Variability in scoring the Hachinski Ischaemic Score.

Multi-infarct dementia (MID) may be the second most common form of dementia in later life. A commonly used aid in the clinical diagnosis of MID is the Hachinski Ischaemic Score (HIS). The usefulness of this score is controversial, and we hypothesized that this is because many items of the HIS are open to a wide range of interpretations. We therefore canvassed 45 research and academic centres in the United Kingdom and Ireland with an interest in dementia to assess the variability of interpretation of the HIS. Five template cases were constructed, in which were embedded items which were felt to be potentially contentious. Fifty-five out of 94 (59%) respondents replied. There was a very wide variation in the scores assigned to each vignette. In only five of 65 items was there complete agreement among replies: in general there was a very large range for each item. Thirty of the items showed less than 90% agreement. The apparent simplicity of the HIS conceals possibilities for ambiguous interpretation of individual items. This is a property common to many 'simple' rating scales. It should not lead to outright rejection of these scales, but rather to a refinement and clarification of the scoring and assessment techniques.

An evaluation of the efficacy and safety of tetrahydroaminoacridine (THA) without lecithin in the treatment of Alzheimer's disease.

Seventy-nine patients with probable Alzheimer's disease were enrolled into a double-blind, placebo-controlled cross-over study to assess the therapeutic effect and safety of THA (tetrahydroaminoacridine; tacrine) without concomitant lecithin administration. Forty-one patients completed the trial which consisted of two 12-week treatment phases separated by a 4-week wash-out period. Twenty-six subjects were withdrawn during the active treatment phase, mostly because of elevated transaminases or cholinergic side-effects, and ten during treatment with placebo. Statistical analyses were conducted on two groups of patients; those completing the cross-over and those with at least one evaluation in the first treatment period. This latter analysis, using the last observation carried forward was used to approximate an intention-to-treat analysis. THA was favoured over placebo in all three primary outcome measures (MMSE, ADAS Non-cognitive Scale, and the Functional Life Scale), but the results did not reach statistical significance. THA was favoured over placebo in five of the seven secondary outcome measures, but for only two of these was statistical significance attained. In terms of a three-point or greater increase in MMSE score, three to four times as many subjects improved on THA as on placebo.

Longitudinal diagnosis of memory disorders.

Early referral for specialist assessment is becoming more common with memory disorders and dementia: the mean Mini-Mental State Examination (MMSE) score of new patients at our clinic rose from 18.7 to 20.7 between 1986 and 1990. The clinical diagnosis of mild to moderate dementia has been recognized to be difficult, but several studies have reported cross-sectional diagnosis. We examined the number of visits required to establish a clinical diagnosis of dementia in the first 125 patients attending a Memory Disorders Clinic who had at least two visits (six months apart) and the stability of the diagnoses. Just under half of the patients required at least two visits to establish the clinical diagnosis. The MMSE was not a good guide to the number of visits required but the diagnosis at the first visit remained stable in all patients who scored < or = 10/30. Sixteen per cent of patients interchanged between the categories of Alzheimer's, mixed and vascular dementias. Possible age-associated memory impairment progressed to dementia in six of eight cases, and depression to dementia in three cases. The diagnosis of mild to moderate dementia should not be restricted to a cross-sectional approach, but should involve serial clinical, psychological and affective assessments.

Dementia and driving.

Many European countries test cars, but not their drivers, as they age. There is evidence to suggest that human factors are more important than vehicular factors as causes of motor crashes. The elderly also are involved in more accidents per distance travelled than middle-aged drivers. As the UK relies on self-certification of health by drivers over the age of 70 years, we examined the driving practices of patients with dementia attending a Memory Clinic. Nearly one-fifth of 329 patients with documented dementia continued to drive after the onset of dementia, and impaired driving ability was noted in two-thirds of these. Their families experienced great difficulty in persuading patients to stop driving, and had to invoke outside help in many cases. Neuropsychological tests did not help to identify those who drove badly while activity of daily living scores were related to driving ability. These findings suggest that many patients with dementia drive in an unsafe fashion after the onset of the illness. The present system of self-certification of health by the elderly for driver-licensing purposes needs to be reassessed.

Clinical experience with and side-effects of tacrine hydrochloride in Alzheimer's disease: a pilot study.

Pharmacological manipulation of central cholinergic neurotransmission may prove beneficial in the treatment of Alzheimer's disease (AD). Tacrine hydrochloride is a central anticholinesterase which has been said to improve intellectual function in patients with AD. We report here our clinical experience with this drug in eight patients with AD, diagnosed according to DSM III and NINCDS-ADRDA criteria. Cholinergic side-effects occurred in five patients, three of whom tolerated a reduced dose. Liver function tests rose within the normal range in all patients and became abnormal in one.