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Biomedical subjects

J Bamford

Publications and source records attributed to J Bamford.

At least 37 records · Page 2Linked to original sources
PubMed2000

Evidence on the efficacy of insert earphone and sound field VRA with young infants.

Visual reinforcement audiometry (VRA) with insert-earphone stimulus delivery provides a means of obtaining early ear-specific information on the auditory status of infants. The aim of this study was to investigate the efficacy of VRA in young infants, and to compare the use of sound field and insert-earphone stimulus presentation. VRA was performed on 41 normally developing infants aged between 20 and 42 weeks. Infants were tested in the sound field (n=22) and with insert earphones (n=19). Results showed significantly more minimum response levels (MRLs) obtained with sound field testing, and with older children. Nevertheless, in the insert-earphone group, 36% of those aged 32 weeks or more gave two or more MRLs, and 25% of the infants aged 25 weeks or less gave one or more MRLs. This study provides data from developmentally normal infants which confirms the efficacy of insert-earphones as well as sound field VRA with 32-42-week-olds, with reasonable expectation of success. The data in this study also suggest that VRA could be usefully employed for younger infants aged approximately 20-26 weeks where information, although less easily obtained, may be of particular value to early diagnosis and habilitation.

Audiometry↗
PubMed1999

Trial of a two-channel hearing aid (low-frequency compression-high-frequency linear amplification) with school age children.

OBJECTIVE: The study was designed to investigate the efficacy of a 2-channel hearing aid with low-frequency compression and high-frequency linear amplification on a group of school-age hearing aid wearers. DESIGN: The study was a single-center, 2-way crossover design in which 25 children (age 6 to 15 yr) were fitted with 2-channel hearing aids for 12 wk and with their own (single-channel) hearing aids for 12 wk, refitted according to published protocols. Speech perception in quiet and in noise was measured at the end of each 12 wk period; in addition, questionnaires were given to teachers, parents, and children. RESULTS: Two-channel hearing aids showed significantly higher mean scores for speech perception in noise and significantly higher composite questionnaire scores (reflecting aspects of satisfaction and benefit). Final choice of hearing aids at the end of the study by parents and children also favored the 2-channel device. CONCLUSIONS: The 2-channel hearing aids appear to be an acceptable management option for audiometrically suitable children. The results provide support for the 2-channel design rationale and suggest the need for further trials.

Adolescent↗
PubMed1997

Epileptic seizures after a first stroke: the Oxfordshire Community Stroke Project.

OBJECTIVE: To describe the immediate and long term risk of epileptic seizures after a first ever stroke. DESIGN: Cohort study following up stroke survivors for 2 to 6.5 years; comparison with age specific incidence rates of epileptic seizures in the general population. SETTING: Community based stroke register. SUBJECTS: 675 patients with a first stroke, followed up for a minimum of 2 years. MAIN OUTCOME MEASURES: Occurrence of single and recurrent seizures. RESULTS: 52 patients had one or more post stroke seizures; in 25 the seizures were recurrent. The 5 year actuarial risk of a post stroke seizure in survivors (excluding 19 patients with a history of epilepsy and 3 patients in whom the seizure occurred shortly before death from another cause) was 11.5% (95% confidence interval 4.8% to 18.2%). The relative risk of seizures, in comparison with the general population, was estimated at 35.2 in the first year after stroke and 19.0 in year 2. The risk of seizures was increased in survivors of subarachnoid and intracerebral haemorrhage (hazard ratio for intracranial haemorrhage v cerebral infarction 10.2 (3.7 to 27.9)). The risk of seizures after ischaemic stroke was substantial only in patients presenting with severe strokes due to total anterior circulation infarction. Only 9 of 295 patients (3%) independent one month after stroke suffered a seizure between 1 month and 5 years (actuarial risk 4.2% (0.1% to 8.3%)). CONCLUSION: Stroke patients have about an 11.5% risk of single or recurrent seizures in the first 5 years after a stroke. Patients with more severe strokes or haemorrhagic strokes are at higher risk.

Adolescent↗
PubMed1997

von Willebrand factor and factor VIII: C in acute cerebrovascular disease. Relationship to stroke subtype and mortality.

BACKGROUND: Elevated von Willebrand factor (vWF) is a risk factor in the development of acute myocardial infarction. The importance of vWF and factor VII:C in the pathogenesis of cerebrovascular disease (CVD) is poorly defined. METHODS AND RESULTS: We studied 208 cases of stroke whose pathological type was defined by cranial computed tomography. Cerebral infarcts were grouped according to the Oxfordshire Community Stroke Project (OCSP) clinical classification. The results in patients were compared with 184 healthy reference subjects. In patients, vWF and FVIII:C levels were determined initially and after three months. Patients were followed prospectively for six months or until death. Levels of vWF and FVIII:C were elevated initially (1.86 IU/ml and 2.20 U/ml respectively) and after 3 months (1.51 IU/ml and 1.90 U/ml) compared with a healthy reference population (1.26 IU/ml and 1.49 U/ml p = 0.0001). In the initial sample, vWF was associated with age (p = 0.01). FVIII:C was related to age (p = 0.04), gender (p = 0.007 higher for females) and a history of diabetes mellitus (2.56 U/ml vs. 2.16 U/ml in non-diabetics, p = 0.008). Initial vWF levels were higher in subjects with large vessel disease (TACI/PACI) group compared with the small vessel disease (LACI) group [2.12 IU/ml, (n = 112) vs. 1.48 IU/ml (n = 59) respectively, p = 0.0001] and similarly in initial FVIII:C levels (2.43 U/ml vs. 1.87 U/ml, p = 0.0001). Analysis of six-month case fatality, vWF levels were associated with risk of death [p = 0.01, OR 1.73 (1.12, 2.66) for an increase of I U/ml], even after allowing for stroke type. CONCLUSION: The relationship of vWF with stroke mortality has not previously been described. Although we have not demonstrated a causal role for vWF in the pathogenesis of CVD, elevated circulating levels of vWF may be associated with increased risk of death following stroke. A prospective study would be required to establish whether vWF is predictive for the development of CVD.

Acute Disease↗
PubMed1997

A critical review of the role of neonatal hearing screening in the detection of congenital hearing impairment.

BACKGROUND: This review was commissioned because of the increasing doubt about the ability of existing screening programmes (mainly the health visitor distraction test (HVDT) at 7-8 months) to identify children with congenital hearing impairment, and technological advances which have made neonatal hearing screening an alternative option. OBJECTIVES: To review the available literature on the screening of permanent childhood hearing impairment. To provide commissioners and providers of health care with information about how to deliver a more uniform service, better outcomes, and more cost-effective screening. To identify areas for further research and service development. HOW THE RESEARCH WAS CONDUCTED: The research involved a review of the available published and unpublished literature, and a comprehensive survey of current pre-school hearing screening provision in the UK coupled with a health economics study of hearing screening costs. The research also included a number of focus groups and visits to key centres in the UK and North America. RESEARCH FINDINGS: EPIDEMIOLOGY OF PERMANENT CHILDHOOD HEARING IMPAIRMENT: There are approximately 840 children a year born in the UK with significant permanent hearing impairment likely to affect their own and their family's quality of life. Present services will miss about 400 of these children by 1 1/2 years of age, and about 200 of these children by 3 1/2 years of age. Such late identification of hearing impairment greatly reduces the responsiveness of the services for individual children. EVIDENCE FOR IMPROVED OUTCOMES WITH EARLIER IDENTIFICATION: Hearing-impaired children identified late are at risk of substantial delay in their acquisition of language and communication skills, with consequent longer-term risk to education achievement, mental health and quality of life. Theoretical arguments on neural development support the limited evidence here for the increased benefit for child and family associated with very early identification. In general, parents and professionals want very early identification, which, if implemented properly, does not cause undue anxiety. CURRENT UK PRACTICE: The survey of current practice indicated a major problem with poor information systems. This problem was further highlighted as a major concern by the multi-disciplinary focus groups. Practice varies. There are two District-wide programmes in which all newborn babies are neonatally screened, a large number of ad hoc programmes for neonatal screening of 'at-risk' babies, a variety of early surveillance programmes, and widespread use of the HVDT. Intervention and habilitation for the majority of those screened neonatally is routinely undertaken within 6 months of birth. For those screened only by the health visitor, identification was on average at about 26 months of age with intervention at about 32 months on average. (ABSTRACT TRUNCATED)

Child, Preschool↗
PubMed1996

Angiotensin-converting enzyme insertion/deletion polymorphism and cerebrovascular disease.

BACKGROUND AND PURPOSE: There is evidence that an allelic variation in the angiotensin-converting enzyme (ACE) gene may confer an increased risk of vascular disease. The roles of the ACE insertion/deletion polymorphism and circulating ACE levels are unknown in cerebrovascular disease. METHODS: We studied an insertion/deletion polymorphism within intron 16 of the ACE gene by polymerase chain reaction and plasma ACE activity in 467 cases of stroke, the pathological type of which was established by cranial CT, and 231 control subjects. ACE genotype and activity were related to stroke type and mortality at 4 weeks and 3 months. RESULTS: No difference in genotype frequency was observed between all subjects with stroke and control subjects or between control subjects and subjects with cerebral infarction or cerebral hemorrhage. Plasma ACE activity was significantly lower in stroke patients at presentation (64.1 IU/L) than in control subjects (79.6 IU/L; P<.0001). Twenty-one patients (4.5%) with cerebral infarction died within 4 weeks and 56 patients (12%) within 3 months. These patients had significantly lower plasma ACE activity than patients who survived. There was some evidence that risk of death within 4 weeks increased with the number of D alleles (P=.02). Among survivors, plasma ACE activity showed a mean increase of 6.9 IU/L (95% confidence interval, 3.0 to 10.8) between levels at presentation and at 3 months (73.6 IU/L), the latter being similar to ACE activity in control subjects. CONCLUSIONS: Low ACE activity at sroke presentation and possession of the D allele may be associated with increased risk of early death from acute cerebral infarction.

Adult↗
PubMed1994

Consultant views on the use of aspirin in acute cerebrovascular disease: implications for clinical trials.

A questionnaire was sent to all 155 consultant physicians and geriatricians in the Yorkshire region who routinely admit patients with acute stroke in order to ascertain: (a) current opinion regarding the prescription of aspirin to patients with various manifestations of cerebrovascular disease, in particular the timing of initial treatment; and (b) the perceived role of computed tomography (CT) scans in relation to such therapy. The response rate was 81% (126/155). Aspirin was reported to be prescribed routinely by 75% (95/126) of physicians for patients with completed stroke. Amongst those prescribing aspirin, treatment was reported to be initiated routinely within 48 hours of the onset of symptoms by 63% (60/95). Only 10% (6/60) of these physicians reported that they would withhold aspirin therapy until the result of a cranial CT scan was known, although 43% (26/60) thought a CT scan was desirable. Our survey, which for logistical reasons is one of opinion rather than actual practice, suggests that aspirin is probably being prescribed acutely (less than 48 hours) after stroke to a significant number of patients and often without a pretreatment CT scan. As with patients who have had a CT scan, the balance of risks and benefits of this practice are unknown. We conclude that it would be ethical for acute treatment trials to allow randomization to aspirin without prior CT scan.

Acute Disease↗
PubMed1994

What causes false clinical prediction of small deep infarcts?

BACKGROUND AND PURPOSE: Our goal was to identify factors that play a role in false clinical diagnosis of small deep infarcts. METHODS: In 350 prospectively registered patients with a first supratentorial ischemic stroke, we clinically differentiated between lacunar and nonlacunar syndromes. Using computed tomography (CT), we distinguished small deep and territorial infarcts and also recorded leukoaraiosis and asymptomatic infarcts. Degree of initial handicap, potential source of cardioembolic stroke, and hypertension were also noted. RESULTS: One hundred forty-seven patients had a lacunar and 203 a nonlacunar syndrome. Forty-two (12%) had a lesion visualized by CT that was compatible with a recent infarct but was considered inappropriate for the clinical syndrome: nineteen had a nonlacunar syndrome but a small deep infarct, and 23 had a lacunar syndrome but a territorial infarct. Patients with a nonlacunar syndrome but a small deep infarct were more severely disabled (a modified Rankin scale rating of 5) (odds ratio [OR], 4.31; 95% confidence interval [CI], 1.25 to 14.88) and had a cardioembolic source (OR, 4.07; 95% CI, 1.04 to 15.95), leukoaraiosis (OR, 3.79; 95% CI, 1.32 to 10.05), or asymptomatic infarcts visualized by CT (OR, 4.13; 95% CI, 1.45 to 11.71) compared with 124 patients with a correctly diagnosed small deep infarct. Twelve of 19 patients with a nonlacunar syndrome but a small deep infarct had a lesion in the left hemisphere, and 9 of these 12 had "aphasia." Patients with a lacunar syndrome but a territorial infarct more often had a cardioembolic source (OR, 4.02; 95% CI, 1.15 to 14.03) and a pure motor syndrome (OR, 4.52; 95% CI, 1.55 to 13.18) than those with lacunar syndrome but a small deep infarct, although 21 (91%) were in the right hemisphere. Of the first 103 patients with lacunar stroke diagnosed by two of the study neurologists, 5 had an inappropriate lesion compared with 14 of the later 40 diagnosed by colleagues without a specific interest in cerebrovascular diseases (OR, 0.09; 95% CI, 0.03 to 0.26). CONCLUSIONS: (1) Diagnosis of lacunar syndromes should not be influenced by deficit severity or the presence of a potential cardiac source of embolism. (2) Speech disorders should carefully be classified. (3) Routine tests of nondominant higher functions may be inadequate. (4) Doctors interested in cerebrovascular neurology have a lower failure rate in differentiating small deep infarcts from territorial infarcts than those less well-trained or interested in neurology. (5) Among the lacunar syndromes, pure motor syndrome may be the least specific predictor of a small deep infarct.

Aged↗
PubMed1994

Long-term risk of recurrent stroke after a first-ever stroke. The Oxfordshire Community Stroke Project.

BACKGROUND AND PURPOSE: There have been few community-based studies of long-term prognosis after acute stroke. This study aims to provide precise estimates of the absolute and relative risks of stroke recurrence in an unselected cohort of patients with a first-ever stroke. METHODS: Six hundred seventy-five patients were registered in a community-based stroke register (the Oxfordshire Community Stroke Project) and prospectively followed for up to 6.5 years. Their relative risk of recurrent stroke was calculated using age- and sex-specific incidence rates for first stroke in Oxfordshire. RESULTS: One hundred eighty recurrent episodes of stroke were identified, of which 135 were first recurrences. Given survival, the actuarial risk of suffering a recurrence was 30% (95% confidence interval, 20% to 39%) by 5 years, about nine times the risk of stroke in the general population. The risk was highest early after the first stroke: 13% (95% confidence interval, 10% to 16%) by 1 year, 15 times the risk in the general population. After the first year the average annual risk was about 4%. The risk of stroke recurrence did not appear to be related to age or pathological type of stroke. CONCLUSIONS: The absolute and relative risks of recurrent stroke are highest early after the first stroke but remain elevated for several years thereafter. Efforts at secondary prevention should be initiated as soon as possible and continued for several years to gain greatest benefit.

Actuarial Analysis↗
PubMed1994

Depressive disorders in long-term survivors of stroke. Associations with demographic and social factors, functional status, and brain lesion volume.

Sixty surviving patients from a community-based stroke register who had computerised tomography (CT) scan evidence of a single brain lesion were interviewed three to five years after their first ever stroke. Depression (DSM-III-R major depression, partially resolved major depression, and dysthymia) was present in 11 (18%) of the patients and was associated with impaired physical and cognitive functioning, greater age, residence in an institution, absence of a close personal relationship, and larger original brain lesion. Of these variables, only functional dependence (odds ratio 16.4; confidence interval 1.6-170), larger lesion volume (6.6; 1-50), and female sex (8; 1.1-56) remained significantly associated with depression after controlling for all other variables. We conclude that depression in long-term survivors of stroke has many of the same associations as depression in non-stroke elderly populations. Depression in long-term stroke survivors may also be associated with larger original brain lesions, although this requires confirmation in a prospective study.

Age Factors↗