PubMed Health⌕ Search

Biomedical subjects

B Stigsby

Publications and source records attributed to B Stigsby.

At least 37 records · Page 2Linked to original sources
PubMed1991

Observer variability in measurements of carpal bone angles on lateral wrist radiographs.

Determinations of carpal bone angles are used in the clinical evaluation of carpal malalignment. Eleven frequently referred radiological measures in lateral projection of the wrists in 23 wrists were assessed using different definitions of axes. Interobserver- and intraobserver variations were calculated. The standard deviation of the interobserver variation ranged from 2.60 degrees to 18.15 degrees, and the intraobserver variation from 1.89 degrees to 4.66 degrees depending on the angles measured. The use of three angles for the least observer variability in assessment of carpal alignment is recommended. These angles were defined from the following carpal bone axes: radius, the line through the center of the medullary canal at 2 cm and 5 cm proximal to the radiocarpal joint; lunate, the line perpendicular to the tangent of the two distal poles; scaphoid, the tangent of the palmar proximal and distal margins, and capitate, the tangent of the dorsal margin of the diaphysis of the third metacarpal bone (substitute axis).

Adult↗
PubMed1991

MRI, VEP, SEP and biothesiometry suggest monosymptomatic acute optic neuritis to be a first manifestation of multiple sclerosis.

A cohort of 50 consecutive patients with acute monosymptomatic optic neuritis (ON) from a defined catchment area joined a prospective study. The aim of this study was to compare the sensitivity of magnetic resonance imaging (MRI), electrophysiological methods (VEP and SEP) and biothesiometry to detect abnormalities in other parts of the CNS than the optic nerves during the acute phase of ON. For each method, a scoring system is proposed. This investigation also hoped to achieve a better understanding of the natural history of ON. MRI proved to be the most sensitive tool (63% abnormal) in confirming a second site of involvement, followed by VEP in the clinically unaffected fellow eye (42%), biothesiometry (32%) and SEP (17%). The combination of all these methods, except for MRI (and VEP in eyes with acute ON), revealed abnormalities in 63% of the patients. When the neurophysiological methods were combined with MRI, 79% of the patients had abnormal findings suggesting additional lesions in the CNS. Hence, MRI and neurophysiological examinations supplement each other and together provide evidence that monosymptomatic ON is usually a first manifestation of MS. The development of definite MS at 1-20 months of follow up in 7 patients (all with abnormal MRI initially) supports this view.

Adolescent↗
PubMed1991

Acute optic neuritis with normal visual acuity. Comparison of symptoms and signs with psychophysiological, electrophysiological and magnetic resonance imaging data.

In a prospective study of hitherto 70 patients with acute optic neuritis (ON), 18 patients aged 15-49 years (12 women, 6 men) were diagnosed as having very subtle form of ON (bilateral in 4 patients), characterized by normal visual acuity. However, their symptoms were sudden functional visual disturbances, most frequently blurred vision accompanied by pain in or around the affected eye(s). In 5 patients, the ON was a manifestation of clinically definite multiple sclerosis (MS); the remaining 13 patients had monosymptomatic ON. The duration of visual symptoms ranged from 2 to 28 days (median 7 days) at the time of examination. Although 18 patients had a normal visual acuity, i.e. 6/6 c.c. (Snellen's notation) or better, extensive studies of the visual functions (using sensitive supplementary tests) revealed various abnormalities, primarily various visual field defects, abnormal contrast sensitivity, abnormal VEP and colour vision deficiencies (often of blue-yellow type). Magnetic resonance imaging (MRI) of the brain revealed demyelinating lesions in 10 of the 13 patients with monosymptomatic ON, and in all 5 patients with definite MS. The extended disease spectrum gives reason to hypothesixe that ON may occur more frequently than previously reported, and that the described subtle form of ON could be an unnotified precocious manifestation of the demyelinating disease.

Acute Disease↗
PubMed1990

Radiography of the wrist. A new device for standardized radiographs.

A number of methods exist for determination of carpal bone angles on lateral wrist radiographs. However, there is no general or precise definition of the angles measured. In this study the positioning of the wrist is emphasized and a device used to obtain standardized radiographs is presented. An analysis of variance of two series of patients revealed no radiological difference between the contralateral wrists in the same person. We conclude that the asymptomatic wrist can be used as normal reference in the assessment of carpal bone angles in the pathological wrist and a difference between the carpal bone angles in the two wrists in the same person exceeding 5 degrees can be considered significant.

Adult↗
PubMed1988

Glycaemic threshold for changes in electroencephalograms during hypoglycaemia in patients with insulin dependent diabetes.

The relation between blood glucose concentration, the symptoms and signs of hypoglycaemia, and electroencephalographic changes in diabetic patients is not known. The effect of hypoglycaemia on brain function was studied in 13 patients with insulin dependent diabetes. During a gradual fall in blood glucose concentration induced by a bolus injection of insulin followed by an intravenous infusion of insulin, during 60 minutes of biochemical hypoglycaemia, and after restoration of normoglycaemia with intravenous glucose electroencephalograms were evaluated continuously by period-amplitude analysis; blood samples were taken every 10 minutes throughout. No changes were seen in electroencephalograms when the blood glucose concentration was above 3 mmol/l. At a median blood glucose concentration of 2.0 (95% confidence interval 1.7 to 2.3) mmol/l alpha activity decreased abruptly in the electroencephalograms concomitant with an increase in theta activity, reflecting neuronal dysfunction in the cortex. When the blood glucose concentration was further lowered changes were observed in the electroencephalograms indicating that deeper brain structures were affected. A normal electroencephalogram was re-established at a blood glucose concentration of 2.0 (1.8 to 2.1) mmol/l. There was no significant correlation between the blood glucose concentration at the onset of changes in the electroencephalograms and age, duration of diabetes, insulin dose, haemoglobin A1c concentration, initial blood glucose concentration, rate of fall in blood glucose concentration, and appearance of symptoms and signs of hypoglycaemia. Changes in electroencephalograms during hypoglycaemia appear and disappear at such a narrow range of blood glucose concentrations that the term threshold blood glucose concentration for the onset of such changes seems justified.

Adult↗
PubMed1988

IgM monoclonal gammopathy and neuropathy in two siblings.

A sister and a brother with a progressive mixed axonal and demyelinating polyneuropathy were found to have a monoclonal IgM gammopathy of kappa and lambda type, respectively. Sural nerve and cutaneous nerve specimens obtained by biopsy showed deposits of IgM on myelin sheets. Sera from both patients contained antibodies directed to bovine peripheral nerve myelin as determined by ELISA technique and to normal human peripheral nerve myelin as demonstrated by indirect immunofluorescence histochemistry. These siblings may have a genetic predisposition to the formation of autoantibodies with peripheral nerve myelin as the target for the immune attack.

Aged↗
PubMed1988

Computer assessment of the intrapartum cardiotocogram. I. Methods of data reduction and diagnostic procedure.

To solve the problem of low predictive values in the visual assessment of the CTG, several computer programs have been designed. Only a few of those programs describe the CTG automatically and thus consistently. The aim of this study was to construct a diagnostic procedure for computer-aided automatic assessment of the CTG. A computer program quantified 17 variables of the CTG. Within a window of user-defined length, a second program calculated the number of measurements, the mean, the trend, and the coefficient of variation of each of the 17 variables, and produced a total of 56 distinct subvariables. A discriminant procedure was set up which could use any number and combination of the 56 subvariables to calculate the probability of a CTG derived from a compromised infant. The diagnostic procedure was optimized by "direct forward search" for the combination of subvariables discriminating best between normal and compromised infants. Using the last half hour of the first stage of labor, 50 CTGs entered the optimizing procedure. A combination of nine subvariables was found. In a separate paper its performance is compared with that of clinicians.

Cardiotocography↗
PubMed1988

Computer assessment of the intrapartum cardiotocogram. II. The value of compared with visual assessment.

The chief aim of our work has been to create a computer Cardiotocographic Assessment System (CAS) and thus eliminate the intra- and inter-observer variability of the visual assessment of the cardiotocogram (CTG), and to improve the assessment of the CTGs to the standard of the most experienced obstetricians. The purpose of this paper is to present the accuracy of the prediction of fetal outcome obtained by the CAS and to compare it with 4 experienced obstetricians' accuracy. Fifty CTGs from the last 30 min. of labor were assessed as normal or pathological by the computer and by the obstetricians. The condition of the newborn was evaluated from the one-minute Apgar score, the umbilical artery pH and standard base excess, and the need for resuscitation. The accuracy of the CAS was significantly better than the accuracy of the obstetrician obtaining the best result. We conclude that the development of a computer-aided cardiotocographic assessment system is worthwhile.

Cardiotocography↗
PubMed1988

Autoimmunity related to IgM monoclonal gammopathy of undetermined significance. Peripheral neuropathy and connective tissue sensibilization caused by IgM M-proteins.

In eight of 10 consecutive cases of IgM monoclonal gammopathy of undetermined significance (MGUS), the M-protein had specificity towards various tissues as estimated by direct and indirect immunofluorescence studies of skin and/or sural nerve biopsies. Five of the cases had neuropathy. In three of them, including two siblings with a demyelinating peripheral neuropathy, the IgM was bound to the myelin-associated glycoprotein (MAG) of peripheral nerves. One had axonal neuropathy with IgM activity against the peri- and endoneurium, while another case with post-infectious neuritis had IgM activity against structures in the endoneurium but no IgM autoimmunity in the direct fluorescence test. The latter improved clinically in parallel with a decrease in the M-protein indicating a pathogenetic role of the autoantibody. In three other cases, the IgM was bound to connective tissue structures, two of them also had plasma antibodies against the peri- and endoneurium in the indirect fluorescence test. Finally, two cases showed no reaction of the M-protein against any tissue structures. Since an autoimmune pathogenesis is suspected, the HLA types of seven patients are reported.

Aged↗
PubMed1987

Pathogenesis of nocturnal urinary incontinence after ileocaecal bladder replacement. Continuous measurement of urethral closure pressure during sleep.

Urethral closure pressure was recorded in four patients during sleep in order to determine the pathogenesis of nocturnal incontinence after radical cystectomy and ileocaecal bladder replacement. The sleep stages were determined by electroencephalography. The resting pressure in the intestinal bladder was low and increased only slightly during filling. The maximum urethral pressure decreased during sleep but the urethral closure pressure remained positive when the intestinal bladder was not contracting. The peristaltic contractions in the intestinal bladder continued during sleep, causing incontinence. The nocturnal incontinence is probably a result of the reduced level of consciousness that makes it impossible to increase the tone of the external urethral sphincter during contractions of the intestinal bladder.

Electroencephalography↗
PubMed1987

Immunoglobulin deposits in peripheral nerve endings detected by skin biopsy in patients with IgM M proteins and neuropathy.

Immunofluorescence studies of sural nerve and skin biopsies from three patients with IgM M proteins and clinical neuropathy showed that IgM M protein was bound to the nerve myelin in two patients and by the peri- and endoneurium in one. It is suggested that immunohistochemical studies of skin biopsies provide a simple effective method of detecting immunoglobulin binding to peripheral nerves in patients suspected of having an autoimmune neuropathy. In contrast to sural nerve biopsy, skin biopsy does not cause sensory loss or pain in a denervated area and can easily be repeated.

Aged↗
PubMed1987

Intra- and inter-observer variability in the assessment of intrapartum cardiotocograms.

The diagnostic value of a test depends on the variability of the test results and the accuracy of the test. The object of this investigation was to estimate the observer variability and the accuracy, when intrapartum CTGs were assessed by experienced obstetricians. Fifty CTGs were evaluated twice by four obstetricians. They were asked to identify the CTGs belonging to the compromised infants. They were told the criteria for a compromised infant and the incidence (one-third). Eleven (22%) of the CTGs were assessed in the same way of all the obstetricians in both evaluations. Between the obstetricians, the accuracy ranged from 50 to 66%. We conclude that the considerable observer variability found in this and other investigations must severely impair the clinical value of electronic fetal monitoring (EFM). The variability must be reduced before the "true" predictive value and the cost/benefit of EFM can be estimated.

Clinical Competence↗
PubMed1986

Evaluation of visual pathways in multiple sclerosis. I. After-images compared to visual evoked potentials.

The value of flight of colours (FOC), i.e. the succession of coloured afterimages following light stimulation, in diagnosing and following visual impairment was evaluated in 65 patients with multiple sclerosis (MS). Previous optimistic reports of the use of a pocket flashlight (PFL) method could not be confirmed, and are ascribed to inadequate methods. An electronic flashlight (EFL) method developed by us, proved a significantly better diagnostic tool (61% abnormal versus 18% abnormal). The EFL method was diagnostically less sensitive than pattern reversal visual evoked potential (PR-VEP) (80% abnormal). It did, however, add to PR-VEP by diagnosing 16 eyes with normal PR-VEP latency. The EFL method reflected the degree of degenerative changes in the central visual pathways and may be of value in following the disease activity in MS. The potential of the EFL method may be further improved by proposed modifications.

Afterimage↗
PubMed1986

Evaluation of the visual system in multiple sclerosis. II. Colour vision.

A study of colour vision (CV) in 65 patients with multiple sclerosis (MS), (30 patients had had previous optic neuritis) and 51 controls was carried out with Ishihara's pseudoisochromatic plates (I-test), Farnsworth's panel D-15 test (F-test), and Lanthony's desaturated 15-hue test (L-test). CV defects were classified as to type and severity. Error scorings were calculated by Bowman's computerized method and our own simple proposal for scoring, which was found of equal value. Results were compared with pattern-reversal (black/white) visual evoked potentials (PR-VEP) (80% of eyes abnormal). The I-test (56% of eyes abnormal) was a more sensitive indicator of demyelination than the L-test (47%) and F-test (26%). In 14 eyes CV defects (10 blue-yellow, 4 red-green) were only revealed with the L-test. Abnormal CV, mostly blue-yellow defects, occurred in 16 patients (19 eyes) having normal VEP latencies; 29 patients were re-tested within one week. It is proposed that the performance of the I-test, which showed the highest reproducibility, could be improved by adding more cards, particularly blue-yellow, to the test.

Color Perception↗
PubMed1984

A computer model simulating the intestinal absorption of bile acids.

Mathematical models were developed for assessment of the absorption kinetics of compounds passing down the length of a perfused intestinal segment. The models considered the intestinal segment as a cylinder composed of a large number of very small (infinitesimal) cylinders and described the concentration decline of the compound in situations with active, passive and combined active and passive transport. The maximal velocity of active transport, Vmax, the Michaëlis-Menten constant, Km, and the permeability coefficient, P, were calculated. A computer program was developed to operate the mathematical expressions. The models were validated by jejunal and ileal perfusions of various bile acids in six healthy volunteers. The fit between the mathematical models and the actually measured data showed an average standard deviation of 0.14 mmol/l (substrate infusion concentration ranging from 0.25 mmol/l to 3.0 mmol/l). It was concluded that the computer models were feasible for practical purposes. Moreover, the models reduced the number of perfusions necessary to determine the absorption kinetics of a given bile acid.

Adult↗