The distribution of CY2PC19*2 allele in a Trinidadian population. Is Clopidogrel the right choice?

OBJECTIVE: To determine the distribution of the CYP2C19*2 allele among Trinidadians. DESIGN AND METHODS: This is a cross sectional study among 100 patients attending primary health centers within the North Central Region of Trinidad. A stratified sampling technique was used in which there were three mutually exclusive subgroups: those of South Asian descent (Indo-Trinidadians), African descent (Afro-Trinidadians) and mixed ethnicity. Subsequently, systematic sampling was applied to each stratum to improve the representativeness of the sample. Hence, the 100 subjects recruited for the study were 40 Indo-Trinidadians, 40 Afro-Trinidadians and 20 of mixed descent. Apart from baseline data which included age, gender and ethnicity, DNA was assessed for the CYP2C19*2 allelic variant using a PCR method. RESULTS: There was a high allelic frequency (37%) for CYP2C19*2 which was found to be more common among Indo-Trinidadians (47.5%, 95% CI 32.0-63.0) compared to Afro-Trinidadians (22.5%, 95% CI 9.6-35.4) or people of mixed origin (45%, 95% CI 23.2-66.8). There was a significant difference (p=0.019) between CYP2C19*2 frequencies for Indo-Trinidadians and Afro-Trinidadians. CONCLUSION: We provided evidence that the prevalence of CYP2C19*2 mutation was high in our setting.

The effects of anti-hypertensive medication on learning and memory.

1. The aim of the study was to investigate whether there were differential effects of three different anti-hypertensive medications (cilazapril, atenolol, nifedipine) on cognitive function. 2. A sub-group of patients participating in a large clinical trial of these three drugs, randomly allocated between the three drug conditions, received cognitive assessment at two points before the commencement of treatment and then after 12 and 24 weeks of treatment. Seventy-six patients began treatment, and 55 completed the full course. 3. Tests of learning and memory were designed specially for the study, with a different but comparable version administered on each assessment occasion, in a fixed order. 4. No significant differences between drug groups were found in any index of learning or memory, at any testing occasion. The results were the same whether or not treatment non-completers were included in the analysis.

Coloured speech perception: is synaesthesia what happens when modularity breaks down?

Evidence was reported earlier from a single case that chromatic-lexical (CL) synaesthesia was a genuine phenomenon. A study is presented in which nine subjects were tested who also reported having coloured hearing. The following questions were addressed: (a) were these cases also genuine (ie consistent over time), (b) were they truly lexical, or rather variants of this condition, such as chromatic-graphemic (CG) or chromatic-phonemic (CP) synaesthesia, (c) did the experimental subjects show any commonalities between them, and (d) were they able to give information on a standard questionnaire about the phenomenology and ontogenesis of the condition? Subjects were asked to describe the colour sensation experienced on hearing items from a list of 130 words, phrases, and letters. The experimental group were not informed of any retest, but were retested more than one year later. A control group (n = 9), matched for IQ, memory, age, and gender, were read the same list and asked to associate a colour with each list item. They were informed at the time of testing that they would be retested on a sample of items from the list a week later. 92.3% of the responses of the experimental group when retested one year later were identical to those given in the original test, compared with only 37.6% of the control subjects' responses (retested one week later). This confirmed the genuinneess of these nine cases. All nine experimental subjects showed CG synaesthesia, none showing either CL or CP synaesthesia. Among the experimental group, some consistency was found in the colours evoked by hearing specific letters, suggesting the condition has a neurological basis.(ABSTRACT TRUNCATED AT 250 WORDS)

The Maudsley Mentation test: a method for extended monitoring of mental status after aneurysmal subarachnoid hemorrhage.

A new scale for the repeated, rapid assessment of mental function in patients with subarachnoid hemorrhage is described. Its reproducibility is evaluated and early experience with its use in the intended clinical setting is reported. The test (Maudsley Mentation Test) proved to be more sensitive to fluctuations in cerebral functioning than existing measures of conscious level, and the results were reproducible among observers with different backgrounds (surgeons, nurses, and psychologists). The results suggest a relationship between performance on mentation testing and quality of outcome. The Maudsley Mentation Test is thought to offer a suitable measure with which to monitor patients during the acute phase of their illness to supplement clinical assessment and provide evidence of deterioration at an early stage. It is also potentially useful as an end point in acute protection and treatment studies.

Prism adaptation and other tasks involving spatial abilities in patients with Parkinson's disease, patients with frontal lobe lesions and patients with unilateral temporal lobectomies.

Patients in the early stages of Parkinson's disease were compared with patients who had sustained damage specific to either the frontal or temporal lobes and normal controls on a delayed alternation task, a test of the left right orientation and a prism adaptation task. On the former two tasks age accounted for more of the variability in performance than did site of brain lesion. However, patients with frontal lobe, right temporal lobe or basal ganglia damage were significantly impaired on the adaptation task. The results are discussed with regard to "switching", "sequencing" and "internal guidance" of movement hypotheses.

Sequence ability in parkinsonians, patients with frontal lobe lesions and patients who have undergone unilateral temporal lobectomies.

Patients in the early stages of Parkinson's disease were compared with patients who had sustained damage specific to either the frontal or temporal lobes and normal controls on a number of sequencing tests. These tests involved the reproduction of sequences of hand gestures, sequences tapped out on blocks, and sequences of digits. Only the groups with frontal lobe lesions or right temporal lobectomies were impaired on any of these tasks, though no group was impaired on all of the sequencing tasks.

The performance on learning tasks of patients in the early stages of Parkinson's disease.

It is known that in animals learning is disrupted by caudate lesions; but there has been no agreement about whether pathology in the basal ganglia causes a similar impairment in man. Nineteen patients in the early stages of Parkinson's disease were tested on two associative learning tasks and on the Wisconsin Card Sorting Task; and their performance was compared with that of patients with frontal or temporal lobe lesions. On the two associative learning tasks there was no overall difference between the Parkinsonian group and the controls. However, a minority of the Parkinsonian patients performed very poorly on these tasks; and it was noted that these tended to be the older patients.

Laterality differences for speed but not for control in sequential finger tapping.

Multiple or sequential finger tapping is preferential to the dominant right hand with respect to speed. However, in more complex movement, variables other than speed become important. The present investigation uses a sequential finger-tapping task which permits assessment of between-hands differences with respect to rate and control of movement, with and without vision. 36 right-handed normal adults rapidly tapped their fingers in sequential order on a block (2.54 cm. sq.), trying not to move the block. Analyses of variance (mode x hand) performed for taps and shift of the block show the right hand to be faster than the left hand with and without vision, adding further to the notion that the left hemisphere predominates in increases in rapid movement and in sequencing aspects of motor activity. However, while both hands were steadier with vision than without, there were no between-hand differences with regard to control, suggesting equivalency of cerebral function for factors of manual sequencing other than speed.

Memory function--effects of different antihypertensive drugs.

Improvement in the efficacy of newer antihypertensive agents has resulted in consideration of the side effects of drug therapy. Impairment of memory function resulting from antihypertensive therapy has been clinically suspected. This observation has been supported by a study in which the effects of methyldopa and propranolol on memory function were reported. Recently, memory function has been assessed in a group of patients treated with either a beta-blocker (atenolol) or an angiotensin-converting enzyme inhibitor (enalapril) in a randomised, observer-blind study in moderate essential hypertension. The patients were assessed, on placebo and after 16 weeks of treatment on active therapy, by use of a series of 4 memory function tests related to everyday life. In the hypertension study group, 13 received atenolol and 12 received enalapril. Similar reduction of diastolic pressure occurred in both groups, but systolic pressure was significantly reduced in the enalapril group (p less than 0.05). In the atenolol group memory performance scores were consistently lower than in the placebo phase in 9 of 28 estimates of memory function. In the enalapril group there were no significant changes. The study indicated that atenolol might produce mild memory impairment, whereas enalapril was devoid of any measurable effect on memory function.

Hearing words and seeing colours: an experimental investigation of a case of synaesthesia.

A case of 'chromatic-lexical' (colour-word) synaesthesia is described, and its genuineness confirmed using the criterion of stable cross-modality imagery across time. The synaesthesia could not be accounted for by a memory hypothesis, nor was it associated with any psychiatric condition. Further analysis did not identify any semantic relationship between real words and colours, but the colours of nonwords were determined by the colours of the individual letters. Numbers also had their own stable colours. The experience of synaesthesia was triggered by other auditory stimuli, but most strongly by words. Cortical electrophysiological recording failed to reveal any abnormalities. An unusual organisation of modalities in the brain is postulated to account for the phenomenon.

Phaeochromocytoma as a cause of reversible dementia.

The case of a 57 year old man with cognitive impairment, hypertension and insulin dependent diabetes mellitus caused by phaeochromocytoma is reported. One year after removal of the tumour there was a significant improvement with the full scale IQ increasing by 15 points, normotension and minimal glucose intolerance. Possible mechanisms accounting for reversible cognitive impairment in such a situation are discussed. No previous reports of this association have been discovered.

Differential effects of atenolol and enalapril on memory during treatment for essential hypertension.

A randomized single-blind study was designed to compare the performance on memory tests requiring recall of information relevant to everyday life of two groups of hypertensive patients. One group of 13 patients were taking a beta-adrenoceptor blocker (atenolol) and the other group of 12 patients received the angiotensin-converting enzyme inhibitor (enalapril). The results suggested that when compared with placebo the group of patients treated with enalapril showed no changes in memory function, whilst there was a mild, but consistent deficit in the group taking atenolol.

Temporal orientation in the pre-senium and old age.

Temporal orientation in 235 normal elderly subjects was examined and compared with previous results from a young adult population. Orientation for time in the elderly remains reasonably intact; the major exception to this was inaccurate recall of the date, which was most pronounced among women in the older group studied (71 +).

Alterations in cognitive performance and affect-arousal state during fluctuations in motor function in Parkinson's disease.

Sixteen patients with idiopathic Parkinson's disease were selected who were all showing severe fluctuations in motor function ("on-off" phenomenon). Measures of cognitive function and of subjective affect/arousal state were taken on two occasions, once when "on" and once when "off". Twenty-five matched normal controls were also assessed on the same measures. Results revealed, on the average, a drop in cognitive function plus an adverse swing in affect/arousal state, in the patient group in the "off" condition, compared to the levels when "on". Analysis of the data suggested that the main factor associated with cognitive function when "off" was not the severity of disability but the level of affect/arousal. The fluctuations in cognitive function found tended to be mild relative to the severe changes in motor ability, and were present in only a proportion of patients.

Memory function of children with spina bifida and shunted hydrocephalus.

A group of 10 children with spina bifida and shunted hydrocephalus, aged between 7 1/2 and nine years, was tested for memory of two types of verbal material and two types of pictorial material. Their performance was compared with a group of children with matched IQ and with a group of average IQ, all matched for age and sex. The parameters investigated were learning ability; immediate and delayed recall, and also long-term recall/recognition; and reacquisition of material learned after a period of 24 hours. The hydrocephalic children and the matched IQ group were significantly poorer than the average IQ group on all tasks except for 'Memory for a Short Story' Comparisons between the hydrocephalic and matched IQ groups showed that the former group was significantly poorer only in a 'Memory for Words' test. It is suggested that this discrepancy in the performance of hydrocephalic children in learning unrelated, as opposed to connected, meaningful verbal material may reflect a deficit in their ability to use appropriate semantic strategies at the level of encoding.

Drawing disability in patients with senile dementia.

A series of drawing tasks was administered to 15 patients with senile dementia who were assessed for intellectual functioning and severity of dementia. Their performance was compared with that of 15 elderly control subjects. The demented patients' spontaneous drawings were found to be impoverished in comparison with those of the controls. Copies of the same objects included more details, but these tended to be wrongly positioned in space. The performance of the patients with dementia was unlike that reported for patients with focal brain lesions. Significant relations were found between drawing performance and intellectual functioning and severity of dementia. The theoretical and practical implications of these findings are discussed.

The performance of professional musicians on the seashore measures of musical talent: an unexpected finding.

During an investigation designed to explore the effects of brain lesions on musical ability in professional musicians, the Seashore Scale was used to discover whether focal damage was associated with specific impairment of any of the basic elements of musical talent. In order to obtain adequate control of the experimental group it was necessary to study a comparable group of professional musicians. For this purpose the Seashore test battery was given to 21 orchestral players. The scores obtained by these professionals were better than an estimate of the population values in only three of the six tests, pitch discrimination, rhythm and tonal memory; they were significantly poorer in the test of timbre. This unexpected finding sheds doubt on Seashore's assumptions about the requirements for high musical talent. It also raises questions on the use of the Seashore battery in certain areas of psychological research.