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Biomedical subjects

D Elliott

Publications and source records attributed to D Elliott.

At least 127 records · Page 7Linked to original sources
PubMed1991

Seizures caused by nontraumatic parenchymal brain hemorrhages.

Seizures occurred in 15% of patients with parenchymal brain hemorrhage (early in 12% and delayed in 3%). Seizures were most frequent with lobar hemorrhages and uncommon with deep subcortical hemorrhages. Lobar hemorrhages in the frontal, parietal, or temporal region were more commonly associated with seizures, whereas occipital hemorrhages were not. Seizures were most common if the hemorrhage was due to an aneurysm, angioma, or neoplasm and less common if hypertensive or spontaneous. If the patient had recurrent seizures or developed delayed seizures, CT showed that the hemorrhage evolved to a hypodense appearance; if the seizure did not recur, CT showed that the hemorrhage evolved to an isodense appearance.

Cerebral Angiography↗
PubMed1990

Nontraumatic temporal subcortical hemorrhage. Clinical-computed tomographic analysis.

Thirty patients with temporal hematomas were analyzed. Four with frontal extension survived. Of 6 with ganglionic extension, three had residual deficit. Of 8 with parietal extension, 4 had delayed deterioration and died, two patients recovered, and two with peritumoral hemorrhage due to glioblastoma multiforme died. Five patients with posterior temporal hematomas recovered. In 7 patients with basal-inferior temporal hematomas, angiography showed aneurysms in 3 cases, angiomas in 2 cases and no vascular lesion in 2 cases. Of 23 cases with negative angiography and no systemic cause for temporal hematoma, 12 patients were hypertensive and 11 were normotensive. Ten hypertensive patients without evidence of chronic vascular disease had the largest hematomas, extending into the parietal or ganglionic regions. Seven of these patients died; 3 had residual deficit. Eleven normotensive and two hypertensive patients with evidence of chronic vascular change had smaller hematomas. They survived with good functional recovery.

Adult↗
PubMed1990

Putaminal hemorrhage: clinical-computed tomographic correlations.

Ninety-two percent of 100 patients with putaminal hemorrhage were hypertensive. Of the eight normotensive patients, seven were substance abusers or had bilateral putaminal hemorrhages. The one other normotensive patient was less than 40 years old. The 100 hemorrhages had the following locations: 1. medial putaminal (17 cases; six were normotensive and less than 40 years old and five were substance abusers); 2. lateral putaminal extending through the external capsule (eleven cases); 3. putaminal-capsular and subcortical white matter (32 cases); 4. putaminal cerebral hemispheric (19 cases); 5. putaminal-thalamic (19 cases); 6. bilateral (two cases). A disproportionate number of black patients suffered hematoma extension to the cerebral hemispheres or thalamus (46%) compared to Caucasians (23%). Overall mortality was 20% (17 blacks and three Caucasians) and occurred in patients with hematoma extension to the thalamus or cerebral hemispheres. Contrast-enhanced CT was performed in all 100 patients and provided no additional diagnostic yield. This indicates limited use for enhanced CT in hypertensive patients with putaminal hemorrhage who have a characteristic appearance of the acute hemorrhage on the nonenhanced CT.

Adult↗
PubMed1990

Manual and oral praxis in adults with Down's syndrome.

Mentally handicapped adults with and without Down's syndrome performed single movements and movement sequences following both verbal and demonstration cueing conditions. While the type of cue did not influence the performance of control subjects, Down's syndrome individuals exhibited more error following verbal cueing. These findings could not be explained on the basis of verbal encoding differences between the groups. The results support the notion that Down's syndrome persons suffer from a dissociation of the functional system responsible for speech perception and the system involved with the organization of complex movement.

Adult↗
PubMed1990

The contribution of vision to asymmetries in manual aiming.

An experiment was conducted to examine the hypothesis that the right hand system is superior in the processing of visual information. A manual aiming task utilizing four visual conditions was employed. In the full-vision (FV) condition subjects were afforded vision of both the hand and the target throughout the course of the movement. In the ambient-illumination-off (AO) condition, the room lights were extinguished at movement initiation, thus preventing vision of the moving limb. The target remained illuminated. In the target-off (TO) condition, the target was extinguished upon initiation of the movement. Ambient illumination and thus vision of the hand remained present. Finally there was a no-vision (NV) condition in which ambient illumination was removed and the target was extinguished upon initiation of the response movement. Although the manipulation of vision had potent effects upon terminal accuracy, and influenced reaction and movement time measures, the hands did not differ in the extent to which these characteristics were expressed. A left hand advantage for reaction time was observed. This may reflect a relative increase in right hemisphere involvement prior to aiming movements which are spatially complex.

Adult↗
PubMed1990

Manual asymmetries in the reproduction of a 3-dimensional spatial location.

Two experiments examined differences in the reproduction of preselected arm positioning movements. In Experiment 1, subjects defined a position in right space with a right index finger, or a position in left space with the left index finger, and then attempted to reproduce the position with either the left or the right hand. Subjects were more accurate when vision was available and when the reproduction hand was the same as the criterion hand. Availability of vision reduced the same hand advantage. There were no accuracy differences between the left and right hands. Experiment 2 was designed to determine whether the left-left and right-right criterion and reproduction advantages evident in the no vision condition of the first experiment were accounted for by the two movements being made by the same hand or by being performed in the same space. The results demonstrated that accuracy depended primarily on whether movements were made with the same hand. No right/left hand advantage was observed. The absence of a right hand advantage in either experiment may be due to the spatial complexity of the task examined or to the relative absence of any temporal constraints.

Adult↗
PubMed1990

Neural contribution to spatiotemporal contrast sensitivity decline in healthy ageing eyes.

Contrast sensitivity thresholds were measured over a range of spatial and temporal frequencies in both a group of young and older observers. Results demonstrate a significant reduction in contrast sensitivity of the older age group at all but the lowest combinations of spatial and temporal frequencies investigated. The senile miosis and reduced optical transmission of the older eye was then mimicked using the younger observers as subjects. This combined effect of reducing retinal illumination produced no significant change in sensitivity. These findings are discussed in terms of neural loss within the visual pathways with increasing age.

Adult↗
PubMed1990

The influence of uncertainty and premovement visual information on manual aiming.

Target-aiming studies in which premovement visual information is manipulated suggest that when vision is occluded, a brief visual representation of the target environment may be used to guide movement. The purpose of this work was to determine if the internal representation contains information about the whole movement environment or just specific information about the position of a single target goal. Two experiments were conducted in which we manipulated both target uncertainty and the visual information available before and during a target-aiming movement. Radial error differences between visual conditions and the independence of the vision and uncertainty manipulations support the hypothesis that subjects form a representation of the overall movement environment.

Adult↗
PubMed1990

Cerebral specialization and the control of oral and limb movements for individuals with Down's syndrome.

In this paper we review existing research on cerebral specialization in Down's syndrome (DS) individuals, and we present a preliminary model. The model proposes that the cerebral organization of DS persons is such that there is a dissociation of brain areas responsible for speech perception and the production of complex movement including speech. Research is presented that confirms some initial predictions of the model.

Journal Article↗
PubMed1990

A visual representation and the control of manual aiming movements.

Three experiments were conducted to determine if a representation of the movement environment is functional in the organization and control of limb movements, when direct visual contact with the environment is prevented. In Experiment 1, a visual rearrangement procedure was employed to show that a representation of the environment that provides inaccurate information about the spatial location of a target can disrupt manual target aiming. In Experiment 2, we demonstrated that spatial information about the position of a target can be destroyed by a visual pattern mask, supporting our claim that the representation is visual. A target-cuing procedure was used in Experiment 3 to show that representation of target position can be useful for premovement organization in a target-aiming task. Together our findings suggest that a short-lived visual representation of the movement environment may serve a useful role in the organization and control of limb movements.

Journal Article↗
PubMed1990

Nontraumatic parenchymal brain hemorrhages.

Before the availability of computerized tomography (CT), it was estimated that 25% of parenchymal brain hemorrhages (PBH) was diagnosed as ischemic stroke. Clinical studies were biased toward large hemorrhages with high mortality rates. More recently, the full clinical spectrum of PBH has been appreciated only with studies correlating clinical findings and CT results. In the pre-CT era, hypertension was thought to be the major risk factor for PBH. Chronic hypertensive vascular changes were believed to cause arteriolar wall damage, and rupture of weakened dilated vessels thought to result in PBH. The occurrence of PBH in previously normotensive patients was underrepresented in pre-CT era studies. Current CT findings in PBH patients have shown that normotensive patients and hypertensive patients with chronic vascular changes have smaller hemorrhages resulting in lower mortality than hypertensive patients without chronic vascular changes. Because chronic hypertensive vascular changes are believed to be common in patients with PBH, this finding is unexpected and previously unreported. Chronic vascular changes may therefore offer some unexplained "protection" for brain blood vessels. Alternatively the mechanism of hypertensive PBH may be somewhat different than previously postulated.

Brain↗
PubMed1990

Lacunar infarction in patients with hypertensive intracerebral hemorrhage.

Of 300 patients with computerized tomographic (CT) evidence of acute hypertensive intracerebral hemorrhage, high-resolution CT scans showed cerebral lacunar infarction (lacunes) in only nine cases (3%). The lacunes were seen in putaminal (six cases), thalamic (one case), and occipital (two cases) hematomas. All patients with lacunes and intracerebral hemorrhage had had systemic arterial hypertension for 7 to 14 years, cardiographic evidence of ventricular hypertrophy, chest radiographic evidence of cardiomegaly, and funduscopic evidence of retinopathy. The intracerebral hemorrhages were small, with maximal diameters of the hematomas 9 to 18 mm. All patients had good clinical outcome. In a 3-year follow-up, three patients had symptomatic lacunar infarcts but none had recurrent hemorrhage, whereas six patients had myocardial infarction or congestive heart failure.

Cerebral Hemorrhage↗
PubMed1990

Self-reported offending, victimization, and the British Crime Survey.

Both the 1982 and 1984 British Crime Surveys contained questions on self-reported offending. In 1984 the questions were changed in order to try and improve admission rates. This article looks at the effect of this change. Admission rates in 1984 are shown to be approximately double those in 1982. Also examined are differences between offenders and non-offenders, what offenses 1984 respondents saw other people as engaging in most often, and who saw other people as least law abiding. The relationship between self-reported offending and victimization in both this and Gottfredson's (1984) analysis of BCS data is taken up.

Adult↗
PubMed1989

Asymmetries in intermanual transfer of training and motor overflow in adults with Down's syndrome and nonhandicapped children.

A sequential finger-lifting task was used to examine asymmetries in intermanual transfer of training and motor overflow in Down's syndrome adults and young, nonhandicapped children. Both groups exhibited more interlimb transfer of training from the left hand to the right hand than the reverse. This finding provides evidence for left-hemisphere specialization for the organization and control of sequential movement. While the motor overflow results were less compelling, they provide some evidence for left-hemisphere dominance for movement control in Down's syndrome persons. It is suggested that perhaps the same neural mechanisms are responsible for motor overflow and transfer of training asymmetries.

Adult↗
PubMed1989

Eclampsia: a pediatric neurologic problem.

Eclampsia is a syndrome of hypertension, proteinuria, edema, and neurologic manifestations such as seizures, focal deficits, or blindness occurring during pregnancy, mainly in primigravidas. Although it is not seen often in the pediatric population, it occurs with greater frequency among pregnant patients under the age of 15 than in the general population. Serious sequelae can be prevented with prompt and adequate treatment, including termination of pregnancy.

Adolescent↗
PubMed1989

Lower extremity telescopic orthosis for immediate fitting in paraplegia.

For initial gait training with the paraplegic patient, a lower extremity telescoping orthosis has been developed. This brace eliminates the time-consuming fabrication, considerable weight, and cumbersome use of conventional knee-ankle-foot orthoses and is easily adjustable to a wide range of patients. Particularly during the early phase of rehabilitation, this brace offers significant advantages to the patient with lower extremity disabilities.

Braces↗