Early treatment with JNJ-46356479, a mGluR2 modulator, improves behavioral and neuropathological deficits in a postnatal ketamine mouse model of schizophrenia

Positive allosteric modulators of the metabotropic glutamate receptor 2 (mGluR2), such as JNJ-46356479 (JNJ), may mitigate the glutamate storm during the early stages of schizophrenia (SZ), which could be especially useful in the treatment of cognitive and negative symptoms. We evaluated the efficacy of early treatment with JNJ or clozapine (CLZ) in reversing behavioral and neuropathological deficits induced in a postnatal ketamine (KET) mouse model of SZ. Mice exposed to KET (30 mg/kg) on postnatal days (PND) 7, 9, and 11 received JNJ or CLZ (10 mg/kg) daily in the adolescent period (PND 35-60). Mice exposed to KET did not show the expected preference for a novel object or for social novelty, but they recovered this preference with JNJ treatment. Similarly, KET group did not show the expected dishabituation in the fifth trial, but mice treated with JNJ or CLZ recovered an interest in the novel animal. Neuronal immunoreactivity also differed between treatment groups with mice exposed to KET showing a reduction in parvalbumin positive cells in the prefrontal cortex and decreased c-Fos expression in the hippocampus, which was normalized with the pharmacological treatment. JNJ-46356479 treatment in early stages may help improve the cognitive and negative symptoms, as well as certain neuropathological deficits, and may even obtain a better response than CLZ treatment. This may have relevant clinical translational applications since early treatment with mGluR2 modulators that inhibit glutamate release at the onset of critical phases of SZ may prevent or slow down the clinical deterioration of the disease.

Personalized medicine begins with the phenotype: identifying antipsychotic response phenotypes in a first-episode psychosis cohort

AIMS

Here, we present a clustering strategy to identify phenotypes of antipsychotic (AP) response by using longitudinal data from patients presenting first-episode psychosis (FEP).

METHOD

One hundred and ninety FEP with complete data were selected from the PEPs project. The efficacy was assessed using total PANSS, and adverse effects using total UKU, during one-year follow-up. We used the Klm3D method to cluster longitudinal data.

RESULTS

We identified four clusters: cluster A, drug not toxic and beneficial; cluster B, drug beneficial but toxic; cluster C, drug neither toxic nor beneficial; and cluster D, drug toxic and not beneficial. These groups significantly differ in baseline demographics, clinical, and neuropsychological characteristics (PAS, total PANSS, DUP, insight, pIQ, age of onset, cocaine use and family history of mental illness).

CONCLUSIONS

The results presented here allow the identification of phenotypes of AP response that differ in well-known simple and classic clinical variables opening the door to clinical prediction and application of personalized medicine.

Survey of Safety and Efficacy of Long-acting Injectable Risperidone in Daily Practice: An Open-label, Non-interventional Prospective Study

Objective:

This post-authorization safety survey evaluated the long-term safety, tolerability, and efficacy of risperidone long-acting injectable (RLAI) in routine clinical practice.

Methods:

In this 6-month, multicenter, European, naturalistic survey, patients were included if, during routine clinical practice, long-term antipsychotic therapy with RLAI was deemed necessary by the treating physician. Efficacy measures (at baseline and after 1, 3, 6 months) included Clinical Global Impression-Severity (CGI-S) and Global Assessment of Functioning (GAF). Safety was evaluated by recording treatment-emergent adverse events (TEAEs) at every visit.

Results:

RLAI was initiated in 5,134 predominantly male (58.6%) patients (aged 14-94 years) with a diagnosis of paranoid schizophrenia (69.8%). RLAI initial doses were 25 mg every-two-weeks in 37.0%, or 50 mg in 44.4% of patients. at endpoint, RLAI dosages were 50 mg in 49.3% of patients, 25 mg in 27.0%, and 37.5 mg in 22.1%. Six-month treatment with RLAI was completed by 4,314 patients (84.0%). RLAI was discontinued due to loss to follow-up (n=346;6.7%), insufficient response (n=116;2.3%), and AEs (n=106;2.1%). CGI-S significantly improved from baseline to endpoint (p< 0.001). Patient functioning in the GAF scale also significantly improved from baseline to endpoint (45.4±16.0 versus 62.4±17.7, respectively, p< 0.001). TEAEs were recorded by 20% of patients. AEs occurring in ≥5% of patients were akathisia, extrapyramidal disorders, depression, psychotic disorder, anxiety, and weight gain. Serious AEs were reported by 384 (8%) patients.

Conclusions:

This large prospective survey confirms the good safety, tolerability, and efficacy of RLAI as reported in previous controlled clinical trials when used in routine clinical practice.

Delayed post-hypoxic leukoencephalopathy: Case report

Introduction

Delayed post-hypoxic leukoencephalopathy (DPHL) is an underrecognized syndrome of delayed demyelination, where patients manifest neuropsychiatric symptoms after a period of 2–40 days of apparent recovery from a cerebral hypo-oxygenation episode.

Objectives

We report a case of a patient who successfully recovered from an overdose of heroin, but then suffered a delayed abrupt neurological deterioration.

Aims

To improve assessment and recognition of DPHL.

Methods

An adequate retrospective collection of clinical data and nonsystematic review of the literature was performed.

Results

A 43-year-old male with schizoaffective disorder who attempted suicide with an overdose of heroin, was successfully revived and return to his previously mental status, but 3 weeks after, he abruptly developed progressive cognitive impairment with akinetic mutism and ataxia. He was admitted to our acute psychiatric unit after brain CT and chemistry analyses were unremarkable. Brain MRI showed diffusely symmetric hyperintensity in the white matter (WM), pronominally the periventricular WM, on FLAIR and T2 weighted sequences. At 16 weeks postoverdose, he presented improvement both cognitive and motor symptoms, lasting deficits in frontal-executive functions.

Discussion

DPHL is characterized by similar clinical and neuroimaging features regardless of the initial insult. The mean lucid interval coincides with the replacement half-life for myelin related lipids and proteins. Prolonged mild-to-moderate hypo-oxygenation of WM is thought to disrupt myelin turnover. It appears probable that these were responsible for DPHL in our patient rather than a direct toxicity.

Conclusion

DPHL can be diagnosed when clinical history, laboratory assessments and MRI findings are concordant. DPHL requires extensive support care and carries a relatively good prognosis.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Metabolic syndrome or glucose challenge in first episode of psychosis?

Patients with schizophrenia exhibit a reduced life expectancy. Although unhealthy lifestyle or suicide risk plays a role, the main causes are diverse medical conditions such as cardiovascular diseases, type 2 diabetes mellitus and metabolic syndrome. Albeit pharmacological secondary side effects might also trigger previous conditions, studies in naïve patients reflect diverse anomalies at the onset. Patients with a first episode of psychosis, display a wide scope of metabolic abnormalities, ranging from normality till pathological values depending on the parameters studied. We attempted to evaluate the metabolic syndrome and glycemic homeostasis in a subset of antipsychotic-naïve patients with a first episode of non-affective psychosis. Patients (n = 84) showed a similar prevalence of metabolic syndrome compared with a matched control sample (n = 98) (6% vs 4%, P = 0.562), while glucose homeostasis values differed significantly (14% vs. 5%, P = 0.034). Our results suggest that metabolic syndrome is not a useful clinical condition to be evaluated in patients before pharmacological treatment. Abnormal glycemic homeostasis at the onset of the disease requires specific diagnostic tools and preventive measures in order to avoid future cardiovascular events. New strategies must be implemented in order to evaluate the cardiovascular risk and subsequent morbidity in patients at the onset of the disease.

Real-world paliperidone palmitate data from acute units: The SHADOW study

Introduction

There is an increasing interest in understanding how antipsychotic treatments work in a real-world-setting. This is especially important with long-acting-antipsychotics, where explanatory trials may not always represent the real-world-population. Observational studies and pragmatic-clinical trials could provide additional information about new therapies, which could inform decision-making processes.

Objectives

To assess the effectiveness of Paliperidone-Palmitate(PP) in an acute setting within real-world-conditions. Functionality, satisfaction with treatment and pattern of use were also evaluated.

Methods

An observational, prospective 6-week follow-up study was performed in acute units including adult patients with acute exacerbation of schizophrenia that started treatment with PP. Data were collected from initiation of PP until week-6 (or patient's discharge if earlier). Clinical-Global Inventory-Severity (CGI-S) was used to assess effectiveness as well as changes in illness severity. Other outcomes included total score on the Personal and Social Performance scale (PSP), patient-satisfaction with medication (MSQ) and tolerability. Student's-t tests were used to assess changes from baseline in CGI-S and PSP.

Results

Two hundred and eighty patients were included in the analysis (mean age: 40.5 ± 12.2 [SD] years). A significant decrease in mean (SD) CGI-S score between baseline (4.7 [0.9]) and endpoint (3.3 [0.9]) (P < 0.0001) was observed. (Note that 21% of patients were discharged on PP-monotherapy). Patient-functioning also significantly improved from baseline to endpoint (P < 0.0001). Seventy-four percent of patients were satisfied (measured by MSQ) at the end of follow-up. Anticholinergic-treatment was less frequent for PP discharged on monotherapy vs. not monotherapy (12.5% vs 21.2% respectively). Overall, PP was well-tolerated. Twenty-five AEs were reported in 20 patients (incidence 7.1%). No serious AEs occurred.

Conclusions

These results support the effectiveness and tolerability of PP in an acute setting under daily-clinical-practice with good acceptance by patients.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Apoptotic markers in cultured fibroblasts correlate with brain metabolites and regional brain volume in antipsychotic-naive first-episode schizophrenia and healthy controls

Cultured fibroblasts from first-episode schizophrenia patients (FES) have shown increased susceptibility to apoptosis, which may be related to glutamate dysfunction and progressive neuroanatomical changes. Here we determine whether apoptotic markers obtained from cultured fibroblasts in FES and controls correlate with changes in brain glutamate and N-acetylaspartate (NAA) and regional brain volumes. Eleven antipsychotic-naive FES and seven age- and gender-matched controls underwent 3-Tesla magnetic resonance imaging scanning. Glutamate plus glutamine (Glx) and NAA levels were measured in the anterior cingulate (AC) and the left thalamus (LT). Hallmarks of apoptotic susceptibility (caspase-3-baseline activity, phosphatidylserine externalization and chromatin condensation) were measured in fibroblast cultures obtained from skin biopsies after inducing apoptosis with staurosporine (STS) at doses of 0.25 and 0.5 μM. Apoptotic biomarkers were correlated to brain metabolites and regional brain volume. FES and controls showed a negative correlation in the AC between Glx levels and percentages of cells with condensed chromatin (CC) after both apoptosis inductions (STS 0.5 μM: r = -0.90; P = 0.001; STS 0.25 μM: r = -0.73; P = 0.003), and between NAA and cells with CC (STS 0.5 μM induction r = -0.76; P = 0.002; STS 0.25 μM r = -0.62; P = 0.01). In addition, we found a negative correlation between percentages of cells with CC and regional brain volume in the right supratemporal cortex and post-central region (STS 0.25 and 0.5 μM; P < 0.05 family-wise error corrected (FWEc)). We reveal for the first time that peripheral markers of apoptotic susceptibility may correlate with brain metabolites, Glx and NAA, and regional brain volume in FES and controls, which is consistent with the neuroprogressive theories around the onset of the schizophrenia illness.

Network analysis of gene expression in peripheral blood identifies mTOR and NF-κB pathways involved in antipsychotic-induced extrapyramidal symptoms

To identify the candidate genes for pharmacogenetic studies of antipsychotic (AP)-induced extrapyramidal symptoms (EPS), we propose a systems biology analytical approach, based on protein-protein interaction network construction and functional annotation analysis, of changes in gene expression (Human Genome U219 Array Plate) induced by treatment with risperidone or paliperidone in peripheral blood. 12 AP-naïve patients with first-episode psychosis participated in the present study. Our analysis revealed that, in response to AP treatment, constructed networks were enriched for different biological processes in patients without EPS (ubiquitination, protein folding and adenosine triphosphate (ATP) metabolism) compared with those presenting EPS (insulin receptor signaling, lipid modification, regulation of autophagy and immune response). Moreover, the observed differences also involved specific pathways, such as anaphase promoting complex /cdc20, prefoldin/CCT/triC and ATP synthesis in no-EPS patients, and mammalian target of rapamycin and NF-κB kinases in patients with EPS. Our results showing different patterns of gene expression in EPS patients, offer new and valuable markers for pharmacogenetic studies.

Amélioration fonctionnelle sous palmitate de paliperidone à doses flexibles chez des patients aigus ou non aigus atteints de schizophrénie, après échec d’un traitement par antipsychotiques oraux

Objectifs

Évaluer l’amélioration fonctionnelle chez des patients atteints de schizophrénie sous palmitate de paliperidone (PP) à doses flexibles après échec d’un traitement par antipsychotiques oraux.

Méthodes

Analyse menée dans deux sous-groupes de patients atteints de schizophrénie : aigus (n = 202) et non aigus (n = 593) après échec d’un traitement par antipsychotiques oraux, inclus dans une étude internationale, prospective, de six mois.

Critères d’évaluation

Changement du score total à la PANSS (Positive and Negative Syndrome Scale), à la PSP (Personal and Psychosocial Performance scale), et à la Mini-ICF-APP (Mini International Classification of Functionality, Disability and Health Rating for Activity and Participation Disorders in Psychological Illnesses).

Résultats

Les deux sous-groupes ont présenté une amélioration significative du score total à la PANSS : de 98,5 ± 20,1 à l’inclusion à 67,4 ± 24,0 à la fin de l’étude (diminution moyenne = −31,0 ± 29,0) chez les patients aigus et de 71,5 ± 14,6 à 59,7 ± 18,1 (diminution moyenne = −11,7 ± 15,9) chez les patients non aigus. Cette réponse thérapeutique était associée à une augmentation significative du score total à la PSP de 43,9 ± 15,0 à 62,9 ± 17,1 (amélioration moyenne = 19,0 ± 18,7, p <0,0001) chez les patients aigus, et de 58,1 ± 13,4 à 66,1 ± 15,7 (amélioration moyenne =8,0 ± 14,0, p < 0,0001) chez les patients non aigus. Il existait une amélioration significative du score à la Mini-ICF-APP qui diminuait de 26,8 ± 8,5 à 18,5 ± 9,8 (diminution moyenne = −8,0 ± 10,4, p < 0,0001) chez les patients aigus et de 19,8 ± 7,9 à 15,9 ± 8,8 (diminution moyenne = −4,0 ± 7,5, p < 0,0001) chez les patients non aigus.

Conclusions

L’amélioration symptomatique sous PP à doses flexibles chez des patients aigus ou non-aigus atteints de schizophrénie après échec d’un traitement par antipsychotique oral s’est accompagnée d’une amélioration fonctionnelle cliniquement significative.

Palmitate de palipéridone à doses flexibles – Réponse thérapeutique, tolérance et sécurité d’emploi: une étude prospective chez des patients en période d’exacerbation aiguë d’un trouble schizophrénique après échec d’un traitement par antipsychotiques oraux

Objectifs

Évaluer la tolérance, la sécurité d’emploi et l’efficacité de doses flexibles de PP chez des patients adultes en période d’exacerbation aiguë d’une schizophrénie, après échec d’un traitement par antipsychotiques oraux.

Méthodes

Étude internationale, prospective, ouverte, de six mois.

Critères d’évaluation

Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression-Severity (CGI-S), événements indésirables (EI), changement de poids.

Résultats

Deux cent douze patients (population en intention de traiter) : âge moyen 36,4 ± 12,1 ans, 59,0 % d’hommes, 85,4 % souffrant de schizophrénie paranoïde ont été inclus. La principale raison de la substitution d’un antipsychotique oral par le PP était un manque d’efficacité (45,8 %). 70,3 % des patients ont terminé l’étude de six mois. Les raisons les plus fréquentes d’arrêt précoce ont été : le choix du patient (9,4 %), des EI (9,0 %), les perdus de vue (4,7 %), le manque d’efficacité (2,8 %). Le score total moyen à la PANSS initiale (98,5 ± 20,1) a diminué, et ce dès j8, pour atteindre 67,4 ± 24,0 à la fin de l’étude (diminution de −31,0 ± 29,0, p < 0,0001). 66,7 % des patients ont eu une amélioration de plus de 30 % du score PANSS total et le pourcentage de patients jugés manifestement malades ou pire (CGI-S) a diminué de 75,1 % à 20,5 %. Les EIs (≥ 5 % patients) : douleur au site d’injection (13,7 %), insomnie (10,8 %), trouble psychotique (10,4 %), céphalées (6,1 %) et anxiété (6,1 %). Le changement moyen de poids a été de 2,6 ± 5,6 kg (IC 95 % [1,8; 3,4]).

Conclusions

Ces résultats confirment que le PP à doses flexibles est bien toléré et permet une réponse clinique précoce et cliniquement significative chez des patients en période d’exacerbation aiguë de leur trouble schizophrénique, après échec d’un traitement par antipsychotiques oraux.

Remission and functioning after two years undergoing Long-Acting Injectable Risperidone (LAIR) in recent-onset schizophrenia

Introduction

Improving adherence in the early stages of illness by means of long-acting antipsychotics can lead to reduced number of readmissions and enhanced remission rates, which could lead to improved performance in the medium-long term.

Objectives

Assessing clinical remission, number of admissions and personal and social performance in recent-onset schizophrenic patients undergoing LAIR.

Methods

Longitudinal retrospective study of a cohort of thirty-one recent-onset schizophrenic patients ( ≤ 2 years) who started LAIR treatment between 2004–2008. Twenty-six (83.9%) were treated for two years. PANSS scale was assessed at baseline; PANSS, Personal and Social Performance scale (PSP) and remission criteria after two years.

Results

Twenty-six patients (83.9%), 61.5% male aged between 16–44 years old, completed two years of treatment. All patients met criteria for schizophrenia (DSM-IV) with an average duration of 0.8 year since diagnosis. The main reason to using LAIR was poor adherence (76.9%). The PANSS total and all its subscale scores improved significantly (p < 0.005) with 80.8% of patients showing a ≥ 50% improvement on the PANSS total. Seventeen patients (65.4%) achieved remission criteria. Five patients (19.2%) were admitted during the follow-up. The average on global functioning (PSP) was 72.4 (IC 95%, 66.4-78.4). LAIR doses at baseline were 25 mg (46.2%), 37.5 mg (30.8%) or 50 mg (23.1%); after two years, 25 mg (34.6%), 37.5 mg (34.6%), 50 mg (23.1%) or 75 mg (7.7%).

Conclusions

Despite the limitation of retrospective observational studies, our data, including the good adherence rate (83.9%), suggest that LAIR could be effective in the treatment of recent-onset schizophrenia.

Intuitive pharmacogenetics: spontaneous risperidone dosage is related to CYP2D6, CYP3A5 and ABCB1 genotypes

The aim of this study is to evaluate whether the quantitative prescription of risperidone (dosage) is related to the patient's metabolic status. Metabolic status was defined in terms of the most relevant polymorphisms of CYP2D6 (*3, *4, *5, *6 and *1xN), CYP3A5 (*3A) and ABCB1 (G2677T) determined a posteriori and blinded to the clinicians. This prospective and observational study includes a cohort of 151 Caucasian psychiatric patients treated with risperidone. Significant differences (Kruskal-Wallis test p=0.01) among the doses administered were observed to correlate (Spearman's r=1, p=0.02) with the different CYP2D6 groups. Poor metabolizers received the lowest doses and ultra rapid metabolizers the highest. No significant correlations were observed with regard to CYP3A5 and ABCB1. We find that, despite not knowing patients' metabolic status, clinicians modify risperidone dosage in order to obtain the best therapeutic option.

Pharmacokinetics and time-course of D(2) receptor occupancy induced by atypical antipsychotics in stabilized schizophrenic patients

The (123)I-IBZM SPECT measured D(2) receptor occupancy (D(2)RO) in chronically dosed, stabilized schizophrenic patients and its relationship with antipsychotic (AP) pharmacokinetics (PK) over time is still unclear. The aims of this study were: 1) To define the relationship between striatal D(2) receptor occupancy (D( 2)RO) and plasma concentration (C(P)) in stabilized schizophrenic patients on clinically relevant doses using (123)I-IBZM SPECT; 2) To investigate the time course of AP-induced D(2)RO and corresponding C(P). Forty-six schizophrenic patients on their clinically required doses of risperidone, olanzapine, clozapine or quetiapine were included. D( 2)RO and C(P) were measured over time following a sparse-sampling experimental design, and individual PK and D(2)RO-time profiles were estimated using a population approach. Observed striatal D(2)RO and C(P) ranges were 28-75% and 9.4-60.5 ng/mL for risperidone, 22-84% and 8.6-89.5 ng/mL for olanzapine, 5-53% and 41.6-818.2 ng/mL for clozapine and 0-64% and 37.9-719.6 ng/mL for quetiapine. A PK-D(2)RO relationship was found for the four APs. D(2)RO pattern over time was stable for risperidone, olanzapine and clozapine but fluctuating for quetiapine. Stabilized schizophrenic patients show a wide range of both D(2)RO and C(P) at clinically effective doses of the four AP, suggesting that clinical response to these AP may be maintained with D(2)RO below 65%. D(2)RO patterns over time differ between AP. These results should be considered for accurate interpretation of D(2)RO measurements, proper design of studies and optimization of drug regimens for patients on AP treatment.

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.

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.

[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.

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.

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.

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.

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.

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.

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.

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.

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

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.