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Biomedical subjects

R Howard

Publications and source records attributed to R Howard.

At least 55 records · Page 3Linked to original sources
PubMed2001

Estimates of the prevalence of acute stroke impairments and disability in a multiethnic population.

BACKGROUND AND PURPOSE: The goals of the present study were to estimate the prevalence of acute impairments and disability in a multiethnic population of first-ever stroke and to identify differences in impairment and early disability between pathological and Bamford subtypes. Associations between impairments and death and disability at 3 months were identified. METHODS: Impairments that occur at the time of maximum neurological deficit were recorded, and disability according to the Barthel Index (BI) was assessed 1 week and 3 months after stroke in patients in the South London Stroke Register: RESULTS: Of 1259 registered patients, 6% had 1 or 2, 31.1% had 3 to 5, 50.6% had 6 to 10, and 10.6% had >10 impairments. Common impairments were weakness (upper limb, 77.4%), urinary incontinence (48.2%), impaired consciousness (44.7%), dysphagia (44.7%), and impaired cognition (43.9%). Patients with total anterior circulation infarcts had the highest age-adjusted prevalence of weakness, dysphagia, urinary incontinence, cognitive impairment, and disability. Patients with subarachnoid hemorrhage had the highest rates of coma. Patients with lacunar stroke had the high prevalence of weakness but were least affected by disability, incontinence, and cognitive dysfunction. Blacks had higher age- and sex-adjusted rates of disability in ischemic stroke (BI <20, odds ratio 2.76, 95% CI 1.47 to 5.21, P=0.002; BI <15, odds ratio 1.8, 95% CI 1.45 to 2.81, P=0.01) but impairment rates similar to those of whites. On multivariable analysis, incontinence, coma, dysphagia, cognitive impairment, and gaze paresis were independently associated with severe disability (BI <10) and death at 3 months. CONCLUSIONS: The extent of these findings indicates that an acute assessment of impairments and disability is necessary to determine the appropriate nursing and rehabilitation needs of patients with stroke.

Age Distribution↗
PubMed2001

Telehealth consultations in rheumatology: cost-effectiveness and user satisfaction.

We conducted a feasibility study to assess user satisfaction with and the cost-effectiveness of a rheumatology telehealth clinic in northern Alberta. Six telehealth clinics were organized between a rural health centre and the specialist rheumatology centre, which was about a 4 h drive away. Fifty-two new patients were seen. Their median age was 54 years (range 7-81 years). After the teleconsultation, no patient required a conventional face-to-face consultation. Overall, patients agreed that the teleconsultation met their needs and that the care they received was as good as conventional care. The physicians involved in the study thought the process practical and effective. The total costs of service delivery would be equal for teleconsultation and for traditional consultation at a workload of 247 consultations a year.

Adolescent↗
PubMed2001

The effect of antithyroid drug pretreatment on acute changes in thyroid hormone levels after (131)I ablation for Graves' disease.

Acute changes in thyroid hormone levels before and after radioiodine therapy for Graves' disease were compared in 42 patients randomized to receive either antithyroid drug pretreatment or no pretreatment. Five patients (11.9%), including 3 in the pretreatment arm and 2 in the no pretreatment arm experienced a late exacerbation of thyrotoxicosis after radioiodine therapy. The majority (19 of 21, 90.5%) of pretreated patients experienced a transient increase in free T(4) and free T(3) after discontinuation of antithyroid drugs, with little further elevation after radioiodine therapy. After stopping antithyroid drugs and before radioiodine administration, mean serum free T(4) values rose from 14.7 +/- 6.9 to 21.6 +/- 12.1 pmol/L, representing a 46.9% increase, whereas serum free T(3) levels rose from 4.9 +/- 1.7 to 8.1 +/- 6.3 pmol/L, representing a 65.3% increase. The average pretreated patient experienced a 52.4% increase [95% confidence interval (CI), +26.4% to +78.5%] in free T(4) and a 61.8% increase (95% CI, +23.5% to +100.0%) in free T(3). Conversely, the majority (19 of 21, 90.5%) of nonpretreated patients experienced a rapid decline in thyroid hormone levels after radioiodine treatment. Over the 14 days after radioiodine therapy mean free T(4) values in nonpretreated patients fell from 85.8 +/- 60.4 to 58.0 +/- 76.5 pmol/L, representing a 32.4% decrease, whereas mean free T(3) levels fell from 16.1 +/- 8.0 to 10.8 +/- 11.1 pmol/L, representing a 32.9% decrease. The average nonpretreated patient experienced a 20.6% decrease (95% CI, -47.3% to +7.0%) in free T(4) and a 24.3% decrease (95% CI, -1.2% to -47.4%) in free T(3) during this time period. Excluding 2 patients with a late exacerbation after radioiodine, 19 nonpretreated patients experienced a decrease in mean free T(4) values from 76.8 +/- 46.6 to 36.6 +/- 19.8 pmol/L, representing a 52.3% decrease, whereas mean free T(3) levels fell from 15.5 +/- 7.7 to 7.8 +/- 3.6 pmol/L, representing a 49.7% decrease. The average decrease in free T(4) levels among this subgroup of patients was 30.1% (95% CI, -4.6% to -55.6%), whereas the average decrease in free T(3) was 34.4% (95% CI, -13.7% to -55.1%). High levels of TSH receptor autoantibodies at diagnosis were associated with an acute worsening of thyrotoxicosis after stopping antithyroid drug pretreatment. We conclude that pretreatment with antithyroid drugs does not protect against worsening thyrotoxicosis after radioiodine, but may allow such patients to start from a lower baseline level should an aggravation in thyrotoxicosis occur. The findings support the recommendation that most patients with Graves' disease do not require antithyroid drug pretreatment before receiving radioiodine.

Adult↗
PubMed2001

Paradigms for recording cognitive brain electrical activity.

Human event-related potentials reflect cognitive processing, and are normally elicited by external events, such as acoustic sounds or visual stimuli. As such they provide an opportunity to study normal and abnormal brain function noninvasively, at sub-second resolution. Advances in multimedia technology permit specialists in informatics and neuropsychology to co-operate in the design and implementation of paradigms, which influence ERP components. The paper illustrates the progression from standard paradigms such as the auditory oddball, which can be used to study memory update through to contingent negative variation and three condition, visual paradigms which can be used to study cognitive and emotional responses. Data from a study investigating the comparative processing of target pictures and words illustrate how external stimuli influence the later cognitive potentials.

Brain Mapping↗
PubMed2001

An evaluation of telehealth in the provision of rheumatologic consults to a remote area.

OBJECTIVE: To evaluate the feasibility and acceptability of providing telehealth consultations in rheumatology. METHODS: A prospective review of new consults from a rural area assessed by a rheumatologist in an urban area using telehealth. Patient demographics were recorded along with a self-administered questionnaire reporting assessment of the acceptability of the process. Referring physician and consultant provided open ended feedback as to relative strengths and weaknesses of telehealth versus traditional consult. A simple cost and time benefit analysis was undertaken. RESULTS: The spectrum of patients with rheumatic disease assessed was similar to a traditional consultation clinic. Patients found the overall process to be acceptable and effective. Apart from accessibility to specialist consultation, the greatest benefit was improved communication among patient, referring physician, and consultant. The process was determined to be efficient in both time and cost savings. CONCLUSION: Telehealth rheumatology consultations are feasible, acceptable, and cost/time effective and are therefore advocated for those geographic areas where traditional consultations are not readily available.

Adolescent↗
PubMed2001

The natural history and associations of sleep disordered breathing in first ever stroke.

Although the prevalence of sleep-disordered breathing (SDB) in patients following stroke has been found to be high, there are few data about whether these changes persist in the months that follow stroke. The present study aims to confirm the prevalence of SDB following first ever stroke, to investigate an association between SDB and subtype of stroke and to determine the change in SDB three months following a first ever stroke.

Aged↗
PubMed2000

Development of Coronal Mass Ejections: Radio Shock Signatures.

We present observational imaging evidence for the existence of metric radio bursts closely associated with the front edge of coronal mass ejections (CMEs). These radio bursts drift in frequency similarly to type II bursts. They are weak and usually go undetected on spectrograph data. We find the same measured projected velocity for the displacement of, respectively, the radio source (when observed at two or more frequencies) and the CME leading edge. The position of the emitting source coincides with the CME leading edge. Among the events analyzed, the fastest of them, with a velocity over 1400 km s-1, was associated with interplanetary type II bursts.

Journal Article↗
PubMed2000

Endometrial cryoablation with ultrasound visualization in women undergoing hysterectomy.

STUDY OBJECTIVES: To evaluate tissue effects of cryosurgical endometrial ablation in women just before hysterectomy, characterize ultrasound monitoring of freezing, determine the feasibility of a new probe-angling procedure, and assess the safety profile by monitoring serosal surface temperatures. DESIGN: Single arm safety study enrolling ten women at two centers (Canadian Task Force classification II-2). SETTING: Two clinical sites. Patients. Ten women scheduled for hysterectomy. INTERVENTION: Hysterectomy with a new cryosurgical device (First Option, CryoGen, Inc., San Diego, CA) that achieves surface temperatures below -90 inverted exclamation mark C to freeze endometrium. MEASUREMENTS AND MAIN RESULTS: The freeze protocol involved angling the probe toward each cornu. Maximum ice front diameter at the end of the first angled freeze ranged from 24 to 34 mm, and maximum ice ball diameter at the end of the second freeze ranged from 28 to 37 mm. The margin between the advancing ice front and serosal surface was monitored by ultrasound. In all cases the margin was safe and no reduction in serosal surface temperatures occurred. Depth of necrosis ranged from 9 to 12 mm as determined by tetrazolium staining and electron microscopy, and there was no full-thickness myometrial destruction. Total endometrial destruction was achieved. CONCLUSION: Cryosurgical ablation of the endometrium with the First Option system with angled freezes and ultrasound monitoring appears to be feasible and safe given our preliminary data.

Adult↗
PubMed2000

A comparison of intratracheal pulmonary ventilation to conventional ventilation in a surfactant deficient animal model.

OBJECTIVE: To compare intratracheal pulmonary ventilation (ITPV) with conventional ventilation in a rabbit model of surfactant deficiency. DESIGN: A prospective randomized animal study. SETTING: The Children's National Medical Center Research Animal Facility in Washington, DC. SUBJECTS: Adult male New Zealand white rabbits (n = 20), weighing 1.4-4.2 kg. INTERVENTIONS: After anesthesia and catheter placement, rabbits were tracheotomized, paralyzed, and placed on the conventional ventilator. We determined pulmonary functions at baseline. We washed surfactant out of the lungs by using serial bronchoalveolar lavages. Pulmonary function studies were determined after completion of the bronchoalveolar lavages and were used as an indication of severity of lung injury. Animals were randomized into two groups: We placed ten animals on ITPV, using the ITPV reverse thruster catheter designed by Kolobow and a prototype ITPV ventilator designed at Children's National Medical Center; we placed ten animals on conventional ventilation using the Sechrist iv-100 ventilator. Arterial blood gases were drawn every 15 mins, and the ventilator settings were adjusted to the minimal level that would maintain arterial blood gases in the following ranges: pH 7.35-7.45, PaCO2 30-40 torr (3.995.33 kPa), PaO2 50-70 torr (6.66-9.33 kPa). Animals were ventilated with the randomized ventilation techniques for 4 hrs. MEASUREMENTS AND MAIN RESULTS: Peak inspiratory pressure, mean airway pressure, and positive end-expiratory pressure were measured at the distal end of the endotracheal tube. We recorded these variables plus respiratory rate at baseline and every 30 mins for a total of 4 hrs of ventilation. Lung compliance did not differ between groups at the postlavage study period (ITPV, 0.56+/-0.13 mL/cm H2O/kg; conventional 0.49+/-0.15 mL/cm H2O/kg). At the end of the 4 hr study period, peak inspiratory pressure (ITPV, 26.2+/-4.6 cm H2O; conventional, 32.4+/-5.04 cm H2O, p = .007) and positive end-expiratory pressure (ITPV, 3.9+/-1.96 cm H2O; conventional, 6.3+/-1.42 cm H2O, p = .005) were lower in the ITPV ventilation group. Peak inspiratory pressure was significantly lower in the ITPV group by 2 hrs into the study. CONCLUSION: In this model of surfactant deficiency lung injury, ventilation and oxygenation were achieved at significantly lower ventilator settings using ITPV compared with conventional ventilation. Long-term studies are needed to determine whether this reduction in ventilation is maintained, and if so, if lung injury is reduced.

Animals↗
PubMed2000

Prospective study of the usefulness of sural nerve biopsy.

OBJECTIVE: This study aimed to determine the usefulness of sural nerve biopsy in neurological practice. METHODS: The first prospective study of sural nerve biopsy in 50 consecutive patients was undertaken. The investigating neurologist declared the prebiopsy diagnosis and management plan and after 3 months an independent neurologist evaluated the contribution of the biopsy to diagnosis and management. An independent audit officer sought information from the patient about the adverse effects and value of the biopsy after 6 weeks and 6 months. RESULTS: In seven cases the nerve biopsy changed the diagnosis, in 35 cases the biopsy confirmed the suspected diagnosis, and in eight cases the biopsy was non-contributory. The biopsy either changed or was helpful in guiding patient management in 60%, especially those with demyelinating neuropathy and multiple mononeuropathy. Seven patients reported having had infection and 10 reported increased pain at the biopsy site 6 months later. CONCLUSION: In a consecutive series of 50 cases, sural nerve biopsy altered the diagnosis in 14%, affected management in 60%, and caused persistent increased pain at the biopsy site in 33%.

Action Potentials↗
PubMed2000

Late-onset schizophrenia and very-late-onset schizophrenia-like psychosis: an international consensus. The International Late-Onset Schizophrenia Group.

OBJECTIVE: Although schizophrenia is generally regarded as an illness with onset in late adolescence or early adult life, a sizeable minority of patients first become ill in middle or old age. Inconsistencies in diagnostic systems and nomenclature, coupled with a tendency among most schizophrenia researchers to ascribe late-onset psychoses to organic factors, have led to such cases occupying an ambiguous position in relation to schizophrenia. Through systematic review of the literature and publication of a consensus statement from an international group of experts in the field, this article aims to clarify the positions of late-onset schizophrenia and very-late-onset schizophrenia-like psychosis. METHOD: The authors conducted a MEDLINE literature review and developed a consensus statement summarizing the findings from 2 days of debate and discussion by members of the International Late-Onset Schizophrenia Group. RESULTS: The group achieved consensus on diagnosis, nomenclature, treatment guidelines, and future research directions. CONCLUSIONS: In terms of epidemiology, symptom profile, and identified pathophysiologies, the diagnoses of late-onset schizophrenia (illness onset after 40 years of age) and very-late-onset schizophrenia-like psychosis (onset after 60 years) have face validity and clinical utility. General adoption of these categories will foster systematic investigation of such patients.

Adolescent↗
PubMed1999

Oral and genital ulceration: a unique presentation of immunodeficiency in Athabascan-speaking American Indian children with severe combined immunodeficiency.

BACKGROUND: Oral and genital ulcerations have been previously reported in 3 Navajo children diagnosed with severe combined immunodeficiency disease with T- and B-cell lymphopenia (T-B(-)-SCID). OBJECTIVE: To evaluate the occurrence of oral and genital ulcerations in 12 Athabascan-speaking American Indians with a diagnosis of T-B(-)-SCID (SCIDA group) and to compare their occurrence in non-Athabascan-speaking children with SCID (control group). We also observed the course of these ulcerations in response to bone marrow transplantation (BMT). DESIGN: Retrospective survey of the medical records of patients with SCID admitted from December 1, 1986, through July 31, 1995. SETTING: Pediatric Bone Marrow Transplantation Division at a university hospital. PATIENTS: Twelve children in the SCIDA group and 21 in the control group. All patients had virtual absence of T- and B-cell numbers and function at time of diagnosis. RESULTS: Oral and/or genital ulcers developed as a presenting feature of the SCIDA group. These ulcerations were not observed in the 21 controls. All patients underwent BMT. Of the 10 patients with oral and/or genital ulcerations, 3 had poor T-cell reconstitution after BMT, with recurrences of ulcers requiring additional BMTs. CONCLUSIONS: Oral and/or genital ulcerations are common in Athabascan-speaking American Indian children with T-B(-)-SCID but are not seen in non-Athabascan-speaking children with SCID. Thus, oral and/or genital ulceration appears to be an important, distinctive finding, and often a presenting feature of immunodeficiency in Athabascan-speaking American Indian children with SCID. Bone marrow transplantation with successful T-cell engraftment appears to be curative in the resolution of the ulcers, with recurrences only in patients who had poor T-cell reconstitution.

Bone Marrow Transplantation↗