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Biomedical subjects

E Parellada

Publications and source records attributed to E Parellada.

18 recordsLinked to original sources
PubMed2005

Patients in the early phases of schizophrenia and schizoaffective disorders effectively treated with risperidone long-acting injectable.

The efficacy and safety of risperidone long-acting injectable (RLAI) was investigated in patients in the early phases of schizophrenia and schizoaffective disorders (< or = 3 years). Patients who required a treatment change received RLAI (2-weekly gluteal injections of 25, 37.5 or 50 mg, per clinical judgement), without an oral risperidone run-in phase.A total of 382 patients were included in this 6-month open-label study; 73% of patients completed the study. A total of 84% had schizophrenia with a median duration of 1.0 year since diagnosis. Previous medications were mainly atypical antipsychotics (70%) and depot neuroleptics (24%). The main reasons for treatment change were non-compliance (42%) and insufficient efficacy (31%) of previous medication. The total Positive and Negative Syndrome Scale (PANSS) and all its subscale scores improved significantly (p < or = 0.0001), with 40% of patients showing a 20% improvement on total PANSS. Global Assessment of Functioning, quality of life, patient satisfaction and movement disorders also improved significantly. Tolerability of RLAI was generally good and no unexpected adverse events were reported. The ensured delivery of medication with RLAI resulted in significant symptom improvement in this patient population. Direct initiation of RLAI is well accepted by patients. RLAI might represent a novel option for patients in the early phases of psychosis.

Adult↗
PubMed2001

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.

Adult↗
PubMed1998

The resting and activation issue of hypofrontality: a single photon emission computed tomography study in neuroleptic-naive and neuroleptic-free schizophrenic female patients.

BACKGROUND: Functional neuroimaging findings of "hypofrontality" in schizophrenic patients is still controversial, due to the heterogeneity of methods and patient samples. This study tries to prevent some of these concerns by studying neuroleptic-naive (NN) and neuroleptic-free (NF) young female patients both in resting conditions and during a frontal cognitive activation task. METHODS: Regional cerebral blood flow (rCBF) was studied at rest and during the Wisconsin Card Sorting Test (WCST) in 25 young acute unmedicated schizophrenic female patients (14 NN and 11 NF) and 15 female controls, using single photon emission computed tomography. RESULTS: The schizophrenic and control groups did not differ in rCBF during the baseline condition, but the schizophrenic group failed to activate the frontal lobe during the WCST condition. In addition, the left anterior temporal rCBF at rest correlated with the Scale for the Assessment of Positive Symptoms total score. CONCLUSIONS: The results suggest that hypofrontality in young acute unmedicated schizophrenic patients is a result of an inability to activate frontal regions during cognition, rather than a baseline decrease in frontal activity. Furthermore, positive symptoms seem to be associated with left temporal cortex activity.

Adult↗
PubMed1998

Role of the cingulate gyrus during the Wisconsin Card Sorting Test: a single photon emission computed tomography study in normal volunteers.

The purpose of this study was to investigate the effect of the Wisconsin Card Sorting Test (WCST) on frontal regional cerebral blood flow (rCBF) in normal subjects, separating the cingulate gyrus from the prefrontal cortex. Two technetium-99m-hexamethyl-propylene-amine-oxime brain single photon emission computed tomography (SPECT) scans, at rest and during WCST performance, were performed in randomized order on 13 right-handed normal volunteers. A statistically significant rCBF increase was found in the left inferior cingulate and the left posterior frontal region, although rCBF ratios in the left and right prefrontal cortex, and in the right inferior cingulate, were slightly higher during WCST performance in nine of the 13 subjects studied. No differences in activation scores (activated-resting rCBF ratios) were found between subjects who had the resting SPECT first and subjects who had the resting condition second. These results suggest that the inferior cingulate cortex, a limbic region that has been implicated in attentional mechanisms, plays a significant role in WCST performance. Furthermore, the motor component of the WCST may account for the activation of the left posterior frontal region. In addition, no order effect was found in this study. These findings illustrate the advantage of independently evaluating the cingulate gyrus and the prefrontal cortex in SPECT studies of frontal cognitive function.

Adult↗
PubMed1996

Regional cerebral blood flow pattern in normal young and aged volunteers: a 99mTc-HMPAO SPET study.

The aim of this study was to investigate the normal pattern of regional cerebral blood flow (rCBF) distribution in normal young and aged volunteers using technetium-99m hexamethylpropylene amine oxime (99m-Tc-HMPAO) as a tracer. The region brain perfusion of young and aged subjects was compared, especially regarding rCBF differences due to age and gender, and interhemispheric rCBF asymmetries. Sixty-eight right-handed normal volunteers - 40 young (mean age 29. 5+/-6.3 years) and 28 aged (mean age 71.2+/-4.3 years) - were included in the study. rCBF was estimated on the basis of a semiquantitative approach by means of a left/right index and two region/reference ratios, using the cerebellum and the whole brain activity as references. A good correlation between these two region/reference ratios was found (P<0.005 in all cerebral regions). The highest rCBF ratios corresponded to the cerebellum, followed by the occipital lobe. The remaining cortical regions (temporal, parietal, frontal and basal ganglia) showed slightly lower values. The white matter showed rCBF ratios substantially lower than the grey matter. In neither young nor aged subjects were significant rCBF differences between the genders found in any of the two region/reference indices employed. Aged subjects showed significantly lower rCBF ratios than young subjects in the left frontal lobe and in the posterior region of the left temporal lobe. In both young and aged subjects, lower perfusion was found in the left hemisphere, except for the white matter region in both age groups and the frontal lobe in the young subjects. Aged subjects presented a slightly higher interhemispheric asymmetry in the frontal lobe. However, interhemispheric asymmetry was minimal (-1. 01% to 3.14%). Consequently, a symmetrical rCBF distribution can be assumed between homologous regions, independent of age.

Adult↗
PubMed1996

Baseline, visual deprivation and visual stimulation 99TCm-HMPAO-related changes in visual cortex can be detected with a single-head SPET system.

To determine the sensitivity of 99TCm-hexamethylpropylene amine oxime (99TCm-HMPAO) and a single-head SPET (single photon emission tomography) system in the detection of perfusion changes in the visual cortex due to different visual conditions, six normal healthy volunteers were studied under conditions of visual deprivation (blindfolded), visual stimulation (stroboscopic light) and baseline (dim light and eyes open). Visual cortex/whole-brain activity ratios, and the percentage of activity change between the different visual conditions were calculated after three-dimensional realignment of the images. The activity in the visual cortex was higher during visual stimulation than during the visual deprivation (P = 0.002, 17.6 +/- 8.6% increase) and baseline conditions (P = 0.009, 8.8 +/- 5.6% increase). Furthermore, the activity in the visual cortex was lower during the visual deprivation than in the baseline condition (P = 0.001, 8.1 +/- 2.9% decrease). 99TCm-HMPAO SPET, even with a single-head system, is capable of detecting changes in rCBF in the striate cortex, not only between conditions of visual stimulation and deprivation, but also between these two conditions and the baseline state.

Adult↗
PubMed1994

Prefrontal dysfunction in young acute neuroleptic-naive schizophrenic patients: a resting and activation SPECT study.

Regional cerebral blood flow (rCBF) was measured with single photon emission computed tomography (SPECT) in six neuroleptic-naive, young, acute schizophrenic patients and six normal control subjects. We evaluated rCBF changes in prefrontal areas at rest and during a prefrontal activation task, the Wisconsin Card Sorting Test (WCST). Schizophrenic patients had significantly higher prefrontal blood flow than did control subjects during the resting conditions. During activation, the control group showed significant increases in prefrontal blood flow, whereas the schizophrenic group did not. These results suggest that at rest there is no evidence of hypofrontality, whereas hyperfrontality seems to be the most frequent pattern in our selected sample of young acute neuroleptic-naive schizophrenic patients. Furthermore, schizophrenic patients seem to be unable to increase prefrontal blood flow under conditions that challenge the prefrontal cortex.

Adult↗
PubMed1994

Prefrontal and temporal blood flow in schizophrenia: resting and activation technetium-99m-HMPAO SPECT patterns in young neuroleptic-naive patients with acute disease.

UNLABELLED: This study assesses prefrontal and temporal regional cerebral blood flow (rCBF) changes in young, neuroleptic-naive schizophrenic patients with acute disease. METHODS: A selected population of 10 young, never-treated schizophrenic women with acute disease was studied by two hexamethylpropyleneamine oxime (HMPAO) brain SPECT sessions, performed 48 hr apart, both at rest and during a prefrontal activation task using the Wisconsin Card Sort Test (WCST). All patients met Diagnostic and Statistical Manual of Mental Disorders, 3rd edition-revised criteria for schizophrenia or schizophreniform disorder, were neuroleptic-naive and had acute symptoms. RESULTS: Under resting conditions, the schizophrenic group had significantly higher rCBF in the prefrontal regions, mainly in the left side and including the anterior cingulate, than did the controls. In addition, schizophrenic patients showed significant interhemispheric differences in prefrontal and posterior temporal index values at rest (left hyperfrontality and left hypotemporality). During WCST activation, the control group showed significant increases in prefrontal blood flow, whereas the schizophrenic group did not. CONCLUSION: These results support a physiologic dysfunction of the prefrontal cortex in schizophrenia that is present at the onset of the illness prior to neuroleptic treatment. Furthermore, both left hyperfrontality and left hypotemporality may indicate a brain lateralization defect in schizophrenia.

Acute Disease↗
PubMedDate not supplied

[Striatal dopamine transporter density decrease in first episode schizophrenic patients treated with risperidone].

UNLABELLED: 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.

Adult↗
PubMedDate not supplied

Psychopathology and wisconsin card sorting test performance in young unmedicated schizophrenic patients.

The relationship between psychopathology and Wisconsin Card Sorting Test (WCST) performance was evaluated in 25 unmedicated young acute schizophrenic female patients (14 neuroleptic-naive and 11 neuroleptic-free) and 15 female controls. The schizophrenic patients (especially the neuroleptic-free) performed more poorly than controls in the WCST. In addition, WCST impairment correlated with both negative and positive symptoms. The results suggest that the neuropsychological dysfunction in schizophrenia is present at the onset of the illness, and is neither secondary to previous neuroleptic treatment nor to chronicity of the illness.

Acute Disease↗
PubMedDate not supplied

[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.

Brain↗