hospital. SUBJECTS: 149 dizzy and 97 control subjects aged over 65 years recruited from a community survey and articles in the local press. MAIN OUTCOME MEASURES: Findings on physical examination, blood testing, electrocardiography (at rest and over 24 hours), electronystagmography, posturography, and magnetic resonance imaging of head and neck (125 (84%) dizzy subjects and 86 (89%) controls); hospital anxiety and depression score; responses to hyperventilation, carotid sinus massage, and the Hallpike manoeuvre. RESULTS: Blood profile, electrocardiography, electronystagmography, and magnetic resonance imaging failed to distinguish dizzy from control subjects because of the frequency of asymptomatic abnormalities in controls. Posturography and clinical assessment (physical examination, dizziness provocation, and psychological assessment) showed significant differences between the groups. A cause of the dizziness was identified from clinical diagnostic criteria based on accepted definitions in 143 subjects, with 126 having more than one cause. The most common diagnoses were central vascular disease (105) and cervical spondylosis (98), often accompanied by poor vision and anxiety. CONCLUSION: Expensive investigations are rarely helpful in dizzy elderly people. The cause of the dizziness can be diagnosed in most cases on the basis of a thorough clinical examination without recourse to hospital referral.

The evaluation of dizziness in elderly patients.

Twenty-one elderly patients with dizziness underwent a comprehensive medical and otoneurological evaluation. The majority had vertigo, limited mobility and restricted neck movements. Poor visual acuity, postural hypotension and presbyacusis were also frequent findings. Electronystagmography revealed positional nystagmus in 12, disordered smooth pursuit in 18, and abnormal caloric responses in nine. Magnetic resonance imaging showed ischaemic changes in six out of eight patients. Although dizziness in the elderly is clearly multifactorial, the suggested importance of vertebrobasilar ischaemia warrants further consideration as vertigo has been shown to be a risk factor for stroke.

Ototoxicity of cis-platinum and its relationship to eye colour.

The following hypothesis is presented: that the susceptibility of an individual patient to hearing loss as a result of cis-platinum administration can be predicted on the basis of eye colour. The rationale is that the melanin content of the inner ears is related to that of the eyes; dark eyes contain more melanin than light-coloured eyes; and melanin causes the accumulation of the ototoxic drug within the inner ear. Hence those with dark eyes will suffer greater damage to the hearing than those with pale eyes. An investigation that confirmed this hypothesis is reported. In addition to cochlear damage there is a significant likelihood of damage to the auditory nerve as a result of the treatment.

Ear wax removal: a survey of current practice.

OBJECTIVE: To determine the methods of removing ear wax used by local general practitioners and the incidence of associated complications. DESIGN: Postal survey of 312 general practitioners serving a population of about 650,000; supplementary study of ear, nose, and throat outpatients to quantify the improvement in aural acuity after wax removal. SETTING: Catchment area of the Edinburgh otolaryngological unit. PARTICIPANTS: 289 General practitioners who responded to the survey; 21 outpatients in the ear, nose, and throat department with occlusive wax. RESULTS: 274 General practitioners removed wax by syringing, but only 53 (19%) always performed the procedure themselves; the remainder routinely delegated the task to practice nurses, some of whom had received no instruction. Ears were rarely examined again after the procedure. Complications had been experienced by 105 practitioners (38%) and included perforation, canal lacerations, and failure of wax removal. The removal of occlusive wax improved hearing by a mean of 5 dB over the frequencies analysed. CONCLUSIONS: About 44,000 ears are syringed each year in the area and complications requiring specialist referral are estimated to occur in 1/1000 ears syringed. The incidence of complications could be reduced by a greater awareness of the potential hazards, increased instruction of personnel, and more careful selection of patients.

The cupped hand as an aid to hearing.

The acoustic effects of cupping the hand behind the ear were measured by means of a miniature microphone placed at the entrance to the ear canal. Pure tone signals from 0.2 to 10 kHz, at 1/3-octave intervals, were used. Amplification was produced when subjects were facing the sound source, mainly in the mid-frequency range, where there was a peak of 8 dB around 1.6 and 2 kHz. When the subjects had their backs towards the sound source, the effect produced was attenuation, the maximum being 9.5 dB at 2.5 kHz.

A theoretical approach to the loop induction system.

In a study of the properties of hearing aids with loop induction coils, it was observed that a group of high-powered aids used primarily for their extended low frequency responses had poor low frequency responses when used on loop input. The consequences of these characteristics are discussed. To asisst in the problem of loop design, equations are presented expressing the magnetic field strength at any point in terms of the electric current and loop location. These were found to predict the field strength with good accuracy, and may be used to calculate the field strength and its variation, produced by almost any loop configuration.

Relief of the occluded ear sensation to improve earmold comfort.

Earmold comfort is an important factor in the overall satisfaction a hearing-impaired person has with a hearing aid system. Recent research into the subjective effects of earmold venting indicates that, for the naive hearing-aid user, the solid mold produces a "closed" and "blocked" sensation that is relieved to a degree, depending on the vent diameter. To improve earmold comfort, all earmolds should be vented. However, there are certain types of hearing loss where conventional venting techniques would be undesirable, in particular, cases of severe to profound hearing loss where venting would not only adversely affect the desired frequency response characteristics of the hearing aid but would also lead to serious acoustic feedback problems. For this reason a simple system has been developed with sintered filters in the vent line, thus allowing all earmolds to be vented to relieve the occluded ear sensation although retaining the acoustic characteristics of the closed earmold.