[Prescription of olanzapine in children and adolescent psychiatric patients]. / Prescription de l'olanzapine chez l'enfant et l'adolescent.

INTRODUCTION: A review of the literature from 1996-2004 on the indications and adverse reactions concerning the use of olanzapine, a second generation antipsychotic agent, in children and adolescents with psychiatric illness is made in this article. Studies lasted for 2 to 3 months and a few had a follow up period up to a year. Olanzapine, dosed from 2.5 to 20 mg/day, is shown to be a useful drug in the treatment of child and adolescent onset schizophrenia, bipolar disorder, anorexia nervosa with delusions, pervasive developmental disorder, tic disorders, and aggression. OPEN AND DOUBLE-BLIND STUDIES: In 4 open labeled studies (26, 34, 39, 43) and 2 case reports (25), 53 patients, aged from 6-18 years old, afflicted by child onset schizophrenia, were treated with olanzapine for 1 1/2 weeks to one year; 19 had treatment resistant childhood schizophrenia and 34 a first episode. In the first group 13/19 showed improvement whereas, in the second group 27/34 were considered responders. Four patients in the first group who had responded to clozapine (stopped because of adverse events) did less well on olanzapine. In 5 studies, 4 open labeled (15, 20, 44) and 1 double blind (27), 59 adolescent onset schizophrenic patients were treated by olanzapine from 8 to 26 weeks; 50/59 patients were considered responders. In the open label study (20) comparing 43 adolescents treated by olanzapine (19 patients), risperidone (17 patients), or haloperidol (7 patients), improvement was significant in the three groups after 4 weeks of treatment and continued after 8 weeks. It is most interesting to mention that 2 months after the end of the study 71% (12/17) of the olanzapine group that had completed the study, 10/15 (67%) of the risperidone group, and 43% (3/7) of the haloperidol group had continued their treatment. Dropouts were for inefficacy and non-compliance in the olanzapine and risperidone groups whereas they were also for adverse events in the haloperidol group (2/4). A final double blind study of 263 adult and adolescent schizophrenic patients (latter are not separated from the former) confirmed the superiority of olanzapine compared to haloperidol and its use for a long period: 67% of the olanzapine and 54% of the haloperidol patients completed the 12-week study. CASE-REPORTS: 12 case reports of children and adolescents diagnosed with acute mania (8, 25, 46, 47) and 23 in an open labeled study (16) were treated by olanzapine; 26/35 were considered to respond well. Some of the patients were on mood stabilizers before adjunction of olanzapine, others on olanzapine monotherapy; 10 case reports of patients with anorexia nervosa associated with psychotic symptomatology, aged from 10-17 years old, relate the use of olanzapine as adjuvant treatment. Improvement was spectacular in these patients who not only gained considerable weight, but were also more compliant to the therapeutic program and their obsessions, delusions, agitation and anxiety became less intense. In this form of anorexia nervosa, olanzapine appears to have an interesting therapeutic role and, in particular, its most important adverse effect, weight gain, became a therapeutic goal. In 2 preliminary studies (24, 30) 31 children and adolescents diagnosed with pervasive developmental disorder were treated by olanzapine from 6 to 13 weeks; 18/25 had good or moderate symptomatic improvement: they were less irritable and hyperactive, and their speech less excessive. In 17 case reports of children and adolescents with aggression (42, 45), associated with tics in 10 patients (49), treatment with olanzapine from 2 weeks to 10 months lowered the presenting symptoms, enhanced the cooperation, and improved the mood of the patients. Only one patient's treatment was changed for inefficacy. DISCUSSION: No matter what the disorder treated, when olanzapine was compared to haloperidol and risperidone, it proved to be as effective as risperidone, and as or more effective than haloperidol; but when compared to clozapine, it was less effective. The most prominent adverse reaction was excessive weight gain, even more so than in adult patients treated with olanzapine. Also weight gain was greater in children and adolescents treated by olanzapine than those treated by risperidone or haloperidol. Though few treatments had to be interrupted because of this side effect, child and adolescent psychiatrists are wary of the long-term disease related to obesity and glucose dysregulation. All should be done to under-stand the process of weight gain better and to prevent or stall excessive caloric intake, encourage activity, and eventually treat by corrector drugs. Secondly, sedation may bother up to 50% of patients even at the end of the study periods, as many as those treated by haloperidol and more than those treated by risperidone. Extrapyramidal symptoms were mild or moderate compared to those that appear with haloperidol, but may be more frequent than in adult patients. Liver enzymes and blood sugar may be slightly elevated. Prolactemia may be elevated but less so with risperidone and haloperidol. CONCLUSION: All the authors emphasized the unfortunate lack of randomized double blind studies for the use of olanzapine in this age group.

Effects of phlebotomy therapy on cytochrome P450 2e1 activity and oxidative stress markers in dysmetabolic iron overload syndrome: a randomized trial.

AIM: To assess the effects of iron removal on cytochrome P450 2E1 activity and oxidative stress in dysmetabolic iron overload syndrome. METHODS: Forty-eight patients were randomized to phlebotomy therapy consisting of removal of 300-500 mL of blood every 14 days until serum ferritin levels dropped under 100 microg/L or to follow-up without phlebotomy therapy. Cytochrome P450 2E1 activity was measured at baseline and at the end of treatment by using the 6-hydroxychlorzoxazone/chlorzoxazone blood metabolic ratio, 2 h after the intake of 500 mg of chlorzoxazone. RESULTS: In the treatment group, a mean of 3.9 +/- 1.3 L of blood was removed and serum ferritin levels dropped from 715 +/- 397 to 74 +/- 34 microg/L. Variation of cytochrome P450 2E1 activity was not significantly different between the 2 groups (0.07 +/- 0.26 vs. 0.03 +/- 0.19, P = 0.36). In the treatment group, low-density lipoprotein cholesterol and vitamin E were lowered after treatment compared with control group (-0.15 +/- 0.51 vs. 0.24 +/- 0.58, P = 0.002 and -1.3 +/- 4.4 vs. 2.3 +/- 5.2, P = 0.03, respectively). Inversely, vitamin C was increased (0.5 +/- 3.5 vs. -1.8 +/- 3.9, P = 0.03). CONCLUSIONS: In dysmetabolic iron overload syndrome, reduction of iron stores does not significantly influence cytochrome P450 2E1 activity but is associated with a significant decrease of low-density lipoprotein cholesterol, suggesting that venesection therapy may be a suitable option in these patients.

Does subthalamic nucleus stimulation induce apathy in Parkinson's disease?

BACKGROUND: Subthalamic Nucleus Deep Brain Stimulation (STN-DBS) has been shown to significantly improve motor symptoms in advanced Parkinson's disease (PD). Only few studies, however, have focused on the non-motor effects of DBS. METHODS: A consecutive series of 15 patients was assessed three months before (M-3), then three months (M3) and six months (M6) after surgery. Mean (+/- SD) age at surgery was 59.7 (7.6). Mean disease duration at surgery was 12.2 (2.8) years. The Mini International Neuropsychiatric Inventory was used to assess psychiatric disorders three months before surgery. Depression was evaluated using Montgomery and Asberg Rating Scale (MADRS). Anxiety was evaluated using the AMDP system (Association for Methodology and Documentation in Psychiatry). Apathy was particularly evaluated using the Apathy Evaluation Scale (AES) and the Starkstein Scale. All these scales were performed at every evaluation. RESULTS: Apathy worsened at M3 and M6 after STN-DBS in comparison with the preoperative evaluation: the AES mean score was significantly impaired between the preoperative (38.4+/-7.1) and both the postoperative M3 (44.6+/-9.5, p = 0.003) and M6 scores (46.0+/-10.9, p = 0.013). Significant worsening of apathy was confirmed using the Starkstein scale. There was no evidence of depression: the mean MADRS score did not differ before surgery (9.1+/-7.4) and at both M3 (8.6+/-8.2) and M6 (9.9+/-7.7) after STN-DBS. The anxiety level did not change between preoperative (9.4+/-9.2) and both M3 (5.5+/-4.5) and M6 (6.6+/-4.6) postoperative states. CONCLUSION: Although STN-DBS constitutes a therapeutic advance for severely disabled patients with Parkinson's disease, we should keep in mind that this surgical procedure may contribute to the inducing of apathy. Our observation raises the issue of the direct influence of STN- DBS on the limbic system by diffusion of stimulus to the medial limbic compartment of STN.

Placebo controlled, randomised, double blind study of the effects of botulinum A toxin on detrusor sphincter dyssynergia in multiple sclerosis patients.

OBJECTIVE: The purpose of the study was to evaluate the efficacy and safety of botulinum A toxin in the treatment of detrusor sphincter dyssynergia in multiple sclerosis patients. METHODS: This was a multicentre, placebo controlled, randomised, double blind study. Patients with chronic urinary retention were included if they had post-voiding residual urine volume between 100 and 500 ml. They received a single transperineal injection of either botulinum A toxin (100 U Allergan) or placebo in the sphincter and also 5 mg slow release alfuzosin bid over 4 months. Main endpoint was post-voiding residual urine volume assessed 1 month after injection. Follow up duration was 4 months. Statistical analysis was performed using a sequential method, the triangular test. RESULTS: The study was stopped after the fourth analysis (86 patients had been included: placebo: 41, botulinum A toxin: 45). At inclusion, there was no significant difference between groups whichever variable was considered. Mean (standard deviation) post-voiding residual urine volume was 217 (96) and 220 (99) ml in placebo and botulinum A toxin groups, respectively. One month later, post-voiding residual urine volume was 206 (145) and 186 (158) ml (p = 0.45) in placebo and botulinum A toxin groups, respectively. However, compared to placebo, botulinum A toxin significantly increased voiding volume (+54%, p = 0.02) and reduced pre-micturition (-29%, p = 0.02) and maximal (-21%, p = 0.02) detrusor pressures. Other secondary urodynamic endpoints and tolerance were similar in the two groups. CONCLUSIONS: In multiple sclerosis patients with detrusor sphincter dyssynergia, a single injection of botulinum A toxin (100 U Allergan) does not decrease post-voiding residual urine volume.

Differential effects of two types of antidepressants, amitriptyline and fluoxetine, on anorectal motility and visceral perception.

BACKGROUND: Although antidepressants are used for functional gastrointestinal disorders, the mechanisms of their effects on gut are incompletely understood. AIM: To assess the effects of two types of antidepressants (tricyclic, serotoninergic) on anorectal motility and visceral perception. METHODS: A placebo-controlled, randomized, double-blind, crossover study was performed in 12 healthy male volunteers who received a single oral dose of amitriptyline (80 mg), fluoxetine (40 mg) or placebo. Drug effects were assessed using phasic isobaric distensions of the rectum with an electronic barostat (11 levels from 1 to 51 mmHg) 4 h after drug intake. Maximal rectal volume and pressure, mean and residual pressures at upper anal canal, mean pressure at lower anal canal, defecation sensation (5-level scale) and visceral perception (visual analogue scale) were recorded at each level of distending pressure. RESULTS: Ten subjects completed the study. Compared with placebo, neither amitriptyline nor fluoxetine modified rectal compliance or visceral perception. Compared with placebo, antidepressants significantly reduced mean and residual pressures at upper anal canal (-18%, P = 0.0019, and -27%, P = 0.0002, respectively, for amitriptyline; -26%, P = 0.0001, and -33%, P = 0.0001, respectively, for fluoxetine) whereas only amitriptyline significantly reduced mean pressure at lower anal canal (-16%, P = 0.0008). CONCLUSION: Both antidepressants similarly relaxed the internal anal sphincter, probably through a non-specific mechanism, without modifying visceral perception. Only amitriptyline relaxed the external anal sphincter.

[Mild Cognitive Impairment: potential therapeutics]. / Le déclin cognitif modéré ou le mild cognitive impairment (MCI): perspectives thérapeutiques.

Mild Cognitive Impairment (MCI) is an emerging concept used to describe memory decline and probably attention disturbances in otherwise intellectually intact individuals. MCI may be considered in 12 to 15 p. 100 of the cases as announcing an Alzheimer's Disease (AD). Although still speculative, the debate concerning the drugs susceptible to normalize symptoms of MCI or to stop conversion to AD must be raised. For that purpose, several long term clinical trials are running (antioxidants, nootropics, anticholinesterasics.) and new molecules in the pipe-line should be assessed in patients with the diagnosis of MCI.

Role of dopaminergic and serotonergic systems on behavioral stimulatory effects of low-dose alprazolam and lorazepam.

Several recent studies have demonstrated that alprazolam and lorazepam, administered at low doses to healthy volunteers, improve cognitive functions and psychomotor performances. Paradoxical effects of low-dose benzodiazepines have been also observed in mice, in experimental pharmacology. The aim of this work was to determine, in rat, the effect of similar low-doses of benzodiazepines on spontaneous locomotor activity and performance in the elevated zero-maze, and to investigate the underlying neurobiological mechanisms. The dose-effect and the time-course of the action were studied for both compounds. Spontaneous locomotor activity was measured using a photoelectric actimeter. The level of anxiety of the animals was assessed in the elevated zero-maze. Dopamine, serotonin, and their metabolites were assayed in the extracellular striatal fluid of the awake rat, obtained by microdialysis, by HPLC--EC. Spontaneous locomotor activity observed in rats given low-dose alprazolam and lorazepam evidenced a stimulatory effect only with alprazolam. The effect was maximum 90 min after administration of 0.0050 mg/kg alprazolam. An anxiogenic-like action was evidenced with the elevated zero-maze for the two compounds. We observed a statistically significant increase in striatal dopamine concentrations only with alprazolam, during the period corresponding to the behavioral stimulatory effects. We also showed a marked trend towards increased levels of serotonin with alprazolam but this modification was not significant, in spite of statistically significant variations of 5-HIAA. In the rat, behavioral stimulatory effects of low-dose benzodiazepines is evidenced with alprazolam but not lorazepam. This effect could be explained, at least in part, by increased extracellular dopamine concentrations in the striatum. Their different structures could explain the different pattern observed for the two benzodiazepines.

[Perspectives for drug treatment in Alzheimer's disease]. / Perspectives médicamenteuses dans la maladie d'Alzheimer.

The last decade was very fruitful in neuropharmacology and notably in the therapeutic strategies of dementia and Alzheimer's disease (AD). The amount of data, information and breakthroughs is nevertheless difficult to apply in direct relationship with patients. The present review aims at classifying information according to their origins: epidemiology, clinical trials, neurosciences. A guide for drug prescription in Alzheimer's disease is thus warranted and becomes clearer, sure that, in the next future modifications and new strategies will appear. The main goal of the present review is to summarize the state-of-the-art for a non specialist in AD.

Procedural memory in recent-onset Parkinson's disease.

Parkinson's disease is accompanied by cognitive disorders which may affect procedural memory. Procedural memory uses a specific knowledge resource that expresses itself through pre-established acting procedures. The aim of this study was to better define the characteristics of procedural memory, first of all, by trying to determine the level of involvement of that memory in the acquisition process (during learning and/or during procedure maintenance), then by specifying the effect of the type of resource involved (verbal or motor). To achieve this, we compared the mnestic performances of 20 recent-onset parkinsonian patients with those of 20 healthy controls, using two memory tasks with a fixed rule (poetry, visuomotor tracking). Result analysis revealed that parkinsonian patients had more difficulty than controls in learning the two rules, regardless of the material involved. Their deficiencies were often associated with an impairment of executive functions, and the procedural memory problems described in parkinsonian patients are linked to the involvement of these resources in the various tasks.

5-HT-moduline, a 5-HT(1B/1D) receptor endogenous modulator, interacts with dopamine release measured in vivo by microdialysis.

5-Hydroxytryptamine-moduline (5-HT-moduline) is an endogenous tetrapeptide (Leu-Ser-Ala-Leu) recently isolated and characterized from mammalian brain. This compound interacts with 5-HT1B receptors as a non-competitive, high-affinity antagonist and has the properties of an allosteric modulator. 5-HT-moduline could play an important role in the regulation of serotonergic transmission and also, through heteroreceptors, dopaminergic transmission. The aim of this work was to examine the potential ability of 5-HT-moduline to modify the basal extracellular concentration of dopamine and its metabolites (3-methoxytyramine, dihydroxyphenylacetic acid and homovanillic acid), in the rat striatum and to determine its potential interaction with the stimulating activity of a specific 5-HT1B receptor agonist, 3-(1,2,5,6-tetrahydropyrid-4-yl) pyrrolo [3,2-b] pyrid-5-one (CP-93,129), on the release of dopamine. The technique is based on in vivo microdialysis using probes implanted in the striatum of the conscious rat. Results showed that the perfusion of 5-HT-moduline directly into this structure (1.25 mM) increased the striatal level of dopamine by two-fold (104% of the absolute basal release values, P = 0.0015) and that of 3-methoxytyramine by 3-fold (293%, P = 0.0001) without any change in the terminal metabolite concentrations. The intrastriatal administration of CP-93,129 induced a statistically significant, dose-dependent increase of dopamine levels (P < 0.0001). Coperfusion of 5-HT-moduline did not significantly alter the effect of CP-93,129 at 0.1 and 0.5 mM, but appeared to have an additive effect on the lowest dose (P = 0.0406). The results obtained show that 5-HT-moduline directly administered into the striatum increases the release of dopamine in this area. Presumably, this effect results from the desensitization of 5-HT1B receptors located on dopamine terminals. However, the fact that a 5-HT1B receptor agonist (CP-93,129) also increased the release of dopamine in the striatum and that 5-HT-moduline exhibited a slight additive effect with that of a low concentration of CP-93,129 suggests that the two substances interact with different mechanisms.

Dopamine D2 receptor agonists protect against ischaemia-induced hippocampal neurodegeneration in global cerebral ischaemia.

To characterise the role played by dopamine receptors in ischaemic brain damage, we have evaluated the effects of pergolide, bromocriptine and lisuride (dopamine D2 receptor agonists), haloperidol (a dopamine D2 receptor antagonist), 2,3,4,5-tetrahydro-7,8,dihydroxy-1-phenyl-1H-3-benzazepine (SKF 38393; a dopamine D1 receptor agonist) and (R)-(+)-8-chloro 2,3,4,5-tetra-hydro-3-methyl-5-phenyl-1H-3-benzazepin-7-ol (SCH 23390; a dopamine D1 receptor antagonist) in the gerbil model of global cerebral ischaemia. Ischaemia was induced by 5 min of bilateral carotid artery occlusion under halothane anaesthesia. Sham operated animals were used as controls. Pergolide (0.5 or 1.0 mg/kg i.p), bromocriptine (0.5 or 1.0 mg/kg i.p.), lisuride (0.5 or 1.0 mg/kg i.p.), SCH 23390 (0.1 or 1.0 mg/kg i.p.), haloperidol (0.5, 1.0 or 2 mg/kg i.p.) and SKF 38393 (1.0 or 2 mg/kg i.p.) were administered 1 h before occlusion. Five-minute-occluded animals had extensive damage in the CA1 region of the hippocampus 5 days after surgery. Pergolide 0.5 and 1.0 mg/kg i.p. provided significant (P < 0.05 and P < 0.01, respectively) neuroprotection against the ischaemia-induced hippocampal damage. Bromocriptine and lisuride also provided significant (P < 0.05) neuroprotection, but only at the higher 1.0 mg/kg dose. In contrast, the dopamine D2 receptor antagonist (haloperidol), the dopamine D1 receptor agonist (SKF 38393) and the dopamine D1 receptor antagonist (SCH 23390) failed to provide any neuroprotection in the model. These results support studies indicating that dopamine is important in ischaemic situations. The results also indicate that dopamine D2 receptor agonists are neuroprotective against ischaemia-induced brain injury and may play a role in neurodegenerative disorders.

Experimental and clinical methods in the development of anti-Alzheimer drugs.

Methodology used for the development of anti-Alzheimer's disease (AD) drugs raises specific problems which are rarely examined in the literature. While the general development scheme is similar to that required for most drugs, some specific aspects must be analyzed, highly dominated by the dual goal of pharmacology, i.e., to obtain both symptomatic and etiopathogenic drugs. During preclinical studies, aged or lesioned animals are mainly useful for symptomatic drugs, whereas transgenic models or neurodegeneration-induced techniques would probably lead to etiopathogenic drugs potentially slowing down the process of AD. The first administrations of a new compound to human beings raise the question of the activity measurement techniques. Psychometry remains the most informative procedure to detect and analyze the activity of the drugs on the different components of cognition. Electrophysiology and neuroimaging need some complementary studies before they can be proposed as surrogate criteria in phase III trials. At this stage of development, American and the recently published European guidelines are of great help while insisting on long-term (6 months) placebo controlled trials with the use of the triple efficacy criterion: an objective cognition scale, a global assessment, and the opinion of the caregiver. In the long term, pharmacoepidemiology and pharmacoeconomy will have to confirm the rationale of this recent progress in the methodology of anti-AD drug development.

Lisuride prevents learning and memory impairment and attenuates the increase in extracellular dopamine induced by transient global cerebral ischemia in rats.

In this experiment, we tested the efficacy of neuroprotection with lisuride, a dopamine agonist, using the 4-vessel occlusion rat model. Functional improvement was evaluated with two behavior tests exploring learning and memorization capacity in the rat, the Morris water maze and the 14-unit T-maze, 18 days after ischemia. Extracellular dopamine levels during ischemia were determined in search of a possible neuroprotection mechanism. Dopamine and its metabolites, DOPAC and HVA, as well as the serotonin metabolite, 5-HIAA, were assayed with HPLC-EC, in striatal extracellular fluid obtained by in vivo microdialysis in the awake rat. Lisuride was administered at a total dose of 10 ng by continuous intrastriatal infusion or at the dose of 0.5 mg/kg by i.p. infusion, 160 minutes before onset of ischemia for the neurochemical study and at the dose of 0.5 mg/kg via i.p. infusion, 1 hour before occlusion of the carotid arteries, for the behavior tests. Behavioral testing showed significantly better recovery in both sets of behavioral tests, with more pronounced positive results with the 14-unit T-maze, in comparison with the saline-treated animals. Microdialysis confirmed a significant attenuation of the ischemia-induced dopamine surge, whatever the mode of administration, compared with saline-treated animals. These results show that lisuride offers significant neuroprotection from the effect of experimental transient global forebrain cerebral ischemia in the rat; the mechanism would imply, at least in part, reduced levels of extracellular dopamine.

Effect of normal aging and of Alzheimer's disease on, episodic memory.

Performances of 12 patients with Alzheimer's disease (AD), 15 healthy elderly subjects and 20 young healthy volunteers were compared on two episodic memory tests. The first, a learning test of semantically related words, enabled an assessment of the effect of semantic relationships on word learning by controlling the encoding and retrieval processes. The second, a dual coding test, is about the assessment of automatic processes operating during drawings encoding. The results obtained demonstrated quantitative and qualitative differences between the population. Manifestations of episodic memory deficit in AD patients were shown not only by lower performance scores than in elderly controls, but also by the lack of any effect of semantic cues and the production of a large number of extra-list intrusions. Automatic processes underlying dual coding appear to be spared in AD, although more time is needed to process information than in young or elderly subjects. These findings confirm former data and emphasize the preservation of certain memory processes (dual coding) in AD which could be used in future therapeutic approaches.

Is chlormethiazole neuroprotective in experimental global cerebral ischemia? A microdialysis and behavioral study.

Chlormethiazole, an anticonvulsive agent, has been shown to have a possible neuroprotective effect against cerebral ischemia. In addition, chlormethiazole inhibits methamphetamine-induced release of dopamine, protecting against this neurotransmitter's neurotoxicity. The aim of this work was to ascertain whether, in experimental cerebral ischemia, chlormethiazole administration attenuated the ischemia-induced rise of the extracellular concentration of aminergic neurotransmitters and whether it reduces ischemia-induced deficits in memory and learning. Histology for assessment of ischemic damage was a so included. The four-vessel occlusion rat model was used to induce global cerebral ischemia. Aminergic neurotransmitters and their metabolites in the striatal extracellular fluid obtained by microdialysis were assayed by high-performance liquid chromatography-electrochemical detection. The drug was administered either IP (50 mg/kg-1) or directly through the dialysis probe (30 microM) 80 min before ischemia. For the behavioral test and histology, the drug was given IP (100 mg/kg-1) 1 h postischemia. The results obtained did not demonstrate any statistically significant evidence that chlormethiazole has an effect on the ischemia-induced rise in extracellular dopamine and serotonin levels. There was also no variation in metabolite levels. Behavioral measures (learning, recall) were not changed appreciably by the treatment. We observed no significant cell protection in the hippocampus (CA1, CA1), striatum, and entorhinal cortex in animals treated with chlormethiazole. We conclude that, under our experimental conditions, chlormethiazole has little or no effect on the neurochemical, neurobehavioral, and histological consequences of global cerebral ischemia.

Assessment of procedural memory in Parkinson's disease.

1. Findings in cognitive psychology and neuropsychology have led to consider the existence of several mnestic systems. This study focuses on a now clearly established distinction between the procedural and the declarative memories. 2. The aim of the present study was to try and determine which of the two acquisition steps (learning and automation) is affected by Parkinsonians' mnestic difficulties, and to verify if these difficulties are linked to the skill content (declarative or motor). 3. To answer these questions, 20 Parkinsonians under treatment underwent specific tests: the maze test and the arithmetic alphabet test. 4. Results show that, by comparison with 20 matched healthy individuals, the deficiencies observed in Parkinson's disease affect both the declarative and the motor skills. In addition, Parkinsonians suffer difficulties in both acquisition steps: learning and automation. 5. These results could account for the cognitive and motor disturbances observed in Parkinson's disease; these abnormalities should be among the pharmacological targets in future.

The dopamine agonists lisuride and piribedil protect against behavioural and histological changes following 4-vessel occlusion in the rat.

The 4-vessel occlusion model of ischaemia in the rat was used to assess the effects of two dopaminergic agonists, lisuride and piribedil, on some behavioural and histological changes. Animals were either sham-operated, subjected to 20 min 4-vessel occlusion, or administered lisuride (0.5 mg/kg i.p.) or piribedil (10 mg/kg i.p.) 1 h before 20 min 4-vessel occlusion. Both drugs attenuated deficits in neurological testing, Morris water maze and 14-unit T-maze (p < 0.05). Extensive neuronal death was observed in the CA1, CA3 and CA4 regions of the hippocampus of 4-vessel-occluded animals. Pretreatment with both lisuride and piribedil provided protection against cell death in the hippocampal regions. These findings suggest dopamine may play a role in cerebral ischaemia and dopaminergic agonists may be beneficial in preventing ischaemia-induced neurodegeneration.

Procedural memory and Parkinson's disease.

A detailed analysis of the mnestic deficits associated with Parkinson's disease (PD) contributes to explaining the cognitive disorders and their well documented consequences. This study was designed to show that, in PD declarative as well as procedural memory is severely impaired. Three tests designed to explore this aspect of mnestic functioning were proposed to a group of 16 parkinsonian patients whose motoricity was controlled: inverted reading, braille reading, sound form association. The results obtained, compared with those of young and aged controls, show that PD is associated with marked deficits in both declarative and procedural memory. Declarative memory impairment was similar to that observed in the control population (healthy elderly subjects, age-matched with the PD patients) but more marked in PD subjects. The procedural memory deficit was linked with age and pathology. Procedural memory involves a variety of processing modules dedicated to the type of information (visual, auditive, tactile codes). The deficits observed were more like a loss of automatism than procedural impairment stricto sensu ('knowing how'). It would be worth pursuing research by studying akinesia and motor disorders from the angle of automatic memory impairment.

Explicit and procedural memory in Parkinson's disease.

One of the aims of cognitive psychology is to breakdown complex tasks into their most basic components. The components of explicit (declarative) and implicit (procedural) memory were thus analyzed in undemented, non-depressed Parkinsonian patients under anti-Parkinsonian treatment, and compared with young and elderly healthy subjects. Three series of experiments were conducted in 61 patients in total. Statistically significant results revealed an impairment of explicit memory (verbal recall of words and drawings) with preserved recall of faces, in Parkinsonians. Implicit memory was also deficient, only in association tests (sound-form; arithmetical alphabet) and maze tests. Braille reading tests and Toronto tower tests did not discriminate between Parkinsonians and elderly subjects. Lastly, analyzing learning and automation revealed a dysfunctioning in Parkinsonian patients. All these data indicate a dysregulation of the cortical-sub-cortical systems, not essentially pre-frontal, and not necessarily dopaminergic. Cognitively, it appears that procedural and implicit memories should be dissociated conceptually.

[Role of isotopic imaging in intensive care]. / Place de l'imagerie isotopique en réanimation.

The real place of isotopic imaging in intensive care patients remains still unclear. This review aimed to consider the indications of isotopic imaging for improved diagnosis and therapy and to specify its place among the other techniques of exploration. Pulmonary perfusion and ventilation scintigraphies are valuable for the diagnosis of pulmonary embolism (PE). A "high probability" scintigraphy of the lungs ascertains the diagnosis of PE and allows to start a specific treatment without requiring a pulmonary angiography. This is not the case in the presence of a history of previous PE or if the arguments for a PE are only weak. A normal lung scintigraphy eliminates the diagnosis of a clinically significant PE all the more as an exploration of good quality of the lower limb veins remains negative. In the opposite a "non diagnostic" scintigraphy justifies a pulmonary angiography in intensive care patients. The diagnosis of myocardial contusion is made uneasy as the clinical symptoms, the ECG, the cardiac enzymes and the chest X-ray are only of limited value. Isotopic explorations of the heart could provide additional valuable data or be an alternative for 2 D echocardiography. The comparison of CPK-MB concentrations with a myocardial scintigraphy using thallium 201 is given as being very reliable, with positive and negative predictive values higher than 80%. An exploration restricted to the cardiac ejection fractions is only of limited value. In the future, an improvement will perhaps be obtained with tracers such as MIBI labelled with technetium 99m, which allow the simultaneous assessment of myocardial perfusion and the ventricular ejection fractions as well. The localisation of centres of infection, especially when intra-abdominal, remains difficult in intensive care patients. Isotopic imaging, especially the scintigraphies with labelled polynuclears, could allow in combination with conventional imaging techniques (computed tomography and 2 D echocardiography) to prevent from errors in diagnosis. An array of arguments is essential for ascertaining the presence of an abscess. Scintigraphies with leucocytes labelled with indium 111 or technetium 99m are qualified as having a sensitivity and a specificity greater than 90%. The conventional techniques of measurement of the cerebral blood flow (CBF) using xenon 133 require a special equipment or are invasive. Other cerebral tracers, such as cyclic amines (HMPAO) labelled with technetium 99m and administrable by i.v. route, allow the use of a standard tomo-gamma camera, and could be of help in various pathological conditions.(ABSTRACT TRUNCATED AT 400 WORDS)