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Biomedical subjects

H S Levin

Publications and source records attributed to H S Levin.

At least 163 records · Page 9Linked to original sources

Hemispheric disconnection syndrome persisting after anterior cerebral artery aneurysm rupture.

Hemispheric disconnection syndrome is a rarely reported sequela of aneurysm rupture. Serial neurobehavioral examinations of such a patient after clipping of a right pericallosal artery that had bled into a large portion of the corpus callosum disclosed defects in interhemispheric transfer of information and competitive movements between the left and right extremities. Although the patient's postoperative memory deficit subsequently resolved, his disconnection syndrome persisted and was primarily responsible for his disability despite otherwise normal neurological findings. We studied a second patient with a hematoma in the genu of the corpus callosum secondary to an arteriovenous malformation (AVM). Although the second patient also exhibited postoperative memory problems, her hemispheric disconnection symptoms were minimal and commensurate with a more circumscribed corpus callosum lesion. Neurobehavioral sequelae of aneurysm or AVM rupture involving the anterior circulation, which may be overlooked in the absence of a detailed examination, can produce persistent disability in many patients.

Adult↗

Neurobehavioral outcome following minor head injury: a three-center study.

The majority of hospital admissions for head trauma are due to minor injuries; that is, no or only transient loss of consciousness without major complications and not requiring intracranial surgery. Despite the low mortality rate following minor head injury, there is controversy surrounding the extent of morbidity and the long-term sequelae. The authors postulated that consecutively admitted patients who fulfilled research diagnostic criteria for minor head injury and who were carefully screened for antecedent neuropsychiatric disorder and prior head injury would exhibit subacute cognitive and memory deficits that would resolve over a period of 1 to 3 months postinjury. To evaluate this hypothesis, the neurobehavioral functioning of 57 patients was compared within 1 week after minor head injury (baseline) and at 1 month postinjury with that of 56 selected control subjects at three medical centers. Quantified tests of memory, attention, and information-processing speed revealed that neurobehavioral impairment demonstrated at baseline by all means of measurement generally resolved during the first 3 months after minor head injury. Although nearly all patients initially reported cognitive problems, somatic complaints, and emotional malaise, these postconcussion symptoms had substantially resolved by the 3-month follow-up examination. The data suggest that a single uncomplicated minor head injury produces no permanent disabling neurobehavioral impairment in the great majority of patients who are free of preexisting neuropsychiatric disorder and substance abuse.

Adolescent↗

Magnetic resonance imaging and computerized tomography in relation to the neurobehavioral sequelae of mild and moderate head injuries.

Twenty patients admitted for minor or moderate closed-head injury were studied to investigate the relationship between magnetic resonance imaging (MRI) and neurobehavioral sequelae. The MRI scans demonstrated 44 more intracranial lesions than did concurrent computerized tomography (CT) scans in 17 patients (85%); most of these lesions were located in the frontal and temporal regions. Estimates of lesion volume based on MRI were frequently greater than with CT; however, MRI disclosed no additional lesions that required surgical evacuation. Neuropsychological assessment during the initial hospitalization revealed deficits in frontal lobe functioning and memory that were related to the size and localization of the lesions as defined by MRI. Follow-up MRI and neuropsychological testing at 1 month (13 cases) and 3 months (six cases) disclosed marked reduction of lesion size paralleled by improvement in cognition and memory. These findings encourage further investigation of the prognostic utility of MRI for the clinical management and rehabilitation of mild or moderate head injury.

Adolescent↗

Neurobehavioral functioning and magnetic resonance imaging findings in young boxers.

In a prospective investigation of neurobehavioral functioning in young boxers, 13 pugilists and 13 matched control subjects underwent tests of attention, information-processing rate, memory, and visuomotor coordination and speed. The results disclosed more proficient verbal learning in the control subjects, whereas delayed recall and other measurements of memory did not differ between the two groups. Reaction time was faster in the boxers than in the control subjects, but no other differences were significant. Ten subjects in each group were retested 6 months later and exhibited improvement in their neuropsychological performance as compared to baseline measurements. However, there were no differences in scores between the boxers and the control subjects at the follow-up examination or in the magnitude of improvement from baseline values. Magnetic resonance imaging, which was performed in nine of the boxers, disclosed normal findings.

Adult↗

CBF gradient changes elicited by visual stimulation and visual memory tasks.

Normal volunteers underwent three successive scans of regional cerebral blood flow (rCBF) using the 133Xe inhalation technique during visual stimulation, a recognition memory task and a resting state defined by high EEG alpha content. Since the stimulation was virtually identical in both non-rest conditions, we were able to separate the CBF pattern resulting from simple stimulation and that resulting from the cognitive (recognition memory) component alone. These turned out to have very nearly opposite effects on the normal anterior-to-posterior resting state gradient: the sensory component diminished the gradient, while the cognitive component exaggerated it. It is suggested that these normative data can be of clinical value in the study of cerebral recovery/reorganization following post-traumatic amnesia.

Adult↗

Memory self-ratings and objective test performance in a normal elderly sample.

Self-rated decline in memory relative to estimated abilities at age 60 was investigated in a group of 88 normal elderly subjects age 60 to 90. Self-ratings of storage, retrieval, attention/concentration, remote memory, and depression formed a factor which was orthogonal to objective measures of memory function. Self-rated remote memory was also associated with objective measures of recent/remote memory, and self-rated depression was additionally related to objective measures of attention/concentration.

Aged↗

Assessment of the accuracy of regression equations proposed for estimating premorbid intellectual functioning on the Wechsler Adult Intelligence Scale.

This investigation examined the accuracy of regression equations proposed by Wilson et al. (1978) for estimating premorbid intellectual quotients (IQs) on the Wechsler Adult Intelligence Scale (WAIS). Actual Verbal, Performance, and Full Scale IQs in a sample of 69 neurologically normal adults were compared against their estimated premorbid levels. While the equations provided an adequate overall fit to the data, actual IQ values at the extremes of the WAIS Scales were found to be most susceptible to underestimation (high actual IQ values) or overestimation (low actual IQ values). The clinical importance of this finding and possible applications of the equations are discussed.

Adolescent↗

Organization of verbal memory after severe closed-head injury.

Verbal learning and memory over repeated trials were studied in 12 severely closed-head-injured patients and a matched control group of 10 subjects for three types of word lists, i.e., unrelated, related but unclustered, and clustered words. Verbal memory was facilitated in both groups by presentation of related words in a clustered format. However, the performance of head-injured patients was characterized by low levels of recall, clustering, and subjective organization. In addition, they had a larger number of intrusive errors. The results provide evidence for some preserved semantic memory following closed-head injury and their implications for rehabilitation are discussed.

Adult↗

Age-related differences in recognition memory for pictures.

This study provided a normative data base for the Continuous Recognition Memory Test and also investigated age-related differences in recognition memory for pictures in a sample of 299 normal subjects (age range 10-89). Data analysis revealed that older subjects consistently set a lower response criterion (Cx), resulting in a significantly higher number of within-class false alarms. Older subjects also displayed significantly lower sensitivity (d'). Changes in sensitivity were attributed to both an increase in false alarms and a concurrent decrease in hits in subjects over 65. Analysis of the likelihood ratio (beta) revealed no significant change across age groups.

Adolescent↗

Effects of oral physostigmine and lecithin on memory and attention in closed head-injured patients.

In view of the evidence for the role of the central cholinergic pathways in memory and preliminary studies suggesting alteration of neurotransmitters after severe head injury, we completed a double-blind, placebo-controlled study of combined oral physostigmine and lecithin. Sixteen survivors of moderate to severe closed head injury who had unequivocal memory deficit were studied during the course of inpatient rehabilitation. Although the results generally indicated no difference in the effects of the physostigmine-lecithin combination as compared to lecithin alone, sustained attention on the continuous performance test was more efficient under physostigmine than placebo when the drug condition occurred first in the crossover design. Further investigation of neurotransmitter manipulation is warranted in patients with traumatic brain injury.

Administration, Oral↗

Magnetic resonance imaging after 'diffuse' nonmissile head injury. A neurobehavioral study.

The diagnosis of diffuse brain injury is considered when computed tomography provides no evidence of an intracranial mass lesion in acute nonmissile head injury. Magnetic resonance imaging (MRI) of a young woman who had sustained severe diffuse brain injury five years earlier disclosed multifocal lesions involving the frontal, temporal, parietal, and occipital lobes. We report the results of serial neurobehavioral assessment for clinical correlation with the brain lesions visualized by MRI. Pending confirmation of our findings in a series of patients studied by MRI during the acute and chronic stages of recovery from head injury, we postulate that the presence and type of neurobehavioral sequelae of diffuse brain injury are related to the intrahemispheric loci of predominantly white matter lesions and degeneration.

Adult↗

Visual agnosia contrasted with visual-verbal disconnection.

Serial neuropsychological findings are contrasted in two cases: one with a syndrome of visual agnosia, the other with a disorder resulting from visual-verbal disconnection. Both patients were impaired in confrontation naming of objects and pictures, but the patient with visual-verbal disconnection was able to perform tasks of color-object matching and pantomime recognition, whereas the patient with visual agnosia could not do so, demonstrating a failure to establish meaningful nonverbal visual-visual association. Additionally, the performance of the patient with visual agnosia reflected an evolution from the apperceptive to associative forms of the disorder, suggesting that the various impairments of visual identification form a continuum of related disorders.

Agnosia↗

Selective reminding test: an examination of the equivalence of four forms.

Four forms of a selective reminding test were administered to 20 male and 20 female subjects 1 week apart in one of four orders determined by a Latin square. On many of the dependent measures, Form 1 was significantly more difficult than the other three forms, which were equivalent in difficulty. For many of the measures, performance on the first test administered was significantly lower than that on the third and fourth tests administered. Performance on the 2nd, 3rd, and 4th tests administered was similar. Males made significantly more intrusions than females. Interclass correlation coefficients ranged from .414 to .654. Implications for clinical use of the selective reminding tests are discussed.

Adolescent↗

Sensitivity of age-decline resistant ("hold") WAIS subtests to Alzheimer's disease.

WAIS age-decline-resistant ("hold") and age-decline-sensitive ("don't hold") subtests were both effective in discriminating 25 patients with Alzheimer-type dementia (DAT) from 25 normal elderly subjects who were matched on age, education, and sex. We found that global ratings of severity of dementia correlated significantly with the WAIS Information and Digit Symbol subtests, but not with memory test scores. These data indicate that (1) the practice of estimating premorbid ability based on current "hold" test performance should be abandoned, and (2) the utility of memory tests is greatest for initial diagnosis of DAT, while WAIS cognitive variables may be more useful in evaluating DAT severity.

Aged↗

Impairment of olfactory recognition after closed head injury.

To investigate the effects of closed head injury (CHI) on olfactory identification, we administered a test of olfactory naming and forced choice recognition to 52 CHI patients who had no evidence of anosmia. The Olfactory Identification Test consisted of 'scratch and sniff' labels of familiar nonirritant odorants. In comparison with a normal control group (n = 19) of similar age, olfactory naming and recognition were impaired in the CHI series, particularly in patients with moderate or severe head injury. The presence of a haematoma or contusion in the frontal/temporal region was also related to impaired olfactory recognition. We suggest that nonmissile head injury can produce at least a partial impairment of olfactory recognition despite relatively preserved olfactory detection.

Adolescent↗

Impairment of remote memory after closed head injury.

Evidence of partial retrograde amnesia for episodic memories of no personal salience was found in head injured patients (n = 10) tested during posttraumatic amnesia or shortly after its resolution (n = 10), but there was no selective preservation of the earliest memories. In contrast, head injured patients tested during posttraumatic amnesia exhibited relatively preserved retention of early autobiographical memories which they recalled as accurately as oriented head injured patients. It is suggested that reminiscence of salient, early events increases their resistance to partial retrograde amnesia and contributes to the observed temporal gradient.

Adolescent↗

Neurobehavioral outcome after gunshot wounds to the head in adult civilians and children.

To assess the quality of long term outcome of civilian gunshot wounds to the head after intensive neurosurgical management, particularly with regard to the possibility of subtle problems due to diffuse injury, we administered neuropsychological tests to six survivors (four adults and two children) at about 1 year after injury. Five patients were moderately disabled, and one patient achieved a good recovery. Residual neurobehavioral sequelae were present in all cases. Defects in long term memory for new information were the most common sequelae, whereas the persistence of linguistic and visuospatial deficits was related to the hemispheric lateralization of injury. In comparison with the outcome reported for patients with closed head injuries who had similar Glasgow coma scale scores, our patients exhibited more severe impairment due to significant focal brain injuries and less evidence of diffuse damage.

Adult↗