The effects of neurocognitive remediation on executive processing in patients with schizophrenia.
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Approaches to cognitive remediation have differed across studies. Most of the larger studies have concentrated on group treatments designed without the benefit of recent laboratory-based studies. The current study describes a randomized trial of an intensive cognitive remediation program involving individual daily sessions of 1 hour for up to 3 months. It targets executive functioning deficits (cognitive flexibility, working memory, and planning) that are known to be problematic in people with schizophrenia. Procedural learning, as well as the principles of errorless learning, targeted reinforcement, and massed practice, was the basis of the intervention. The program was compared with an alternative therapy (intensive occupational therapy) to control for some of the effects of therapeutic contact. Some improvements in cognition followed both therapies. A differential effect in favor of cognitive remediation therapy was found for tests in the cognitive flexibility and the memory subgroups. There was a trend for those receiving atypical antipsychotic medication to benefit more from cognitive remediation for tests of cognitive flexibility. Although there were no consistent changes in symptoms or social functioning between groups, if improvement in cognitive flexibility tasks reached a threshold then there is some evidence that social functioning improved, even over the short duration of the trial. In addition, cognitive remediation differentially improved self-esteem. This study supports the view that cognitive remediation can reduce cognitive deficits and that this reduction may affect social outcome, at least in the short term. (+info)
Should schizophrenia be treated as a neurocognitive disorder?
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The search is on for meaningful psychopharmacological and cognitive/behavioral interventions for neurocognitive deficits in schizophrenia. Findings in this area are emerging rapidly, and in the absence of integrating frameworks, they are destined to emerge chaotically. Clear guidelines for testing neurocognitive interventions and interpreting results are critical at this early stage. In this article, we present three models of increasing complexity that attempt to elucidate the role of neurocognitive deficits in schizophrenia in relation to treatment and outcome. Through discussion of the models, we will consider methodological issues and interpretive challenges facing this line of investigation, including direct versus indirect neurocognitive effects of antipsychotic medications, selection of particular neurocognitive constructs for intervention, the importance of construct validity in interpreting cognitive/behavioral studies, and the expected durability of treatment effects. With a growing confidence that some neurocognitive deficits in schizophrenia can be modified, questions that seemed irrelevant only a few years ago are now fundamental. The field will need to reconsider what constitutes a successful intervention, what the relevant outcomes are, and how to define treatment efficacy. (+info)
Outcome of schizophrenia in relation to brain abnormalities.
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This article reviews the 21 studies that investigated possible relationships between structural brain abnormalities and outcome in schizophrenia. Fifteen studies used computer tomography to visualize brain morphology. In these studies, images were obtained of the ventricles but not of specific brain regions. The remaining six studies used magnetic resonance imaging, examining possible relationships between outcome, ventricular size, and specific brain regions. One out of two studies found relationships between brain structure and outcome. The data suggest that the extent of ventricular enlargement in patients with schizophrenia may be related to outcome. No clear relationship between outcome and changes in specific brain regions was found. Apart from considerations about the methodology of measuring different brain regions, the procedure used to measure outcome is important. Outcome, as it is assessed at various points during the course of illness, may be variable and seems to fluctuate during the first 10 to 15 years of disease. Significantly, to date no studies relating outcome to brain structure have used patient samples with a duration of illness longer than 15 years. (+info)
Benign rolandic epilepsy (BRE) is a partial idiopathic epilepsy of childhood presenting with a nocturnal seizure and with a typical EEG showing centrotemporal spike and multifocal or generalized sharp slow waves. Although normal neurological and intellectual development are expected in BRE, it is not infrequent to detect subtle defects in neuropsychological functions and neuromotor development. This study included 20 cases of BRE diagnosed according to the criteria of ILAE. The patients underwent several tests of neuropsychological functions as well as detailed neurological examination and the results were compared statistically to normal controls. In the patient group, a family history of language delay or learning disability (P < 0.005), presence of consanguinity (P < 0. 05), dyspraxia in the lower extremities (to imitation) (P < 0.05), difficulties in go-no-go test (P < 0.001), as well as some problems related to language such as dysprosody (P = 0.05), minor motor deficits in the left (P < 0.05) and right upper extremity (P < 0.05) were significantly more frequent compared to the control group. One should be rather guarded against the prognosis in BRE with respect to the higher cortical functions and neurodevelopmental problems. (+info)
Impaired declarative memory for emotional material following bilateral amygdala damage in humans.
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Everyday experience suggests that highly emotional events are often the most memorable, an observation supported by psychological and pharmacological studies in humans. Although studies in animals have shown that nondeclarative emotional memory (behaviors associated with emotional situations) may be impaired by lesions of the amygdala, little is known about the neural underpinnings of emotional memory in humans, especially in regard to declarative memory (memory for facts that can be assessed verbally). We investigated the declarative memory of two rare patients with selective bilateral amygdala damage. Both subjects showed impairments in long-term declarative memory for emotionally arousing material. The data support the hypothesis that the human amygdala normally enhances acquisition of declarative knowledge regarding emotionally arousing stimuli. (+info)
Left frontal transcranial magnetic stimulation reduces contralesional extinction in patients with unilateral right brain damage.
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It has been demonstrated previously that transcranial magnetic stimulation (TMS) of the sensorimotor cortex can induce transient suppression of the perception of cutaneous near-threshold stimuli from fingers of the contralateral hand in normal individuals. One explanation accounting for deficits in the exploration of contralateral space following a unilateral hemispheric lesion refers to a loss of the normal interhemispheric balance, with a resultant hyperactivation of the unaffected hemisphere due to the release of reciprocal inhibition by the affected one. In order to verify this hypothesis, we investigated the effects of a TMS-induced transient dysfunction of the normal hemisphere upon contralateral tactile extinctions in two groups: (i) 14 right brain-damaged patients and (ii) 14 left brain-damaged control patients. Single-pulse TMS was delivered to frontal and parietal scalp sites of the unaffected hemisphere after an interval of 40 ms from an electrical unimanual or bimanual digit stimulation. In right brain-damaged patients, left frontal TMS significantly reduced the rate of contralateral extinctions compared with controls. After left parietal TMS, the number of extinctions was comparable to the baseline. This pattern of increased sensitivity to cutaneous stimulation ipsilateral to TMS was not observed in left brain-damaged control patients. In this group, right hemisphere TMS did not significantly alter the recognition of bimanual stimuli delivered to the space contralateral to the lesion. The suggestion is made that extinctions produced by right brain damage may be dependent on a breakdown in the balance of hemispheric rivalry in directing spatial attention to contralateral hemispace, so that the unaffected hemisphere generates an unopposed orienting response to the side of the lesion. The mechanisms whereby the left frontal TMS transiently ameliorates these deficits may involve stimulus-induced removal of a left frontal-right parietal transcallosal inhibitory flow, although interactions at subcortical levels cannot be excluded. (+info)
Inducible nitric oxide synthase is an endogenous neuroprotectant after traumatic brain injury in rats and mice.
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Nitric oxide (NO) derived from the inducible isoform of NO synthase (iNOS) is an inflammatory product implicated both in secondary damage and in recovery from brain injury. To address the role of iNOS in experimental traumatic brain injury (TBI), we used 2 paradigms in 2 species. In a model of controlled cortical impact (CCI) with secondary hypoxemia, rats were treated with vehicle or with 1 of 2 iNOS inhibitors (aminoguanidine and L-N-iminoethyl-lysine), administered by Alzet pump for 5 days and 1. 5 days after injury, respectively. In a model of CCI, knockout mice lacking the iNOS gene (iNOS(-/-)) were compared with wild-type (iNOS(+/+)) mice. Functional outcome (motor and cognitive) during the first 20 days after injury, and histopathology at 21 days, were assessed in both studies. Treatment of rats with either of the iNOS inhibitors after TBI significantly exacerbated deficits in cognitive performance, as assessed by Morris water maze (MWM) and increased neuron loss in vulnerable regions (CA3 and CA1) of hippocampus. Uninjured iNOS(+/+) and iNOS(-/-) mice performed equally well in both motor and cognitive tasks. However, after TBI, iNOS(-/-) mice showed markedly worse performance in the MWM task than iNOS(+/+) mice. A beneficial role for iNOS in TBI is supported. (+info)
Disturbance of cerebral function in people exposed to drinking water contaminated with aluminium sulphate: retrospective study of the Camelford water incident.
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OBJECTIVE: To establish whether people exposed to drinking water contaminated with 20 tonnes of aluminium sulphate in the Camelford area of Cornwall in the south west of England in July 1988 had suffered organic brain damage as opposed to psychological trauma only. DESIGN: Retrospective study of affected people. PARTICIPANTS: 55 affected people and 15 siblings nearest in age to one of the group but who had not been exposed to the contaminated water were studied. MAIN OUTCOME MEASURES: Various clinical and psychological tests to determine medical condition and anxiety levels in affected people. Assessment of premorbid IQ (pFSIQ) with the national adult reading test, a computerised battery of psychomotor testing, and measurement of the difference in latencies between the flash and pattern visual evoked potentials in all participants. RESULTS: The mean (SE) pFSIQ was above average at 114.4 (1.1). The most sensitive of the psychomotor tests for organic brain disease was the symbol digit coding (SDC) test (normal score 100, abnormal <85). PARTICIPANTS performed less well on this test (54.5 (6.0)) than expected from their pFSIQ (P<0.0001) and a little less poorly on the averaged less discriminating tests within the battery (86.1 (2.5), P<0.0001). In a comparison with the 15 sibling pairs (affected people's age 41.0 (3.3) years v sibling age of 42.7 (3.1) years (P=0.36) the exposed people had similar pFSIQ (114.7 (2.1)) to their siblings (116.3 (2.1), (P=0.59) but performed badly on the symbol digit coding test (51.8 (16.6)) v (87.5 (4.9) for siblings, P=0.03). The flash-pattern differences in exposed people were greater than in 42 unrelated control subjects of similar age (27.33 (1.64) ms v 18. 57 (1.47) ms, P=0.0002). The 15 unexposed siblings had significantly better flash-pattern differences than their affected siblings (13.4 (2.4) ms v 29.6 (2.9) ms, P=0.0002). No effect of anxiety could be shown on these measurements from the analysis of the anxiety scores of exposed people. CONCLUSION: People who were exposed to the contaminated water at Camelford suffered considerable damage to cerebral function, which was not related to anxiety. Follow up studies would be required to determine the longer term prognosis for affected individuals. (+info)