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Biomedical subjects

J M Gold

Publications and source records attributed to J M Gold.

At least 55 records · Page 3Linked to original sources
PubMed1993

A topographical study of senile plaques and neurofibrillary tangles in the hippocampi of patients with Alzheimer's disease and cognitively impaired patients with schizophrenia.

Neuropsychological testing of elderly schizophrenic patients reveals that a significant portion of this population exhibit varying degrees of cognitive impairment. Since Alzheimer's disease is the most common cause of dementia in geriatric patients, we investigated whether the cognitive decline observed in schizophrenia is the result of degenerative changes analogous to those characteristic of Alzheimer's disease. For this purpose, the number and distribution of senile plaques and neurofibrillary tangles were mapped in the hippocampi of 10 cognitively impaired schizophrenic patients, 10 patients with Alzheimer's disease, and 10 patients with dementia not attributed to either schizophrenia or Alzheimer's disease. In Alzheimer's disease, degenerative changes invariably predominated in the CA1 subfield, subiculum, and proisocortex. By contrast, findings characteristic of Alzheimer's disease were virtually never observed in the hippocampi of schizophrenic and other cognitively impaired patients. In some patients with Alzheimer's disease, the presence of senile plaques in the molecular layer of the dentate gyrus suggested the existence of an underlying entorhinal cortex lesion. Similar dentate gyrus pathology was never found in any of the other patients. The authors conclude that cognitive impairment in schizophrenia is not the result of degenerative changes analogous to those found in Alzheimer's disease.

Aged↗
PubMed1993

Handedness in twins with schizophrenia: was Boklage correct?

Boklage's report of increased non-right handedness among monozygotic twins with schizophrenia has been cited as evidence to support an association of abnormal brain lateralization with the development of schizophrenia. The present study found no such association. Two previous attempts to replicate Boklage's findings (Luchins et al. 1980; Lewis et al. 1989) also reported little support. Studies of twin handedness do not appear to support an association of brain lateralization and schizophrenia.

Adolescent↗
PubMed1993

Learning and memory in monozygotic twins discordant for schizophrenia.

Learning and memory were assessed in 24 monozygotic (MZ) pairs of individuals discordant for schizophrenia or delusional disorder and seven normal pairs of MZ twins. On declarative memory tasks, the affected group displayed a pattern that might best be characterized as dysmnesic in that they performed significantly worse than the discordant unaffected group on story recall, paired associated learning, and visual recall of designs, but they learned over time, had relatively preserved recognition memory, and did not show profoundly accelerated rates of forgetting. Effortful, volitional retrieval from the lexicon, measured by verbal fluency, was also compromised in the affected group. On the other hand, procedural learning of the motor skill in a pursuit rotor task was relatively intact in the affected group. Comparisons of the normal group and unaffected group indicated that the latter group had very mild impairments in some aspects of episodic memory, namely, immediate and delayed recall of stories and delayed recall of designs. It is highly unlikely that the impairments observed in the affected group can be attributed to differences in genome, family environment, socioeconomic circumstance, or educational opportunity, as all of these were controlled by the twin paradigm. Rather, the impairments appear to be related to the intercession of disease. The neuropsychological profile is consistent with frontal lobe and medial temporal lobe dysfunction, as noted in this sample as well as other samples of schizophrenic singletons. Significant correlations between many measures of memory and global level of social and vocational functioning within the discordant group were also found. Thus difficulties in rapidly acquiring new information and propitiously retrieving old information may burden patients with schizophrenia in many of the transactions of everyday life.

Adolescent↗
PubMed1993

Implicit memory in patients with schizophrenia and normal controls: effects of task demands on susceptibility to priming.

Two experiments employing a stem-completion priming paradigm are reported. The first of these compared patients with schizophrenia (SC) to normal controls and demonstrated impaired implicit memory in the SC patients under task conditions identical to those used previously with other patient groups. The second experiment was designed to examine the effects of implicit task demands and stimulus selection upon susceptibility to priming, with a second group of SC patients and normal controls. Results indicated that the ability to carry out the task demands of the implicit condition (i.e., generate completions for word-stems) was inversely related to susceptibility to priming in both the SC patients and controls. In addition, the baseline probability of specific completions was found to be correlated with the ease of priming those completions, suggesting a possible mechanism for producing statistical dissociations between implicit and explicit retrieval conditions with this paradigm. These findings suggest that certain implicit tasks may be susceptible to nonmemory psychological influences that have not been adequately investigated to date; these may be responsible for "normalizing" the performance of amnesic patients as well as producing statistical dissociations from explicit memory tasks.

Adult↗
PubMed1993

Contrasts between patients with affective disorders and patients with schizophrenia on a neuropsychological test battery.

OBJECTIVE: This study was designed to ascertain the degree and specificity of cognitive impairments in patients with schizophrenia and patients with affective disorders. METHOD: Cognitive function was assessed with a neuropsychological test battery in consecutively admitted patients with schizophrenia (N = 57), unipolar depression (N = 29), and bipolar disorder (N = 16). RESULTS: The performance of the schizophrenic group was significantly below that of the groups with affective disorders on measures of attention and psychomotor speed, verbal and visual memory, and problem solving and abstraction. IQ was lower in the schizophrenic group and appeared to have deteriorated from a normal premorbid level that was not different from that of the affective disorder groups, as determined by the Wide Range Achievement Test--Revised reading test, a putative measure of premorbid intelligence. When IQ was controlled, differences between the groups in problem solving and visual memory remained. Psychiatric symptoms had a larger impact on test performance in the affective disorder groups than in the schizophrenic group. CONCLUSIONS: These results suggest that patients with schizophrenia perform systematically worse on cognitive measures than patients with affective disorders, which is consistent with their generally poorer outcome. The results also indicate that schizophrenia and affective disorders are qualitatively distinguishable in neuropsychological terms, given differences in apparent intellectual deterioration, profiles of cognitive impairment, and associations between cognitive performance and psychopathology.

Adult↗
PubMed1993

The effect of clozapine on cognition and psychiatric symptoms in patients with schizophrenia.

Psychiatric symptoms and cognition were assessed in 13 patients with schizophrenia, one patient with schizoaffective disorder, and one patient with psychosis not otherwise specified while they received a conventional neuroleptic and again after an average of 15 months on clozapine. Despite improvements in psychiatric symptoms, attention, memory, and higher-level problem-solving were essentially unchanged. This suggests that certain cognitive deficits are relatively independent of psychotic symptoms in schizophrenia, and are probably central and enduring features of the disorder. Cognitive disability appeared to have been rate-limiting in the sample's rehabilitation, as patients' social and vocational adjustment remained marginal during the study. We also observed that treatment with clozapine was associated with a decline in some memory functions; the potent anticholinergic properties of the drug may have been responsible for this.

Clozapine↗
PubMed1993

Cognitive deficits in schizophrenia.

There is accumulating evidence that impairment of neuropsychological and basic information processing abilities is an important feature of schizophrenia. Despite the size of this literature and persistent controversy on many specific points, there are several key reliable findings that are relevant to everyday clinical practice. First, impaired cognition is a fundamental aspect of the illness. It can be detected in nearly every case when appropriate controls are used and is often present from before the onset of major signs of the illness. Impairment of most functions is stable even in the face of clinical-symptomatic change. Thus, impairment is not an epiphenomenal feature of symptomatic state, although it is probably a good measure of the overall severity of the illness. In contrast to the perspective of many clinicians, the florid symptoms of schizophrenia are quite unlikely to be the cause of most cognitive deficits. Impairments of attention, memory, and problem solving appear to have particular neurobiologic significance. Although impairments of these functions are not diagnostic of schizophrenia, they are observed frequently and provide converging evidence that schizophrenia is fundamentally an illness of the brain and that cognitive impairment is a symptom domain in its own right, with as much importance for understanding and treating the disorder as positive or negative behavioral symptoms.

Attention↗
PubMed1992

Visual orienting in schizophrenia.

Patients with schizophrenia demonstrate a variety of attentional impairments which have proven difficult to relate to specific neural systems. Posner et al. (1988) reported an asymmetric slowing of right visual field orienting in schizophrenia similar to that observed in patients with parietal lesions. We examined the visual orienting performance of 19 patients and controls using two different versions of the Posner paradigm. In overall ANOVAs we found main effects of group, cue condition, and delay interval. However, we did not observe any main effect of visual field or interactions involving visual field. There was some evidence of an asymmetric cost of invalid cues similar to those reported by Posner et al. The bulk of data suggests bilateral attentional deficits.

Adult↗
PubMed1992

Dichotic listening in monozygotic twins discordant and concordant for schizophrenia.

Emotional and neutral word versions of the fused rhymed words dichotic listening test were administered to members of 18 pairs of monozygotic twins discordant for schizophrenia, 7 pairs concordant for schizophrenia, and 7 pairs of normal twins. In the discordant group, affected twins had smaller right ear advantages than did their unaffected cotwins for neutral words. The difference was completely attenuated with the presentation of emotional words or in less powerful between-group comparisons that included twins concordant for schizophrenia and normal twins. It is unlikely that this finding reflects an abnormality in the lateralized representation of language, both because we did not find a correlation between handedness scores and dichotic listening scores and because emotional stimuli normalized results. The finding may reflect abnormalities in the allocation of attention for priming language centers in the left hemisphere. 'At risk' subjects, i.e., the unaffected members of the discordant pairs, did not differ significantly from normal monozygotic twins on measures of dichotic listening.

Adult↗
PubMed1992

Forms of memory failure in schizophrenia.

Effortful and automatic memory task performances were examined in 36 schizophrenic patients and 18 normal control Ss. Tasks included free recall, recognition, and frequency estimation. Patients demonstrated impairment in recall, in recognition, in semantic encoding, and in frequency estimation. Deficits were observed across tasks despite differences in attentional demands. The results suggest a basic compromise of memory function, which is consistent with recent neuroimaging evidence of structural or physiological abnormalities in frontal and temporal lobe structures in schizophrenia.

Adult↗
PubMed1992

Release from proactive interference: determinants of performance and neuropsychological correlates.

The Wickens (1970) modification of the Brown-Peterson short-term memory task has been used to investigate release from proactive interference (PI) in a number of memory-impaired groups. It has been suggested that failure to release from PI is observed only in patients with compromise of both memory and 'frontal-lobe' functions. The present study examined performance on this paradigm in patients with schizophrenia (SC), a neuropsychiatric disorder which typically includes both frontal and mnemonic impairments. Patients with SC were found to exhibit significantly less release from PI than normal controls. It was determined through correlational analyses that average Trial 1 performance on this task could predict performance on all subsequent trials, indicating that 'release' from PI may measure the same psychological process as the Brown-Peterson task, which does not include a release condition. Trial 1 performance in the SC group was correlated with a wide range of neuropsychological measures, but after the effect of full scale IQ was partialled out, only correlations with measures of memory and measures of frontal-lobe function remained significant. The results support previous formulations of the neuropsychological concomitants of release from PI, but suggest that failure to release on this paradigm may be secondary to a significant compromise of the ability to perform the Brown-Peterson task. It is proposed that the experimental design constraints necessary to elicit a failure to release from PI in any patient group may limit the utility of this measure, and that Brown-Peterson performance may be a more reliable index of the neuropsychological functions involved.

Adult↗
PubMed1991

Tardive dyskinesia: neuropsychological, computerized tomographic, and psychiatric symptom findings.

Prior studies have suggested that schizophrenic patients with tardive dyskinesia (TD) have an unusual incidence of cognitive impairment, structural brain abnormalities, and negative symptoms. Twenty-seven schizophrenic patients with TD and an equal number of age-, gender-, and education-matched schizophrenic controls were studied. Each patient received neuropsychological testing, psychiatric symptom ratings, and most had cerebral computed tomography (CT) scans. Patients with TD significantly differed from controls on only 1 of 23, cognitive measures, and the overall group performance profiles were highly similar. No differences were observed on symptom ratings. Patients with TD had significantly smaller ventricular-brain ratios (VBRs) than controls. These data fail to support an association of TD with global measures of "organicity." Abnormal movements may result from specific dysfunction within the more purely motor circuits of the basal ganglia without compromising other neural systems involved in cognitive processing.

Adult↗
PubMed1990

Neuropsychological assessment of monozygotic twins discordant for schizophrenia.

A comparison of monozygotic twins discordant for schizophrenia controls for genetic variance and reduces variance due to environmental circumstances, thus serving to highlight differences due to phenotypic-related variables. In this study, we assessed 16 such twin pairs on a wide range of neuropsychological tests. The affected twins tended to perform worse than their unaffected counterparts on most of the tests. Deficits were especially severe on tests of vigilance, memory, and concept formation, suggesting that dysfunction is greatest in the frontotemporal cortex. While manifest symptoms were not highly associated with neuropsychological scores, global level of functioning was. To address the issue of genetic liability, we also compared the sample of discordant unaffected twins with a sample of seven pairs of normal monozygotic twins. No significant differences between the groups were found for any neuropsychological test. In fact, the results suggest that neuropsychological dysfunction is a consistent feature of schizophrenia and that it is related primarily to the clinical disease process and not to genetic or nonspecific environmental factors.

Adult↗
PubMed1990

The effects of haloperidol on thought disorder and IQ in schizophrenia.

The impact of haloperidol treatment on the Wechsler Adult Intelligence Scale (WAIS) and the Thought Disorder Index was investigated in a group of 19 patients with schizophrenia tested both before and after 26 days of treatment with haloperidol. Thought disorder scores declined significantly over the course of treatment and fewer patients demonstrated severe forms of thought disorder at the end of the trial. WAIS performance improved significantly but the magnitude of change was consistent with the literature on expected practice effects. Thought disorder scores were negatively correlated with IQ at baseline, but not at Day 26. The results suggest a partial dissociation of thought disorder and other cognitive functions in schizophrenia.

Adult↗
PubMed1988

Stereoselective recognition in phospholipid monolayers.

During the past ten years we have investigated the stereochemistry of intermolecular interactions in monolayers at the air-water interface, a field which has never been developed explicitly before to our knowledge. Although we demonstrated clear enantiomeric and diastereomeric interactions for a number of chiral surfactants, we found no evidence whatsoever for stereoselective interaction in dipalmitoylphosphatidylcholine (DPPC) monolayers or vesicles by standard monolayer techniques, differential scanning calorimetry or ultra-highfield NMR. The present article extends these observations to dimyristoyl- and dilauroylphosphatidylcholine. Results from dynamic surface tension studies are also reported. In no case could chiral recognition be demonstrated using the 95% confidence limit as the criterion. In our previous study of DPPC mixtures with another chiral surfactant the question arose as to whether chiral interactions could be transmitted through intervening phospholipid molecules. This question is addressed by examining the force-area curves for a variety of mixed monolayers composed of chiral surfactants and phospholipids. We conclude that the chiral discrimination observed in some of these mixed monolayers is due to the direct interaction of chiral centers, and not due to the transmission of chirality from one stereocenter to the next through intermediate achiral molecules. Finally, we will consider the question of why phospholipids, the most ubiquitous of natural chiral surfactants, should show so little chiral discrimination in view of the wide occurrence of high stereoselectivity in many natural processes.

Dimyristoylphosphatidylcholine↗
PubMed1987

The role of verbalization in the Rorschach response process: a review.

Traditional Rorschach theory has consistently overlooked the linguistic aspect of the response process. Most conceptualizations focus on the perceptual and cognitive aspects of the process, never examining the subject's need to find a linguistic representation for the inner, perceptual process. This review examines the traditional formulations and suggests that new research from information-processing, neuropsychological, and dual-coding memory theory paradigms offer new possibilities for Rorschach research that would incorporate an appreciation of the unique cognitive demand of the test--the linking of percept with language.

Cognition↗
PubMed1986

Bilateral toxoplasma retinochoroiditis in a patient with acquired immune deficiency syndrome.

A 32-year-old patient with acquired immune deficiency syndrome (AIDS) was evaluated for bilateral visual loss accompanied by uveitis, vitritis and retinochoroiditis. Diagnostic vitrectomy was performed on the right eye, and the diagnosis of ocular toxoplasmosis made. Central nervous system involvement was suggested by ring enhancing lesions on CT scan. The patient improved on a pyrimethamine, sulfadiazine and clindamycin, but succumbed to disseminated toxoplasmosis when treatment was discontinued.

Acquired Immunodeficiency Syndrome↗