Disminución del transportador de dopamina estriatal en primeros episodios psicóticos de pacientes esquizofrénicos tratados con risperidona

Extrapyramidal symptoms and Parkinsonism (PS) are side effects commonly observed with antipsychotic treatment. However, about 24% of never-treated schizophrenic patients may suffer from PS, which contrast with that 1% observed from the general population. 123I-FP-CIT SPECT has probe useful to differentiate degenerative from non-degenerative PS, so it could be interesting using it for establishing the functional state of presynaptic dopamine neurons of these patients.

AIM

To determine the dopamine transporter binding (DAT) in a homogeneous group of first-episode schizophrenic patients.

METHODS

An open, transversal study. Thirty schizophrenic in-patients and 15 healthy subjects were recruited. Patients were treated with similar doses of risperidone and all subjects were scanned with 123I-FP-CIT. Extrapyramidal symptoms and psychopathological status was assessed by Simpson-Angus, CGI and PANSS. Semi-quantitative analyses of SPECT images were performed using ROIs placed in caudate nucleus, anterior, medium and posterior putamen and occipital cortex.

RESULTS

Whole striatum 123I-FP-CIT binding ratio was significantly lower in patients than healthy subjects (t = 2.56, p < 0.014). This was observed in whole putamen (t = 2.66, p < 0.011), anterior (t = 2.35, p < 0.023), medium (t = 2.38, p < 0.022) and posterior putamen (t = 2.09, p < 0.042). No differences were observed in caudate nucleus (t = 1.81, p = 0.076). Females obtained higher binding ratios than males (t = -3.13, p < 0.003). No correlation was observed between 123I-FP-CIT binding ratios and clinical scales.

CONCLUSION

In our series, first episode schizophrenic patients treated with risperidone have a decrease striatal DAT binding assessed with 123I-FP-CIT SPECT. This alteration could be related to their own schizophrenia disease or be secondary to the antipsychotic treatment.

Standardized remission criteria in schizophrenia

OBJECTIVE

Recent work has focussed on schizophrenia as a 'deficit' state but little attention has been paid to defining illness plasticity in terms of symptomatic remission.

METHOD

A qualitative review of a recently proposed concept of remission [N.C. Andreasen, W.T. Carpenter Jr, J.M. Kane, R.A. Lasser, S.R. Marder, D.R. Weinberger (2005) Am J Psychiatry 162: 441] is presented.

RESULTS

The proposed definition of remission is conceptually viable, and can be easily implemented in clinical trials and clinical practice. Its increasing acceptance may reset expectations of treatment to a higher level, improve documentation of clinical status and facilitate dialogue on treatment expectations. The availability of validated outcome measures based on remission will enhance the conduct and reporting of clinical investigations, and could facilitate the design and interpretation of new studies on cognition and functional outcomes. While useful as a concept, it is important to consider that remission is distinct from recovery.

CONCLUSION

The introduction of standardized remission criteria may offer significant opportunities for clinical practice, health services research and clinical trials.

The mef(A) gene predominates among seven macrolide resistance genes identified in gram-negative strains representing 13 genera, isolated from healthy Portuguese children

Of the 176 randomly selected, commensal, gram-negative bacteria isolated from healthy children with low exposure to antibiotics, 138 (78%) carried one or more of the seven macrolide resistance genes tested in this study. These isolates included 79 (91%) isolates from the oral cavity and 59 (66%) isolates from urine samples. The mef(A) gene, coding for an efflux protein, was found in 73 isolates (41%) and was the most frequently carried gene. The mef(A) gene could be transferred from the donors into a gram-positive E. faecalis recipient and a gram-negative Escherichia coli recipient. The erm(B) gene transferred and was maintained in the E. coli transconjugants but was found in 0 to 100% of the E. faecalis transconjugants tested, while the other five genes could be transferred only into the E. coli recipient. The individual macrolide resistance genes were identified in 3 to 12 new genera. Eight (10%) of the oral isolates and 30 (34%) of the urine isolates for which the MICs were 2 to >500 microg of erythromycin per ml did not hybridize with any of the seven genes and may carry novel macrolide resistance genes.

No brain perfusion impairment at long-term follow-up in elderly patients treated with electroconvulsive therapy for major depression

No functional neuroimaging study has previously assessed the long-term effects of electroconvulsive therapy (ECT) on brain perfusion. In this study, long-term follow-up brain perfusion in elderly patients treated with ECT for severe unipolar major depression was assessed. In 14 elderly major depressed patients who were ECT remitters, 22 elderly major depressed patients who were pharmacological treatment remitters and 25 age- and sex-matched healthy controls, a medication-free brain 9mTc-HMPAO-SPECT was performed after a minimum period of 12 months of euthymia and, in the case of the ECT remitters, at least 12 months after the last ECT session. Brain perfusion ratios in major depressed patients administered ECT were similar to those in major depressed patients receiving pharmacological treatment and in control subjects. This result suggests that elderly patients given ECT for severe unipolar major depression do not suffer brain perfusion abnormalities at long-term follow-up. Our study adds new evidence in favor of the safety of the ECT, particularly in elderly subjects.

Internal magnetic gradient fields in glass bead packs from numerical simulations and constant time diffusion spin echo measurements

Internal magnetic field gradients in water saturated glass bead packs were studied by numerical simulations and a constant time spin echo (CTSE) experiment. The CTSE is comprised of two spin echo refocusing periods where each of the two evolution periods, tau1 and tau2, is varied so that the total evolution, 2(tau1 + tau2), is held constant. The experiment is similar to that introduced by Norwood and Quilter and allows the effects of dephasing due to diffusion in a magnetic field gradient to be separated from other relaxation mechanisms. In our experiments, the magnetic susceptibility difference between the pore fluid and glass beads creates the internal field gradient. CTSE measurements were performed at 7 T (300 MHz 1H) for water saturated in 50 microm diameter glass bead pack. We find that the internal gradients in the center of the pore bodies, where free diffusion applies, is in the range of 10 to 100 G/cm. This fluid volume accounts for < or =10% of the total pore volume. From direct numerical simulations of the internal magnetic field based on a first principles calculation, we find that the major fraction, >90%, of the pore volume has internal gradients of order 500 to 5,000 G/cm. Signals from water in these large gradients is not observed in our CTSE measurements.

Observation of electro-osmotic flow echoes in porous media by nuclear magnetic resonance

A method for assessing the time reversibility of molecular displacements in fluids is presented. The method utilizes pulsed field gradient NMR experiments, in which the flow driving force is inverted during the magnetization lifetime in each measurement cycle. The method is suitable for opaque three-dimensional systems and short displacements, and provides inherent separation between thermal diffusion and displacements driven by externally controlled forces. This approach was applied to study the time reversibility of an electric-field-driven flow of water in natural sand samples, over time scales of up to 0.4 s and displacement scales of the order of one particle diameter. It is demonstrated that the intensity loss of the NMR signal, caused by flow-induced phase dispersion, is fully refocused upon inversion of the polarity of the applied electric field, resulting in flow echoes.

[Assessment of frontal functions in psychiatric patients during maintenance electroconvulsive therapy]

INTRODUCTION

Previous studies on adverse cognitive effects of electroconvulsive therapy (ECT) have not found any significant alteration of the frontal functions after an acute treatment course. This study aims to assess frontal executive functions in psychiatric patients during maintenance electroconvulsive therapy (M-ECT).

SUBJECTS AND METHODS

Thirty two patients treated with M-ECT and 29 psychiatric patients never treated with ECT were evaluated with neuropsychological tests that assessed the following frontal functions: work memory, planning, cognitive flexibility, attention, visuomotor velocity, verbal abstract reasoning and phonetic verbal fluency.

RESULTS

Multivariate global analysis did not detect significant frontal function tests differences between both groups. The M-ECT group only scored significantly lower on the FAS test, a test that measures phonetic verbal fluency. A significant correlation between number of previous ECT sessions and performance in the FAS was found.

CONCLUSIONS

The M-ECT patient group presented a phonetic verbal fluency alteration that may also be associated to the previous number of ECT sessions. No significant differences in the other frontal functions were detected.

Pattern of cognitive dysfunction in depressive patients during maintenance electroconvulsive therapy

BACKGROUND

Objective data regarding adverse cognitive deficits associated with maintenance electroconvulsive therapy (M-ECT) are lacking. This study examined the cognitive state of depressive patients during M-ECT.

METHOD

A cross-sectional study was carried out in 11 depressive patients in remission, all with a DSM-IV diagnosis of major depressive disorder. The mean number of previous ECT sessions was 36.1, and the mean intersession interval was 52.7 days. A group of 11 patients who had not received ECT was selected for comparison and matched for diagnosis, sex, age and years of schooling. All subjects were assessed using a complete neuropsychological battery including memory, attention and frontal function tests.

RESULTS

Groups did not present differences in long delay verbal recall. Encoding of new information and results on the frontal function tests were significantly lower in the M-ECT patients.

CONCLUSION

Depressed patients preserve long-term memory, but suffer short-term memory impairment and frontal function alteration during M-ECT. Further longitudinal studies are necessary to determine the influence of M-ECT on non-memory functions and different memory subtypes.

[Functional neuroimaging of auditory hallucinations in schizophrenia]

The neurobiological bases underlying the generation of auditory hallucinations, a distressing and paradigmatic symptom of schizophrenia, are still unknown in spite of in-depth phenomenological descriptions. This work aims to make a critical review of the latest published literature in recent years, focusing on functional neuroimaging studies (PET, SPECT, fMRI) of auditory hallucinations. Thus, the studies are classified according to whether they are sensory activation, trait and state. The two main hypotheses proposed to explain the phenomenon, external speech vs. subvocal or inner speech, are also explained. Finally, the latest unitary theory as well as the limitations the studies published are commented on. The need to continue investigating in this field, that is still underdeveloped, is posed in order to understand better the etiopathogenesis of auditory hallucinations in schizophrenia.

[Venlafaxine titration dosage in depressive in-patients. A series of cases]

This series of patients was gathered to assess the use of last and slow titration dosage of venlafaxine in in-patients with major depression and to evaluate the action onset. An observational open study was performed in 3 centers in 18 in-patients. Nine patients were included in fast titration dosage group (FT) and 9 in slow titration dosage group (ST). As results, it was found that the FT group showed faster improvement than the ST group in HAM-D score. This improvement was sustained to the final visit, with a lower score in the FT group (6.75) than the ST group (10.67). MADRS scores up to the 15th visit were similar; however, the score was lower in the ST group on the 20th visit. Improvement was sustained to the final visit, the FT group score being lower (6.50) than the ST group score (14). CGI - i mprovement and CGI-seve rity scores we re similar to the above mentioned results. The most common events in both groups were considered mild. The data of these patients show faster response to antidepressant therapy with faster titration dosage, with maintenance of the molecule's tolerability profile.

[Selective alteration of the declarative memory systems in patients treated with a high number of electroconvulsive therapy sessions]

INTRODUCTION

The reversible electrochemical effects of electroconvulsive therapy (ECT) on specific areas of the brain enable the neuroanatomical bases of some cognitive functions to be studied. In research carried out on memory systems, a selective alteration of the declarative ones has been observed after treatment with ECT. Little work has been done to explore the differential alteration of the memory subsystems in patients with a high number of ECT sessions. AIM. To study the declarative and non declarative memory system in psychiatric patients submitted to maintenance ECT treatment, with a high number of previous ECT sessions.

PATIENTS AND METHODS

20 patients submitted to treatment with ECT (10 diagnosed as having depression and 10 with schizophrenia) and 20 controls, who were paired by age, sex and psychopathological diagnosis. For the evaluation of the declarative memory system, the Wechsler Memory Scale (WMS) logical memory test was used. The Hanoi Tower procedural test was employed to evaluate the non declarative system.

RESULTS

Patients treated with ECT performed worse in the WMS logical memory test, but this was only significant in patients diagnosed as suffering from depression. No significant differences were observed in the Hanoi Tower test.

CONCLUSIONS

A selective alteration of the declarative systems was observed in patients who had been treated with a high number of ECT sessions, while the non declarative memory systems remain unaffected.

Persistence of oral Candida albicans carriage in healthy Portuguese schoolchildren followed for 3 years

Little is known about carriage of Candida albicans, the predominant pathogenic yeast in oral infection, in children. We cultured buccal mucosal and gingival swabs from 150 Portuguese children to investigate the prevalence of C. albicans at baseline (before dental treatment), post-treatment, and 12, 24, and 36 months post-baseline. The children, aged 8 to 11 years at baseline, had no systemic disease or clinical symptoms of oral candidiasis. At each successive visit, respectively, 47, 32, 21, 27, and 28% of children were C. albicans positive, resulting in an almost 50% reduction in prevalence from baseline to post-treatment (P < 0.0005). Children who carried C. albicans at one visit had 3 to 20 times greater odds of carrying C. albicans at another visit. C. albicans was cultured from 12 children at all time-points and from 10 children at four time-points. Children with oral C. albicans frequently maintained carriage over time, even with regular dental care.

Cardiovascular Response and Anesthetic Recovery in Electroconvulsive Therapy with Propofol or Thiopental

Propofol provokes a slight hypotensive effect that could mitigate the cardiovascular response to electroconvulsive therapy (ECT). In this study we compared the effects of propofol and thiopental for ECT anesthesia in seven women (22-67 years of age). Anesthesia was induced with either thiopental or propofol, and with atropine and suxamethonium for each treatment. The first anesthesia was assigned to thiopental or propofol at random; the next anesthesia was induced with the other drug, and alternated thereafter. Systolic blood pressure, diastolic blood pressure (DBP), and heart rate (HR) were recorded before anesthesia, after anesthetic induction, and 1 and 5 min after ECT. ECT-induced increases in DBP and HR were less marked with propofol than with thiopental. Seizure durations were decreased with propofol compared with thiopental.

Examination of dietary methylmercury exposure in the Casa Pia Study of the health effects of dental amalgams in children

This study examined methylmercury concentrations in blood of children participating in the Casa Pia Study of the Health Effects of Dental Amalgams in Children over a 1-yr period and related them to their diets in terms of fish and other seafood consumption. One hundred and fifty children between the ages of 8 and 10 yr who were residents of the Casa Pia School System of Lisbon, Portugal, participated. Parents or caregivers completed a food frequency questionnaire designed specifically for this study at baseline. Children provided urinary and blood samples for mercury determinations at baseline and at 1 yr following placement of dental tooth fillings. Mercury levels in fish samples from children's diets were also obtained. Mercury determinations in urine, blood, and fish were performed using cold vapor atomic fluorescence spectroscopy. The mean value of baseline methylmercury concentrations in blood increased as the report of seafood consumption increased, although not statistically significantly. However, blood methylmercury and total mercury concentrations were significantly lower at 1-yr follow-up than at baseline. Sixty-one percent of parents/caregivers reported that their children consumed fish on a weekly basis. The fish offered at a sample of the schools contained low levels of methylmercury (range 13.9-23.6 ng/g). Thus, children participating in the Casa Pia dental amalgam study are exposed to low dietary levels of methylmercury by way of fish consumption, and this finding was reflected in the low mean blood methylmercury concentrations observed. The present findings indicate that dietary methylmercury is not a significant source of mercury exposure and is not likely to confound the association of dental amalgam mercury with potential health effects in the present study.

Comparative hemodynamic effects of urapidil and labetalol after electroconvulsive therapy

Urapidil, a postsynaptic alpha 1 -adrenergic antagonist, has been reported to improve intraoperative hemodynamic stability, although it has never been used to prevent the hemodynamic response of electroconvulsive therapy (ECT). This study was designed to evaluate the clinical effectiveness of urapidil, as an alternative to labetalol, in preventing the hemodynamic response of ECT. Twenty-seven patients undergoing a series of six consecutive ECT treatments were studied. Each patient received all three pretreatments twice: no drug, labetalol 0.2 mg/kg, or urapidil 25 mg. Systolic, diastolic, and mean blood pressure and heart rate (HR) were recorded during the awake state, after anesthesia induction, and 1, 2, 5, 10 and 30 minutes after electroencephalographic (EEG) seizure ended. The duration of the EEG convulsion was also recorded. After induction, the HR increased for no drug and urapidil pretreatments, whereas it decreased when labetalol was given. Labetalol and urapidil attenuated the peak increase of blood pressure and returned it to earlier baseline values. There were no differences in the duration of EEG convulsion between the three pretreatments. Urapidil seems to be a good alternative to labetalol for attenuating the hypertensive response to ECT in cases where there is a contraindication to beta-antagonists.

Double-blind olanzapine vs. haloperidol D2 dopamine receptor blockade in schizophrenic patients: a baseline-endpoint

The aim of this study was to compare in vivo striatal D2 dopamine receptor occupancy induced by olanzapine and haloperidol in schizophrenic patients using a baseline-endpoint [(123)I]IBZM single photon computed emission tomography (SPECT) design. The relationships of striatal D2 receptor occupancy with clinical efficacy and extrapyramidal symptoms (EPS) were also assessed. Twenty-seven inpatients with schizophrenia or schizophreniform disorder were included in a 4-week prospective, randomized, double-blind, parallel and comparative clinical trial. Thirteen patients were treated with haloperidol (10 mg/day) and 14 with olanzapine (10 mg/day). Ratings of clinical status and EPS were obtained weekly. The percentage of D2 receptor occupancy was estimated by using basal ganglia (striatum)/frontal cortex IBZM uptake ratios obtained from each patient before and after 4 weeks of maintained antipsychotic treatment. Olanzapine led to a mean striatal D2 receptor occupancy of 49% (range 28-69%), which was significantly lower than that induced by haloperidol (mean 64%, range 46-90%). The baseline-endpoint SPECT design used in this study revealed lower antipsychotic D2 occupancy percentage values than those reported in the literature, using other approaches. The degree of striatal D2 receptor occupancy correlated to the EPS, which predominantly appeared in patients on haloperidol. No relationship was found between the striatal D2 receptor occupancy and clinical improvement. Olanzapine induced a lower striatal D2 occupancy than haloperidol. This low striatal D2 occupancy, together with the lower incidence of EPS in olanzapine-treated patients, contributed to confirm the atypical behavior of this new antipsychotic drug. Nevertheless, conclusions based on SPECT-estimated percentages of antipsychotic D2 occupancy should be cautious, since the SPECT design could influence the results. In this regard, SPECT studies including baseline and endpoint examinations should be encouraged.