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Biomedical subjects

C Counsell

Publications and source records attributed to C Counsell.

At least 19 recordsLinked to original sources
PubMed1998

Vagus nerve stimulator as a treatment for intractable epilepsy.

Vagus nerve stimulation was recently approved for control of medically intractable seizures. This therapy provides some relief of seizures for selective patients, however seizure freedom using this device is uncommon. Vagus nerve stimulation appears to work by calming "hyperexcited" nerve cells and reverting brain activity to its normal patterns. Many people do have significant relief in the intensity and duration of their seizures and report improved quality of life using this device.

Adult↗
PubMed1998

Assessment of clinical outcomes in acute stroke trials.

BACKGROUND AND PURPOSE: Adequate outcome assessment is crucial to randomized trials. We wished to assess the types of outcomes used in acute stroke trials and the appropriateness of these outcomes and their analyses. METHODS: Acute stroke trials from the Cochrane Stroke Group's database were included from 1955 to 1995 if they were published in full text in English. For each trial we collected year of publication, number of patients randomized, blinding of outcome assessment, the specific outcome instruments used, the statistical methods used for analysis, and the significance of the results. The validity and reliability of each outcome measure were assessed by review of the literature. RESULTS: Our study included 174 trials. Outcomes were assessed blindly in 69%. Death was recorded in only 76% of trials, impairment in 76%, disability in 42%, and handicap or quality of life in only 2%. Of the trials that measured impairment, 35% used a measure of established validity or reliability. For disability and handicap, the proportions with valid or reliable measures were 70% and 25%, respectively. Impairment and handicap measures were primarily analyzed as continuous variables, while disability was mainly analyzed as a dichotomous variable. Continuous data were usually analyzed with inappropriate parametric statistics. There was no relationship between the method of analysis, the type of outcome, and the statistical significance of results. CONCLUSIONS: Most acute stroke trials up to 1995 have used clinical outcome measures that were inadequate in terms of their content, reliability, validity, blinded assessment, and statistical analysis. This has important implications for future stroke research.

Acute Disease↗
PubMed1998

Is visible infarction on computed tomography associated with an adverse prognosis in acute ischemic stroke?

BACKGROUND AND PURPOSE: It is unclear whether visible infarction on a CT scan at any time after the stroke is an adverse prognostic factor once other factors such as stroke severity are taken into consideration. We examined whether visible infarction was associated with a poor outcome after stroke using univariate and multivariate analyses, including easily identifiable clinical baseline variables, and adjusting for time from stroke onset to CT. METHODS: All inpatients and outpatients with an acute ischemic stroke attending our hospital stroke service were examined by a stroke physician and entered into a register prospectively. The CT scan was coded prospectively for the site and size of any relevant recent visible infarct. The patients were followed up at 6 months to ascertain their functional status with the use of the modified Rankin Scale. Analyses of the effect of visible infarction on the outcomes "dead or dependent" or "dead" at 6 months were performed with adjustment for time from stroke to CT, clinical stroke type (lacunar, hemispheric, or posterior circulation), and in a multiple logistic regression model to adjust for confounding baseline variables such as stroke severity. RESULTS: In 993 patients in the stroke registry, visible infarction increased the risk of being dead or dependent at 6 months (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.9 to 3.3) or dead (OR, 4.5; 95% CI, 2.7 to 7.5), both on its own and after adjustment for time from stroke to CT, stroke symptoms, and other important clinical prognostic variables (OR for death or dependence in the predictive model, 1.5; 95% CI, 1.0 to 2.0; OR for death, 2.4; 95% CI, 1.4 to 4.1). CONCLUSIONS: Visible infarction on CT is an adverse prognostic indicator (albeit of borderline significance) even after adjustment for stroke severity and time lapse between the stroke and the CT scan.

Acute Disease↗
PubMed1997

Formulating questions and locating primary studies for inclusion in systematic reviews.

Much time and effort are spent on designing primary research studies. Similar care must be given to planning systematic reviews. The review should be based on an important, well-focused question that is relevant to patient care. By formulating the question properly, the criteria that primary studies must meet to be included in the review become clear. These criteria, which comprise the types of persons involved, exposure, control group, outcomes, and study designs of interest, can then be refined so that they are clinically relevant, sensible, and workable. Inclusion criteria that are too narrow will limit the amount of data in the review, thereby increasing the risk for chance results and making the review less useful for the reader. Reviews should include studies whose designs offer the least biased answer to the question being asked. To maximize available data and reduce the risk for bias, as many relevant studies as possible need to be identified, regardless of publication status or language. Multiple overlapping search strategies should therefore be used and must be carefully planned. Strategies include searching the many electronic databases available (after careful consideration of which terms to enter), manually searching journals and conference proceedings, searching bibliographies of articles, searching existing registers of studies, and contacting companies or researchers. The time taken to formulate the question adequately and develop appropriate searches will increase the chance of producing a high-quality, meaningful review.

Clinical Trials as Topic↗
PubMed1997

Systematic review of evidence on thrombolytic therapy for acute ischaemic stroke.

BACKGROUND: Recent trials of thrombolytic therapy in acute ischaemic stroke have given apparently conflicting results. Only one trial, the National Institute of Neurological Disorders and Stroke trial of tissue plasminogen activator (tPA), suggested that thrombolysis was definitely beneficial. To make sense of these results, we have done a systematic review of all available randomised trials of thrombolysis in acute ischaemic stroke. METHODS: From all available completed randomised trials of thrombolytic therapy compared with control in acute ischaemic stroke (with prerandomisation CT), we checked tabular data on deaths during roughly the first 2 weeks, deaths from all causes and functional outcome (disability) at the end of the trial follow-up period, and early symptomatic and fatal intracranial haemorrhages. FINDINGS: 12 trials included 3435 patients, of whom 694 (20%) were dead and 1001 (39%) of 2567 were functionally dependent at the end of follow-up (duration of follow-up varied between trials, but the longest was 6 months). 214 (6%) of the 3435 patients had early symptomatic or fatal intracranial haemorrhages. Thrombolytic therapy was associated with a significant excess of early deaths (91 per 1000 patients treated [95% CI 54-134]), and total deaths (37 per 1000 [20-83]), but there was nevertheless a significant reduction in the number of patients in the combined outcome of dead or dependent (65 fewer per 1000 patients treated [28-107]). There was a substantial and significant excess of symptomatic and fatal intracranial haemorrhages with thrombolysis-which was similar in all recent trials-of about 70 extra symptomatic intracranial haemorrhages per 1000 patients treated (of which 51 per 1000 were fatal). In the cohort of patients randomised within 3 h of stroke, there was a significant reduction in the number of patients who were dead or dependent at the end of follow-up (141 fewer dead or dependent per 1000 patients treated [75-206] and a non-significant increase in the number dead (nine per 1000 treated [-39 to 70]). There was significant heterogeneity between the trials for total deaths at the end of follow-up, which may be partly explained by differences in the use of antithrombotic drugs within the first 24 h of thrombolysis; the variation in severity of strokes included: the time window to thrombolytic treatment; and the dose of thrombolytic drug used. There were no direct comparisons of tPA with streptokinase or urokinase: much of the poor outcome in the streptokinase-treated patients might be explained by the inclusion of more severe strokes, greater use of antithrombotic drugs, higher doses, and the longer time to treatment compared with the trials that used tPA. INTERPRETATION: Thrombolysis requires further testing in large randomised trials because the risks seem substantial, and the benefit uncertain. The time window for effective treatment remains unclear. There is no objective evidence to suggest that tPA is safer than streptokinase; the apparent hazards and benefits may be similar when differences in trial design and baseline variables are accounted for.

Brain Ischemia↗
PubMed1996

The incidence of cerebral glioma in the working population: a forgotten cancer?

We studied the incidence of intracranial tumours in Lothian Region in south-east Scotland in 1989-90. Among 106 patients resident in the Region, 60 (57%) were of working age (15-64 years). All but two cases (97%) were histologically confirmed. The average annual incidence of cerebral glioma in this age range was 5.9 (95% CI 3.8-8.0) per 100,000 per year. Cerebral glioma will affect approximately 2100 people of working age in the UK every year.

Adolescent↗
PubMed1996

Altered taste sensation in newly-diagnosed NIDDM.

OBJECTIVE: To assess gustatory appreciation in newly diagnosed NIDDM patients and to determine whether it altered with the improvement of glycemic control after treatment with diet and oral hypoglycemic drugs. RESEARCH DESIGN AND METHODS: Assessments of taste, peripheral and autonomic neural function, diet, and oral microbiological flora were performed in 20 patients before and after treatment of hyperglycemia, 20 matched nondiabetic control subjects, and 11 patients with long duration of diabetes and advanced peripheral neuropathy. RESULTS: Median total HbA1 fell from 12.6 to 8.8% in new diabetic patients after 3-5 months of treatment. Electrical taste thresholds, detection threshold for glucose, and recognition threshold for glucose and salt were increased in newly-diagnosed NIDDM patients compared with the control subjects. The dose-response curve to glucose (using a visual analogue scale [VAS]) of newly-diagnosed NIDDM patients was significantly impaired and improved after treatment. By contrast, newly-diagnosed NIDDM patients had normal VAS taste responses to fructose, salt, and urea. Measurements of somatic and autonomic nerve function did not correlate with electrical or chemical taste function. CONCLUSIONS: Newly-diagnosed NIDDM patients have a blunted taste response, which displays a degree of specificity to glucose, is partially reversed after correction of hyperglycemia, and is independent of somatic or autonomic nerve function. This taste abnormality may influence the premorbid choice of nutrients, with a preference for sweet-tasting foods, thereby exacerbating hyperglycemia.

Autonomic Nervous System Diseases↗
PubMed1995

Nimodipine: a drug therapy for treatment of vasospasm.

Cerebral vasospasm presents a challenge for the nursing staff. To date, no effective prevention methods have been identified. The key to decreasing the mortality rates is in discovering a method of preventing or reversing the arterial narrowing caused by vasospasm. The nurse needs to be aware of the theories of vasospasm and the rationale for treatment. Neurologic assessment skills are important for the nurse to detect minimal changes that may indicate vasospasm. Nurses who are informed will be able to provide optimal care to patients with cerebral vasospasm and provide the necessary support for family members. Drug therapy continues to be the first-line defense in treating vasospasm. Nimodipine is a very promising drug with demonstrated effectiveness to reduce the neurologic deficits caused by vasospasm. Further research on the treatment of vasospasm following SAH is currently in progress.

Humans↗
PubMed1995

School attainment, cognitive ability and motor function in a total Scottish very-low-birthweight population at eight years: a controlled study.

The prevalence of learning problems and of cognitive and motor impairment in a total geographically based very-low-birthweight population (N = 324) was compared at eight years of age with that in a population comprising two classroom peers, matched for gender and age (N = 590). 15 per cent of those with birthweights less than 1000g and 6 per cent of those weighing 1000 to 1499 g attended special schools. Index children in main-stream schools performed significantly less well in tests of neuromotor function than their comparison groups. Their mean IQs were 90.4 and 93.7 for those below and above 1000 g, respectively, while their comparison groups' IQs were 102.5 and 101.2. In all cognitive subscales apart from that testing short-term auditory sequential memory, both index groups were less competent. They were also less able in Word Reading and Basic Number Skills. These children placed heavy demands on mainstream schools, with 52 per cent and 37 per cent of the index groups, respectively, requiring learning support compared with 16 per cent in both comparison groups.

Achievement↗