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Biomedical subjects

D Coakley

Publications and source records attributed to D Coakley.

At least 37 records · Page 2Linked to original sources

Dysthymia among the community-dwelling elderly.

There are few data on the clinical features of dysthymia among the community-dwelling elderly. Forty elderly individuals with dysthymic disorder were identified following screening in the community with GMS-AGECAT. A detailed clinical history was obtained and DSM-IV checklists and standardized scales were used, at a second interview. Comparisons were made with a group of 630 non-depressed elderly from the same community. Dysthymia was predominately of late onset (93%) and associated with a major stressor in 65% of cases. Comorbid axis 1 disorders were present in 15% of dysthymics and an axis 2 disorder in 10%. The dysthymic group had significantly higher degrees of physical impairment than the non-depressed elderly. The symptom profile demonstrated prominent anxiety and functional features. Eighty-three per cent of the elderly with dysthymia had presented to their GP with anxiety/depressive symptoms at some stage during the dysthymic disorder. The presentation of dysthymia in older people differs from that in earlier life. Late life dysthymia is less associated with axes 1 and 2 comorbidity but is associated with significant degrees of physical impairment. Dysthymia in older people presents to primary care, rather than specialist services, and interventions must be delivered at this level.

Age of Onset↗

Dominant frequency content of ocular microtremor from normal subjects.

Ocular microtremor (OMT) is a high frequency tremor of the eyes present during fixation and probably related to brainstem activity (Coakley, D. (1983). Minute eye movement and brain stem function. CRC Press, FL.). Published observations on the frequency of OMT have varied widely. Ocular microtremor was recorded in 105 normal healthy subjects using the Piezoelectric strain gauge technique. The dominant frequency content of a signal was determined using the peak counting method. Values recorded ranged from 70 to 103 Hz, the mean frequency being 83.68 Hz (S.D. +/- 5.78 Hz).

Adult↗

The association between demographic factors, disease severity and the duration of symptoms at clinical presentation in elderly people with dementia.

OBJECTIVE: To determine the association between factors unrelated to the disease process, the duration of symptoms and the degree of cognitive or functional impairment in elderly patients presenting with dementia. METHOD: The living situation, educational level, age, gender and diagnosis based on standardized criteria were recorded for 209 elderly patients presenting to a memory clinic with dementia. Cognitive and functional deficits were measured with the cognitive section of the Cambridge Mental Disorders of the Elderly Examination combined with the Mini-Mental State Examination and the abbreviated version of the Blessed dementia scale, respectively. RESULTS: 129 patients had a diagnosis of probable Alzheimer's disease, 19 had probable ischaemic vascular dementia and 61 had mixed dementia. There was no effect of diagnosis on duration of symptoms or dementia severity at the time of presentation. Patients living with a son or daughter were more functionally impaired than those living alone or with a spouse. Males had higher cognitive scores but did not have milder functional deficits. Patients with only a primary-school education had a trend towards lower cognitive scores at presentation but did not have more functional deficits. CONCLUSIONS: The gender of the patient and the relationship to the carer are associated with cognitive and functional scores at the time of presentation in patients with dementia.

Age Factors↗

Tissue culture adherence and haemagglutination characteristics of Moraxella (Branhamella) catarrhalis.

The haemagglutination and tissue culture adherence properties of 20 isolates of Moraxella catarrhalis obtained from the sputum of elderly patients with lower respiratory tract infections were compared with those of 20 isolates of M. catarrhalis obtained from the nasopharynx of elderly persons colonised by the organism. Eighty percent of isolates from the infected group as opposed to 5% of isolates from the colonised group haemagglutinated human erythrocytes (P < 0.001), indicating that the haemagglutinin might be a marker of pathogenicity for M. catarrhalis. There was a significant difference in the adherence to HEp-2 cells of isolates from the infected group in comparison to isolates from the colonised group (P = 0.03). Haemagglutination and tissue culture adherence properties were unrelated, indicating that separate adhesin systems are involved. The adherence of M. catarrhalis to HEp-2 cells was unaffected following pronase and trypsin treatment, however, sodium periodate pre-treatment of the bacteria significantly reduced the tissue culture adherence index, indicating that the adhesin by which the bacteria bind to HEp-2 cells may have a carbohydrate moiety. Transmission electron microscopy studies revealed that adherence of M. catarrhalis to HEp-2 cells was mediated by trypsin-resistant 'tack-/spicule-like' structures protruding from the surface of the bacteria.

Aged↗

Transmission electron microscopy studies of Moraxella (Branhamella) catarrhalis.

A trypsin-sensitive 200-kDa protein has been reported to be exclusively associated with haemagglutinating isolates of Moraxella (Branhamella) catarrhalis. Transmission electron microscopy studies revealed that haemagglutination by M. catarrhalis to both human and rabbit erythrocytes was mediated by a trypsin-sensitive outer fibrillar coat. This fibrillar layer was absent on non-haemagglutinating isolates examined. Immuno-electron microscopy, using a polyclonal antiserum containing antibodies to the 200-kDa protein as a probe, showed that the 200-kDa protein is present on the outer fibrillar layer of the bacterium. These findings suggest that the haemagglutinin of M. catarrhalis is a 200-kDa protein present on the outer fibrillar coat.

Animals↗

Ocular microtremor in patients with idiopathic Parkinson's disease.

Abnormalities in the oculomotor control mechanism of patients with idiopathic Parkinson's disease are well recognised. In this study the effect of Parkinson's disease on tonic output from oculomotor nuclei was studied by using oculomicrotremor as an index of such output. Oculomicrotremor readings were taken from 22 parkinsonian patients and 22 normal healthy volunteers using the piezoelectric strain gauge technique. There was a slower overall tremor frequency, baseline, and burst frequency in the parkinsonian group. There was also a significant increase in the duration of baseline, with a decrease in the number of bursts a second and a decrease in average duration of bursts in the patient group compared with the normal group. One patient, whose medication was withdrawn, showed a marked decrease in mean frequency and baseline frequency with a decrease in number of bursts and increase in baseline duration compared with readings taken when treatment recommenced. These results suggest that variables measured in oculomicrotremor are altered compared with normal subjects, reflecting altered tonic output from oculomotor nuclei in patients with idiopathic Parkinson's disease.

Aged↗

Genetic analysis of the thermolabile variant of 5, 10-methylenetetrahydrofolate reductase as a risk factor for ischemic stroke.

Mild hyperhomocysteinemia is a risk factor for atherosclerotic vascular disease. Homozygosity for the C677T mutation in the gene for 5,10-methylenetetrahydrofolate reductase (MTHFR) is frequently associated with hyperhomocysteinemia, particularly in individuals with low levels of serum folate, and has been directly associated with cardiovascular disease in certain populations. The purpose of this study was to establish whether the C677T mutation, which causes thermolabile MTHFR, is a risk factor for ischemic stroke in the Irish population. The homozygous C677T genotype has previously been associated with coronary heart disease in Ireland. We collected blood from 174 individuals (minimum age 60 years) who had suffered an ischemic stroke that was confirmed by computed tomography brain scan. Control subjects (n=183) aged >/=60 years, who had never suffered a stroke or transient ischemic attack, were recruited from hospitals and active retirement groups in the same geographical area. MTHFR genotypes were determined and other known risk factors for stroke were documented. In the control group, the frequency of subjects with the homozygous C677T genotype was 10.4%. In patients who had suffered ischemic stroke, the frequency was 15.5%. This difference was not statistically significant. The odds ratio of stroke for C677T homozygotes, with other genotypes as a reference group, was 1.59, 95% CI=0.85, 2.97. The data indicate that the homozygous C677T MTHFR genotype is at most a moderate risk factor for ischemic stroke.

Aged↗

Ocular microtremor in oculomotor palsy.

OBJECTIVES: Ocular microtremor (OMT) is a high frequency tremor of the eyes present in all individuals. Recent reports suggest that OMT may be a useful indicator of brainstem function. However, the actual origin of ocular microtremor remains controversial. This study aims to provide evidence that OMT has a neurogenic origin. MATERIALS AND METHODS: The OMT activity of five subjects with unilateral oculomotor nerve palsy and one subject with complete unilateral internal and external ophthalmoplegia were recorded from both eyes of each subject using the piezoelectric strain gauge technique, with the normal eye acting as a control. Five parameters of OMT activity were studied in each subject: the peak count, the power of the high frequency peak, the percentage power between 60 and 100 Hz, the percentage power between 70 and 80 Hz, and the 10 dB cut-off point. RESULTS: In the five subjects with oculomotor nerve palsy, the mean peak count in the normal eye was 88.4 Hz (SD+/-16.9) and in the affected eye was 59 Hz (SD+/-8.6), P < 0.0096. There was also a fall in the peak power, the power between 60 and 100 Hz, and the power between 70 and 80 Hz. In subject six, who had complete opthalmoplegia, there was no evidence of OMT activity in the denervated eye. CONCLUSIONS: These results suggest that innervation of the extraocular muscles is necessary for normal OMT activity, and OMT therefore has a neurogenic origin.

Adult↗

Benzodiazepine use among the elderly in the community.

Benzodiazepines are the most commonly prescribed psychotropic drug in the elderly. Benzodiazepines with a long duration of action can produce marked sedation and psychomotor impairment in older people, and are associated with an increased risk of hip fracture and of motor vehicle crash. One thousand seven hundred and one individuals of 65 years and over, identified from General Practitioner lists, were interviewed using the Geriatric Mental State-AGECAT package and current psychotropic drug use was recorded. Benzodiazepines were classified as having a short or long elimination half-life. Two hundred and ninety-five (17.3%) individuals were taking a benzodiazepine, with use in females being twice that in males. Of the 295, 152 (51.5%) were taking a long acting benzodiazepine and the use of long acting anxiolytic type benzodiazepines was particularly common. Fifty-two (17.6%) benzodiazepine users were taking one or more other psychotropic drugs. A benzodiazepine was used by eight of 18 (44.4%) subjects with an anxiety disorder, 62 of 180 (34.4%) individuals with depression, and seven of 71 (9.9%) people with dementia. Four-fifths of older people on a psychotropic drug were taking a benzodiazepine, highlighting the importance of this class of drug in the elderly population. The choice of a benzodiazepine with a long duration of action, which have been shown to be associated with serious adverse events in the elderly in over one half of benzodiazepine users, is of concern. The potential for adverse effects was further accentuated by polypharmacy practices. The choice of benzodiazepine for an older person has important consequences and should be addressed in greater detail with primary care.

Aged↗

Dementia carer education and patient behaviour disturbance.

OBJECTIVE: To evaluate the impact of a dementia Carer Education Programme on carer quality of life (QoL), burden, and well-being. DESIGN: Single group before-after intervention study. The group was subdivided by perceived status post-programme for intragroup analysis. SETTING: Hospital memory clinic. PARTICIPANTS: Convenience sample of 32 dementia carers. INTERVENTION: Eight weekly 2 h education and support sessions run by a psychogeriatric clinical team. MEASURES: Pre-programme and 6 months post-programme data were obtained. Measures included individually perceived QoL, burden, well-being, managing problem behaviour, appraisal of social support, knowledge of dementia, and perception of the programme. Patients were characterized in terms of cognition, behaviour disturbance and functional status. RESULTS: Twelve carers reported their situation post-programme as 'better', 12 as 'worse', and four as 'no change'. There were no significant baseline differences. For 'better/no change' carers the only significant change over time was increased knowledge about dementia. For 'worse' carers knowledge also increased, but there was evidence of poorer QoL, increased burden, a poorer appraisal of social support, and increased patient behaviour disturbance. Only patient behaviour disturbance significantly discriminated 'no change/better' from 'worse' carers (F = 4.08, p = 0.055). CONCLUSIONS: The programme increased carers' knowledge about dementia, but had no significant impact on QoL, burden, or well-being. Increased patient behaviour disturbance appeared to be a major factor when the carer's situation worsened over time. Despite high carer satisfaction the efficacy of a group-based education approach to the management of behaviour disturbance in dementia appears limited. More intensive or individually tailored interventions may be necessary alternatives.

Adult↗

Ocular microtremor in brain stem death

OBJECTIVE: This study was undertaken to establish whether measurement of ocular microtremor (OMT) activity could be used as a method to establish brain stem death. Presently, the diagnosis of brain stem death can be made using clinical criteria alone. OMT is a high-frequency, low-amplitude physiological tremor of the eye caused by impulses emanating from the brain stem. There have been a number of reports indicating that the recording of OMT may be useful in the assessment of comatose states and in establishing brain stem viability or death. METHODS: We obtained the OMT recordings of 32 patients suspected of having brain stem death using the piezoelectric strain gauge technique. This method involves mounting the piezoelectric probe in a headset and lowering the rubber-tipped end piece onto the anesthetized scleral surface of the subject. The signal produced is recorded on audiomagnetic tape and later played back and analyzed on an electrocardiographic tape analyzer. RESULTS: In 28 patients, initial clinical assessment confirmed the diagnosis of brain stem death and no OMT activity was recorded from these subjects. In three patients in whom initial clinical assessment demonstrated brain stem function, OMT activity was present; when brain stem death was subsequently diagnosed in these three patients, no OMT activity could be demonstrated. In the remaining patient, two of three OMT recordings demonstrated activity in spite of the absence of clinical evidence of brain stem function. A post mortem revealed bacterial cerebritis in this subject. CONCLUSION: The results suggest that OMT is a sensitive method of detecting brain stem life and that it could play an important role in the assessment of brain stem death.

Journal Article↗

Prognostic value of electrophysiological markers in Alzheimer's disease.

The authors assessed the usefulness of event-related potentials (ERP) and flash visual evoked potentials (FVEP) as prognostic markers in a sample of 25 subjects with probable Alzheimer's disease (AD). ERP and FVEP recordings were obtained from 21 and 23 subjects, respectively. Ranking of the annual rate of change in cognitive scales vs. baseline ERP/FVEP latencies was compared, and those with longer FVEP N(2) component latencies showed slower subsequent rates of decline (tau=0.32; z=2.16; P=0.015), suggesting that further study of FVEP responses as prognostic markers in AD is warranted.

Aged↗

Assessment of progression and prognosis in 'possible' and 'probable' Alzheimer's disease.

OBJECTIVE: The objective of this study was to assess the rate of progression and clinical predictors of decline in subjects with possible and probable Alzheimer's disease (AD). DESIGN/SETTING: The annual rate of change (ARC) for cognitive/functional scales was calculated for 95 subjects with AD attending a memory clinic. Two consecutive ARCs were calculated for a subgroup of 39 subjects. RESULTS: The ARCs were relatively normally distributed; however, there was a large degree of variability. Neither age nor duration of symptoms at presentations were predictive of the rate of decline. However, the data suggested an effect of gender, with males having a greater rate of decline in cognition (p = 0.02). Finally, the rate of progression over the first year did not predict the subsequent ARC (p = 0.25). CONCLUSIONS: The high variability in ARCs observed in this study and poor correlation between consecutive ARCs suggest that neither mean ARC values nor the previous rate of decline can be used to aid clinicians in the assessment of response to acetylcholinesterase inhibitors or other specific treatments for AD.

Age Factors↗

Psychiatric morbidity in cohabitants of community-dwelling elderly depressives.

OBJECTIVE: To determine the effect of living with a depressed elderly individual on the mental health of the cohabitant carer. METHOD: Case-control study comparing rates of psychiatric morbidity in cohabitants of depressed versus well elderly. SETTING: Community sample. PARTICIPANTS: 44 couples, one partner with AGECAT depression, and 44 couples, one partner diagnosed well by AGECAT. Cohabitants were matched for gender, age and physical health status. All subjects were aged 65 years and over. MAIN OUTCOME MEASURE: Odds ratio of case or subcase depression and/or neurotic disorder in cohabitants of depressed elderly. RESULTS: 28/44 (64%) cohabitants of depressed subjects were cases (N = 9) or subcases (N = 19) of depression, neurotic disorder or both, compared to 13/44 (29%) cases (N = 1) or subcases (N = 12) in cohabitants of well subjects (OR = 6.33, 95% CI (1.7-18.3), p = < 0.001). CONCLUSION: This study reveals high levels of psychiatric morbidity, primarily depression and anxiety symptoms, in the cohabitants of depressed community-dwelling elderly. This suggest that living with a depressed elderly person may have an adverse effect on the mental health of the cohabitant. Increased recognition of the potential psychiatric morbidity in this group is needed.

Aged↗

Vitamin D-fortified liquid milk: benefits for the elderly community-based population.

To assess the efficacy and acceptability of vitamin D-fortified liquid milk in the management of hypovitaminosis D we carried out a double-blind, randomized, controlled trial on 51 community-based, elderly subjects with serum 25 hydroxyvitamin D (25OHD) levels of less than 12.9 ng/ml (normal range 10-80 ng/ml). Each subject had a dietary assessment, mental test score, outdoor score, serum 25 hydroxyvitamin D level, and a general biochemical screening at baseline in April 1993 which was repeated in September 1993, April 1994, and September 1994. All subjects received 500 ml of milk per day, delivered to their homes in specially manufactured, blank, tetrapak cartons, from June 1993 to June 1994: 23 subjects received unfortified milk (control group) and 28 subjects received fortified milk (active group). Our results showed a baseline mean 25OHD level in the active group of 9.6 (range < 5.5-12.7) ng/ml and in the control group of 10.0 (range < 5.5-12.9) ng/ml (P < 0.4). One year later the mean 25OHD level in the active group had risen significantly from its baseline to 18.5 (range 9.6-26.7) ng/ml (P < 0.001) and was significantly different from the control group with a 1-year mean of 12.7 (range < 4-24.1) ng/ml (P < 0.001). Serum calcium levels in the active group also showed a significant rise over the 1-year period (P < 0.001) whereas those in the control group did not. We conclude that vitamin D-fortified liquid milk is a safe, effective, and acceptable method of administering vitamin D to the elderly, community-based population.

Aged↗