Search PubMed⌕ Search

Biomedical subjects

M J Cohen

Publications and source records attributed to M J Cohen.

At least 37 records · Page 2Linked to original sources
PubMed1997

Neuropsychological profiles of children diagnosed as specific language impaired with and without hyperlexia.

This study compared the neuropsychological profiles of 46 children with Specific Language Impairment (SLI) and 16 children with SLI and Hyperlexia (SLI + H). The results indicated that the essential feature of Hyperlexia is Specific Language Impairment and not reading disability. Thus, Hyperlexia would be best conceptualized as a subgroup of Developmental Language Disorder rather than as a subgroup of Developmental Dyslexia. Further, the SLI + H group exhibited significantly better developed visual/spatial memory which, along with average visual perceptual skills, appears to be the major contributing factor to their elevated word recognition and spelling ability. Finally, it should be noted that both groups of children exhibited decreasing performance on tasks of immediate auditory/verbal memory as the language/semantic demands of the memory task increased. This finding appears to be the result of a limited capacity for immediate verbal processing and not the result of a deficit in verbal learning and recall.

Journal Article↗
PubMed1996

Treatment for depigmentation following burn injuries.

Partial-thickness burn injuries frequently heal with pigmentary changes. Occasionally, permanent depigmentation is observed, especially in areas such as the hands, fingers and wrists. This article reports our surgical technique and our success in using it to treat depigmentation after burn injuries. This technique consists of superficial dermabrasion of the depigmented region, followed by transplantation of melanocytes vie epithelial sheet grafts. With this technique, 30 separate surgical procedures have been performed on 21 patients. The follow-up period for these patients has ranged from 2 weeks to 94 months with an average of 17 months. The skin-graft take has been good to excellent in all patients. The colour match has been good or excellent in all but one patient. No complications have been observed. This procedure has consistently and reliably improved the disfigurement from depigmentation in all of the patients we have treated.

Adult↗
PubMed1996

Visuospatial information processing in intoxicated, recently detoxified, and long-term abstinent alcoholics.

Visuospatial information processing has been shown to be particularly sensitive to acute alcohol intoxication and chronic alcohol abuse. This study extended previous studies by determining if recently detoxified alcoholics recover visuospatial processing after long-term abstinence. If visuospatial function returns to the level displayed by intoxicated alcoholics, then the deficit displayed by recently detoxified alcoholics may represent a short-term adjustment due to the removal of alcohol. However, if the visuospatial deficit remains in long-term abstinent alcoholics, then the superior processing of the intoxicated alcoholic could reflect a normalization of processing produced by alcohol ingestion. Twenty active and 40 recovering alcoholic male volunteers participated. The active alcoholics were seen intoxicated at the time of admission into a 21-day alcohol detoxification and treatment program. Of the recovering alcoholics, 20 were designated as recently detoxified alcoholics and had just completed the same treatment program. The remaining 20 long-term abstinent alcoholics had completed alcohol treatment several years previously with no relapse. Participants selected were similar in general demographic status, alcohol treatment histories, and psychomotor ability. Two main effects emerged from the results: First, the intoxicated alcoholics displayed visuospatial learning that was superior to the learning of alcoholics recently detoxified or abstinent for several years; a second principal finding was nearly identical visuospatial learning displayed by recently detoxified and long-term abstinent alcoholics.

Adult↗
PubMed1996

Changes in the P300 component of the tactile event-related potential following spinal cord injury.

Previous studies have demonstrated that significant changes in action or behaviour (function) and morphology occur in the deafferentated and the adjacent somatosensory cortex after amputation or experimental spinal cord injury. These studies have shown changes in somatotopic mappings and somatosensory perception as well as altered evoked responses. The purpose of the present study was to examine the potential effect of these changes on cognitive processes using the tactile P300 event-related potential (ERP) in a spinal cord injured (SCI) population. The P300 ERP has been associated with more complex cognitive functioning such as selective attention, memory, and stimulus evaluation rather than earlier sensory processing of stimuli. Three groups consisting of healthy control, paraplegic, and tetraplegic subjects participated in a transcutaneous electrical stimulation 'oddball' task. Results indicate that all groups were successful in maintaining target counts and produced significantly larger P300 amplitudes with longer latencies to target trials compared to non-target trials. The SCI groups, however, produced P300 ERPs for both targets and non-targets that were significantly reduced in amplitude compared to the control group. In the case of the tetraplegia patients, the P300 was almost abolished. No differences in latency of the P300 was observed between any of the groups.

Adolescent↗
PubMed1996

Problem solving and coping strategies in persons with spinal cord injury who have and do not have a family history of alcoholism.

Recovery from spinal cord injury (SCI) requires substantial coping by the patient. The coping process reflects both physical adjustment to permanent biological changes and psychological acceptance of these changes and their limitations to function. A history of family alcoholism appears as one prominent factor in persons with SCI. This factor is associated with several personality characteristics that could directly influence adjustment to the injury. As an initial exploration of this premise, the present study examined the relationship between family history of alcoholism and coping processes in SCI patients. Ninety volunteer subjects were selected from inpatient and outpatient populations of a Veterans Affairs spinal cord injury service. Based on structured interviews and responses to a standardized questionnaire, one group of 45 subjects, designated Family History Positive (FHP), were from families in which the father and at least one other second generation relative were alcoholics. The 45 Family History Negative (FHN) subjects were from families with no alcoholism subjects were from families with no alcoholism history. Once assigned to a group, subjects completed the Ways of Coping Questionnaire. Compared to subjects with no family alcoholism history, FHP subjects reported significantly more use of constructive coping strategies as measured by the Ways of Coping Questionnaire, but their alcohol use and anti-social behaviors indicated that they were less effective in actual coping behaviors. Persons with SCI and a family history of alcoholism reported utilization of coping methods that differ from those used by patients with SCI and no family alcoholism history. From the perspective of treatment and rehabilitation, this finding suggests the need to consider different therapeutic approaches for these groups.

Adaptation, Psychological↗
PubMed1996

Validity of the Auditory Continuous Performance Test in differentiating central processing auditory disorders with and without ADHD.

The use of continuous performance tasks has been examined as a potential measure for clinical/laboratory identification of Attention-deficit/hyperactivity disorder. The present study compared the performance of 30 children, 26 boys and 4 girls ranging in age from 9-0 to 12-11, with central auditory processing disorders (CAPD) who did not meet criteria for coexisting ADHD with the performance of children with CAPD coexisting with ADHD (CAPD/ADHD) on the Auditory Continuous Performance Test (ACPT). In interpreting the results, the variability as well as the actual counts for correct responses and total errors were considered. Results indicated limited potential for the use of the ACPT in the differential diagnosis of ADHD. Implications of the results as well as considerations for future research are discussed.

Attention↗
PubMed1996

Sensory detection and pain thresholds in spinal cord injury patients with and without dysesthetic pain, and in chronic low back pain patients.

In an effort to understand the mechanisms involved in dysesthetic pain syndrome (DPS) in spinal cord injury (SCI) patients, four groups of 13 subjects each--SCI subjects with DPS, SCI subjects without pain, chronic low back pain subjects, and control subjects--were examined for sensory detection and pain thresholds at forearm, neck, and rostral trunk areas. Results indicated that the SCI pain group had significantly lower pain thresholds at all skin sites, compared to the SCI no-pain and chronic low back pain groups, and at the rostral trunk skin site, compared to the control group. The SCI pain group also showed a lower sensory detection threshold at the rostral trunk skin site than did the SCI no-pain group. Equally important, the SCI no-pain group had detection and pain thresholds significantly higher than those of the control group. The results suggest fundamental differences in somatosensory processing when DPS is or is not a consequence of SCI.

Adult↗
PubMed1995

Early cytoskeletal changes following injury of giant spinal axons in the lamprey.

The spinal cord of the larval sea lamprey contains identified giant axons that readily regenerate following spinal transection. In this study, we used serial light and electron microscopy to analyze the early ultrastructural consequences of axotomy in the proximal stumps of these axons near the lesion site. Axotomy results in two types of striking ultrastructural changes: 1) changes associated with the degeneration of axoplasm and subsequent retraction of the cut axon from the lesion and 2) changes associated with the early stages of axonal regeneration. Degenerative changes include the disruption of mitochondria to form large vacuoles, the collapse of neurofilaments into closely packed masses (condensed filamentous cores; CFCs), and the appearance of amorphous electron-dense bodies (dense granular masses; DGMs). Events associated with regeneration include the disappearance of vacuoles, DGMs, and CFCs and the appearance of small, sprout-like projections from the axon stump. Thus, we show that degenerative and regenerative events can be clearly separated from one another in identified axons, unlike the situation in the central nervous systems of amniote vertebrates such as mammals.

Animals↗
PubMed1995

Vitiligo: treatment by dermabrasion and epithelial sheet grafting.

BACKGROUND: Several years ago, a surgical technique for treating depigmentation resulting from burn injuries was developed. The treatment of this problem in the patient with burns was consistently successful. OBJECTIVE: The purpose of this study was to investigate the usefulness of the surgical technique developed for patients with burn injuries to determine whether the same technique would be useful in treating patients with vitiligo whose skin did not repigment with conventional medical treatments. METHODS: Five patients with stable vitiligo were treated. The epithelium of the vitiliginous areas was removed by dermabrasion. The dermabraded area was then reepithelialized with epithelial sheet grafts sufficient to cover the entirety of the vitiliginous dermabraded region. RESULTS: Each operation was successful. Scarring did not develop in the repigmented or donor site regions. The final color match has been good to excellent in all patients. CONCLUSION: Good to excellent repigmentation was observed in each patient. We believe our results, to date, are more successful than the results of other procedures reported previously in the medical literature.

Adult↗
PubMed1995

Auditory P3 event related potentials (ERP) and brainstem auditory evoked responses (BAER) after spinal cord injury in humans.

Previous studies have observed altered somatotopic sensory fields after experimental deafferentation in animals as well as enhanced somatosensory evoked potentials and altered cortical motor pathways following spinal cord injury (SCI) in humans. These observations indicate that cortical reorganization may occur subsequent to SCI. In earlier work, we have observed attenuated amplitudes for both tactile P3 and auditory N1/P2 orienting event-related potentials (ERP) in spinal cord injured groups. These results suggest that the reorganization process may have functional perceptual and cognitive consequences. In an effort to determine if deafferentation affects the P3 ERP using stimuli other than somatosensory, we measured brain activity from central recording sites during an auditory "oddball" task. Additionally, we obtained brainstem auditory evoked responses (BAER) in order to assess subcortical primary auditory pathways as well. Results show that the SCI groups produced significantly attenuated N1/P2 complexes and P3 when compared to controls. Also, the quadriplegic group exhibited increased latencies of the P3 at frontal and central sites. There were no differences between groups in BAER results. These findings suggest that primary subcortical auditory information processing stages remain intact after SCI although later stages may be significantly altered.

Adult↗
PubMed1995

Spatial learning deficits in preschool children of alcoholics.

When compared with nonalcoholics, chronic alcoholics and their children show significant deficits in the processing of visuospatial information. The literature supports two possible explanations of a visuospatial processing deficit in the child of an alcoholic (COA) when compared with the child of a nonalcoholic (NCOA). Either the COA may suffer cognitive disruptions produced by personal and social development within an alcoholic family, or the COA may inherit or very early develop alterations in central nervous system substrates of neurocognitive operations. The present study was designed to continue our examinations of visuospatial information processing differences and the source of these differences in COAs. An evaluation of very young subjects not only assisted in providing a more complete view of visuospatial processing across the COA's life span, but also helped explain why the deficit occurs. Thirty matched male and female preschool children, aged 35.8-51.6 months, served as participants. Fifteen children were COAs from families in which the biological father and two other relatives had an alcoholism history. The other group of 15 children were NCOAs. Each child performed a visuospatial learning task similar to the task used in previous studies of older COAs. The visuospatial learning performance of the preschool COAs was inferior to that displayed by preschool NCOAs. The patterns of correct, error, and nonresponses emitted by the preschool COAs and the interrelationships of these data closely resembled the data from our previous studies of older children, adolescent, and adult COAs.(ABSTRACT TRUNCATED AT 250 WORDS)

Attention↗
PubMed1995

Academic achievement and attention-deficit/hyperactivity disorder in children with left- or right-hemisphere dysfunction.

The neuropsychological investigation of learning disabilities has contributed much toward a more complete understanding of how the hemispheres are functionally organized and how differences in this functional organization may affect differential patterns of learning and behavior. It has been suggested that right-hemisphere dysfunction increases the likelihood of difficulty with attention/concentration and of overactive behavior, and interferes with arithmetic calculation more readily than reading and spelling. The present study examined the influence of right-versus left-hemisphere neuropsychological dysfunction on academic achievement and attention using two groups of children with learning disabilities and a group of nondisabled children. Results provide limited support for the hypothesis that the right hemisphere subserves attention and concentration. No support was found for the hypothesis that right-hemisphere deficits are more frequently associated with deficient arithmetic calculation, as opposed to reading and spelling performance. Results are discussed in the context of previous research on right-hemisphere dysfunction and learning disabilities.

Aptitude Tests↗
PubMed1995

Incidence and characteristics of spinal cord injured patients with a family history of alcoholism.

OBJECTIVE: Of the many factors that affect the occurrence of and rehabilitation from spinal cord injury, alcohol use and abuse are particularly prominent. Persons with a family history of alcoholism are at greater risk for alcohol abuse and alcoholism. Preliminary data show a much higher than normal proportion of these persons in the spinal cord injured population. If these data are reliable, they may show that family history of alcoholism is a premorbid or comorbid factor to the occurrence of accidents that results in catastrophic injuries. Our investigation represented an evaluation of this premise. METHOD: Male volunteer subjects (N = 100) were selected from inpatient and outpatient populations of a Veterans Affairs spinal cord injury service. Subjects received a comprehensive interview and completed two standardized questionnaires and a general information form designed to evaluate their past and present use of alcohol and the use of alcohol by their parents and relatives. RESULTS: The incidence (45%) of spinal cord injured patients with a family history of alcoholism was over four times that found in the general population. Spinal cord injured subjects with a family history of alcoholism reported significantly more problems with alcohol before, at the time of, and after their injury. CONCLUSIONS: The data suggest a relationship between the predisposition to alcoholism and accidents that result in catastrophic injury.

Accidents↗
PubMed1994

Receptive prosody in children with left or right hemisphere dysfunction.

Different groups of researchers have ascribed different roles and functions to the right cerebral hemisphere. In particular, it has been suggested that right hemisphere dysfunction interferes with the prosodic aspects of language. The present study examined this hypothesis using two groups of children identified through neuropsychological evaluation as having left or right hemisphere dysfunction and a control group of normal children. Specifically, the performances of the three groups on measures of receptive prosody were compared. Results provided support for the hypothesis that, in children, the right hemisphere subserves functions related to the prosodic aspects of language. Conclusions are interpreted in the context of previous research on right hemisphere language functions in children and implications for future research are discussed.

Adolescent↗