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Biomedical subjects

H S Levin

Publications and source records attributed to H S Levin.

At least 37 records · Page 2Linked to original sources
PubMed2001

Intercenter variance in clinical trials of head trauma--experience of the National Acute Brain Injury Study: Hypothermia.

OBJECT: In a recently conducted trial of hypothermia in patients with severe brain injury, differences were found in the effects of hypothermia treatment among various centers. This analysis explores the reasons for such differences. METHODS: The authors reviewed data obtained in 392 patients treated for severe brain injury. Prerandomization variables, critical physiological variables, treatment variables, and accrual methodologies were investigated among various centers. Hypothermia was found to be detrimental in patients older than the age of 45 years, beneficial in patients younger than 45 years of age in whom hypothermia was present on admission, and without effect in those in whom normothermia was documented on admission. Marginally significant differences (p < 0.054) in the intercenter outcomes of hypothermia-treated patients were likely the result of wide differences in the percentage of patients older than 45 years of age and in the percentage of patients in whom hypothermia was present on admission among centers. The trial sensitivity was likely diminished by significant differences in the incidence of mean arterial blood pressure (MABP) less than 70 mm Hg (p < 0.001) and cerebral perfusion pressure (CPP) less than 50 mm Hg (p < 0.05) but not intracranial pressure (ICP) greater than 25 mm Hg (not significant) among patients in the various centers. Hours of vasopressor usage (p < 0.03) and morphine dose (p < 0.001) and the percentage of dehydrated patients varied significantly among centers (p < 0.001). The participation of small centers increased intercenter variance and diminished the quality of data. CONCLUSIONS: For Phase III clinical trials we recommend: 1) a detailed protocol specifying fluid and MABP, ICP, and CPP management: 2) continuous monitoring of protocol compliance; 3) a run-in period for new centers to test accrual and protocol adherence; and 4) inclusion of only centers in which patients are regularly randomized.

Adult↗
PubMed2000

Reduction of corpus callosum growth after severe traumatic brain injury in children.

OBJECTIVE: To study effects of closed head injury (CHI) severity on development of corpus callosum (CC) in children, using MRI. BACKGROUND: Vulnerability of CC to diffuse axonal injury has been shown in adults and children by neuropathologic and MRI studies. Given continued development of CC through the second decade, serial MRI could characterize effects of CHI on CC growth in children. METHOD: MRI performed at 3 and 36 months after severe (mean age = 10.3 years, n = 25) and mild to moderate (mean age = 9.7 years, n = 28) CHI. Mild to moderate and severe CHI groups did not differ in demographic features. Morphometry of T1-weighted midsagittal CC by two operators with satisfactory interrater reliability yielded uncorrected and corrected CC volume. RESULTS: An interaction of occasion with CHI severity was present as CC area decreased from 3 to 36 months in severely injured children and increased in the mild to moderate CHI group. Uncorrected CC area was correlated with acute CHI severity and functional outcome at 36 months postinjury. CONCLUSIONS: Morphometric measurement of CC area provides a useful index of diffuse injury, which is related to functional outcome of CHI in children.

Brain Injuries↗
PubMed2000

Assessment of neuropsychologic impairments after head injury: interrater reliability and factorial and criterion validity of the Neurobehavioral Rating Scale-Revised.

OBJECTIVE: To study interrater reliability and factorial and criterion validity of the Neurobehavioral Rating Scale-Revised (NRS-R). DESIGN: Validity study on persons with traumatic brain injury (TBI) and test-retest reliability study on a randomly selected subset of patients. Factor analyses, kappa statistics, intraclass correlation coefficients, and Cronbach's alphas were used. SETTING: Inpatients from 15 French hospitals, mainly rehabilitation units. Other recruitment sites included a neurology hospital unit and a psychiatry hospital specifically devoted to TBI rehabilitation. PATIENTS: Two hundred eighty-six TBI patients ages 16 to 70 years (convenience sample). RESULTS: For the reliability study, the average of percentages of agreement among the items was 74.3% and the average of kappa statistics was .40. Factor analyses disclosed a maximum likelihood extraction of 5 correlated factors (F), explaining 42.2% of total variance: (F1) deficits in intentional behavior and in memory, (F2) lowering of emotional state, (F3) emotional and behavioral hyperactivation, (F4) lowering of arousal state and of attention, and (F5) language and speech problems. Results support the criterion validity of the factors. Reliability of the factor scores and internal consistencies of factors were very good. CONCLUSIONS: Results describe some important properties of the NRS-R and, through an understanding of its underlying structure and relationships with the patients' clinical characteristics, contribute to the conceptual framework of neuropsychologic impairments after TBI.

Adolescent↗
PubMed2000

A case of prosopagnosia following moderate closed head injury with left hemisphere focal lesion.

This study describes a left handed woman with prosopagnosia following traumatic brain injury with a focal lesion confined to the left-posterior hemisphere. Few cases of prosopagnosia following unilateral left hemisphere lesions have previously been reported in the literature. Corrected visual acuity was 20/70 (binocular), color vision was intact on screening, and shape detection was borderline. Impairments in higher order visual perception were evident to varying degrees on nonfacial tasks. Matching of unfamiliar faces was very slow but accurate. A marked impairment in the ability to recognize familiar faces and learn new face-name associations was evident on experimental tasks relative to the performance of healthy control subjects. In contrast, identification of characteristics of faces (gender, age) and identification and matching of facial expressions were relatively preserved. We discuss the cognitive processing stages that appear to be disrupted using Bruce and Young's (1986) model of facial recognition and perception as a framework.

Adult↗
PubMed2000

No difference in biochemical failure rates with or without pelvic lymph node dissection during radical prostatectomy in low-risk patients.

OBJECTIVES: To detect the short-term differences in biochemical relapse-free rates between patients with and without pelvic lymph node dissection (PLND). Recently, a trend has begun to omit PLND in patients undergoing radical prostatectomy considered at low risk of pelvic lymph node metastases. METHODS: The records of 1152 consecutive radical prostatectomy cases were reviewed. A total of 575 patients with favorable tumor characteristics (prostate-specific antigen [PSA] 10 ng/mL or less, Gleason score 6 or less, and clinical Stage T1 or T2) who were not receiving adjuvant or neoadjuvant therapy were divided into two groups according to whether PLND was performed (PLND group, n = 372) or omitted (no PLND group, n = 203). Proportional hazards were used to analyze the effect of age, race, family history, stage, biopsy Gleason score, initial PSA, PLND, and pathologic findings on the likelihood of biochemical failure. Biochemical failure-free survival for each group was estimated by Kaplan-Meier analysis. The mean follow-up was 38 months (range 1 to 141). RESULTS: The actuarial 4-year biochemical relapse-free rate for the PLND versus no PLND groups was 91% and 97%, respectively (P = 0.16). On multivariate analysis, PLND was not an independent predictor of outcome (P = 0.24). CONCLUSIONS: The results of our study indicate that the omission of PLND in patients with favorable tumor characteristics does not adversely affect biochemical relapse rates.

Aged↗
PubMed2000

Extent of extracapsular extension in localized prostate cancer.

OBJECTIVES: To measure the radial extent of extracapsular penetration by tumor cells, thereby providing estimates of the margins needed around target volumes. New radiotherapeutic techniques, like brachytherapy and conformal radiotherapy, irradiate small volumes and reduce the dose to periprostatic tissues. Even in the early stages of localized prostate cancer, extracapsular extension (ECE) is commonly seen. METHODS: Two hundred sixty-five consecutive radical prostatectomy specimens were analyzed for the presence of ECE. ECE was found in 92 of all cases (35%); measurements were performed in 79 of the 92 cases. A total of 98 ECE sites were evaluated in the 79 cases. The distance of tumor outside the capsule was measured in millimeters. Extension less than 0.1 mm was considered as "focal". RESULTS: The site of ECE was posterolateral in 53% of cases, lateral in 24%, posterior in 13%, and at the base in 10%. The median amount of ECE at all sites was 1. 1 mm (mean 1.7). However, the range was wide; the minimum measurable extent was 0.1 mm and the maximum 10.0 mm. The extent was within 3.8 mm for 90% of all cases. By stratifying cases with favorable and unfavorable tumors, the 90th percentiles of ECE were as follows: 3.3 mm for favorable tumors (clinical Stage T1-2, initial prostate-specific antigen 10 ng/mL or less, and biopsy Gleason score 6 or less) and 3.9 mm for unfavorable tumors (clinical Stage T3, initial prostate-specific antigen greater than 10 ng/mL, or biopsy Gleason score 7 or greater). CONCLUSIONS: Most of the ECE was at posterolateral sites. The extent of disease outside the prostate was within 4 mm in 90% of cases. Since ECE was observed in 30% to 60% of all patients with clinical Stage T1-2 prostate cancer, only 3% to 7% of all such cases would have disease extent exceeding 4 mm. The present study provides useful estimates of the amount of ECE. These estimates could be potentially used in planning the target volumes for treatment of prostate cancer with either conformal radiotherapy or brachytherapy.

Humans↗
PubMed2000

Tumors of the testis in intersex syndromes.

Patients with intersex syndrome are rare in the general population. In these patients, cryptorchid gonads that have an Y chromosome or Y chromosomal material are at risk for development of germinal and non-germinal neoplasm and non-neoplastic masses. Diagnosis of individual patients should be accurate for optimal care and risk assessment.

Adrenal Hyperplasia, Congenital↗
PubMed2000

Cognitive and linguistic correlates of children's discourse after closed head injury: a three-year follow-up.

The discourse of 91 children who had sustained severe (n = 68) or mild (n = 23) closed head injury (CHI) was examined at least three years postinjury. The groups' retellings of a narrative story were analyzed according to two domains, information and language. In comparison to the mild CHI group, the severe group produced stories characterized by reduced content and information, impaired organization, fewer words, and less complex sentences. The relationships between discourse production and the groups' performance on measures of language, executive function, memory, and processing speed were examined. Correlations were found between discourse production and general verbal ability including verbal fluency. Correlations were also found for discourse performance and executive function measures associated with problem solving and working memory. Site and extent of lesion were not useful in predicting discourse production. These findings indicate that children who sustain a severe closed head injury during early to middle childhood are at risk for persisting deficits in discourse processing and other cognitive abilities.

Adolescent↗
PubMed2000

Dissociation of frequency and recency processing from list recall after severe closed head injury in children and adolescents.

To investigate judgment of the frequency and recency of events relative to word list recall in children following closed head injury (CHI), 124 children and adolescents, including 79 severe CHI patients (mean age at test = 13.2 years), 27 mild CHI cases (mean age at test = 12.1 years), and 18 uninjured comparison subjects (mean age = 12.8 years) were studied. The mean postinjury interval was 63.6 months for the severe and 46.7 months for the mild CHI groups. The experimental tasks included estimation of the frequency of presentation of words and designs and recency judgment to select the most recently presented of two stimuli on verbal (words) and nonverbal (faces) tasks. To compare frequency and recency judgments to performance on a task which has been shown to be sensitive to CHI severity and age at test, verbal recall was tested using the California Verbal Learning Test-Children's Version. Severity of CHI (group) affected verbal recall across trials and after delays, but had no effect on estimating frequency and isolated effects on judgment of recency. Age was also primarily related to verbal recall. A subgroup of severe CHI patients with frontal lesions was impaired on delayed recall. The results are discussed in relation to previous research on the effects of CHI on processing the frequency and recency of events.

Adolescent↗
PubMed2000

Normative data for a six-trial administration of the Verbal Selective Reminding Test.

Normative data for 267 neurologically normal adults (age range 18-91) are provided for a six-trial administration of Form I of the Verbal Selective Reminding Test (VSRT; Hannay & Levin, 1985). Gender corrections were generated by age- and education-matched pair analyses of the VSRT performance of 82 males and 82 females. Normative data are grouped by seven age cohorts: 18-29, 30-39, 40-49, 50-59, 60-69, 70-79, and 80-91. A regression-based procedure is provided, so that existing delayed recall norms, based on a 12-trial administration, can be utilized, following a 6-trial administration.

Adult↗
PubMed2000

Volume of focal brain lesions and hippocampal formation in relation to memory function after closed head injury in children.

OBJECTIVES: (1) A study of verbal learning and memory in children who had sustained a closed head injury (CHI) at least 3 months earlier. (2) To relate memory function to focal brain lesion and hippocampal formation volumes using morphometric analysis of MRI. METHODS: A group of 245 children who had been admitted to hospital for CHI graded by the Glasgow coma scale (GCS), including 161 patients with severe and 84 with mild CHI completed the California verbal learning test (CVLT) and underwent MRI which was analysed for focal brain lesion volume independently of memory test data. Brain MRI with 1.5 mm coronal slices obtained in subsets of 25 patients with severe and 25 patients with mild CHI were analysed for hippocampal formation volume. Interoperator reliability in morphometry was satisfactory. RESULTS: Severity of CHI and age at study significantly affected memory performance. Regression analysis showed that bifrontal, left frontal, and right frontal lesion volumes incremented prediction of various learning and memory indices after entering the GCS score and age into the model. Extrafrontal lesion volume did not contribute to predicting memory performance. CONCLUSIONS: Prefrontal lesions contribute to residual impairment of learning and memory after severe CHI in children. Although effects of CHI on hippocampal formation volume might be difficult to demonstrate in non-fatal paediatric CHI, further investigation using functional brain imaging could potentially demonstrate hippocampal dysfunction.

Adolescent↗
PubMed2000

Neuropsychological outcome after unilateral pallidotomy for the treatment of Parkinson's disease.

OBJECTIVE: To assess the long term cognitive outcome of unilateral posteroventral pallidotomy (PVP) and the overall efficacy of the surgery. METHODS: Forty two (29 left and 13 right PVP) patients with Parkinson's disease underwent neurological and neuropsychological testing before PVP and at 3 and 12 months after PVP. The neuropsychological testing battery emphasised measures of verbal learning and memory, visuospatial abilities, speed of information processing, executive functioning, and affective functioning. RESULTS: All patients demonstrated motor improvements after surgery during their off state, and 86% of patients also showed improvements in motor functioning in their on state. Repeated measures ANOVA showed significant improvements in confrontational naming, visuospatial organisation, and affective functioning 3 months and 12 months after surgery, with inconsistent improvements in executive functioning 12 months post-PVP. Patients demonstrated a transient impairment in verbal memory, with verbal learning performance returning to baseline 12 months post-PVP after a significant decline 3 months after PVP. When three patients with lesions extending outside of the PVP were excluded from the analysis, a decline in verbal fluency performance after PVP was not found to be significant. Differences due to side of lesion placement were not found on any of the cognitive measures. CONCLUSIONS: In the largest long term follow up study reported to date, the cognitive changes found up to a year after PVP are minimal compared with the robust improvements in motor function. The findings highlight the need to investigate the relation between the specific fibre tracts affected by the lesions and cognitive outcome.

Activities of Daily Living↗
PubMed2000

Metacognition following pediatric traumatic brain injury: a preliminary study.

Metacognition is one of the cognitive processes included under the general term executive functions. The executive functions are widely held to be under the control of the prefrontal cortex, an area often damaged after severe traumatic brain injury (TBI). We examined the metacognitive processing of a group of 9 children with TBI, and a group of 9 healthy, age-matched control children. Children with TBI showed significant impairments in their accuracy of prediction of the ease with which an item would be learned and their ability to predict recall of an item after a 2-hr delay. No significant differences in recall performance between the TBI and control groups were exhibited. The results are interpreted as suggesting an impairment in metacognitive processing resulting from frontal lobe damage after TBI in children. Additional research is necessary to confirm the relation of frontal lobe pathology and severity of injury to metacognitive impairments.

Adolescent↗
PubMed1999

Corpus callosum damage and interhemispheric transfer of information following closed head injury in children.

We evaluated the relationship of corpus callosum atrophy and/or lesions on magnetic resonance imaging (MRI) to functional hemispheric disconnection following closed head injury (CHI) in 51 pediatric patients, including mild CHI, moderate to severe CHI with extracallosal lesions, and moderate to severe CHI with callosal atrophy and/or lesions. Interhemispheric transfer of information was assessed using auditory, motor, tactile, and visual tests in patients and in 16 uninjured children. Total and regional callosal areas were measured from the midsagittal MRI slice by morphometry. The corpus callosum lesion group demonstrated a greater right ear advantage on verbal dichotic listening than all other groups. Areas of the posterior corpus callosum were negatively correlated with laterality indices of verbal dichotic listening performance and tachistoscopic identification of verbal material. The relationship of corpus callosum atrophy and/or lesions to asymmetry in dichotic listening is consistent with previous investigation of posttraumatic hemispheric disconnection effects in adults.

Adolescent↗
PubMed1999

Neuropsychological outcome following unilateral pallidotomy.

Despite the findings of significantly improved motor functioning following pallidotomy for the treatment of Parkinson's disease, the cognitive sequelae following surgery have yet to be clearly defined. With increasing knowledge of the surgery's effect on frontostriatal circuits, the cognitive processes potentially affected by the procedure require further exploration to evaluate fully the efficacy of the treatment. We reviewed 10 studies on the neuropsychological outcome after pallidotomy that were published in peer-reviewed journals. A general agreement exists that pallidotomy is a relatively safe and effective treatment for ameliorating the motor symptoms of Parkinson's disease, with relatively few cognitive changes reported following surgery. However, a number of conceptual and methodological concerns, including diverse selection criteria, small sample sizes and short follow-up periods, limit the interpretation and generalizability of these findings. These concerns are discussed in detail, along with a summary of the current neuropsychological literature, suggested guidelines for the conduct of research and future research directions. The neuropsychological findings are critically reviewed and tabulated by study, cognitive domain and follow-up period, with particular emphasis on hemisphere-specific cognitive changes.

Affect↗
PubMed1999

Cognitive and behavioral sequelae of closed head injury in older adults according to their significant others.

This study examined the neurobehavioral effects of closed head injury (CHI) in older adults according to their significant others. Informants of 17 mild and moderate CHI patients > or = 50 years old when injured completed the Geriatric Evaluation of Relative's Rating Instrument, a questionnaire inquiring about the patient's cognition, affect, interpersonal relations, and daily activities. The significant others provided retrospective ratings of preinjury functioning and completed the same instrument an average of 4 and 13 months post-injury. The significant others of 10 community-residing, normal control subjects completed the questionnaire at comparable intervals between each rating. Compared with their preinjury functioning, and unlike the control subjects, patients showed declines in cognition and mood. The possible impact of these changes, including their effect on subjective burden in caregivers, is discussed.

Aged↗
PubMed1999

Declining rates of extracapsular extension after radical prostatectomy: evidence for continued stage migration.

PURPOSE: Prostate-specific antigen (PSA)-based screening is responsible for a profound clinical stage migration in newly detected prostate cancers. Extracapsular extension (ECE) is an important predictor of outcome after radical prostatectomy (RP). We examined trends in the rate of ECE for cancers detected by PSA screening in 731 RP specimens between 1987 and 1997, when screening became routine urologic practice in the United States. METHODS: The rates of ECE were examined in 311 prostates with nonpalpable (stage T1c) disease and 420 with palpable but clinically localized (stage T2) disease. Specimens were step-sectioned and examined by a senior pathologist. Rates of ECE were compared with respect to time, and logistic regression was used to identify predictors of ECE. RESULTS: The rate of ECE decreased from 81% to 36% during the 10-year observation period. Multivariateanalysis involving clinical tumor stage, preoperative serum PSA level, and Gleason score demonstrated that year of treatment was an independent predictor of ECE, with a two-fold reduction of risk occurring during the study period (P <. 001; odds ratio, 1.96; 95% confidence interval, 1.37 to 2.78). CONCLUSION: PSA screening has resulted in a downward trend in pathologic stage in clinically localized prostate cancer, independent of preoperative PSA level, tumor stage, and Gleason score. This time-dependent downward stage migration suggests the need for continuous updating of predictive nomograms and caution in interpreting differences in contemporarily treated patients compared with historical controls. Further study is needed to determine whether this trend will translate into improved disease-free survival.

Aged↗