Biomedical subjects

D M MacKenzie

Publications and source records attributed to D M MacKenzie.

4 recordsLinked to original sources

PubMed1996

Brief cognitive screening of the elderly: a comparison of the Mini-Mental State Examination (MMSE), Abbreviated Mental Test (AMT) and Mental Status Questionnaire (MSQ).

One hundred and fifty unselected elderly community subjects were assessed by Mini-Mental State Examination (MMSE), Abbreviated Mental Test (AMT) and Mental Status Questionnaire (MSQ). The effects on cognitive test scores of potential confounding (non-cognitive) variables were evaluated. Sensitivities and specificities were: MMSE 80% and 98%; AMT 77% and 90%; and MSQ 70% and 89%. The MMSE identified significantly fewer false positives than the AMT and MSQ. The major effect of intelligence on cognitive test scores has previously been underestimated. Age, social class, sensitivity of hearing and history of stroke were also significantly correlated with cognitive test scores. Years of full time education and depression only affected the longer MMSE and CAMCOG. The MMSE (cut-off 20/21) can be recommended for routine screening. However, as scores are affected by variables other than cognitive function, particularly intelligence, further assessment of identified cases may fail to reveal significant functional impairment.

Aged↗

PubMed1995

Cognitive brain potentials and regional cerebral blood flow equivalents during two- and three-sound auditory "oddball tasks".

Ten healthy volunteers were examined with single photon emission tomography and 99mTc-exametazime. They were studied on 2 occasions, during a 2- and a 3-sound auditory discrimination (oddball) task. Twenty healthy volunteers were used as controls, studied once at rest. During the 2-tone task there was a bilateral posterior (occipito-) temporal and medial frontal activation, a left pericentral increase, and posterior cingulate suppression. During the 3-sound task activation was again found in posterior (occipito-) temporal, medial frontal cortex, left pericentral, with a small non-significant reduction in posterior cingulate uptake. Compared with the 2-tone task, there was a trend towards higher activity in left medial frontal, right posterior temporal and posterior cingulate cortex in the 3-sound task. P3b amplitudes were negatively correlated with posterior cingulate tracer uptake during both tasks. Positive correlations with P3b amplitudes were found in various frontal and temporal regions. These results are consistent with more invasive localisation studies of P3b. Posterior cingulate cortex appears to be inhibited during the oddball tasks, the more so, the more restricted the range of stimuli, and the greater the task-related recruitment of neurones (P3b amplitude). As expected from its more frontal distribution, P3a amplitude was positively correlated with anterior cingulate tracer uptake, and negatively correlated with temporal cortical activity.

Aged↗

PubMed1994

Assessing cognitive estimation.

The Cognitive Estimation Test (CET) was devised in an attempt to quantify the tendency observed in patients with frontal lobe lesions to produce bizarre estimations in response to fairly simple questions, despite performing normally on standard intelligence tests. Several studies have been published where CET performance in patient groups has been examined. However, there is a paucity of adequate normative data. In the present study, representative normative data are provided from 150 healthy controls. CET performance was found to be moderately related to general intellectual ability, with females performing more poorly than males. The scale was examined psychometrically, and was found to be factorially impure, with poor internal reliability but adequate inter-rater reliability. Further revision of the CET is required in order to render it a psychometrically acceptable instrument.

Adolescent↗

PubMed1993

Psychiatric emergency clinic attenders: what can we learn from them?

Patients attending the Royal Edinburgh Hospital emergency psychiatric clinic over a four month period were assessed by semi-structured interview. General Practitioner and self-referrals were compared with respect to presenting features and subsequent management. Self-referral was associated with young age, male sex, unemployment, poor social cohesion, problem drinking, a forensic history, and mild levels of psychiatric disorder. Only 10% of self-referrals were considered appropriate psychiatric emergencies, but 69% of General Practitioner referrals. Five per cent of self- and 34% of General Practitioner-referrals were admitted. These findings indicate that if the psychiatric emergency clinic is to be of benefit to those it serves, it must not confine itself simply to assessment of mental disorder, but seek to facilitate crisis resolution.

Adult↗