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Biomedical subjects

H S Levin

Publications and source records attributed to H S Levin.

At least 145 records · Page 8Linked to original sources
PubMed1989

Dichotic listening and manual performance in relation to magnetic resonance imaging after closed head injury.

In order to investigate post-traumatic hemispheric disconnection effects, dichotic listening and intermanual tasks were administered to 69 patients who had sustained a closed head injury of varying severity. The manual tasks consisted of naming objects palpated in either hand, transfer of postures from one hand to the other and writing. Consistent with predictions, the degree of ear asymmetry in dichotic listening performance was directly related to the severity of the head injury as reflected by the degree of impaired consciousness. Depth and localisation of parenchymal lesion characterised by magnetic resonance imaging were also related to the degree of ear asymmetry. Parenchymal lesions situated in sites which could potentially interfere with callosal auditory or geniculocortical pathways produced a greater disparity in response to left versus right ear inputs as compared with parenchymal lesions in areas such as the frontal lobes which are purportedly unrelated to asymmetries in dichotic listening performance. The results provide further evidence for the effects of multifocal brain lesions involving the white matter on tasks which require intra and/or interhemispheric integration.

Adolescent↗
PubMed1989

Magnetic resonance imaging after closed head injury in children.

Magnetic resonance imaging (MRI) was performed in a series of 21 children and adolescents who had been hospitalized after sustaining closed head injuries of varying severity at least 6 months previously. Areas of high intensity in the parenchyma were present in 8 of the 11 severely injured patients, whereas MRI findings were normal in all 10 patients with mild-to-moderate head injuries. Lesions involving the subcortical white matter were confined to severely injured patients whose clinical features were compatible with diffuse axonal injury. Neuropsychological assessment disclosed deficits primarily in the severely injured patients; these deficits were significantly associated with persistent lesions visualized by MRI. Serial MRI and neurobehavioral assessment following early injury may be useful in documenting cognitive impairment in relation to structural alterations of the young brain.

Adolescent↗
PubMed1989

Neurobehavioral and magnetic resonance imaging findings in two cases of decompression sickness.

Two divers underwent neurobehavioral examinations and magnetic resonance imaging (MRI) while hospitalized during the first 2 weeks after sustaining decompression sickness (DCS). Their neurologic findings included a Brown-Séquard Syndrome consistent with spinal cord lesion, and focal deficits consistent with cerebral lesion(s). MRI revealed subcortical white matter lesions in the brains of both divers, whereas no lesion of the spinal cord was demonstrated. The patients exhibited neurobehavioral sequelae including disturbances of memory, divergent thinking, and visuospatial and motor functioning. Focal neurologic deficits resolved in both patients, and their cognitive and memory problems improved slowly. Findings in these two divers raise the possibility that cerebral insult more frequently accompanies spinal cord injury in DCS than previously thought.

Adult↗
PubMed1988

Evidence for right-hemisphere involvement in recovery from aphasia.

Cortical evoked potentials and dichotic listening test scores were used to assess the extent of activation of the two cerebral hemispheres during various language tasks in a group of 21 recovering aphasics, 15 nonaphasic patients with right-hemisphere stroke, and 17 normal volunteers. In agreement with previous findings, both measures suggest greater right-hemisphere activation during language processing in the recovering aphasics than in nonaphasic patients and normal subjects. These data support the view that restitution of language entails reorganization of brain function with increased participation of the nondominant hemisphere.

Aphasia↗
PubMed1988

Automatic and effortful processing after severe closed head injury.

To investigate the automatic versus effortful distinction following severe closed head injury (CHI), we administered free recall and frequency of occurrence tasks to patients and controls. In Experiment 1 we found that both free recall (an effortful task) and judgment of relative frequency of occurrence (an automatic task) were impaired in 15 CHI patients as compared to 14 controls. In Experiment 2 we corroborated this finding and showed that absolute estimates of frequency were also impaired in new samples of 16 patients and 16 controls. We infer that cognitive tasks which normal individuals can perform without practice, feedback, or instructions may demand more effortful strategies following severe CHI.

Adult↗
PubMed1988

Nephrogenic adenoma in patients with transitional cell carcinoma of the bladder receiving intravesical thiotepa.

Nephrogenic adenoma is a rare, benign lesion of the urothelium that generally occurs after open surgery or other bladder trauma. We present 2 recently treated patients with nephrogenic adenomas, both of whom had been treated previously with transurethral resection and intravesical thiotepa for histologically proved transitional cell carcinoma of the bladder. The occurrence of nephrogenic adenoma after transurethral resection alone is extremely rare and suggests a possible adjuvant role of the intravesical thiotepa. With the increasing use of such local chemotherapeutic agents, the incidence of nephrogenic adenoma in such patients may be increasing.

Administration, Intravesical↗
PubMed1988

Surgical treatment of localized renal cell carcinoma in von Hippel-Lindau's disease.

From 1981 to 1986, 10 patients with von Hippel-Lindau's disease underwent an operation for bilateral nonmetastatic renal cell carcinoma. Of the patients 9 underwent unilateral partial nephrectomy and contralateral radical nephrectomy, and 1 underwent bilateral nephrectomy with subsequent hemodialysis and cadaver renal transplantation. Pathologically, the tumor was stage I in 9 patients and stage III in 1. Currently, 8 patients are alive after partial nephrectomy (5 to 56 months) with good renal function (mean serum creatinine 2.0 mg. per dl.) and no evidence of malignancy; 1 of these patients underwent excision of a cerebral metastasis 2 years after partial nephrectomy. One patient is alive on dialysis after removal of the renal remnant for local tumor recurrence. The patient who underwent transplantation is free of tumor with a well functioning allograft. The distinctive features of renal cell carcinoma in von Hippel-Lindau's disease that influence the management of these patients are reviewed.

Adult↗
PubMed1988

Mitosis counting in seminoma: an exercise of questionable significance.

Two pathologists reviewed and classified 45 cases of testicular seminoma, evaluating each case for multiple histologic variables, including mitotic rate. In addition to recording the mitotic count for each of thirty 0.1963-mm2 high-power fields, the investigators recorded the distribution of mitotic counts in many non-spermatocytic seminomas. Statistically significant differences for mitotic rate in the nonspermatocytic tumors were noted between the observers; one observer found a mean mitotic rate of 1.815/high-power field for 43 such tumors, whereas the other noted a mean mitotic rate of 1.388/high-power field (p = 0.001). These differences led to disagreement on the classification of 3 tumors. Of the 4 cases considered to be high-mitotic-rate seminomas by one or both observers, all patients had presented with stage I disease. Three of the patients were followed up for 23, 55, and 56 months, and all were free of disease; the fourth was lost to follow-up. The patient with the highest mitotic rate was free of disease at 55 months of follow-up. On the basis of our findings we question the value of the designation high-mitotic-rate seminoma. Analysis of the distribution of mitotic counts within the tumors revealed them to be Poisson distributed. With these data and other empirically derived data, it was possible to estimate the probability of misclassification of seminoma based on mitotic rate, the diagnostic mitotic rate threshold, and the number of fields counted for mitoses. Similar analysis might be valuable for other tumors, particularly those of smooth muscle origin, in which mitotic rate is of diagnostic or prognostic value.

Adult↗
PubMed1988

Learning and forgetting during posttraumatic amnesia in head injured patients.

To investigate forgetting during recovery from head injury, colour slides were initially projected for long durations to ensure acquisition on a recognition test given 10 minutes later. Patients tested during posttraumatic amnesia (PTA) exhibited accelerated forgetting over 32 hours as compared with head trauma patients studied after the period of PTA and normal controls.

Adult↗
PubMed1988

Disproportionately severe memory deficit in relation to normal intellectual functioning after closed head injury.

The presence of disproportionate memory impairment with relatively preserved intellectual functioning was examined in 87 survivors of moderate or severe closed head injury. Approximately one-fourth of the patients tested at 5 to 15 and/or 16 to 42 months after injury manifested defective memory on both auditory and pictorial measures despite obtaining Wechsler Verbal and Performance Intelligence Quotients within the average range. The findings indicate that disproportionately severe memory deficit persists in a subgroup of closed head injured survivors which is reminiscent in some cases of the amnesic disturbance arising from other causes. Evaluation of long term memory in relation to cognitive ability could potentially identify important distinctions for prognosis and rehabilitation in head injured patients.

Adult↗
PubMed1988

Memory functioning during the first year after closed head injury in children and adolescents.

Effects of the severity of closed head injury (CHI) on verbal learning and memory and visual recognition memory were studied at base line and on a 1-year follow-up examination in 58 pediatric admissions sampled from three age ranges, 6-8, 9-12, and 13-15 years. Within each age range, recovery of memory was compared in patients with mild to moderate CHI and survivors of severe injury. Consistent with previous findings obtained in head-injured children sampled from a wide age range, the present study confirms that memory deficit persists at least 1 year after severe CHI. Impairment of visual recognition memory was directly related to severity of CHI in all three age ranges. The severity of CHI was directly related to initial and residual verbal memory deficit in adolescents, but this effect was inconsistent in children. We suggest that the cerebral substrate for visual recognition memory was well established in all three age ranges and thus was vulnerable to the effects of injury. In contrast, verbal memory skills were undergoing rapid development in the adolescents, but were still immature in children. Extended follow-up could conceivably demonstrate the late appearance of verbal memory deficit in the children who had apparent sparing of function.

Adolescent↗
PubMed1988

Relationship of depth of brain lesions to consciousness and outcome after closed head injury.

Magnetic resonance (MR) imaging was performed in 94 patients who sustained closed head injury of varying severity. Results of MR studies obtained after the intensive care phase of treatment disclosed that intracranial lesions were present in about 88% of the patients. Consistent with the centripetal model of progressive brain injury proposed in 1974 by Ommaya and Gennarelli, the depth of brain lesion was positively related to the degree and duration of impaired consciousness. Further analysis indicated that the relationship between depth of brain lesion and impaired consciousness could not be attributed to secondary effects of raised intracranial pressure or to the size of intracranial lesion(s).

Adolescent↗
PubMed1988

Sustained attention and information processing speed in chronic survivors of severe closed head injury.

Sustained attention and information processing speed in 15 long-term survivors of severe closed head injury and 14 demographically matched controls have been examined. The average time between head injury and testing was 3.6 years. The performance of patients on all tasks was impaired relative to controls, thus documenting persistent deficits in attention. Of particular interest was the finding that controls were capable of redirecting and improving their sustained attention during a test session versus the steady decline in patient performance. The findings are discussed within the framework of controlled attentional processes.

Adult↗
PubMed1987

Malignant fibrous histiocytoma of the heart. A case report and review of the literature.

A case report of a 28-year-old woman with malignant fibrous histiocytoma (MFH) of the left atrium is presented, and the six previous reports of this rare cardiac tumor are reviewed. A tendency for malignant fibrous histiocytoma of the heart to occur in the left atrium of young women is suggested; this sarcoma's usual location is in the soft tissue of elderly men. The apparent predilection for the left atrium is unique among cardiac malignancies. Careful pathologic study is necessary to differentiate the uniformly fatal MFH of the heart from the more common benign atrial myxoma.

Adult↗
PubMed1987

Evoked potential correlates of right hemisphere involvement in language recovery following stroke.

A probe evoked potentials procedure was used to assess the relative engagement of both cerebral hemispheres during a language task in the following four groups of dextral adults: left hemisphere (LH)-damaged aphasics recovering from stroke, dysarthrics, right hemisphere (RH)-damaged nonaphasic patients, and normal control subjects. In agreement with previous findings using the probe procedure, the present results indicate greater task-specific RH activation in recovering aphasics and, to a lesser degree, dysarthric patients and greater LH activation in both nonaphasic, RH-damaged patients and normal control subjects. On the basis of these data, we suggest that increasing participation of the nondominant hemisphere may subserve restitution of language in adults sustaining LH lesions.

Adult↗
PubMed1987

Language functions following closed-head injury in children and adolescents.

Fifty-six children and adolescents who sustained a closed-head injury were divided into two groups based on neurological criteria. Language performance was assessed using the Neurosensory Center Comprehensive Examination for Aphasia during the subacute stage of recovery. Naming, expressive, and written language were more impaired than receptive-language functions. At least 20% of the sample exhibited deficits on measures of describing the function of objects, sentence repetition, verbal associative fluency, writing to dictation, and copying sentences. No sparing of function was observed in children relative to adolescents. Moreover, written-language performance was more depressed in children than adolescents. Results were discussed in terms of acquired aphasia in children and posttraumatic linguistic deficits in adults.

Adolescent↗
PubMed1987

The neurobehavioural rating scale: assessment of the behavioural sequelae of head injury by the clinician.

To investigate the inter-rater reliability and validity of the Neurobehavioural Rating Scale at various stages of recovery after hospitalisation for closed head injury, we studied 101 head trauma patients who had no antecedent neuropsychiatric disorder. The results demonstrated satisfactory inter-rater reliability and showed that the Neurobehavioural Rating Scale reflects both the severity and chronicity of closed head injury. A principal components analysis revealed four factors which were differentially related to severity of head injury and the presence of a frontal lobe mass lesion. Although our findings provide support for utilising clinical ratings of behaviour to investigate sequelae of head injury, extension of this technique to other settings is necessary to evaluate the distinctiveness of the neurobehavioural profile of closed head injury as compared with other aetiologies of brain damage.

Adolescent↗