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PubMed2003

Retest reliability of dynamic balance during standing in older people after surgical treatment of hip fracture.

BACKGROUND AND PURPOSE: Computerized force platform systems are becoming more widely used in clinical practice to measure balance control; however, their retest reliability has not been documented in people with hip fracture. The present study examined the retest reliability of dynamic weight shift during standing in older people after surgical treatment of hip fractures. METHOD: This single group test-retest research design employed a computerized force platform system (the Neurocom Pro-Balance Master; PBM) to measure the amplitude and symmetry of weight shift in 14 patients with unilateral hip fracture on three test occasions held one hour and 24 hours apart. Subjects performed six trials of a forward-backward and side-to-side weight shift task at each test session. RESULTS: The results showed that reliability was, at best, moderate for forward-backward and side-to-side weight shift measures taken over an hour and over a day. CONCLUSIONS: Clinicians should be cautious when using the computerized balance assessment procedures investigated in this study to assess change in dynamic balance ability in older people during the early stages of rehabilitation after surgical treatment of hip fractures.

Aged↗
PubMed2003

Exploring the link between character, personality disorder, and neuropsychological function.

Personality deviations and deficits in cognitive executive function are common among forensic populations. The present study on incarcerated offenders explored whether there are links between the two domains. Personality was assessed using the Temperament and Character Inventory (TCI). Neuropsychological performance, including visual working memory, attentional set-shifting and planning, were tested with the Cambridge Neuropsychological Test Automated Battery (CANTAB). Subjects with personality disorders scored high on harm avoidance, and low on self-directedness and cooperativeness. Personality disordered offenders did not differ from the comparison groups (offenders without personality disorder, and non-criminal controls) with regard to CANTAB measures of visual working memory (delayed matching to sample, spatial working memory) and planning (Stockings of Cambridge), but they made a larger number of errors on the attentional set-shifting task. Dimensional analysis of the personality and neuropsychological variables revealed significant associations between self-directedness and cooperativeness on the one hand, and attentional set-shifting on the other. Intellectually disabled, non-criminal individuals (marginal mental retardation) who performed poorly on attentional set-shifting also scored low on self-directedness and cooperativeness. The results indicate that poor development of certain personality traits may be associated with deficits in neuropsychological functioning.

Adult↗
PubMed2004

Cognitive flexibility in anorexia nervosa and bulimia nervosa.

The aim of this study was to determine if there are differences in cognitive flexibility in anorexia nervosa and bulimia nervosa. Fifty-three patients with an eating disorder (34 with anorexia nervosa and 19 with bulimia nervosa) and 35 healthy controls participated in the study. A battery of neuropsychological tests for cognitive flexibility was used, including Trail Making B, the Brixton Test, Verbal Fluency, the Haptic Illusion Test, a cognitive shifting task (CatBat) and a picture set test. Using exploratory factor analysis, four factors were obtained: 1: Simple Alternation; 2: Mental Flexibility; 3: Perseveration; and 4: Perceptual Shift. Patients with anorexia nervosa had abnormal scores on Factors 1 and 4. Patients with bulimia nervosa showed a different pattern, with significant impairments in Factors 2 and 4. These findings suggest that differential neuropsychological disturbance in the domain of mental flexibility/rigidity may underlie the spectrum of eating disorders.

Adult↗
PubMed1993

Memory enhancement by post-training peripheral administration of low doses of dopamine agonists: possible autoreceptor effect.

These experiments examined the effect of post-training injections of low doses of dopamine (DA) agonists on the acquisition of two 8-arm radial maze tasks. On a winstay simultaneous discrimination task, a light cue signaled the location of food in four randomly selected arms on each trial, and animals were required to visit each of the lit arms twice within a trial. Animals received one food trial per day and were injected immediately after training on Day 5. The direct DA receptor agonist, apomorphine (0.05 mg/kg), and the direct D2-DA receptor agonists, LY 177555 (quinpirole: 0.05, 0.1 mg/kg) and B-HT 920 (0.05 mg/kg), all improved acquisition of winstay radial maze behavior relative to saline-injected controls. On a win-shift task, rats were allowed to obtain food from four randomly selected maze arms, followed by a delay period in which they were removed from the maze. Animals were returned to the maze for a retention test in which only those arms that had not been visited prior to the delay contained food. After training on shorter delays, a delay of 18 h was imposed between the first four and second four choices, and DA agonists were injected immediately after the first four choices. Apomorphine, LY 171555, and B-HT 920 (all at 0.05 mg/kg), all improved win-shift retention relative to saline-injected controls. On both tasks, delaying the injections for 2 h post-training eliminated the memory-improving effects of all drugs. The results indicate that post-training administration of DA agonists at doses that may preferentially stimulate autoreceptors improves memory.

Animals↗
PubMed2001

Comparison of the basal ganglia and cerebellum in shifting attention.

The basal ganglia and cerebellum have traditionally been associated with motor performance. Recently, there has been considerable interest regarding the contributions of these subcortical structures to aspects of cognition. In particular, both the basal ganglia and cerebellum have been hypothesized to be involved in the control of attentional set. To date, no neuropsychological studies have directly compared the effects of basal ganglia and cerebellar dysfunction on the same attention shifting tasks. To this end, we employed an alternating attention task that has been used to demonstrate putative attentional control deficits in children with cerebellar pathology, either related to autism or neurological insult. When adult patients with either Parkinson's disease or cerebellar lesions were tested on this task, a similar pattern of deficits was observed for both groups. However, when the motor demands were reduced, cerebellar patients showed a significant improvement on the alternating attention task, whereas the Parkinson patients continued to exhibit an impairment. This dissociation suggests that attentional deficits reported previously as being due to cerebellar dysfunction may be, at least in part, secondary to problems related to coordinating successive responses. In contrast, attention-shifting deficits associated with basal ganglia impairment cannot be explained by recourse to the motor demands of the task.

Acoustic Stimulation↗
PubMed2002

Impairment of executive function induced by hypertension in the rhesus monkey (Macaca mulatta).

The effects of chronic, untreated hypertension on executive function were investigated in a nonhuman primate model of hypertensive cerebrovascular disease. Executive function was assessed with the Conceptual Set-Shifting Task (CSST). a task adapted from the human Wisconsin Card Sorting Test (WCST). Like the WCST, the CSST requires abstraction of a stimulus set, followed by a series of set shifts. Performance on the CSST by 7 young adult monkeys (Macaca mulatta) with surgically induced hypertension was compared with that of 6 normotensive monkeys. The hypertensive group was significantly impaired relative to the normotensive group in abstraction and set shifting. Although the neural basis of this impairment is unclear, evidence from studies with humans and monkeys suggests that the prefrontal cortex may be the locus for this effect of hypertension.

Animals↗
PubMed1983

Children's photograph selections and verbal reports in a spatial task.

The tendency for children to select a photograph of their own view of a scene when asked to represent the view seen by another observer in a different position has been attributed to an egocentric view of the world. It seems likely, however, that the egocentric response need not necessarily be related to the question of sensitivity to the viewpoints of others. Rather, it may reflect the way in which children treat two-dimensional representations of three-dimensional arrays in mental-rotation tasks. In the present investigation, strong visual and verbal cues were given for correct selection of a photograph of another observer's view in a perspective-shift task. Justifications for choices were required. Whilst floor effects were seen with children 3 to 4 years old, the responses of 8-year olds polarised into a choice between the correct and egocentric view, as Freeman would predict. Verbal justifications for these choices were mainly in terms of appropriate content. After first selection, this chosen view was removed from the array. Two-thirds of children who had chosen egocentrically then went on to choose correctly on a second attempt. It is suggested that the egocentric response may form an easier alternative for the child, but that the provision of such an alternative may prevent the child from displaying the knowledge that he or she has.

Child Development↗
PubMed2006

Dissociable roles for the nucleus accumbens core and shell in regulating set shifting.

The ability to behave in a flexible manner is an executive function mediated in part by different regions of the prefrontal cortex. The present study investigated the role of two major efferents of the prefrontal cortex, the nucleus accumbens (NAc) core and shell, in behavioral flexibility using a maze-based strategy set-shifting task. During initial discrimination training, rats learned to use either an egocentric response or a visual-cue discrimination strategy to obtain food reward. During the set shift, animals had to shift from the previously acquired response or visual-cue-based strategy and learn the alternate discrimination. Inactivation of the NAc core, induced by infusion of the GABA agonists baclofen and muscimol, did not impair initial acquisition of either a response or visual-cue discrimination but severely disrupted shifting from one strategy to another. Analysis of the type of errors revealed that impairments in set shifting were not attributable to increased perseveration but to a disruption of the acquisition and maintenance of a new strategy. In contrast, inactivation of the NAc shell did not impair acquisition of either a response or a visual-cue discrimination, or shifting from one strategy to another. However, inactivation of the NAc shell before initial discrimination training improved performance during the set shift relative to control animals. These data indicate that the NAc core and shell make dissociable contributions to behavioral flexibility during set shifting. The NAc core facilitates the acquisition and maintenance of novel behavioral strategies and elimination of inappropriate response options, whereas the shell may mediate learning about irrelevant stimuli.

Analysis of Variance↗
PubMed1999

The effects of shifts in the balance of care on general practice workload.

BACKGROUND: The consequences of the move towards a primary-care-led NHS are shifts in activity from secondary care to primary care and more involvement of GPs in purchasing decisions. Although there are many anecdotal reports of an increasing primary care workload, there is little empirical evidence on the extent of such shifts. This paper reports the results of a survey of GPs in Grampian, in the north-east of Scotland, in which we attempted to gather information on the effects of shifts in the balance of care on general practice. OBJECTIVE: We aimed to examine GPs perceptions of the extent to which general practice workload has changed due to planned and unplanned shifts in the balance of care. METHODS: The design of the study was a self-reported questionnaire, which was administered in general practices in the Grampian Health Board, Scotland. The subjects were senior partners of all general practices and the main outcome measures were the types of changes which have taken place in general practice, their source, their effect on practice workload and how practices have reacted. RESULTS: A 60% response rate was achieved (52/86); 85% (44/52) of GPs claimed that their workload had increased due to shifts in the balance of care and that 72% of the shifts were initiated outside the practice. Geriatric care, early discharge and psychiatric and psychology services, as well as nursing home care, were reported to have had the greatest impact on workload. The main aspects of practice workload which had increased included the number of GP consultations, general stress at work and number of home visits, whereas the net income of the practice and health outcome of patients were reported to have decreased. Practices have dealt with the increase in workload by shifting tasks from GPs to nurses and absorbing the workload into existing practices/patterns. Responders reported that ideally more nursing and GP staffing would be required. Overall, GPs welcomed the shifts in the balance of care, were more concerned about poor communication rather than actual increases in workload and claimed that morale had fallen. CONCLUSION: GPs perceive that the move towards a primary-care-led NHS is increasing the workload in general practice. If the shift in the balance of care away from secondary care is to be successful, then more information is required about such shifts to support practices as change continues.

Attitude of Health Personnel↗
PubMed1991

Effect of video feedback on the performance of a weight shifting controlled tracking task in subjects with parkinsonism and neurologically intact individuals.

This study compared the performance of a visual motor task, accomplished by standing weight shifting, of 34 people with Parkinson's disease (P.D.) and 34 neurologically intact (N.I.) subjects. Twenty of the P.D. subjects were in Stage 1 and 14 were in Stage 2. The performance of ten, 10-s trials was each examined under two feedback (FB) conditions: continuous video display of performance and end of trial position. Visual FB was composed of displaying a target and cursor on a video monitor, with the cursor controlled by the subject through weight shifting on a platform interfaced with a microprocessor. Once the cursor was centered, the computer then transferred the target to the upper right quadrant of the monitor, and the subject was required, through weight shifting, to relocate the cursor inside the target. ANOVA with repeated measures was used for data analysis. The visual motor performance of P.D. subjects was significantly worse than that of N.I. (P less than 0.01), as well as between FB conditions (P less than 0.01). The interaction of the FB condition by trial segment was significant (P less than 0.01), as was the interaction of group membership by the trial segment (P less than 0.01). FB condition and group membership did not significantly interact, confirming that performance was worse under end of trial position FB, regardless of group membership (P less than 0.01). Post hoc analysis yielded significant differences (P less than 0.05) in task performance between N.I. and P.D. subjects after the first second of the trials regardless of FB condition. In either group, significant differences between continuous visual FB and end of trial position FB (P less than 0.05) were verified after the fourth second. Performance between N.I., Stage 1, and Stage 2 P.D. subjects revealed significant differences (P less than 0.01) among all three groups, regardless of FB condition. One of the revealing aspects of this investigation was the establishment of significant differences in visual motor performance of individuals in the early stages of the disease compared to previous reports of extremity deficits in the later stages.

Adult↗
PubMed1989

Memory facilitation produced by dopamine agonists: role of receptor subtype and mnemonic requirements.

The role of dopamine (DA) receptor subtypes in the acquisition of two memory tasks in the 8-arm radial maze was examined. The receptors were manipulated with posttraining, subcutaneous injections of an indirect DA receptor agonist (D-amphetamine), a selective D2 receptor agonist (LY171555), and a selective D1 receptor agonist (SKF-38393). On a win-stay task (sensitive to caudate nucleus lesions) a light cue signalled the location of food in 4 randomly selected arms on each trial. Rats were given one trial per day and injected after training on day 5. D-Amphetamine (2.0 mg/kg) and LY171555 (2.0 mg/kg) improved performance relative to controls; however SKF-38393 (1-4 mg/kg) had no effect on the acquisition of win-stay behavior. On a win-shift task (sensitive to fornix/hippocampal lesions) a delay of 18 hr was imposed between the first 4 and second 4 choices; drugs were injected after the first 4 choices. D-Amphetamine (1.0 mg/kg) and LY171555 (2.0 mg/kg) significantly improved retention relative to controls. SKF-38393 (1-4 mg/kg) had no effect on win-shift retention. These results suggest that the memory-improving properties of DA agonists on tasks sensitive to both hippocampal and caudate lesions are mediated by the D2 receptor.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed2002

Neuropsychological function in female victims of intimate partner violence with and without posttraumatic stress disorder.

BACKGROUND: Various aspects of neuropsychologic function have been reported to be abnormal in patients with posttraumatic stress disorder (PTSD); however, the majority of these data come from studies of seriously ill, treatment-seeking samples with substantial substance use comorbidity. Few studies have included similarly trauma-exposed subjects without PTSD, and fewer still have focused on women. METHODS: Thirty-nine female victims of intimate partner violence (IPV; 22 without lifetime PTSD and 17 with current PTSD), and 22 nonvictimized comparison (NC) subjects were administered tests of attention, working memory, visuoconstruction, language ability, learning and memory, and executive functioning. RESULTS: The IPV and NC subjects did not demonstrate statistically significant differences on most neuropsychologic tests, with the exception of those in the realm of working memory, visuoconstruction, and executive functioning. The IPV subjects, regardless of PTSD status, had poorer performance on tasks of speeded, sustained auditory attention and working memory (Paced Auditory Serial Addition Test) and response inhibition (Stroop). The IPV subjects with PTSD performed worse than NCs on a set-shifting task (Trail Making Test, Part B). No consistent relationships were noted between neuropsychologic functioning and severity of childhood abuse or domestic violence experiences. CONCLUSIONS: Cognitive deficits in IPV subjects were confined to measures of working memory, visuoconstruction, and executive function; were subtle; and were not uniformly worse among those with current PTSD. This pattern, however, is consistent with frontal-subcortical dysfunction in traumatized women. The clinical significance of these findings deserves further study.

Adult↗
PubMed2005

Executive function in Tourette's syndrome and obsessive-compulsive disorder.

BACKGROUND: Cognitive performance was compared in the genetically and neurobiologically related disorders of Tourette's syndrome (TS) and obsessive-compulsive disorder (OCD), in three domains of executive function: planning, decision-making and inhibitory response control. METHOD: Twenty TS patients, twenty OCD patients and a group of age- and IQ-matched normal controls completed psychometric and computerized cognitive tests and psychiatric rating scales. The cognitive tests were well-characterized in terms of their sensitivity to other fronto-striatal disorders, and included pattern and spatial recognition memory, attentional set-shifting, and a Go/No-go set-shifting task, planning, and decision-making. RESULTS: Compared to controls, OCD patients showed selective deficits in pattern recognition memory and slower responding in both pattern and spatial recognition, impaired extra-dimensional shifting on the set-shifting test and impaired reversal of response set on the Go/No-go test. In contrast, TS patients were impaired in spatial recognition memory, extra-dimensional set-shifting, and decision-making. Neither group was impaired in planning. Direct comparisons between the TS and OCD groups revealed significantly different greater deficits for recognition memory latency and Go/No-go reversal for the OCD group, and quality of decision-making for the TS group. CONCLUSIONS: TS and OCD show both differences (recognition memory, decision-making) and similarities (set-shifting) in selective profiles of cognitive function. Specific set-shifting deficits in the OCD group contrasted with their intact performance on other tests of executive function, such as planning and decision-making, and suggested only limited involvement of frontal lobe dysfunction, possibly consistent with OCD symptomatology.

Adult↗
PubMed2006

D1 receptor modulation of memory retrieval performance is associated with changes in pCREB and pDARPP-32 in rat prefrontal cortex.

We have recently shown a significant role of dopamine D(1) receptors in recognition and temporal order memory retrieval for objects in rodents [Hotte M, Naudon L, Jay TM. Modulation of recognition and temporal order memory retrieval by dopamine D(1) receptor in rats. Neurobiol Learn Mem 2005;84:85-92]. The present study investigates the signal transduction pathways underlying dopamine D(1) receptor modulation of retrieval performance in these memory tasks at different delays. We analyzed the level of phosphorylation of both CREB (cAMP response element binding protein) and DARPP-32 (dopamine and cAMP-regulated phosphoprotein, 32 kDa) in (1) the prefrontal cortex of rats that had performed the object recognition task, (2) the prefrontal and perirhinal cortices of rats that had performed the temporal order memory task for objects. For comparison, we explored the phosphorylation state of CREB and DARPP-32 in the prefrontal cortex, nucleus accumbens and hippocampus of rats having performed badly on the delayed spatial win-shift task after D(1) blockade. The improvement in recognition and temporal order memory performance at a 4h-delay was associated with an increased phosphorylation of both CREB and DARPP-32 in the prefrontal cortex of rats treated with the D(1) agonist SKF 81297. By contrast, the significant impairment of delayed spatial memory retrieval after administration of the selective D(1) antagonist SCH 23390 was associated with decreased phosphorylation of CREB and DARPP-32 in the prefrontal cortex. These results provide insight into molecular mechanisms involved in D(1) receptor-dependent modulation of short- versus long-term memory in prefrontal cortex where DARPP-32 in synergy with CREB may represent a pivotal role.

Animals↗
PubMed1989

Cognitive impairments associated with early Parkinson's disease.

We administered a battery of cognitive tests to 41 recently diagnosed Parkinson patients and 41 controls to assess the early neuropsychological changes associated with Parkinson's disease (PD). Parkinson subjects did as well as controls on tasks assessing attention and select language and visuospatial measures. However, PD subjects did significantly worse on embedded figures, facial recognition, proverbs, and verbal and figural memory measures, and made more perseverative responses on a set shifting task. A discriminant function of measures of proverbs, embedded figures, and memory accounted for 22% of the variance between groups. These data suggest that the cognitive changes in early PD are more pervasive than originally described and may reflect the onset of a more widespread pathologic process.

Cognition Disorders↗
PubMed2007

Effects of acute and chronic antidepressant treatments on memory performance: a comparison between paroxetine and imipramine.

RATIONALE: The cognitive impairments apparent in many depressed patients appear to be alleviated by chronic treatments with antidepressants. However, evaluation of antidepressant treatments in rodents rarely includes investigation of their effects on cognitive performance. OBJECTIVES: The aim of this study was to investigate in rat the effects of paroxetine, a selective serotonin reuptake inhibitor antidepressant, and imipramine, a tricyclic antidepressant, on learning and memory in spatial and non-spatial tasks. MATERIALS AND METHODS: Adult male Sprague-Dawley rats weighing 230-250 g were used in two sets of experiments. RESULTS: Spatial working memory was first tested in a radial-arm maze using the delayed spatial win-shift task. During the course of a 10-day treatment, paroxetine-treated rats (10 mg/kg) did not show any deficit in memory performance. Conversely, imipramine-treated rats (10 mg/kg) made significantly more errors than controls. Secondly, we tested temporal order memory for objects. Rats received one injection or chronic injections (28 days) of imipramine (10 mg/kg), paroxetine (10 mg/kg) or saline. In contrast to controls, on the day after the acute injection, both imipramine- and paroxetine-treated rats were unable to discriminate the old from the recent objects. After chronic treatment, the imipramine-treated rats were unable to differentiate between the two objects, whereas paroxetine-treated rats, as controls, spent more time exploring the old one. When the delay before the test phase was increased to 4 h, controls could not discriminate the objects, whereas rats treated for 28 days with paroxetine were able to distinguish the old from the recent object. CONCLUSIONS: In contrast to the persistent harmful effects of imipramine, chronic treatment with paroxetine does not alter spatial working memory performance and appears to improve temporal order memory performance.

Analysis of Variance↗
PubMed1995

[Strained relations between federal health insurance and the public health service].

A close cooperation between all partners according to section 20 IV SGB V is basically welcome. However, in times of financial straits in public budgets, attempts have to be avoided to shift tasks and financial burdens to statutory health insurance (SHI). A series of examples shows that because of the different responsibilities-related to the insured persons on the one hand, and the general population on the other-tendencies to shift burdens to SHI are observed. However, such measures are neither adequate nor without problems (e.g. protection by vaccination). Public health service is requested to improve its epidemiological capacities and the qualification of its doctors. Furthermore, the service should be re-orient to a modern citizen-oriented service organization. Communities and provincial ("Land") governments have to provide the financial prerequisites.

Budgets↗
PubMed1995

Clinical correlates of motor performance during paced postural tasks in Parkinson's disease.

Bradykinesia and hypokinesia may both play a significant role in postural instability commonly seen in patients with Parkinson's disease. We investigated which factor--movement time or movement amplitude--is the more significant limiting variable in patients with Parkinson's disease during a paced postural task. We also assessed the effect of antiparkinson medication upon these movement factors and the degree of correlation with changes in clinical performance. Subjects performed paced left-right (L-R) and forward-backward (F-B) continuous weight-shifting tasks at slow, medium and fast paces. Ten Parkinson patients were studied both OFF and ON their usual antiparkinson medication. Ten age-matched healthy controls were also tested and subsequently retested on the same schedule as the patients. Movement times and amplitudes were measured and correlated with clinical changes in UPDRS motor subscores. Parkinson patients performed similar to controls with respect to movement time, but significantly displayed underscaled (reduced) movement amplitude. Movement amplitude improved after antiparkinson medication, but remained significantly less than that of controls. Improvements in L-R movement amplitude correlated with clinical improvements in bradykinesia and postural instability, while improved F-B movement amplitude correlated only with reduced postural instability. We conclude that hypometric movement amplitude, and not abnormal movement time, is the primary abnormality observed in Parkinson patients during a paced postural task. Amplitude underscaling seems antiparkinson medication-dependent and improvement correlates with favorable clinical changes in bradykinesia and postural instability scores.

Aged↗