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Biomedical subjects

C Pantelis

Publications and source records attributed to C Pantelis.

At least 55 records · Page 3Linked to original sources
PubMed1998

Cognitive deficits in obsessive-compulsive disorder on tests of frontal-striatal function.

BACKGROUND: Although neuropsychological and neuroimaging studies of obsessive-compulsive disorder (OCD) have implicated the frontal cortex and subcortical structures in the pathophysiology of the disorder, few studies have examined cognitive function in patients with OCD on tasks validated in the assessment of frontal lobe and subcortical dysfunction. METHODS: The accuracy and latency of executive and visual memory function was assessed in 23 nondepressed OCD patients and 23 normal healthy controls matched for age, sex, education, and estimated IQ. RESULTS: The patients with OCD performed within the normal range on tasks of short-term memory capacity, delay dependent visual memory, pattern recognition, attentional shifting, and planning ability; however, specific cognitive deficits related to spatial working memory, spatial recognition, and motor initiation and execution were observed in the patient group. These deficits were not correlated with aspects of the patients' intellectual functioning or comorbid psychological symptoms, suggesting that the impairments were related to the specific clinical features of OCD. CONCLUSIONS: Patients with OCD showed specific cognitive deficits on tasks of executive and visual memory function. The pattern of impaired performance in these patients was qualitatively similar to the performance of patients with frontal lobe excisions and subcortical pathology on the same test battery, suggesting that the underlying pathophysiology of the disorder could best be conceptualized as reflecting dysfunction of frontal-striatal systems.

Adult↗
PubMed1998

Neuropsychological deficits in obsessive-compulsive disorder: a comparison with unipolar depression, panic disorder, and normal controls.

BACKGROUND: The neuropsychological dysfunction associated with obsessive-compulsive disorder (OCD) has similarities to the deficits reported in other affective or anxiety disorders. We directly compared cognitive function in patients with OCD with that in matched patients with unipolar depression and panic disorder and healthy control subjects to establish the specific nature of neuropsychological deficits in OCD. METHODS: Thirty patients with OCD, 30 patients with panic disorder, 20 patients with unipolar depression, and 30 controls completed a computerized neuropsychological battery that assessed the accuracy and latency of executive, visual memory, and attentional functions. RESULTS: The groups did not differ according to age, years of education, or estimated IQ. However, we found group differences in cognitive performance. The patients with OCD were impaired on measures of spatial working memory, spatial recognition, and motor initiation and execution. In contrast, performance of these tasks by patients with panic disorder or depression did not differ from that of controls. There were no group differences for performance on the measures of planning, cognitive speed, pattern recognition, and delayed matching to sample, although patients with depression were impaired for attentional set shifting. CONCLUSIONS: Neuropsychological deficits were observed in patients with OCD that were not observed in matched patients with panic disorder or unipolar depression. As such, the cognitive dysfunction in OCD appears to be related to the specific illness processes associated with the disorder.

Adult↗
PubMed1998

Response programming in patients with schizophrenia: a kinematic analysis.

Schizophrenia may involve disturbed subcortical mechanisms or anomalous functional asymmetries. We therefore examined any anomalies of functional asymmetry in a kinematic analysis of a cued sequential movement task previously found to be sensitive to basal ganglia dysfunction. Twenty patients with schizophrenia and 20 matched controls used preferred or non-preferred hand to connect a series of targets on a WACOM SD420 graphics tablet, in response to the pattern of illumination of light emitting diodes (LEDs). Movements were to be initiated with or without an external cue as to target location. Patients with schizophrenia exhibited relatively normal functional asymmetries, but had programming deficits, taking longer to initiate (i.e. self generate) movements in the absence of an external cue. The movements of patients with schizophrenia were more variable and less efficient, resembling those seen in Huntington's disease. Results supported a hypothesis of disturbance at some level in fronto-subcortical circuitry in schizophrenia.

Adolescent↗
PubMed1998

Saccadic and attentional abnormalities in patients with schizophrenia.

BACKGROUND: Abnormal performance on the antisaccade task suggests that patients with schizophrenia have difficulty with the inhibition of reflexive attentional shifts. The aim of the study was to investigate whether deficits in the inhibition of reflexive attentional shifts were specific to the oculomotor modality or whether they could also occur when attentional shifts were made without eye movements (e.g. covert attentional shifts). METHODS: Fifteen medicated patients with chronic schizophrenia and 15 matched controls performed the antisaccade task and the covert orientating task (COVAT) where the probability of targets appearing at the same location of a peripheral cue was varied so that voluntary and reflexive orientating systems had the same goal (80% probability of target and cued condition) or opposite goals (20% probability of target at cued location). A condition where only reflexive orientating was initiated was also included (50% probability of target at cued location). For each of these conditions the stimulus onset asynchrony (SOA) varied between 150 and 350 ms. RESULTS: Patients with schizophrenia showed normal latency and accuracy for visually guided saccades but increased error rates and latency on the antisaccade task. For the COVAT, patients with schizophrenia were unable to use voluntary orientating strategies to inhibit reflexive shifts of covert attention. On conditions where only reflexive orientating was required or when the goals of the reflexive and voluntary orientating systems were the same, patients with schizophrenia showed normal performance. CONCLUSIONS: These results suggest the reflexive orientating mode is normal in patients with chronic schizophrenia. However, these patients have a reduced ability to utilize the voluntary orientating mode to control or inhibit reflexive orientating. This impairment of voluntary control is evident for both overt and covert attentional shifts.

Adult↗
PubMed1998

Cue dependent right hemineglect in schizophrenia: a kinematic analysis.

OBJECTIVES: Schizophrenia may result from disturbed attentional processes and/or defective internal cueing. Attention for subsequent action within a cued movement task was therefore studied, testing specific hypotheses of hemispheric dysfunction and of impaired interhemispheric communication. METHOD: Fifteen patients with schizophrenia and 15 matched controls were either cued or uncued when moving a pen to a target on their right or left side with their right or left hand. Pen tip position was sampled at 200 Hz on a WACOM SD420 graphics tablet for subsequent kinematic analysis. RESULTS: Patients with schizophrenia were slower initiating rightwards movements without a cue. Patients also exhibited reduced abductive/adductive differences in the shape of their movement trajectories, implying differences in interhemispheric communication. CONCLUSIONS: It is speculated that schizophrenia is a form of cue dependent right hemineglect.

Adolescent↗
PubMed1997

Neuropsychological function in young patients with unipolar major depression.

BACKGROUND: While neuropsychological studies have consistently reported impaired cognition in elderly patients with unipolar depression, studies of cognitive function in younger patients with depression have produced equivocal results. The aim of this study was to examine the presence and nature of cognitive deficits in young patients with depression. METHODS: Neuropsychological function was assessed in 20 young patients with unipolar depression, in comparison to 20 age-, education- and IQ- matched controls. Subtests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were employed, as this battery has proved sensitive to deficits in middle-aged and elderly patients with depression. RESULTS: The patients were not impaired for short-term memory capacity, spatial working memory, planning ability, cognitive speed, delayed matching to sample or recognition memory. Compared to controls, the patients showed impaired subsequent movement latencies on the Tower of London task, suggesting deficits in the ability to sustain motor responses in depression. The depression group were also impaired on the task of attentional set shifting, requiring more trials to criterion at the intradimensional stage of the task and being more likely to fail the task at the extradimensional shift stage than controls. Further analysis indicated that half of the depression group failed to complete all stages of the set shifting task. These patients were more likely to have required in-patient hospitalization at some time during their illness. CONCLUSIONS: These results indicate that there are specific cognitive deficits in young patients with depression and that their presence may be related to a history of hospitalization.

Adolescent↗
PubMed1997

Frontal-striatal cognitive deficits in patients with chronic schizophrenia.

Spatial working memory and planning abilities were assessed in 36 hospitalized patients with chronic schizophrenia, using the computerized Cambridge Neuropsychological Test Automated Battery (CANTAB), and compared with those of normal subjects and patients with neurological disorders (frontal lobe lesions; temporal lobe and amygdalohippocampal lesions; Parkinson's disease), matched for age, sex and National Adult Reading Test IQ. The patients in the group with temporal lobe lesions were unimpaired in their performance on these tasks. Patients with schizophrenia were impaired on visuo-spatial memory span compared with all the other groups, while severity of Parkinson's disease was correlated with the degree of impairment on this task. The patients with schizophrenia and those with frontal lobe lesions were impaired on a 'spatial working memory' task, with increased 'between-search errors'. Patients with Parkinson's disease performed this task poorly compared with the younger control subjects. Patients with schizophrenia were unable to develop a systematic strategy to complete this task, relying instead on a limited visuo-spatial memory span. Higher level planning ability was investigated using the CANTAB 'Tower of London'. All groups were equally able to complete the task. However, the groups of patients with schizophrenia and frontal lobe lesions made fewer perfect solutions and required more moves for completion. Movement times were significantly slower in the schizophrenia group, suggesting impairment in the sensorimotor requirements of the task. The patients with schizophrenia were not impaired in their 'initial thinking' (planning) latencies, but had significantly prolonged 'subsequent thinking' (execution) latencies. This pattern resembled that of the group with frontal lobe lesions and contrasted with the prolonged 'initial thinking' time seen in Parkinson's disease. The results of this study are indicative of an overall deficit of executive functioning in schizophrenia, even greater than that seen in patients with frontal lobe lesions. However, the pattern of results in schizophrenia resembled that seen in patients with lesions of the frontal lobe or with basal ganglia dysfunction, providing support for the notion of a disturbance of frontostriatal circuits in schizophrenia. Our findings also indicate that there is a loss of the normal relationships between different domains of executive function in schizophrenia, with implications for impaired functional connectivity between different regions of the neocortex.

Adolescent↗
PubMed1997

One-year, low-dose neuroleptic study of in-patients with chronic schizophrenia characterised by persistent negative symptoms. Amisulpride v. haloperidol.

BACKGROUND: Amisulpride is a potent substituted benzamide antipsychotic drug claimed to improve the negative symptoms of schizophrenia, particularly at low dosage. METHOD: Sixty long-term in-patients with schizophrenia and selected for predominant negative symptoms were randomised to receive either haloperidol or amisulpride. Over a year there was systematic dose reduction, as symptoms allowed. RESULTS: There were no significant differences between the treatment groups in the proportion receiving low-dose treatment, the control of positive symptoms, or ratings of social behaviour, side-effects or tardive dyskinesia. For negative symptoms, there were consistent but non-significant trends in favour of amisulpride. The amisulpride patients required significantly less anticholinergic medication. CONCLUSIONS: In chronically-hospitalised in-patients with schizophrenia characterised by persistent negative symptoms, amisulpride was a well-tolerated maintenance antipsychotic medication. The drug had only a limited effect in reducing negative symptoms, which were relatively stable, enduring phenomena in this sample, despite dosage reduction.

Adult↗
PubMed1997

Characteristics of the new long-stay population in an inner Melbourne acute psychiatric hospital.

OBJECTIVE: There has been an accumulation of so-called 'new long-stay' (NLS) patients in psychiatric hospitals. To date, no Australian studies have characterised this patient group. We aimed to study the demography, and clinical and social functioning of the NLS population at Royal Park Hospital (RPH) together with patients' attitudes to treatment and views on future placement. METHOD: All 30 NLS patients at RPH were identified. Twenty-seven consenting patients were assessed using the following standardised instruments: Manchester Scale for psychopathology, Life Skills Profile (LSP), Physical Health Index and Patient Attitude Questionnaire. Information on past psychiatric history, past treatment and current treatment was collected. Insight and compliance were assessed. RESULTS: The majority of patients were single men with a diagnosis of schizophrenia. Forty-one percent were detained in hospital involuntarily and 56% were considered dangerous to themselves or others. The patients were characterised by high levels of positive and negative symptoms. They were most impaired with respect to 'social contact' relative to the other subscales of the LSP. While 10 (48%) patients expressed a desire to leave hospital, only one patient considered that anyone would cohabit with them. Over two-thirds considered they had been unwell and that medication had helped. Staff rated one-third as having major problems with compliance. About two-thirds of patients had disability secondary to comorbid physical illnesses. CONCLUSION: Like other NLS patients studied in the United Kingdom and Ireland, this group had significant handicaps secondary to psychiatric illness, concomitant physical illness and disability and behaviour unacceptable in community settings. They were also characterised by significant social isolation. These factors may be important determinants of rehabilitation failure and need to be addressed in the process of de-institutionalisation as well as in longitudinal studies examining these and other factors predicting NLS status.

Activities of Daily Living↗
PubMed1997

Ocular abnormalities in chronic schizophrenia: clinical implications.

OBJECTIVE: As part of a randomised double-blind study of a new atypical antipsychotic we sought to determine both the levels of visual acuity and the occurrence of toxic side-effects in a group of patients treated for many years on a variety of antipsychotics. METHODS: Twenty-three inpatients with a DSM-III-R diagnosis of chronic schizophrenia from two separate hospital locations who met the criteria for the double-blind trial were examined for ocular abnormalities at both baseline and at trial completion. RESULTS: At baseline a high prevalence of abnormalities was identified: 19 patients (82.6%) were found to have one or more ocular abnormalities, including lens opacities/cataracts and corneal pigmentation; three patients, with delusions related to the sun, were noted to have solar burns; a high proportion (almost 70%) of patients had untreated visual acuity problems. No further changes were observed at the follow-up examinations. CONCLUSIONS: The possible causes of ocular disturbance in schizophrenia and the reasons for the relatively high ocular morbidity in this group are thought to result from both illness-related factors and the effects of antipsychotic medication. Causality is confounded by a number of issues such as the high prevalence of smoking, poor general health and the variety of antipsychotic medications used in the treatment of psychosis as well as substance abuse. The clinical implications are considered in this paper in relation to the move towards community-based psychiatric services.

Adult↗
PubMed1996

Neuropsychological, olfactory, and hygiene deficits in men with negative symptom schizophrenia.

Associations between symptom subtypes, life skills, olfactory identification, and neuropsychological ability were investigated in patients with schizophrenia and related to observations of poor personal hygiene and implied functional compromise of orbitofrontal integrity. Twenty-seven men with chronic schizophrenia were assessed using the Positive and Negative Syndrome Scale for Schizophrenia and the Life Skills Profile. Performance on the University of Pennsylvania Smell Identification Test (UPSIT), the Modified Wisconsin Card Sorting Test (MWCST), delayed response/alternation, and memory tasks derived from the Wechsler Memory Scale-Revised (WMS-R) was also compared to that of an age-, sex-, and IQ-matched control group. Patient UPSIT, MWCST, and WMS-R performance was significantly impaired in comparison to controls. Poor UPSIT performance and poor self-care were significantly associated with negative symptoms. Also, UPSIT ability was associated with performance on the MWCST in both patients and controls, whereas an association with performance on the WMS-R was only found in normal subjects rather than in the patients with schizophrenia. The importance of these findings to postulated mechanisms involving prefrontal rather than mediotemporal lobe (MTL) function in schizophrenia are discussed, as is the relevance of the use of smell identification ability to subtype identification and rehabilitative strategies.

Activities of Daily Living↗
PubMed1996

Brief report: bradyphrenia in Parkinson's disease, Huntington's disease, and schizophrenia.

The current paper assessed bradyphrenia, or slowed thinking, in patients with Parkinson's disease, Huntington's disease, and schizophrenia using a modified planning measure designed to maximise the demands on cognitive processing. Findings indicated normal performance in schizophrenia but prolonged thinking time in Parkinson's disease and, to a lesser degree, Huntington's disease and a relationship between thinking time and task complexity.

Journal Article↗
PubMed1996

Deficits in the endogenous redirection of covert visual attention in chronic schizophrenia.

In patients with schizophrenia, abnormal performance on the antisaccade task suggests that for overt attentional shifts, there is difficulty with the endogenous modes have opposite goals. We examined whether patients with schizophrenia also have difficulty with the endogenous control of exogenous orienting when endogenous and exogenous control of exogenous orienting for covert shifts of attention. Fifteen medicated patients with chronic schizophrenia and 15 matched controls performed two versions of the covert orienting of attention task (COVAT). On one COVAT, targets appeared at the cued location (TAC) on all trials. On the second COVAT, targets appeared at the contralateral location to the cue (TCC) on all trials. Reaction time (RT) for TAC and TCC trials was equal in the control group. However, for the schizophrenia group, RT for TCC trials was significantly slower than RT for TAC trials. This indicates that patients with schizophrenia were unable to inhibit the orienting of attention to peripheral cues even when they knew that targets would never appear at the same location as the cue. These results suggest that patients with chronic schizophrenia have difficulty utilizing the endogenous strategies to inhibit exogenous covert attentional shifts.

Adult↗
PubMed1996

Subcortical dysfunction in schizophrenia: a comparison with Parkinson's disease and Huntington's disease.

Neuropsychological performance in 20 chronic schizophrenic patients was contrasted to 25 Parkinson's disease, 12 Huntington's disease patients and 26 normal controls on measures shown to be sensitive to subcortical dysfunction. Some overlap was observed in the performance of the schizophrenic and basal ganglia groups on tasks of executive and mnestic function, but the general pattern indicated significant differences in performance. Notably, in contrast to the two basal ganglia groups, there was no evidence of slowed thinking, or impaired motor function in schizophrenia, which are considered hallmarks of subcortical grey matter disease. An association was observed between poor performance on the tests of executive function and the severity of negative symptoms. Our findings suggest that schizophrenia is not associated with primary subcortical impairment, but is more likely to reflect frontotemporal dysfunction. We consider that the similarities between this disorder and subcortical degenerative syndromes may be due to a difficulty in generating action in schizophrenia, perhaps arising from dorsolateral prefrontal disconnection.

Adult↗
PubMed1996

Psychopathology, social and cognitive functioning in a hostel for homeless women.

BACKGROUND: This study surveyed all residents in a hostel for homeless women. Demographic data, and information on past and present psychiatric and social morbidity, and current and premorbid cognitive functioning were collected. METHOD: A four week prevalence study, using: SCID-PD; a semi-structured interview; GHQ; SBS; Manchester Scale; MMSE; and NART; the data were analysed using SPSS. RESULTS: The women originated from across the social spectrum and disruption of early family life was common. Fifty per cent had a 'severe mental illness' and most were not receiving drug treatment. High levels of active psychotic symptoms were present. Women with psychosis had suffered a greater intellectual decline from their premorbid levels of functioning than those without psychosis. CONCLUSIONS: The study affirmed findings of earlier studies employing case-studies methodology. Women with high levels of psychiatric morbidity and social dysfunction were being managed by care workers in a way that may promote stability rather than a drift into street-life.

Adolescent↗
PubMed1996

The Camden schizophrenia surveys. II. High prevalence of schizophrenia in an inner London borough and its relationship to socio-demographic factors.

BACKGROUND: Investigation of the geographical distribution of schizophrenia and its relationship to socio-demographic factors is useful for planning services. METHOD: Individuals with schizophrenia (n = 980) were identified by key informants within an inner London borough and point prevalence calculated for broad, Feighner and DSM-III-R schizophrenia. The distribution of cases was tested for significant variation using the Poisson process model. Regression models using the Jarman-8 score and its component variables were tested for their ability to predict the prevalence of schizophrenia. RESULTS: A high point prevalence of schizophrenia (5.3 per 1000 resident population) was demonstrated. Case distribution showed a marked and significant variation associated with socio-demographic factors. The prediction of prevalence was more accurate for broad than for narrower definitions of schizophrenia; unemployment rate performed best. CONCLUSIONS: Unemployment rates and Jarman-8 scores may provide crude estimates for resource allocation in planning mental health services, highlighting the need for additional services in deprived inner city areas.

Adolescent↗
PubMed1996

Four behavioural syndromes of schizophrenia.

BACKGROUND: A complementary approach to defining symptomatic subtypes of schizophrenia is to identify characteristic patterns of 'problem behaviours' associated with the capacity of patients to function in the community. METHOD: In a large epidemiological survey, patients fulfilling Feighner criteria for schizophrenia were identified by key informants and assessed using the MRC Social Behaviour Schedule (SBS) and the Manchester Scale. An exploratory factor analysis was used to extract behavioural syndromes from the SBS data in order to compare the syndrome profiles in community, acute and long-stay subgroups and to examine their associations with symptoms and social functioning. RESULTS: Four behavioural syndromes were identified: 'Thought disturbance', 'Social withdrawal', 'Depressed behaviour' and 'Anti-social behaviour', which distinguished between the patient subgroups and had significant differential relationships to symptoms and social functioning variables. CONCLUSIONS: The evaluation of disability in schizophrenia and effectiveness of treatment interventions is incomplete without an assessment of problem behaviours.

Adult↗