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 early hospital readmission of elderly people.

Two hundred and twenty six consecutive patients aged over 75 years discharged following an acute medical admission to a district general hospital were followed up six months later. 46 (20.3%) required emergency admission within three months of discharge. 19 had a diagnosis related to their original admission, and 27 an unrelated diagnosis. The mean time to readmission was 34 days, but this was significantly shorter (21 days) in those with a related diagnosis. Those readmitted had more often required admission in the year prior to their index admission, had more comorbidities, higher use of social services, and no carer. There were no significant differences in age, gender, mental test score, length of stay, home circumstances or diagnosis. The results suggest that most readmissions are due to medical rather than social problems, and that most are unavoidable. Efforts to reduce readmissions should be directed at preventing early medical relapse in at risk patients.

The prevalence and characteristics of dizziness in an elderly community.

A postal questionnaire was sent to 1000 subjects aged over 65 years randomly selected from the age/sex register of five group practices, 90% of subjects returning adequate information. Thirty per cent of responders reported dizziness; 27% of these had symptoms more than once per month and 37% had symptoms which lasted longer than 1 minute. Dizziness was most commonly provoked by postural change and head and neck movement. The prevalence of dizziness increased with age and was higher in women but these differences were not statistically significant. The prevalence of symptoms occurring more than once per month was significantly greater with increasing age (p = 0.0003). Dizziness was significantly associated with angina and previous myocardial infarction (p < 0.001) and antihypertensive therapy (p < 0.05) but not with current smoking, diabetes mellitus or previous stroke.

Ageing and balance: the measurement of spontaneous sway by posturography.

Sway was measured by static posturography in 74 healthy subjects. Four age groups were investigated: 20-40, 40-60, 60-70 and over 70 years with equal numbers of males and females in each group. Sway increased linearly with age but was not affected by gender at any age. All age groups were more dependent on proprioception than vision in the maintenance of balance, but when reliable pressoreceptor information was removed, dependence on vision increased. The relative contributions of the sensory systems to balance did not alter with advancing age. The increase in sway demonstrated with normal ageing does not appear due to altered peripheral sensibility. It is more likely that it is due to slowing of central integrative processes.

Type IV renal tubular acidosis and spironolactone therapy in the elderly.

Spironolactone therapy is a well-known cause of hyperkalaemia, but in susceptible patient, it may also be associated with metabolic acidosis. We report a case of severe renal tubular acidosis (Type IV) with life-threatening hyperkalaemia caused by spironolactone, and discuss the mechanisms by which this may occur.

The delivery of interim discharge summaries to general practitioners by the elderly.

Two hundred and four patients discharged from an acute geriatric unit were given an interim discharge summary for delivery to their General Practitioner (GP). All but three summaries were received by the practices. Information regarding mode and timing of receipt was available in 191 patients. The summaries were received in a median of 1.0 day in both those living alone and those living with family; 75% of summaries had been received within two days of discharge and 93% within four days. General practitioners collected the summaries from patients' homes in a high proportion of both groups. Interim discharge summaries should be given to elderly patients for delivery to their GPs: this is both reliable and rapid, and clearly more cost-effective than any other form of delivery.

Symptomatic awareness of hypoglycaemia: does it change on transfer from animal to human insulin?

A retrospective survey of symptomatic awareness of hypoglycaemia was performed in 189 randomly selected patients with insulin-treated diabetes who had been transferred from highly purified animal insulins to human insulin in the preceding 24 months. Of the 189 patients 44 (23%) complained of chronic hypoglycaemic unawareness, unrelated to ambient blood glucose control, before change of insulin species. Only 12 of the remaining 145 patients reported a reduction in awareness of hypoglycaemia following transfer to human insulin (6% of the whole group), while 6 (3%) reported an increase in awareness following the transfer. The 12 patients reporting reduced awareness had a mean duration of diabetes of 24 +/ 10 years compared to a duration of 15 +/- 10 years in the patients with normal awareness. The mean glycosylated haemoglobin concentrations were similar in all of the groups of patients. Six patients had developed total loss of awareness of the onset of hypoglycaemia, with all but one patient having suffered multiple episodes of severe hypoglycaemia. This reduced hypoglycaemic awareness on human insulin therapy was not associated with any significant improvement in blood glucose control.

Survival after massive overdose of slow-release potassium.

Self-poisoning with potassium salts is uncommon but the consequences are often fatal. Previous reports describe death after ingestion of between 40 and 50 tablets of slow-release potassium but we report a patient who survived after taking approximately 100 tablets.

Severe pulmonary hypertension and multiple left coronary arterial fistulas in association with congenital hepatic fibrosis.

Multiple fistulous communications between the left anterior descending coronary artery and the left ventricle were found in a 55 year old woman with congenital hepatic fibrosis presenting with breathlessness. At cardiac catheterisation severe pulmonary hypertension was also found. In view of the persistent hypoprothrombinaemia, severe thrombocytopenia, and the multiple fistulas the risk of operation was thought to be unacceptable and she continues on medical treatment.

Action of deoxycoformycin on human T cell colonies in vitro.

The potent adenosine deaminase inhibitor, deoxycoformycin (dCF), is currently under evaluation in the treatment of lymphoid malignancy. We show that dCF inhibits the growth in soft agar of T cell colonies from PHA stimulated human peripheral blood lymphocytes. In contrast to previous attempts to develop an in vitro model for analysis of the drug's action, concentrations lower than 10(-9)M are effective, and no 'priming' by pharmacological concentrations of adenosine is required. Maximum inhibition is obtained when dCF is present over the first 4 hr of cellular exposure to PHA. T cells already proliferating in response to PHA are less sensitive to dCF, implying that S-phase events are not primary targets of the drug's action. Colony inhibition does not appear to be due to alteration in the production of, or sensitivity to, soluble T cell growth factors. In suspension cultures, dCF at concentrations up to 10(-5)M fails to inhibit early PHA-induced volume changes, or later mitosis, in peripheral blood lymphocytes. The results show that there is a critical dCF sensitive step early in PHA stimulation. It involves those T cells capable of forming colonies and may be conditioned by the cellular microenvironment.