Search PubMed⌕ Search

Biomedical subjects

D L Na

Publications and source records attributed to D L Na.

44 records · Page 3Linked to original sources
PubMed1998

Nervous system involvement by metastatic hepatocellular carcinoma.

Nineteen patients with nervous system metastasis of hepatocellular carcinoma (HCC) were evaluated retrospectively. Nervous system metastasis was frequently initial presentation of HCC (seven out of 19 patients). Seven patients had metastases of the brain, of whom four had a stroke-like presentation. CT or MRI in these patients showed intracerebral hematomas in watershed areas. Enhancing lesion or edema adjacent to the hematoma helped differentiate these lesions from classical hypertensive hematomas. One patient with metastasis to the clivus presented with isolated six nerve palsy. The remaining 11 patients had spinal epidural metastases producing myelopathy in seven and radiculopathy in four. Radiation therapy failed to control the clinical course.

Adult↗
PubMed1998

Dissociation of sensory-attentional from motor-intentional neglect.

OBJECTIVES: Spatial neglect may result from disruption of sensory-attentional systems that spatially allocate perceptual resources and the motor-intentional systems that direct exploration and action. Previous studies have suggested that the line bisection task is more sensitive to sensory-attentional disorders and the cancellation task to motor-intentional disorders. A new technique was developed that allows the dissociation of sensory-attentional and motor-intentional deficits in both tasks and thereby allows comparison of these tasks. METHODS: Ten patients with right hemispheric injury and hemispatial neglect performed line bisection and cancellation tasks while viewing stimuli on closed circuit TV. Direct view of the exploring hand and the target was precluded; the TV monitor guided performance. The direct condition made the direction of hand movement on the table (workspace) congruent with that on the monitor. Inverting the camera produced the indirect condition wherein the lateral movement in the workspace occurred in the opposite direction on the monitor. RESULTS: On the cancellation task, five patients marked targets in the right workspace in the direct condition but the left workspace in the indirect condition, indicating sensory-attentional neglect. However, four other patients cancelled targets only in the right workspace in both conditions, failing to explore the left workspace, suggesting motor-intentional neglect. A patient who performed ambiguously may have elements of both types of neglect. Only two out of five patients designated as sensory-attentional in cancellation tasks showed sensory neglect on line bisection. The other three patients, as well as patients defined as motor-intentional by cancellation performance, exhibited motor-intentional neglect on line bisection. CONCLUSION: The designation of sensory-attentional versus motor-intentional neglect therefore, in part, depends on task specific demands.

Adult↗
PubMed1998

Ipsilateral neglect during intracarotid amobarbital test.

Neglect usually occurs in the space contralateral to brain injury. Recent studies describe ipsilateral neglect (IN) whereby patients with right hemisphere injury misbisect lines to the left of midpoint. IN usually develops after contralateral neglect (CN) resolves. We observed whether IN occurs during intracarotid amobarbital infusion. After clinical testing but before resolution of barbiturate effect, 20 right-handed subjects bisected lines until baseline performance returned. More than half (12 of 20) showed transient CN. IN occurred in 40% (8 of 20) of patients, always during the recovery stage of anesthesia, and most frequently followed initial CN.

Adolescent↗
PubMed1997

Anosognosia: examining the disconnection hypothesis.

OBJECTIVE: To test the hypothesis that anosognosia for hemiparesis results from intrahemispheric disconnection. METHODS: Using right carotid barbiturate injection as a model for anosognosia for hemiparesis, systematic attempts were made to modify deficit awareness by providing the left hemisphere with explicit information regarding left upper extremity function. RESULTS: Experimental interventions failed to modify deficit awareness in 19 of 32 patients. In those patients who discovered their weakness, attempted movement of the weak limb seems more important than explicit observation of the extremity by the left hemisphere. CONCLUSIONS: The results fail to support Geschwind's disconnection hypothesis for anosognosia for hemiparesis.

Adult↗
PubMed1995

Neglect of radial and vertical space: importance of the retinotopic reference frame.

Neglect from bilateral brain injury can disrupt responses along space defined by the vertical and radial axes. The spatial reference frames for vertical and radial neglect remain largely undefined, however. The viewer centred system, for example, consists of retinocentric and cephalocentric/corporacentric frames. In the present study, different viewer centred reference frames were dissociated in a patient with combined far radial superior vertical neglect through performance of radial line bisections above and below eye level. To separate reference frames for vertical space, bisections were performed while the patient was lying sideways. Results suggest that this patient's neglect respected a retinotopic viewer centred reference frame.

Adult↗
PubMed1995

Anosognosia for hemiplegia: test of the personal neglect hypothesis.

OBJECTIVE: To test the personal neglect hypothesis of anosognosia for hemiplegia (AHP) using selective anesthesia of the right hemisphere. BACKGROUND: Although AHP most commonly follows right-hemisphere injury, the mechanism responsible for this hemispheric asymmetry has not been entirely elucidated. Because denial of ownership of parts on the contralesional side of one's body (personal neglect) also more commonly follows right-hemisphere damage, personal neglect might account for AHP. DESIGN/METHODS: AHP and personal neglect were assessed in 20 patients during right intracarotid barbiturate infusion. With vision restricted to the central field, patients were randomly presented with either their own hands or those of examiners matched for size, gender, and race. Patients were asked to read numbers placed on the hands to establish that hemianopia did not confound hand recognition. RESULTS: All subjects correctly read the numbers on all trials. Only 4 of 20 subjects misidentified their hands and denied awareness of left hemiplegia. All errors occurred for the left hand, indicating personal neglect. However, the 16 subjects without personal neglect also demonstrated AHP. CONCLUSION: Because AHP and personal neglect are dissociable, personal neglect cannot completely account for AHP.

Adult↗
PubMed1991

Alcoholic pellagra encephalopathy combined with Wernicke disease.

Clinical and postmortem findings of a case that had combined alcoholic pellagra encephalopathy and Wernicke disease are described. This 51-year-old malnourished and chronic alcoholic man presented with progressive mental deterioration, pellagra dermatitis, hypertonus of the neck and other musculatures, myoclonic jerks with bizarre involuntary movements, in addition to total external ophthalmoplegia and gait disturbance. After administration of multivitamins, including thiamine and nicotinamide, these neurologic abnormalities were dramatically improved in a few days. However, the patient died thereafter because of sepsis associated with pneumonia. Postmortem examination revealed marked abnormalities in CNS, characterized by diffuse atrophy of gray matter and widespread neuronal degeneration and characteristic central chromatolysis in pontine nuclei, dentate nuclei, cranial nerve nuclei in the brain stem, Betz cells of the cerebral cortex, and Clarke's column and anterior horn cells of the spinal cord. There were also atrophy and gliosis of the mammillary bodies, degeneration and vascular proliferation of periaqueductal gray matter, and massive gliosis around the third ventricle. These neuropathological changes were compatible with symptoms of both alcoholic pellagra encephalopathy and Wernicke's disease, but they were also strongly suspected on clinical grounds.

Alcoholism↗