Search PubMed⌕ Search

Biomedical subjects

E Stip

Publications and source records attributed to E Stip.

At least 37 records · Page 2Linked to original sources
PubMed1998

The functional neuroanatomy of major depression: an fMRI study using an emotional activation paradigm.

An important issue regarding the neural basis of major depression is whether the functional brain changes associated with the affect disturbance seen in this syndrome are similar to those that accompany transient sadness in normal subjects. To address this question, we carried out an fMRI study using an emotional activation paradigm. Brain activity associated with passive viewing of an emotionally laden film clip aimed at inducing a transient state of sadness was contrasted with that associated with passive viewing of an emotionally neutral film clip in patients suffering from unipolar depression and in normal control subjects. Results showed that transient sadness produced significant activation in the medial and inferior prefrontal cortices, the middle temporal cortex, the cerebellum and the caudate in both depressed and normal subjects. They also revealed that passive viewing of the emotionally laden film clip produced a significantly greater activation in the left medial prefrontal cortex and in the right cingulate gyrus in depressed patients than in normal control subjects. These findings suggest that these two cortical regions might be part of a neural network implicated in the pathophysiology of major depression. Taken together, these results strongly support the view that activation paradigms represent an extremely useful and powerful way of delineating the functional anatomy of the various symptoms that characterize major depression.

Adult↗
PubMed1998

Atypical memory performance in an autistic savant.

This study explored the mechanisms underlying the hypermnesia of an autistic savant (NM) through three experiments. The first two served to assess whether absence of interference was responsible for NM's exceptional list memory. The third investigated the type of cues used in recall. Results indicated absence of retroactive interference but presence of slight proactive interference in list recall of proper names. Normal interference effects were found, however, in list recall of common nouns. Exceptional performance was also demonstrated in a missing-name task involving spatial and verbal recall cues. The findings suggest that the outstanding episodic memory presented by some savant persons with autism might be related to an abnormally high resistance to interference.

Adolescent↗
PubMed1998

[Cerebellar degeneration following acute lithium intoxication].

Lithium is a neurotoxin with a particular affinity for the cerebellum. The risk of permanent neurotoxic sequelae of lithium is increased by the concomitant use of certain conventional neuroleptics. We report two new cases of lithium neurotoxicity; one received lithium alone, not in combination with a neuroleptic. Both cases showed severe cerebellar atrophy on brain CT and MRI. Additional factors such as dehydration, systemic infection, other medications, or rapid correction of frequently-coexisting hyponatremia may contribute to the risk of lithium neurotoxicity. We discuss possible pathophysiologic mechanisms and preventive measures.

Antipsychotic Agents↗
PubMed1996

Proper name hypermnesia in an autistic subject.

The case study of an autistic "savant" subject with person names hypermnesia is presented. NM's performance in memorizing person names is compared to that of normal controls, IQ-matched controls, and one overtrained control. The data show a selective hypermnesia for both the free recall of person names and the recognition of faces. Recall of common names and of biographical informations linked to faces is unremarkable. NM's hypermnesia is restricted to list learning as low performance is observed in face-name learning tasks. A comparison of the data with that of the overtrained control indicates that training is not responsible for NM's pattern of results. These findings, when combined with previous results involving proper names, demonstrate a double dissociation between proper names and other types of semantic and referential information. However, aspects of NM's performance pattern are more compatible with a network model of proper names than with a sequential model. We propose that the contextual regularity of proper names in ecological situations can be responsible for their high memorization by NM.

Adult↗
PubMed1996

[Capgras syndrome: evolution of the hypotheses].

OBJECTIVE: to trace the evolution of hypotheses concerning Capgras' syndrome. METHODS: The data consist of slightly over 60 studies published between 1866 and 1994 which were selected in terms of their innovative nature and relevance to the clinical description of the syndrome and to psychodynamic, neurological and neuropsychological interpretations. RESULTS: Two partially overlapping major stages can be identified in the evolution of hypotheses regarding the mechanisms of the syndrome. The 1st, beginning in 1923, is characterized by the predominance of psychodynamic interpretations. The 2nd, resulting from the observation of organic dysfunctions in a high percentage of cases, is distinguished by the advent of neurological interpretations, and by a few mixed hypotheses. CONCLUSIONS: Overall, this review highlights the broad diversity of viewpoints concerning the syndrome. It will be used as a basis for the following study, which is designed to show that it is possible to test each of the viewpoints experimentally.

Capgras Syndrome↗
PubMed1996

[Capgras syndrome: open perspectives for cognitive neuropsychology].

OBJECTIVE: To examine the way in which certain concepts regarding the physiopathology of Capgras' syndrome (1) have been tested neuropsychologically. METHODS: Data consist of approximately 30 studies selected for their relevance to the cerebral stages of face processing in patients with schizophrenia, patients with Capgras' syndrome and normal subjects. RESULTS: Study of this work shows: a) that with respect to patients, authors have focused on the stage of treatment corresponding to the facial recognition phase per se; b) but that it is also possible to study the phase corresponding to knowledge and beliefs relative to individuals and to evaluate the existence of the cleavage proposed by numerous psychodynamicians. CONCLUSIONS: Views from the field of neuropsychology, like those from the field of psychodynamics, can therefore be tested. By offering a means of developing testable predictions in experimental protocols, cognitive neuropsychology methods will, in short, make it possible to reject erroneous concepts and demonstrate accurate ones. Limited here to the example of Capgras' syndrome, we advocate that the same methods be applied to Capgras' syndrome as to each symptom of schizophrenia.

Capgras Syndrome↗
PubMed1996

The heterogeneity of memory dysfunction in schizophrenia.

OBJECTIVE: To characterize the memory dysfunction of schizophrenic patients. METHOD: The components of the human memory system are described, and then a review of the various memory deficits identified among patients suffering from schizophrenia is presented. Finally, an overview of the latest developments in the comprehension of schizophrenia and a discussion on certain proposals advanced by various researchers in the field intended to shed light on the disorder is provided. RESULTS: Schizophrenia appears to be an amalgamation of many different disorders. No single model for identifying the disorder has been able to encompass every aspect of schizophrenia. CONCLUSION: Future studies will need to consider new ways of selecting and grouping schizophrenic patients.

Brain Mapping↗
PubMed1996

Differential effects of D2- and D4-blocking neuroleptics on the procedural learning of schizophrenic patients.

OBJECTIVE: To illustrate the differential effects of D2- and D4-blocking neuroleptics on the procedural learning of patients with schizophrenia. METHOD: Twenty-nine schizophrenic patients were divided into 3 groups according to their pharmacological treatment: 1) drug naive, 2) haloperidol, and 3) clozapine. They were all assessed on clinical and procedural measures, the latter being the mirror drawing task. RESULTS: All groups showed progressive learning over the successive trials, and drug-naive patients performed better than the other groups. Patients in the haloperidol group showed many fluctuations over trials, suggesting difficulty in the progressive automation of the task. Such fluctuations did not occur in the clozapine group, but performances per se were worse than in the other groups during the learning trials. Automation of the task occurred at the same point (second block of trials) for all groups. CONCLUSION: These results suggest that D2- and D4-blocking neuroleptics do not similarly affect striatal dependent procedural learning in schizophrenia.

Adult↗
PubMed1996

The effect of risperidone on cognition in patients with schizophrenia.

OBJECTIVE: To evaluate the effect of risperidone on cognitive functions after both 6 weeks and 6 months of treatment and to determine whether any improvement on neuropsychological function relates to improvement in psychopathology. METHOD: Patients' psychiatric and extrapyramidal symptoms were assessed while they were receiving classical neuroleptic treatment and adjunctive medications. Patients were then reassessed after changing to a new treatment of risperidone. RESULTS: During treatment with risperidone, schizophrenic patients displayed improved performance mainly on attentional components, specifically, selective attention and alertness. CONCLUSION: In patients who were given risperidone, there was a positive correlation between improvement in psychopathology and improvement in cognitive tests of explicit memory and alertness.

Adult↗
PubMed1996

Memory impairment in schizophrenia: perspectives from psychopathology and pharmacotherapy.

OBJECTIVE: To describe the concept of memory impairment in schizophrenia and the clinical implications of this concept in terms of patient assessment and neuroleptic drug use. METHOD: Narrative literature review. RESULTS: Individuals suffering from schizophrenia normally exhibit some degree of memory impairment. Recent work in psychopathology indicates that the impairment is comprehensive, involving the sensory, short-term, and long-term memory stores. Memory impairment appears to be a primary symptom of the disease, and its underlying causes are likely organic. A number of medications, however (for example, traditional neuroleptics and drugs that have pronounced anticholinergic activity), may cause or exacerbate impairment. In particular, anticholinergic agents used to treat extrapyramidal symptoms, a common complication of neuroleptic drugs, appear to have a deleterious effect on memory. CONCLUSIONS: Memory impairment is an important consideration in the clinical assessment and management of patients with schizophrenia. The use of atypical antipsychotics like risperidone appears to have no impact on memory function; because risperidone is associated with a low incidence of extrapyramidal side effects, it can obviate the need for anticholinergic medications-thus offering greater hope of nondebilitative intervention. The advent of medications that are safer (on cognition) could also lead to generally better outcomes by facilitating compliance with drug regimens and rehabilitation programs.

Amnesia↗