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Biomedical subjects

Michael Farrell

Publications and source records attributed to Michael Farrell.

At least 37 records · Page 2Linked to original sources

Choroid plexus adenoma: case report and review of the literature.

CASE REPORT: An 8-month-old infant with macrocephaly was found to have hydrocephalus and a cystic third ventricular tumour; biopsy of the tumour showed a choroid plexus adenoma. The tumour was attached to the ependymal lining and was strongly adherent to the walls and floor of the anterior third ventricle. TREATMENT: After biopsy, it was felt that a radical resection would carry a high risk of injury to the floor of the third ventricle and cause new neurological deficits. Therefore, an external ventricular drain was inserted and bilateral ventriculo-peritoneal shunts were inserted 1 week post-operatively. In view of the benign nature of the tumour, no adjuvant radiotherapy or chemotherapy was given. OUTCOME: There was no further tumour growth or clinical deterioration over a 6-year follow-up period.

Adenoma↗

Cervical lipoblastomatosis producing quadriparesis: case report of surgery with chemotherapy and 10-year follow-up.

INTRODUCTION: Cervical lipoblastomatosis is a rare spinal tumour. Management of recurrence and long-term outcome data are not well described. CASE REPORT: A 10-month-old infant presented with an upper extremity weakness. Magnetic resonance imaging (MRI) revealed an extradural cervical spinal tumour. It was debulked and histopathology revealed it to be lipoblastomatosis. The infant improved postoperatively. However, 5 months later the patient deteriorated and developed quadriparesis. The patient was managed with a more extensive resection and had chemotherapy. Ten years post-presentation the patient is well having made a full recovery and is living a normal life. Recent MRI shows minimal residual quiescent tumour. CONCLUSION: The treatment of cervical lipoblastomatosis should involve the resection of as much tumour as possible at the first sitting as recurrence can be a problem. In cases of spinal recurrence we recommend aggressive decompression and adjuvant chemotherapy.

Cervical Vertebrae↗

Creutzfeldt-Jakob disease in Ireland: epidemiological aspects 1980-2002.

Surveillance for Creutzfeldt-Jakob disease (CJD) has been carried out in the Republic of Ireland since 1980. Initial surveillance was passive and based on consented autopsy confirmation of CJD in patients in whom there was a high index of clinical suspicion. Since 1999, an active surveillance programme involving formal notification of all suspect CJD cases has been in place. The annual mortality rate has increased from 0.34 cases/million in 1980 to 1.27 cases/million in 2001. In all, 29 cases have been pathologically confirmed: 1 had variant CJD (vCJD), 1 had iatrogenic human growth hormone-induced CJD and 1 had fatal insomnia. Sporadic CJD (sCJD) accounted for the remainder. This paper details the change in incidence over 22 years as the surveillance programme in Ireland got under way; the increased incidence is attributed to better case ascertainment, as has occurred in other countries where active surveillance programmes have been established.

Adult↗

Risk factors and the prevalence of neurosis and psychosis in ethnic groups in Great Britain.

BACKGROUND: Our aim was to examine whether variations in the prevalence of neurosis and psychosis between ethnic minorities throughout Great Britain are explained by social disadvantage. METHOD: A total of 10,108 adult householders throughout Great Britain were assessed in a two-stage survey with the Revised Clinical Interview Schedule (CIS-R) and Psychosis Screening Questionnaire (PSQ). Respondents with a positive PSQ or who received a diagnosis of, or treatment for, psychosis were examined by a psychiatrist using the Schedules for Clinical Assessment in Neuropsychiatry (SCAN). Data on respondents' preferred ethnic group were collapsed into four groups: Whites, African-Caribbean or Africans, south Asians and other. RESULTS: Ethnic grouping was strongly associated with: unemployment; lone parent status; lower social class; low perceived social support; poverty (indicated by lack of car ownership) and having a primary social support group of less than three close others. All these associations applied to the group Africans and Afro-Caribbeans, but only some applied to the other groups. No ethnic group had significantly increased rates of neurosis. Only the African-Caribbean group were at significantly increased risk of a psychotic disorder (odds ratio 4.55; 95% CI: 1.13, 18.30). After adjustment for risk factors, the odds of psychosis were lower (odds ratio 2.97; 95% CI: 0.66, 13.36). CONCLUSIONS: The excess of psychosis in Africans and Afro-Caribbeans in Great Britain appears to be partly explained by socio-economic disadvantage, but larger studies are needed to confirm this.

Adolescent↗

Psychosis, victimisation and childhood disadvantage: evidence from the second British National Survey of Psychiatric Morbidity.

BACKGROUND: Adverse early circumstances may be more common in people who later develop psychotic disorders. AIMS: To use data from the second British National Survey of Psychiatric Morbidity to examine associations between psychotic disorders and a number of early victimisation experiences. METHOD: Psychiatric disorders were identified through structured assessment of adults resident in private households in Britain (n=8580). Respondents were asked whether they had experienced selected events displayed on cards. RESULTS: Compared with respondents with other psychiatric disorders or with none, the prevalence of every experience bar one was significantly elevated in those with definite or probable psychosis. The largest odds ratio was for sexual abuse. Controlling for depressed mood somewhat reduced the odds ratios for the individual experiences. CONCLUSIONS: In people with psychosis, there is a marked excess of victimising experiences, many of which will have occurred during childhood. This is suggestive of a social contribution to aetiology.

Accidents↗

Prevalence and correlates of self-reported psychotic symptoms in the British population.

BACKGROUND: The psychosis phenotype is generally thought of as a categorical entity. However, there is increasing evidence that psychosis exists in the population as a continuum of severity rather than an all-or-none phenomenon. AIMS: To investigate the prevalence and correlates of self-reported psychotic symptoms using data from the 2000 British National Survey of Psychiatric Morbidity. METHOD: A total of 8580 respondents aged 16-74 years were interviewed. Questions covered mental health, physical health, substance use, life events and socio-demographic variables. The Psychosis Screening Questionnaire (PSQ) was used to identify psychotic symptoms. RESULTS: Of the respondents, 5.5% endorsed one or more items on the PSQ. Factors independently associated with psychotic symptoms were cannabis dependence, alcohol dependence, victimisation, recent stressful life events, lower intellectual ability and neurotic symptoms. Male gender was associated with paranoid thoughts, whereas female gender predicted hallucinatory experiences. CONCLUSIONS: Self-reported psychotic symptoms are less common in this study than reported elsewhere, because of the measure used. These symptoms have demographic and clinical correlates similar to clinical psychosis.

Adolescent↗

Trends in service use and treatment for mental disorders in adults throughout Great Britain.

BACKGROUND: Trends in health treatments and outcomes in the general population may be used to monitor achievement of health targets. AIMS: To investigate changes in mental health services and treatment in Britain over a 7-year period. METHOD: National surveys of psychiatric morbidity were completed in 1993 and 2000 in households throughout Great Britain. Standardised interviews were used to establish psychiatric case status and service and treatment utilisation in adults aged 16-64 years. RESULTS: Use of psychotropic medication doubled in those designated as psychiatric cases. In the non-case-status population antidepressant use rose from 0.16% in 1993 (95% CI 0.07-0.25) to 2.02% in 2000 (95% CI 1.69-2.35). However, the overall prevalence of neurotic and psychotic disorder hardly changed from 1993 to 2000. Use of specialised 'talking treatments'did not increase significantly, except in the non-case group. CONCLUSIONS: Treatment with psychotropic medication alone is unlikely to improve the overall mental health of the nation. A policy based almost exclusively on treatment of identified cases should be augmented by preventive approaches.

Adolescent↗

The Association Between Spirituality and Depression in an Urban Clinic.

OBJECTIVE: To investigate the correlation between spiritual beliefs and depression in an urban population. METHOD: A convenience sample of adult patients of an urban primary care clinic completed a self-administered questionnaire consisting of the Zung Depression Scale and the Spiritual Involvement and Beliefs Scale (SIBS). RESULTS: Among 122 respondents, 99 (81%) reported that they consider themselves religious. Responses from the Zung Depression Scale found that 76 (62%) of the patients were depressed and 46 (38%) were not. The Pearson correlation coefficient between the Zung Depression Scale and the SIBS was -0.36 (p <.0001). Backward stepwise regression analysis revealed that SIBS score and physical health predicted the Zung Depression Scale score. Age, gender, ethnicity, religious affiliation, and income showed no significant association with depression. Analysis of individual SIBS items revealed that high spirituality scores on items in the domain of intrinsic beliefs, such as belief in a higher power (p <.01), the importance of prayer (p <.0001), and finding meaning in times of hardship (p <.05), were associated negatively with depression. Attendance of religious services had no significant association with depression. CONCLUSION: Appropriate encouragement of a patient's spiritual beliefs may be a helpful adjunct to treating depression.

Journal Article↗

Neural correlates of the emergence of consciousness of thirst.

Thirst was induced by rapid i.v. infusion of hypertonic saline (0.51 M at 13.4 ml/min). Ten humans were neuroimaged by positron-emission tomography (PET) and four by functional MRI (fMRI). PET images were made 25 min after beginning infusion, when the sensation of thirst began to enter the stream of consciousness. The fMRI images were made when the maximum rate of increase of thirst occurred. The PET results showed regional cerebral blood flow changes similar to those delineated when thirst was maximal. These loci involved the phylogenetically ancient areas of the brain. fMRI showed activation in the anterior wall of the third ventricle, an area that is key in the genesis of thirst but is not an area revealed by PET imaging. Thus, this region plays as major a role in thirst for humans as for animals. Strong activations in the brain with fMRI included the anterior cingulate, parahippocampal gyrus, inferior and middle frontal gyri, insula, and cerebellum. When the subjects drank water to satiation, thirst declined immediately to baseline. A precipitate decline in intensity of activation signal occurred in the anterior cingulate area (Brodmann area 32) putatively related to consciousness of thirst. The intensity of activation in the anterior wall of the third ventricle was essentially unchanged, which is consistent with the fact that a significant time (15-20 min) would be needed before plasma Na concentration changed as a result of water absorption from the gut.

Adult↗

vCJD risk in the Republic of Ireland.

BACKGROUND: The Republic of Ireland has the second highest incidence of BSE worldwide. Only a single case of vCJD has been identified to date. METHODS: We estimate the total future number of clinical cases of vCJD using an established mathematical model, and based on infectivity of bovine tissue calculated from UK data and on the relative exposure to BSE contaminated meat. RESULTS: We estimate 1 future clinical case (95% CI 0-15) of vCJD in the Republic of Ireland. Irish exposure is from BSE infected indigenous beef products and from imported UK beef products. Additionally, 2.5% of the Irish population was exposed to UK beef through residing in the UK during the 'at-risk' period. The relative proportion of risk attributable to each of these three exposures individually is 2:2:1 respectively. CONCLUSIONS: The low numbers of future vCJD cases estimated in this study is reassuring for the Irish population and for other countries with a similar level of BSE exposure.

Animals↗

Minimizing respondent attrition in longitudinal research: practical implications from a cohort study of adolescent drinking.

The methods used to maximize retention in a longitudinal study of adolescent drinking are discussed. Data were collected at three time points: at recruitment to the study, after nine months and at 18 months. Strategies to minimize attrition included the collection of detailed contact information, incentives for participation, postcard and telephone reminders and telephone interviews. Ninety-six percent of the original sample completed the first follow-up questionnaire, 92% completed the second and the study lost contact with just 3% of participants. The success of the current project is notable as this type of population is notoriously difficult to retain in longitudinal studies.

Adolescent↗

Early death from paracetamol (acetaminophen) induced fulminant hepatic failure without cerebral oedema.

BACKGROUND: Paracetamol overdose is a frequent cause of fulminant hepatic failure. In fatal cases the most frequent causes of death are cerebral oedema in the early phase or sepsis and multiorgan failure later. However some patients do not fit this pattern. AIM: To review cause of death in paracetamol induced fulminant hepatic failure. METHODS: We reviewed all fatal cases of paracetamol induced fulminant hepatic failure in our liver unit between 1995 and 2000. RESULTS: Twenty one patients died without liver transplantation and post mortem examinations were performed on all. Significant cerebral oedema was present in 13 patients and absent in eight. The patients without cerebral oedema were significantly older (55.4+/-5.3 versus 36.3+/-3 years: P=0.0034), had a lower arterial pH on admission (pH 7.0+/-0.03 versus 7.3+/-0.05: P=0.0008), a shorter interval between overdose and death (3.75+/-0.7 versus 7.6+/-1.3 days: P=0.043) and a shorter interval between admission and death (1.9+/-0.6 versus 5.7+/-1.0 days: P=0.0097) than patients with cerebral oedema. The cause of death in the sub-group of patients without cerebral oedema was predominantly cardiovascular collapse with rapidly progressive resistant hypotension and/or cardiac arrest. No source of sepsis was identified in 7/8 patients without cerebral oedema. CONCLUSIONS: In this series the most frequent causes of death were cerebral oedema or cardiovascular collapse. Patients without cerebral oedema appear to form a distinct subgroup associated with early mortality and may require specific management strategies.

Acetaminophen↗

Rapid stereological quantitation of temporal neocortex in TLE.

To determine the extent of neocortical atrophy in the temporal lobe using rapid stereological analysis of magnetic resonance slices in patients with temporal lobe epilepsy and to compare the findings to those obtained by visual analysis of high-resolution magnetic resonance images. 25 patients with temporal lobe epilepsy, along with 25 age-matched controls were scanned using a 1.5 Tesla magnetic resonance imaging machine (GE signa systems Paris). Visual analysis was performed on standard high-resolution images. Volumetric analysis of hippocampus and temporal neocortex was performed using computer-aided stereology (MEASURE program, Patrick Barta, Johns Hopkins, Baltimore, USA). Stereological volumetric analysis demonstrated isolated hippocampal atrophy in only nine (36%) cases including three (12%) with bilateral disease. However, eight (32%) cases had combined hippocampal and neocortical atrophy and three (12%) had isolated neocortical atrophy. All volumetric measurements took less than 10 min. On the other hand, visual analysis suggested that 17 (68%) had hippocampal atrophy alone with only two (8%) having combined neocortical atrophy and a further two (8%) having isolated neocortical atrophy. Nearly half of the patients had temporal neocortical atrophy with or without hippocampal atrophy. This rapid, accurate and non-biased quantitative technique has wide clinical utility and is significantly more valuable in detecting neocortical atrophy than visual analysis alone. The results support the notion that abnormalities may be overlooked by current standards of routine magnetic resonance imaging.

Adult↗

Living with the Ilizarov frame: adolescent perceptions.

INTRODUCTION: The Ilizarov technique has become an established method in the treatment of children with serious skeletal disorders. Whilst the technique is acknowledged for solving difficult conditions, the application of the external fixator marks the beginning of an arduous treatment programme. Research has suggested that undergoing such treatment can negatively impact upon the physical and psychological well-being of the young person. Yet limitations in research design reduce the usefulness of the findings, given in that most of the previous studies have used retrospective, quantitative data collection approaches, often with a heterogeneous sample population. We wished to gain a richer insight into the experiences of adolescents living with the frame by drawing on both qualitative and quantitative approaches. AIMS: To explore adolescents' perceptions of the anticipated and actual impact of the Ilizarov frame on aspects of daily activity. DESIGN: A mixed-method approach, using a prospective and longitudinal study design. METHOD: Fifteen adolescents undergoing the Ilizarov treatment were contacted at several predetermined time-points during the course of their treatment to share their perceptions of living with the frame. At several of these points semi-structured interviews were used to ascertain their perceptions, whilst quantitative data were gained at all time-points by adolescents completing a range of psychometric measures. FINDINGS: Adolescents found that life with the frame was not as bad as anticipated, and they adopted a pragmatic approach, appreciating that this was something they 'just had to get through'. Peers had a substantial role in supporting their friend to adjust and cope with the frame. Psychometric scores were largely within normal limits. CONCLUSION: This study suggests that, while the Ilizarov treatment is demanding for adolescents, it is one that they can tolerate without sustained adverse psychological impact.

Adaptation, Psychological↗

Drug-related mortality and fatal overdose risk: pilot cohort study of heroin users recruited from specialist drug treatment sites in London.

Fatal overdose and drug-related mortality are key harms associated with heroin use, especially injecting drug use (IDU), and are a significant contribution to premature mortality among young adults. Routine mortality statistics tend to underreport the number of overdose deaths and do not reflect the wider causes of death associated with heroin use. Cohort studies could provide evidence for interpreting trends in routine mortality statistics and monitoring the effectiveness of strategies that aim to reduce drug-related deaths. We aimed to conduct a retrospective mortality cohort study of heroin users recruited from an anonymous reporting system from specialist drug clinics. Our focus was to test whether (1). specialist agencies would agree to participate with a mortality cohort study, (2). a sample could be recruited to achieve credible estimates of the mortality rate, and (3). ethical considerations could be met. In total, 881 heroin users were recruited from 15 specialist drug agencies. The overall mortality rate of the cohort of heroin users was 1.6 (95% confidence interval [CI], 1.1 to 2.2) per 100 person-years. Mortality was higher among males, heroin users older than 30 years, and injectors, but not significantly higher after adjustment in a Cox proportional hazard model. Among the 33 deaths, 17 (52%) were certified from a heroin/methadone or opiate overdose, 4 (12%) from drug misuse, 4 (12%) unascertained, and 8 (24%) unrelated to acute toxic effects of drug use. Overall, the overdose mortality rate was estimated to be at least 1.0 per 100 person-years. The standardized mortality ratio (SMR) was 17 times higher for female and male heroin users in the cohort compared to mortality in the non-heroin-using London population aged 15-59 years. The pilot study showed that these studies are feasible and ethical, and that specialist drug agencies could have a vital role to play in the monitoring of drug-related mortality.

Adult↗

Apolipoprotein(A) expression in intracranial aneurysms.

OBJECTIVE: Elevated serum levels of lipoprotein(a), a risk factor for atherosclerosis (AS), are also associated with the presence of asymptomatic intracranial aneurysms. AS is present in some aneurysms, but its contribution to aneurysm formation and growth is unclear. Apolipoprotein(a) [apo(a)], the active moiety of lipoprotein(a), is present in atherosclerotic circle of Willis vessels but not in normal circle of Willis vessels. We wished to determine whether apo(a) is present in intracranial aneurysms independently of AS. METHODS: With a purified anti-apo(a) monoclonal antibody, aneurysms (n = 25) and feeding vessels (n = 23) were examined for apo(a) expression by immunohistochemical analysis. Circle of Willis arteries with and without AS (n = 19), cavernous angiomas (n = 5), and arteriovenous malformations (n = 6) acted as control samples. RESULTS: AS was present in 32% of aneurysms, and all of those aneurysms demonstrated mural immunopositivity for apo(a). However, aneurysms devoid of AS also demonstrated apo(a) immunopositivity. Apo(a) was demonstrated in 86% of available feeding vessels. Apo(a) deposition was not observed in cavernous angiomas but was present in arteriovenous malformations. Eleven Circle of Willis arteries (57.9%) were devoid of AS and demonstrated no apo(a) immunostaining, whereas the eight (42.1%) with AS were immunopositive for apo(a). CONCLUSION: Apo(a) expression in intracranial aneurysms may occur independently of AS. Apo(a) in feeding vessels suggests a possible role for apo(a) in early events leading to aneurysm formation. Multilayered transmural apo(a) deposition in established aneurysms suggests apo(a) involvement in aneurysm growth, possibly via cycles of injury and repair. The absence of apo(a) in cavernous angiomas suggests that such injury might be pressure-mediated.

Adolescent↗