Experimental and clinical neuropsychological measures of prefrontal dysfunction in schizophrenia.

Eighteen chronic schizophrenia patients and 14 controls were given tests that have been linked primarily to ventral (orbitofrontal) or to dorsolateral prefrontal dysfunctions in neurological patients and in nonhuman animal Ss having discrete frontal lesions. Schizophrenia patients were significantly impaired on object alternation and delayed alternation tasks but not on classical delayed response (DR). Schizophrenia patients performed well on the classical version of the DR task and their DR performance correlated significantly with measures of sustained attention. Future research is needed to interpret the contributions of attention, interference, and memory load to neuropsychological performance in schizophrenia. Additional studies are required to determine whether the frontal deficits reflect diffuse brain damage, circumscribed prefrontal damage, or damage in other brain regions having prefrontal connections. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parietal lobe syndrome and schizophrenia: Comparison of neuropsychological deficits.

Investigated reported communalities in the perceptual impairments and body image distortions found after parietal lobe lesions and in schizophrenia. To compare these 2 syndromes, 15 patients with lesions of the parietal lobe and 15 patients with schizophrenia were tested on a neuropsychological battery designed to assess deficits in proprioception, tactile functions, and body image experience. Control groups consisted of 15 normal persons and of a series of 15 brain-injured cases in which the parietal lobe had been spared. Results indicate that both schizophrenic and parietally damaged Ss showed significant impairments in weight-discrimination measures of proprioceptive acuity when compared to the control brain-injured and normal Ss. No significant differences among groups were found on a comparable tactile size-estimation task, but the group with parietal injury exhibited a significant deficit in tactile sensory perception on the Finger Agnosia Test. Only the schizophrenic group showed evidence of disturbed body image when reality factors of body dysfunction were taken into account in the brain-injured patients. It is concluded that persons with schizophrenia and parietal lobe damage share a deficit in proprioception that may be based on different neurological substrates leading to (a) tactile impairments in cases with parietal damage, and (b) body-image disturbance in schizophrenia. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The paradox of normal neuropsychological function in schizophrenia.

Mounting evidence suggests that compromised neurocognitive function is a core feature of schizophrenia. However, some studies have found neuropsychologically normal schizophrenia patients. To address this apparent contradiction, we blindly rated individual neuropsychological profiles of 75 schizophrenia patients and 91 control participants on the basis of methods developed by L. J. Seidman, S. V. Faraone, W. S. Kremen, J. R. Pepple, M. J. Lyons, and M. T. Tsuang (1993). Almost one-quarter of the patients were classified as neuropsychologically within normal limits (WNL). Despite significantly worse neuropsychological performance, WNL patients had higher estimated premorbid ability than did controls. Compared to a subset of controls matched on overall neuropsychological function, WNL patients had higher estimated premorbid ability and current IQs. Our results favor the view that even neuropsychologically normal schizophrenia patients have compromised cognitive function relative to their presumed expected or premorbid level of intellectual ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological performance and positive and negative symptoms in schizophrenia.

Examined cognitive functions in 11 positive-symptom (mean age 36 yrs), 10 negative-symptom (mean age 33.8 yrs), and 23 mixed-symptom (mean age 31.4 yrs) schizophrenics; 15 bipolar patients (mean age 34.7 yrs); and 12 normal controls (mean age 34.8 yrs) to explore the relation between symptoms and performance. Ss were administered a neuropsychological test battery including the Purdue Pegboard, the Revised Visual Retention Test, and the Block Design subtest of the Wechsler Adult Intelligence Scale—Revised (WAIS—R). Group comparisons revealed generalized deficits in schizophrenics. Positive-symptom schizophrenics scored below normal Ss and negative-symptom Ss on 2 measures tapping verbal memory. Multiple regression analyses revealed that negative symptom ratings were inversely associated with performance on visual-motor tasks, whereas positive symptoms were inversely associated with verbal memory performance. Findings are not consistent with the notion that cognitive deficits are uniquely associated with negative symptoms. Instead, results suggest that there may be specific cognitive correlates of both the positive and negative symptom dimensions. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Olanzapine: efficacy in treating the positive and negative symptoms of schizophrenia

In the second of this series of updates on recent advances in medication, RICHARD GRAY summarises trials into the novel antipsychotic olanzapine, which has been shown to compare well to haloperidol, and is now widely used for treating schizophrenia and related psychoses.     

Expectations for communication with positive and negative subtypes of older adults

The study uses a recently-developed scale for eliciting perceptions, expectations, and evaluations of intergenerational communication. As predicted, it is found that younger adults expect to experience more anxiety, receive more complaining, and receive lower levels of attunement from an older adult who is portrayed as "despondent" than one who is portrayed as a "perfect grandparent." In addition, younger adults with more negative attitudes toward older adults expect to experience more negative effect, anxiety, and communication apprehension, to feel more compassion for the older adult, and to receive lower levels of attunement and more complaining from the older adult than those with more positive attitudes. Surprisingly, younger adults with higher levels of young age identification expect to experience lower levels of apprehension, more attunement from the older adult, and to feel more compassion for the older adult than those with lower levels of age identity. These findings are discussed in terms of theoretical models of intergenerational communication, in particular the communication predicament model. In addition, younger people's feelings of having "helped" an older person are discussed in the context of intergroup theory.     

Another view of schizophrenia subtypes. A report from the international pilot study of schizophrenia

We studied respiratory mechanics in young volunteers before and after 5-wk training programs limited to the ventilatory muscles. Four strength trainers (S) performed repeated static maximum inspiratory and expiratory maneuvers against obstructed airways. Four endurance trainers (E) performed voluntary normocarbic hyperpnea to exhaustion. Subjects spent 30-45 min each day in these exercises, 5 days a week. Four control subjects (C) did no training. We attempted to minimize the effect of learning. S increased pressure maximums by about 55%, but vital capacity and total lung capacity by only about 4%. Initially all subjects could sustain hyperpnea at about 81% of their control 15-s maximum voluntary ventilation (MVV) for 15 min; E increased this to about 96% and increased their MVV by 14% as well. No other statistically significant changes were recognized in any group. We conclude that ventilatory muscle strength or endurance can be specifically increased by appropriate ventilatory muscle training programs.     

Anhedonia, positive and negative affect, and social functioning in schizophrenia

This study examines the relationship between anhedonia and the trait dimensions of positive affect (PA) and negative affect (NA) in schizophrenia. The relationship between poor social functioning in schizophrenia and these individual differences in affectivity is also examined. Schizophrenia outpatients (n = 37) and normal controls (n = 15) were assessed at a baseline evaluation and again approximately 90 days later. Consistent with the hypothesized decrease in hedonic capacity in schizophrenia, patients reported significantly greater physical and social anhedonia and less PA than controls. However, the schizophrenia group also reported significantly greater NA and social anxiety than did controls. In support of the dispositional view of these individual differences in affectivity, trait measures demonstrated test-retest reliability, and group differences between the schizophrenia group and controls were stable over the 90-day followup period. Within the schizophrenia group, physical and social anhedonia were comparably negatively correlated with trait PA; however, social but not physical anhedonia was significantly positively correlated with NA and social anxiety. Poor social functioning in the schizophrenia group was associated with greater physical and social anhedonia and greater NA and social anxiety. Alternatively, greater trait PA was related to better social functioning. These findings indicate that schizophrenia is characterized by both low PA and elevated NA and that these affective characteristics are a stable feature of the illness. The results also suggest important links between affect and social functioning in schizophrenia.     

Validity of specific subscales of the positive and negative symptom scales in older schizophrenia outpatients

The principal natural food colorants used in modern food manufacture are anthocyanins, betalains, carotenoids, chlorophylls, riboflavin and caramel. Carotenoids (carotenes and xanthophylls) occur naturally in some foods such as carrots, red tomatoes, butter, cheese, paprika, palm oil, corn kernels, marigold petals, annatto, and red salmon. Carotenoids (alpha- or beta-carotene and xanthophylls) are excellent antioxidants and inhibit some types of cancers. In the present study, we used the Salmonella typhimurium tester strain YG1024 in the plate-incorporation test to examine the antimutagenicity of xanthophylls extracted from Aztec Marigold (Tagetes erecta) on 1-nitropyrene (1-NP) mutagenicity. Further, we investigated the effect of lutein on DNA-repair system of tester strain YG1024, using a preincubation test. The possible mechanism of lutein on 1-NP mutagenicity was studied by comparing the absorption spectrum of lutein, 1-NP and lutein plus 1-NP. In a dose-response curve of 1-NP, the mutagenic potency was 4317 revertants/nmol, and the dose of 0.06 microgram of 1-NP/plate was chosen for the antimutagenicity studies. Lutein and xanthophylls from Aztec Marigold (pigments for poultry and human use) inhibited mutagenicity of 1-NP in a dose-dependent manner. Lutein and the pigments were not toxic to the bacteria at the concentrations tested (0.002, 0.02, 0.2, 2.0 and 10 micrograms/plate). The percentages of inhibition of 1-NP mutagenicity were 72%, 92% and 66.2% for lutein (10 micrograms/plate), pigment for poultry use (10 micrograms/plate) and pigment for human use (2 micrograms/plate), respectively. Lutein had no effect on the DNA-repair system of strain YG1024. A new peak was detected at 429 nm when lutein was added at 1-NP, and it was stable throughout the incubation time. The results suggest that the major mechanisms of lutein against 1-NP mutagenicity is the potential formation of a complex between lutein and 1-NP, which could limit the bioavailability of 1-NP.     

Soft signs and neuropsychological performance in schizophrenia

S-2150 is a new 1,5-benzothiazepine derivative that inhibits [3H]diltiazem and [3H]WB4101 bindings to the membrane of rat tissue. The effects of S-2150 on ischemia/ reperfusion injury were studied in anesthetized rats. S-2150 reduced the myocardial infarct size (IS) induced by 20-min coronary artery occlusion followed by reperfusion. To evaluate reperfusion-induced ventricular tachycardia and fibrillation (VT, VF), we occluded the coronary artery for 4 min and then reperfused it. The incidence of arrhythmia was blocked by S-2150, and this effect offered protection against cardiac death. Prazosin did not modify the IS or incidence of reperfusion arrhythmias, but combined treatment with a noneffective dose of diltiazem showed significant cardioprotective effects. We also compared the direct effects of S-2150 and diltiazem on cardiac function and coronary perfusion flow using isolated rat hearts. Both drugs decreased mechanical function and increased coronary flow, with S-2150 being less cardiodepressive and more vasodilatory. S-2150 is cardioprotective at doses comparable to hypotensive doses even though its cardiodepressant effect is much weaker than that of diltiazem. This effectiveness may be partly explained by its dual characteristics: blocking the Ca channel and the alpha 1-adrenoceptor.     

Serotonergic function and negative and depressive symptomatology in schizophrenia and major depression

BACKGROUND: Serotonergic abnormalities are found in both major depressive disorder (MDD) and schizophrenia. Depressive symptoms commonly occur alongside the negative or defect symptoms in schizophrenia and antiserotonergic drugs may be particularly effective in their treatment. We wished to explore whether these symptoms could be distinguished biologically by directly comparing serotonergic function in these two illnesses. METHOD: Fifteen patients with MDD and 13 patients with schizophrenia underwent testing with the specific serotonin releasing agent D-fenfluramine (D-FEN). Prolactin and cortisol responses were measured to ascertain central serotonergic function. Individual patient results were compared with their own carefully matched control to correct for the effect of age, sex, weight and menstrual cycle, before the two patient groups were then compared. RESULTS: Prolactin responses differed significantly between the two patient groups, being lower in MDD patients and higher in schizophrenia patients than their individually matched controls. Cortisol responses did not differ. Within the schizophrenia group, increased serotonergic function correlated positively with depressive symptoms, but there was no such correlation with defect symptoms. Depressive scores were negatively correlated with the presence of negative symptoms in the schizophrenic group. CONCLUSIONS: Schizophrenia and MDD have distinct and opposite neuroendocrine responses to D-FEN. There is no evidence that depressive symptoms in these two conditions have a common serotonergic basis. Moreover, these responses distinguished between negative and depressive symptoms in our schizophrenic group.     

A neuropsychological investigation into frontal lobe involvement in dementia of the Alzheimer type.

Studied frontal lobe involvement in dementia of the Alzheimer type (DAT) using 4 neuropsychological tests (verbal fluency, delayed alternation, subject-ordered pointing, and the Wisconsin Card Sorting Test) in 25 patients suffering from DAT and 12 age-matched normal controls. The first 3 tasks demonstrated that a frontal lobe impairment is present at all stages of the disease and is related to disease severity. Results offer information regarding the frontal component in DAT by providing neuropsychological support for the findings of an anterior pathology as reflected in blood flow and metabolism studies. The need for suitable frontal tasks with minimal memory involvement in the study of dementia is emphasized, and the delayed alternation task is recommended. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A critical study of the influence of negative symptoms on the therapeutic response in schizophrenia]

The treatment modalities for gliomas are still questioning and searching. We reviewed the effect of the extent of surgical resection and reoperation on the length and quality of survival in 152 consecutive patients who underwent operation for supratentorial gliomas at GATA Neurosurgery clinic between 1985 to 1995. Seventy-two patients (50%) had glioblastoma multiforme (GBM), and 48 patients (33%) had anaplastic astrocytoma (AA). Gross total resection was achieved in 70 cases (49%), subtotal resection was performed in 60 cases (42%), and biopsy was carried out in 14 cases (9%). Thirty-two patients were reoperated for recurrency and the median interval between the first operation and reoperation was 9.5 months in glioblastoma multiforme, and 11.7 months in anaplastic astrocytoma. The resection groups were compared for age, sex, preoperative and postoperative Karnofsky rating, tumor location, postoperative radiation therapy, and chemotherapy, and survival according to multivariate analysis. Preoperative Karnofsky rating and surgical resection type were the most important factors related to survival after operation or reoperation. The gross total resection group lived longer than the subtotal resection group by life table analysis. Median survival of GBM was 76 weeks in gross total resection group, and 33 months in AA group with total resection (p < 0.001). Preoperative Karnofsky scores had a statistically significant effect on the quality of life and survival after operation and reoperation in all cases (p = 0.005). Radical surgery and reoperation also improve quality and length of life in selective malignant supratentorial gliomas.     

A review of neuropsychological differences between paranoid and nonparanoid schizophrenia patients

This review examines the literature on neuropsychological differences between paranoid and nonparanoid schizophrenia subjects. Thirty-two studies related to intellectual functioning, attention, memory, language, visual-spatial, and motor functions are discussed. Subjects with paranoid schizophrenia did not demonstrate higher intellectual functioning than those with nonparanoid schizophrenia, and both groups performed similarly on tests of verbal ability and visual-spatial functions. Several studies suggest that the paranoid subtype is associated with higher performance on tests of executive functions, attention, memory, and motor skills. However, the findings are inconsistent. Methodological issues in the literature are examined, including varying degrees of participants' chronicity and severity of illness among studies, criteria for diagnostic group membership, medication effects, reliability and validity of the neuropsychological measures, and statistical power.     

Failure of positive but not negative emotional valence to enhance memory in schizophrenia.

Abnormalities in the integration of emotion and cognition have long been considered hallmark characteristics of schizophrenia. Study authors used a well-established emotional memory model from the neuroscience literature to assess the facilitative impact of emotional valence of information on long-term memory consolidation in schizophrenia. Participants with schizophrenia (n=33) indicated somewhat higher levels of emotional intensity in response to emotional images than did healthy (n=28) participants. However, when recognition memory was tested 24 hr later, schizophrenia participants did not show enhancement of memory for positive images as was found in healthy participants. Their memory enhancement for negative images did not differ from that of healthy participants. Correlations between self-reported physical and social anhedonia were significantly inversely correlated with intensity ratings of positive stimuli during the encoding phase for healthy participants but were negligible for schizophrenia participants. These results suggest a failure to adequately integrate positive emotional experience in memory consolidation processes in schizophrenia participants, despite appropriate initial response to positive stimuli, which may contribute to symptoms such as anhedonia by reducing the long-term impact of positive experiences in motivating hedonic behavior in day-to-day life. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Models of positive and negative symptoms in schizophrenia: An empirical evaluation of latent structures.

The present investigation empirically evaluated three competing models of the relations between positive and negative symptoms in schizophrenia, namely the I. I. Gottesman et al (see record 2005-09771-003), N. C. Andreasen and S. Olsen's (see record 1982-30452-001), and T. J. Crow's (see record 1981-28160-001) severity-liability model unidimensional bipolar model, independent dual-process model. Using positive and negative symptom ratings based on 220 schizophrenic subjects, the results of a LISREL VI confirmatory factor analysis revealed that Crow's model of positive and negative symptoms provided the best fit to the observed data among the 3 models. The severity-liability model provided a modest fit to observed data, and Andreasen's model fit the data poorly. Results support the validity of the positive and negative symptom distinction in schizophrenia and as providing substantive empirical support for Crow's independent dual-process model. The methodological advantages of confirmatory factor analysis in the specification and evaluation of theoretical models in experimental and developmental psychopathology are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)