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Biomedical subjects

R D Adams

Publications and source records attributed to R D Adams.

At least 37 records · Page 2Linked to original sources
PubMed1996

Stiffness judgments are affected by visual occlusion.

OBJECTIVE: The current protocol for judging posteroanterior (PA) spinal stiffness has been shown to provide unreliable estimates of PA stiffness. It is possible that a failure to standardize therapists' use of vision in the test protocol partly contributes to the disagreement between raters. This study sought to establish whether vision affects stiffness judgments and so needs to be standardized when judging PA stiffness. DESIGN: Perceptual study using a mechanical device to provide stiffness stimuli with physiotherapists and lay people as judges. SETTING: University psychophysics laboratory. INTERVENTIONS: Occlusion of vision via opaque goggles. MAIN OUTCOME MEASURES: Measures of interstimulus discriminability and bias. RESULTS: Occluding vision had no effect on judges' ability to discriminate between stiffness stimuli; however, the same stimuli were judged as significantly stiffer under the visual occlusion condition. CONCLUSION: The data from this study suggest that vision needs to be controlled when using manual tests to judge PA spinal stiffness.

Analysis of Variance↗
PubMed1995

Breathing patterns during spontaneous speech.

Lung volumes, speech intensity, the linguistic location of inspirations, and the variability of each, were studied during spontaneous speech in 6 healthy young women over 7 to 10 sessions each, using respiratory inductance plethysmography. Although average lung volume levels were within the vital capacity range previously reported for speech (Hixon, Goldman, & Mead, 1973), significant inter- and intrasubject variability was observed. This variability was considerable for some subjects (average initiation lung volume varying between 42 and 63% VC over the sessions) and relatively small for others (between 47 and 53% VC). Some of the lung volume variation was associated with changes in mood state, examined by self-report questionnaire at each measurement occasion. Linguistic factors were important influences in the lung volume variation. The majority of breaths in the conversations and monologues preceded structural (clause) boundaries. The volume of air inspired preutterance was found to be linked to the length of the ensuing breath group in each of our 6 subjects, as longer breath groups, spanning up to seven clauses in the spontaneous speech, were anticipated by inspiring to a higher lung volume. The subjects used a comfortable speaking intensity range, which varied for different individuals and sessions over 4 to 18 dB. Increases in speech intensity within individual ranges were not associated with increased lung volumes. The data provide novel insight into associations between physiological and linguistic factors in the control of speech breathing, and are suggestive of the existence of neural planning of the respiratory system, in anticipation of the demands of the utterance.

Adult↗
PubMed1995

Variability of grip strength during isometric contraction.

The use of measures of strength variability as a means of determining sincerity of effort is becoming a more common practice, particularly in medico-legal and rehabilitation settings. The stability of such variability measures, however, has not been documented. This research investigated, in two studies, the trial-to-trial variability of grip strength under maximal and submaximal effort conditions. In the first study, 63 subjects were asked to give 100% grip effort, and in the second study 40 subjects from the original group were asked to give 50% grip effort. The Jamar hand dynamometer was used to measure grip strength in both experiments, and a coefficient of variation (CV) was calculated for every three repeat measures at each handle position. Testing was conducted on two separate occasions for both experiments. Although the interoccasion reliability of grip strength was very high, in comparison, the CV was not stable over test occasions, with interoccasion reliability indices close to zero. Factors significantly influencing CV were effort level, with submaximal effort producing larger CVs, and gender, with females having greater strength variability. If the rule is applied that one or more CVs above the 7.5% cut-off value could indicate submaximal effort, then for this sample of subjects giving maximal effort, 97% of females and 64% of males would be misclassified. Applying a single CV classification cut-off value to a mixed sample of subjects appears to unfairly discriminate against the females. Further research into the factors associated with high CV values is essential before the CV can be used with any confidence in a clinical setting as a method for determining sincerity of effort.

Adult↗
PubMed1994

Transhiatal stapled esophagojejunostomy without a pursestring suture in patients with previous gastric resection.

Previous gastric resection complicates alimentary tract reconstruction after esophagectomy. Colonic interposition is the standard conduit in this circumstance, but has substantial mortality and morbidity, especially important when treatment goals are to provide effective alimentation and minimize hospital stay. This report details the technique of a transabdominal, intrathoracic, stapled esophagojejunostomy created without a pursestring suture, which was used to reconstruct the esophagus in 3 patients who had previously undergone partial gastrectomy. This technique avoids both colon interposition and thoracotomy, thereby minimizing the associated complications.

Aged↗
PubMed1994

A dose-response relationship between amount of weight-bearing exercise and walking outcome following cerebrovascular accident.

To supplement a motor relearning approach to rehabilitation for patients following cerebrovascular accident (CVA), a weight-bearing exercise was used that was designed specifically to strengthen the leg extensor muscles to simulate the output required in the single support phase of walking. For patients who were initially able to stand on their affected leg and step forward with their other leg, a dose-response relationship was found between an increasing number of repetitions of this weight-bearing exercise and improved walking outcome as measured on the Motor Assessment Scale (MAS) for stroke. For patients who could not stand and step forward at initial assessment (MAS-0), there was no relationship between the amount of practice done and walking outcome, however, all of the patients who practiced the exercise achieved independent walking for at least a 3m distance, which gave a final MAS score of three or greater.

Aged↗
PubMed1994

Variability and consistency in speech breathing during reading: lung volumes, speech intensity, and linguistic factors.

Lung volumes during reading and associated factors such as speech intensity and linguistic influences were studied in six healthy young women over 7 to 10 sessions, using respiratory inductive plethysmography. Intrasubject variability of lung volumes over the sessions was almost as great as the intersubject variability. Some of the intrasubject variability was associated with natural variations of speech intensity within a "comfortable loudness" range. The lung volume variability during reading is contrasted with high degrees of both inter- and intrasubject consistency in the location of inspirations, which occurred almost exclusively at grammatically appropriate places in the texts (paragraph, sentence, clause, and phrase boundaries). Within each reading passage, lung volumes were significantly increased for (a) louder utterances, (b) inspirations at sentence and paragraph boundaries compared to inspirations at other locations within sentences, (c) longer utterances compared to shorter utterances, and (d) initial breaths compared to final breaths. The implications of these findings for the neural control of breathing during speech are considered.

Adult↗
PubMed1994

Selectivity in aortic root reconstruction.

Anatomical variations in aortic root pathology, including combinations of dissection, aneurysmal dilatation, annuloaortic ectasia, and valve disease, defy standardized repair and mandate application of various surgical reconstructions. To examine these techniques, and their influence on morbidity and mortality, we reviewed 53 consecutive patients undergoing aortic root procedures. Thirty-two patients underwent total root reconstruction. Of these, 21 underwent Bentall procedures, 9 had a modification thereof, and 2 underwent a Cabrol reconstruction. Less extensive pathology was corrected in 21 patients with a partial root reconstruction. These included aortic valve replacement (AVR) and a separate tube graft in 14 patients, AVR and primary aortic repair +/- wrapping in 4 individuals, and AVR and patch aortic root enlargement in 3 patients. Mean age was 53.2 years (range 20 to 79). Nearly 20% had undergone previous cardiac surgery and 7.5% were emergencies. Early mortality was 4%. Complications included dysrhythmias (48%), myocardial infarction (4%), stroke (4%), pneumonia (14%), and pancreatitis (2%). There were no reoperations for bleeding. Three late complications, one pseudoaneurysm and two perivalvular leaks, were successfully repaired. Late deaths (13.7%) were caused by congestive heart failure (3), myocardial infarction (MI) (1), cancer (1), stroke (1), and accidental fall (1). Kaplan-Meier analysis reveals 1-, 5-, and 10-year survivals of 98%, 81%, and 66%. Survival and mortality data did not differ between groups, and except for the incidence of atrial dysrhythmias, complication rates also were not significantly different. This series illustrates the need for and the successful application of a selective approach to aortic root reconstruction.

Aorta↗
PubMed1991

Reliability and agreement of ratings of ataxic dysarthric speech samples with varying intelligibility.

Indices of interjudge reliability and inter- and intrajudge agreement were calculated from the ratings made by 15 experienced speech clinicians on five deviant speech dimensions with respect to 15 speakers with ataxic dysarthria. Speakers were chosen to cover a wide range of speech intelligibility (16-97%) as measured by the sentence intelligibility transcriptions of the Assessment of Intelligibility of Dysarthric Speech (Yorkston & Beukelman, 1981). Intraclass correlation coefficients derived from each judge on two occasions were above .6 for imprecise consonants, excess and equal stress, and harsh voice, but below .6 for distorted vowels and below .5 for irregular articulatory breakdown. The last dimension also had the lowest percent agreement for the interjudge and intrajudge comparisons. Poor speech dimension definition seems to be the most likely source of error on irregular articulatory breakdown. Judges agreed equally well in rating dysarthric speech across the range from low to high intelligibility.

Aged↗
PubMed1991

Chronic nontraumatic diseases of the spinal cord.

This article reviews common chronic diseases of the spinal cord such as spinal multiple sclerosis, cervical spondylosis, and motor system diseases, including amyotrophic lateral sclerosis. Secondary epidural and meningeal tumors and syringomyelia are also discussed.

Chronic Disease↗
PubMed1990

Earthquake occurrence and effects.

Although earthquakes are mainly concentrated in zones close to boundaries of tectonic plates of the Earth's lithosphere, infrequent events away from the main seismic regions can cause major disasters. The major cause of damage and injury following earthquakes is elastic vibration, rather than fault displacement. This vibration at a particular site will depend not only on the size and distance of the earthquake but also on the local soil conditions. Earthquake prediction is not yet generally fruitful in avoiding earthquake disasters, but much useful planning to reduce earthquake effects can be done by studying the general earthquake hazard in an area, and taking some simple precautions.

Disaster Planning↗
PubMed1990

Pregnancy and the risk of hemorrhage from cerebral arteriovenous malformations.

We conducted a retrospective analysis of 451 women with an arteriovenous malformation (AVM) of the brain to determine whether pregnancy is a risk factor for cerebral hemorrhages. A total of 540 pregnancies occurred among our patient population, resulting in 438 live births and 102 abortions. There were 17 pregnancies complicated by a cerebral hemorrhage. The hemorrhage rate during pregnancy for women with an unruptured AVM was 0.035 +/- 0.005 per person-year. The hemorrhage rate for nonpregnant women of childbearing age with an unruptured AVM was 0.031 +/- 0.002 per person-year. Pregnancy did not increase significantly the rate of first cerebral hemorrhage from an AVM (P = 0.35). We found that women with an AVM face a 3.5% risk of hemorrhage during pregnancy. Pregnancy is not a risk factor for hemorrhage in women without a previous hemorrhage. This conclusion assumes no selection bias exists in our study population; a bias would be introduced if the risk of fatal outcome after a hemorrhage were greater in pregnant women than in nonpregnant women.

Adolescent↗
PubMed1989

Clinical presentations of vascular malformations of the brain stem: comparison of angiographically positive and negative types.

Clinical and radiographic features of 63 patients with a vascular malformation of the brain stem are described. On radiological grounds they were divided into two groups: one with angiographically visible lesions (AVAVMs), the other with lesions not seen angiographically, that is, occult (AOVMs). In the first group the initial clinical manifestation was due to haemorrhage in 20 of the 33 cases and consisted of a progressive neurological deficit in 12. In the second group 29 of the 30 initially presented with a brain stem haemorrhage. The latter was often characterised by development of symptoms over two days or more (16 cases), absence of headache (48 cases) and tendency to recurrence (20 cases). Clinical diagnosis was difficult in many cases especially in the AOVM group. Several of the patients were misdiagnosed as having multiple sclerosis. Clinical data in conjunction with magnetic resonance imaging were helpful in determining the nature of these lesions.

Adult↗
PubMed1986

Brainstem auditory hallucinosis.

We studied three patients with findings suggesting that auditory hallucinations may occur with lesions of the tegmentum of the pons and lower midbrain. The evidence was clinical (indicating location of the lesion), radiologic (CT), pathologic in one case, and physiologic (affirming integrity of the cochleas and auditory nerves). The condition is comparable with the Lhermitte peduncular-diencephalic visual hallucinosis.

Adult↗