Effects of Clozapine on Cortical Inhibition: A Transcranial Magnetic Stimulation Follow-up Study

BACKGROUND

Preclinical and clinical investigations have revealed deficits in cortical inhibition in individuals with schizophrenia. Transcranial magnetic stimulation, a commonly used noninvasive measurement technique, is used for assessing these deficits. Limited research has been conducted on the effects of antipsychotic medications on cortical inhibition. This study aimed to evaluate the effects of clozapine on cortical inhibition with transcranial magnetic stimulation longitudinally and compare it with unaffected controls.

METHODS

Ten patients who started clozapine were assessed at baseline, with 8 reassessed after 4 months. Eight age- and sex-matched unaffected controls were included. Psychopathology, neurocognitive performance, formal thought disorder, and disability were assessed, and the cortical excitability parameters (resting motor threshold, cortical silent period, short-interval intracortical inhibition, intracortical facilitation, and short-latency afferent inhibition [SAI]) were measured at baseline and four months after clozapine treatment.

RESULTS

Resting motor threshold, ICF, and SAI were significantly different between patients and controls at baseline, whereas resting motor threshold, SAI, and ICF became similar to controls after clozapine with only ICF having a trend for significance. Clozapine prolonged cortical silent period significantly in the patients.

CONCLUSIONS

This is the first study to investigate the effect of clozapine on SAI, a potential cholinergic biomarker, and the first follow-up study to investigate the relationship between the effects of clozapine on cortical inhibition and cognition. Clozapine seems to cause an increase in cortical inhibition through GABAergic and possibly cholinergic mechanisms. However, additional follow-up studies with larger sample sizes are required to reach more robust conclusions.

A systematic chart review of pharmacological interventions in patients with clozapine-induced hypersalivation

OBJECTIVES

To investigate the efficacy and tolerability of medications, such as mouthwash use of 1 % atropine sulfate and tropicamide drops, oral amitriptyline and amisulpride used for clozapine-induced hypersalivation (CIH).

METHODS

The medical charts of inpatients with psychotic disorders between 2010 and 2022 were reviewed retrospectively. We detected 161 patients with eligible data who received or commenced clozapine. Primary outcome was defined as the percentage change in the diameter of a wet patch on the pillow (DWP) for improvements in CIH.

RESULTS

The frequency of CIH was 42 % (n = 68). The first step medications for CIH were tropicamide drops (49 %), atropine drops (43 %) and amitriptyline (3 %). After the first step, the median DWP significantly decreased by -33 %. During the index hospitalization, in 18 patients with persistent CIH, the median DWP significantly decreased by -42 % with the second step medications which also included amisulpride. There were no reported serious adverse events. The change in DWP was significantly correlated with the duration of clozapine treatment (r = 306) and clozapine serum level at discharge (r = 0.294). A linear regression model showed a link between the change in DWP and reduced Positive and Negative Syndrome Scale scores.

CONCLUSIONS

Our findings emphasize that mouthwash use of atropine or tropicamide drops has a satisfying and tolerable effect in treating CIH. Switching medications for CIH seems to be effective when CIH persists despite a first step agent. Controlled follow-up studies are needed to understand the relationship between CIH, clozapine serum levels, illness severity, and functioning.

A diffusion tensor imaging study in schizophrenia patients with clozapine induced obsessive compulsive symptoms

OBJECTIVE

The aim of this study was to evaluate brain connectivity by diffusion tensor imaging (DTI) in schizophrenia patients with clozapine-induced obsessive compulsive symptoms (OCS).

METHODS

Eighteen schizophrenia patients, nine of which had clozapine-induced OCS (Clz-OCS (+)), 9 without OCS (Clz-OCS (-)) and 9 healthy controls were included. Psychopathology was evaluated with Positive and Negative Syndrome Scale and Yale-Brown Obsession and Compulsion Scale in the patient groups. All groups were assesed with neurocognitive tests and DTI.

RESULTS

Tract-Based Spatial Statistics based comparison of DTI revealed lower fractional anisotropy in the genu of corpus callosum (CC), right cingulum, left frontal white matter (WM) in the Clz-OCS (+) group, compared to controls. Fractional anisotropy was found to be lower in the bilateral occipital WM and higher in the bilateral medial temporal regions, anterior limb of internal capsule, cingulum, frontoparietal peripheral WM, right external capsule and genu of CC in Clz-OCS (+) patients compared to Clz-OCS (-).

CONCLUSIONS

WM integrity in several pathways such as cortico-striato-thalamo-cortical circuitry and orbito-frontal tracts seems to be affected differently in patients with Clz-OCS (+). Different neuroplastic effects of clozapine leading to occurrence of OCS in a subgroup of patients is possible, and needs further evaluation by longitudinal follow-up studies.

Should we routinely add CRP to clozapine titrations? - Learning from three cases

Objectives: An international guideline recently provided certain personalized schedules for titrating clozapine in adult inpatients by considering: 1) DNA ancestry group, 2) sexsmoking subgroup, and 3) presence/absence of clozapine poor metabolizer (PM) status. Measuring CRP levels at baseline and during the first 4 weeks is recommended. Titrations too fast for the metabolism of specific patients can lead to clozapine-induced inflammations and CRP elevations. Methods: Three published cases are reinterpreted. Better outcomes might have been obtained by using the guideline. Results: Case 1 was a Chinese male non-smoker, a clozapine PM due to an underlying inflammation. Case 2 was a Turkish female non-smoker who developed clozapine-induced myocarditis in the context of 4 risk factors (undiagnosed infl ammation, obesity, valproate and olanzapine co-prescription). Case 3 was a United States patient of European ancestry with no known risk factors who developed myocarditis after a routine titration and had an unsuccessful rechallenge with 12.5 mg/day. Application of the international clozapine titration guideline may have prevented: 1) Case 1 by recommending against clozapine titration for a patient with an abnormal CRP level, 2) Case 2 by considering 4 risk factors and using a slow titration for clozapine PMs, and 3) Case 3 by using CRP elevations for early identification of a possible genetic PM. Conclusions: When baseline or prior CRPs are normal and then become abnormal during a clozapine titration, this indicates: 1) clozapine-induced inflammation associated with too-rapid titration for that specific patient, and/or 2) co-occurrence of an infection. Prospective studies need to verify this hypothesis.

Valproate, obesity and other causes of clozapine poor metabolism in the context of rapid titration may explain clozapine-induced myocarditis: A re-analysis of a Turkish case series

INTRODUCTION

Clozapine-induced myocarditis or any clozapine-induced inflammation may be a hypersensitivity reaction due to titration that was too rapid for the patient's clozapine metabolism. Clozapine metabolism is influenced by ancestry, sex, smoking and the presence of confounders including obesity, infections, and inhibitors (e.g., valproate) causing the patient to behave as a clozapine poor metabolizer (PM). A published study in a Turkish hospital identified 1 case of clozapine-induced pancreatitis and hepatitis and 9 cases of clozapine-induced myocarditis. To explore the hypothesis that the 10 patients were clozapine PMs, their serum clozapine concentrations were investigated using concentration-to-dose (C/D) ratios and their titrations carefully reviewed.

METHODS

Dividing the trough serum concentration by the dose produces the clozapine C/D ratio. The dose required to reach 350ng/ml was considered the minimum therapeutic dosage and was used to classify patients according to clozapine PM status. Titration speed was assessed.

RESULTS

All 10 patients were possibly clozapine PMs (3 of them had as minimum therapeutic doses: 72, 82 or 83mg/day). Nine of the 10 patients may have behaved as clozapine PMs due to obesity and/or valproate co-prescription during titration. One also had an undiagnosed infection. Of the 10 patients, 9 had at least 1 of 3 factors: too-rapid titration in the first or second weeks, or a final dosage that was too high.

CONCLUSIONS

Future studies using clozapine levels and considering the role of clozapine PM status should explore whether or not all cases of clozapine-induced inflammation could be explained by lack of individualized titration.

Renal effects of long-term lithium therapy, revisited

OBJECTIVE

The aim of this study was to investigate the effect of lithium treatment on renal function and to determine influencing factors. In addition, the utility of spot urine protein/creatinine ratio in detection of lithium induced nephropathy was also investigated.

METHODS

Serum concentrations of lithium, blood urea nitrogen (BUN), creatinine, estimated glomerular filtration rate (eGFR), and urinalysis including protein/creatinine ratio were measured in 375 patients using lithium.

RESULTS

Patients taking lithium for ≥8 years had higher BUN, creatinine levels, percentage of proteinuria, percentages of stage 2 and 3 chronic kidney disease (CKD); lower urine density and eGFR compared to patients taking lithium <8 years. Urine density was lower in groups with >0.8 and 0.6-0.8 mmol/L lithium level than <0.6 mmol/L. Predictors of CKD were serum level of lithium, dose of lithium, cumulative duration of lithium use, age at onset of illness, and caffeine consumption.

CONCLUSIONS

Detrimental effects of lithium on renal functions were detected after lithium use for ≥8 years. Proteinuria measured by spot urine protein/creatinine ratio can be detected even when eGFR is >90 ml/min/1.73 m² . Spot urine protein/creatinine ratio, which is a cost-effective and practical laboratory test, can be used to monitor lithium-treated patients.

An International Adult Guideline for Making Clozapine Titration Safer by Using Six Ancestry-Based Personalized Dosing Titrations, CRP, and Clozapine Levels

This international guideline proposes improving clozapine package inserts worldwide by using ancestry-based dosing and titration. Adverse drug reaction (ADR) databases suggest that clozapine is the third most toxic drug in the United States (US), and it produces four times higher worldwide pneumonia mortality than that by agranulocytosis or myocarditis. For trough steady-state clozapine serum concentrations, the therapeutic reference range is narrow, from 350 to 600 ng/mL with the potential for toxicity and ADRs as concentrations increase. Clozapine is mainly metabolized by CYP1A2 (female non-smokers, the lowest dose; male smokers, the highest dose). Poor metabolizer status through phenotypic conversion is associated with co-prescription of inhibitors (including oral contraceptives and valproate), obesity, or inflammation with C-reactive protein (CRP) elevations. The Asian population (Pakistan to Japan) or the Americas' original inhabitants have lower CYP1A2 activity and require lower clozapine doses to reach concentrations of 350 ng/mL. In the US, daily doses of 300-600 mg/day are recommended. Slow personalized titration may prevent early ADRs (including syncope, myocarditis, and pneumonia). This guideline defines six personalized titration schedules for inpatients: 1) ancestry from Asia or the original people from the Americas with lower metabolism (obesity or valproate) needing minimum therapeutic dosages of 75-150 mg/day, 2) ancestry from Asia or the original people from the Americas with average metabolism needing 175-300 mg/day, 3) European/Western Asian ancestry with lower metabolism (obesity or valproate) needing 100-200 mg/day, 4) European/Western Asian ancestry with average metabolism needing 250-400 mg/day, 5) in the US with ancestries other than from Asia or the original people from the Americas with lower clozapine metabolism (obesity or valproate) needing 150-300 mg/day, and 6) in the US with ancestries other than from Asia or the original people from the Americas with average clozapine metabolism needing 300-600 mg/day. Baseline and weekly CRP monitoring for at least four weeks is required to identify any inflammation, including inflammation secondary to clozapine rapid titration.

The cognitive aspect of formal thought disorder and its relationship with global social functioning and the quality of life in schizophrenia

PURPOSE

It was expected that using a comprehensive scale like the Thought and Language Disorder Scale (TALD) for measurement of FTD would enable assessing its heterogeneity and its associations with cognitive impairment and functionality. This study has aimed to analyze the relationship between formal thought disorder (FTD) and cognitive functions, functionality, and quality of life in schizophrenia.

METHODS

This cross-sectional exploratory study included 46 clinical participants meeting the DSM-5 diagnostic criteria for schizophrenia and 35 healthy individuals as the control groups. Data were acquired by means of the Turkish language version of the TALD, the Positive and Negative Syndrome Scale, the Clinical Global Impression Scale, the Functioning Assessment Short Test, the Social Functioning Scale, the World Health Organization Quality of Life Instrument-Short Form, and a neuropsychological test battery on executive functions, working memory, verbal fluency, abstract thinking, and response inhibition. Correlation analyses were conducted to detect significant relationships.

RESULTS

The clinical group scored failures in all cognitive tests. The objective positive FTD was associated with deficits in executive functions and social functioning. The objective negative FTD was associated with poor performance in all cognitive domains, physical quality of life, and social and global functioning. The subjective negative FTD was negatively correlated with psychological quality of life.

CONCLUSION

This study demonstrated that objective FTD factors reflect different underlying cognitive deficits and correlate with different functioning domains. Significant correlation was determined between subjective negative FTD and psychological quality of life. Given the close relationship of FTD with functioning and quality of life, the FTD-related cognitive deficits should be the key treatment goal in schizophrenia.

Common Side Effects and Metabolic Syndrome due to Clozapine: Relationship with the Clinical Variables and Disability

OBJECTIVE

Common side effects of clozapine may affect the treatment process negatively. In this study, we aimed to assess the common side effects and the prevalence of metabolic syndrome in schizophrenia patients treated with clozapine, and to study their relationship with clinical variables and disability.

METHOD

One hundred and twenty two patients who met DSM-IV criteria for schizophrenia, and were on clozapine treatment were included in the study. Clinical status was evaluated through a clinical interview and review of the medical records, and physical measures and laboratory tests were recorded. Patients were assessed with the Structured Clinical Interview for DSM-IV Axis I Disorders, UKU (Udvalg for Kliniske Undersogelser) Side Effect Rating Scale, World Health Organization (WHO)-Disability Assessment Schedule II, Positive and Negative Syndrome Scale, Global Assessment Scale, Clinical Global Impression Scale.

RESULTS

Common side effects of clozapine were hypersalivation, fatigue, sedation and constipation. The relationship between constipation and clozapine dose, and dizziness and norclozapine plasma levels were significant. The prevalence of metabolic syndrome was 50%, and patients with metabolic syndrome had higher means of age and lifetime cigarette consumption. Disability was positively correlated with the severity of psychopathology and the number of side effects, and negatively correlated with the age at onset of illness. Severity of the psychopathology and the number of side effects predicted the severity of the disability.

CONCLUSION

Clozapine was associated with various side effects and half of the patients had metabolic syndrome. Assessment of common side effects due to clozapine is important for reducing disability.

Effect of Clozapine on Proton Magnetic Resonance Spectroscopy Findings in Hippocampus

OBJECTIVE

The purpose of this study was to investigate the effect of clozapine on proton magnetic resonance spectroscopy (1H-MRS) findings in hippocampus in patients with schizophrenia. In addition, the relationship between the change in 1H-MRS findings and the change in psychopathology and neurocognitive functions was evaluated.

METHOD

Patients with schizophrenia (n=16) were assessed with the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression Scale (CGI), a neurocognitive test battery and 1H-MRS at baseline, and twelve weeks after the initiation of clozapine. Healthy controls (n=8) were assessed once with a neurocognitive test battery and 1H-MRS. Bilateral multivoxel and left single voxel NAA/Cr, Cho/Cr, MI/Cr was calculated in the hippocampi.

RESULTS

After 12 weeks of clozapine treatment, PANSS and CGI scores decreased; immediate recall, cumulative learning subtests of the Rey Auditory Verbal Learning Test, Category Verbal Fluency Test and Wechsler Memory Scale's visual reproduction delayed subtest scores increased significantly. Compared with healthy controls and patients after clozapine, hippocampi multivoxel and single voxel NAA/Cr, Cho/ Cr, MI/Cr ratios were not different in patients before clozapine. No significant correlations between change in 1H-MRS metabolite ratios and change in psychopathology, neurocognitive functions were detected.

CONCLUSION

This study is the first longitudinal study to investigate the effect of clozapine in hippocampus with 1H-MRS. There were no significant changes in 1H-MRS findings in hippocampi after twelve weeks of clozapine treatment. Clozapine's effect in hippocampus should be investigated further in longer follow up studies with larger samples to reach a final conclusion.

A comparative study of detection of myocarditis induced by clozapine: With and without cardiac monitoring

The aim of this study was to investigate and compare the incidence of suspected or definite cases of clozapine induced myocarditis (SDM) and clinical factors which could influence its onset in two different time periods, defined by pre- and post-cardiac monitoring at an inpatient setting, during the initiation phase of clozapine treatment. Hospital records of patients started on clozapine in the inpatient unit between 2011 and 2018 were investigated. Eight in 38 patients (11.3%) were classified as SDM after the initiation of the monitoring protocol, whereas only 1 in 33 patients (1.4%) was classified as SDM, before. Monitored and non-monitored patient groups were similar with regard to demographic and clinical variables. Diagnosis of schizoaffective disorder and use of concominant lithium, valproic acid and atypical antipsychotics were higher in patients with SDM, while clozapine dose titration was similar compared to the rest of the patients. Cardiac monitoring seems to be the main factor leading to the increase in the detection of clozapine induced myocarditis (CIM). If not monitored, the outcome of CIM can be fatal without any warning signs and symptoms. Concominant use of mood stabilizers including valproic acid and lithium, are important risk factors for the development of CIM.

Examination of formal thought disorder and its clinical correlates with the Turkish Version of the Thought and Language Disorder Scale (TALD-TR) in schizophrenia

BACKGROUND

Formal thought disorder (FTD) is considered to be a fundamental feature of schizophrenia. This study aims to analyze psychometric properties of the Turkish version of "Thought and Language Disorder Scale (TALD)" and investigate the relationship between FTD and various clinical characteristics in patients with schizophrenia.

METHODS

TALD was adapted into Turkish and applied to a total of 149 participants of which 114 had DSM-5 psychiatric diagnoses (schizophrenia N = 70, mania N = 20, depression N = 24) and 35 were healthy controls. Positive and Negative Syndrome Scale (PANSS), Hamilton Depression Rating Scale, Young Mania Rating Scale, and Clinical Global Impression were administered to detect illness severity.

RESULTS

The principal component analyses revealed that the Turkish version of TALD (TALD-TR) consisted of four factors including the Objective Positive (OP), Subjective Negative (SN), Objective Negative (ON) and Subjective Positive (SP) symptom dimensions which were in line with the original TALD factorial structure. It was concluded that TALD-TR shows strong construct validity and high interrater reliability. The correlation analyses with TALD-TR and PANSS showed that there are positive correlations between the TALD-TR total score and the PANSS total and subscale scores. Each diagnostic group showed the distinct pattern of FTD. The mania group exhibited the highest mean total score in the OP, whereas the schizophrenia group exhibited the highest mean total score in the ON factor. In the schizophrenia group, the severity of FTD correlated positively with duration of illness and negatively with age at onset of illness.

CONCLUSION

Adaptation of TALD into different languages seems to be possible, bringing in an international tool for research on FTD.

Effect of Clozapine on Psychiatric Comorbidities in Patients with Schizophrenia

Introduction

Clozapine has superior efficacy in treatment-resistant schizophrenia, and has various effects on psychiatric comorbidities, which may affect the illness course.

Aims

We aimed to assess the past and current psychiatric comorbidities in schizophrenia patients treated with clozapine, and study their relationship with clinical variables.

Methods

Consecutive 122 outpatients who met DSM-IV criteria for schizophrenia receiving clozapine were included. Information about past and current clinical status were gathered through a clinical interview and review of the medical records, along with laboratory test results. Patients were assessed with structured clinical interview for Axis-I Disorders for DSM-IV, Clinical Global Impression Scale, Positive and Negative Syndrome Scale (PANSS), Calgary Depression Scale, Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Panic and Agoraphobia Scale (PAS), WHO-Disability Assessment Schedule-II.

Results

There was a significant decrease in the diagnosis of depression, alcohol and substance use disorder, number of suicide attempts, and an increase in the diagnosis of obsessive compulsive disorder (OCD) after clozapine initiation. Clozapine related de novo OCD appeared in 48.4% of the patients, and there was a positive correlation between Y-BOCS total scores and clozapine dose and plasma levels. In the de novo OCD group, compulsion scores were higher than obsession scores with checking most prevalent among compulsions. Total PANSS, Y-BOCS, PASscores were positively correlated withtotal disability score.

Conclusions

Clozapine seems to decrease comorbid depression, alcohol and substance use and number of suicide attempts and increase OCD. Assessment and treatment of psychiatric comorbidities in clozapine using schizophrenia patients is vital to decrease disability.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Side Effects of Clozapine and Their Relationship with Clinical Variables in Patients with Schizophrenia

Introduction

The side effects of clozapine may affect the treatment process negatively, and increase the disability.

Aims

We aimed to assess the side effects of clozapine, and their relationship with the clinical variables in schizophrenia patients, and study the predictors of disability.

Methods

Consecutive 122 outpatients who met DSM-IV criteria for schizophrenia, and were on clozapine treatment were included in the study. Information about sociodemographic characteristics, past and current clinical status were gathered through a clinical interview and review of the medical records, and physical measures and laboratory tests, including clozapine plasma levels, were recorded. The patients were assessed with SCID-I, Positive and Negative Syndrome Scale, UKU-Side Effect Rating Scale, WHO-Disability Assessment Schedule-II.

Results

Hypersalivation, weight gain, sedation and constipation were the most common side effects of clozapine. Although the mean plasma clozapine levels were high (828.11 ± 445.5 ng/mL), no significant effect of clozapine dose and plasma levels were detected on the severity of side effects, except for constipation. Metabolic syndrome prevalence was found to be 50% according to ATP IIIA criteria. Duration of clozapine treatment, clozapine dose and plasma levels were not significantly different between patients with and without metabolic syndrome. Regression analysis showed that the severity of schizophrenia psychopathology and the number of side effects predicted the severity of disability.

Conclusions

Side effects of clozapine increase the disability of patients with schizophrenia and should be monitored regularly. On the other hand, clozapine dose and plasma levels do not determine the severity of most of the common side effects.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

[The Relationship of the Change in Symptoms and Cognitive Functions With the Change in Cortical Inhibition Parameters Measured by Transcranial Magnetic Stimulation: An Eight-Week Follow-Up Study]

OBJECTIVE

Transcranial magnetic stimulation (TMS) studies show cortical inhibition (CI) abnormalities in patients with schizophrenia. However, the relationship between the changes in CI and the changes in psychopathology and cognition caused by antipsychotic treatment is not known. This is an 8 week follow up study which aims to evaluate the relationship of the change in the symptoms and cognitive functions with the change in the CI of the patients, who are switched to new  atypical antipsychotic treatment, and to compare the TMS measures of patients with those of controls.

METHOD

Thirteen patients and age, sex, education matched 13 controls were included in the study. Patients were assessed with TMS, Positive and Negative Syndrome Scale (PANSS) and neurocognitive battery at baseline and 8th week, while the control group was evaluated once, with neurocognitive battery and TMS. The CI parameters studied by TMS were resting motor threshold, cortical silent period, ipsilateral silent period (ISP), short interval-intracortical inhibition (SICI) and intracortical facilitation.

RESULTS

Intracortical facilitation (ICF) was weaker, ISP was longer in patients than the controls both at the baseline and at the end of the eight weeks. Intracortical facilitation decreased with 8 weeks of antipsychotic treatment indicating an increase in CI. The decrease in PANSS general psychopathology score was related positively with the decrease in ICF.  SICI was related positively with cognitive test performances cross-sectionally and longitudinally.

CONCLUSION

Our findings suggest that increase in CI is associated with the improvement in the symptoms and the action of the atypical antipsychotics.

Psychiatric disorders and epigenetics

The term epigenetic refers to long-lasting changes in gene expression that are beyond the DNA base sequence. Understanding the dynamic role of epigenetic mechanisms in the regulation of gene expression in adulthood has led researchers to investigate epigenetic mechanisms in psychiatric disorders. The aim of this review was to describe epigenetic mechanisms and to discuss the role of epigenetic modifications in stress, depression, schizophrenia, and substance dependence. For this purpose PubMed was searched using the keywords epigenetic, stress, depression, schizophrenia, and substance dependence; studies published between 2000 and 2011 were reviewed. Different maternal behavioral patterns and early life stress have been reported to yield heritable changes in gene expression via epigenetic mechanisms, which are reversible. Studies that investigated the role of epigenetic modifications in stress and depression focused on the proteins involved in the regulation of the hypothalamo-pituitary adrenal (HPA) axis, whereas epigenetic studies of schizophrenia primarily focused on changes in the GABAergic system. Studies on substance dependence, on the other hand, showed that substance use might change the expression of many genes by causing short- or long-lasting epigenetic modifications. These findings have led to the development of new therapeutic strategies that target epigenetic mechanisms. Among these strategies, histone deacetylase inhibitors are especially promising. More studies are needed to improve our understanding of the role of epigenetic modifications in the development of psychiatric disorders, and to aid in the development of new treatment strategies that focus on epigenetic mechanisms.

[Two stiff person cases misdiagnosed as conversion disorder]

Modern psychiatric diagnostic systems classify neurological symptoms that cannot be explained by a physical disease or another psychiatric disorder as conversion disorder (CD) or dissociative motor disorder. It is a well-known fact that the overall rate of misdiagnosis of conversion symptoms is high. The most common presenting symptoms of misdiagnosed patients are gait and movement disturbances. Stiff-person syndrome (SPS) is a rare progressive autoimmune neurological disorder. The identification of antibodies against glutamic acid decarboxylase (GAD) in association with SPS provided an important contribution to the understanding of the pathophysiology of this syndrome. Patients may present with severe muscle rigidity and sudden contractions. Simultaneous contraction of agonist and antagonist muscles produces gait disturbance. SPS can be exacerbated by emotional stressors, and sudden auditory, visual, and tactile stimuli. Herein we present 2 patients that were referred for psychiatric assessment, because their neurological symptoms initially could not be explained by a neurological disease, and subsequently diagnosed as SPS. The aim of this case report is to draw attention to the psychiatric presentations of SPS and to emphasize the importance of complete psychiatric and neurological examination, including brain imaging and electrophysiological studies, in the differential diagnosis of CD.

[Neuroimaging findings in autism: a brief review]

OBJECTIVE

Many structural and functional neuroimaging studies have investigated the neuroanatomical changes and possible pathophysiological pathways in autism. In this review the objective was to assess, with an integrative perspective, recent neuroimaging studies that have contributed to the explanation of the possible pathophysiological pathways in autism.

METHOD

Relevant attainable studies published between 1997 and 2007 were included in this retrospective literature review. The PubMed search engine and the keywords, autism, autistic spectrum disorders, neuroimaging, computerized tomography, magnetic resonance imaging, functional magnetic resonance imaging, magnetic resonance spectroscopy, positron emission tomography, single photon emission computed tomography, and diffusion tensor imaging were used.

RESULTS

Structural neuroimaging studies reported an increase in total cerebral volume, both in grey and white matter, mostly in the frontal, temporal and parietal lobes. These global volumetric changes are suggested to indicate a diffuse disturbance in neural networks during early development. In functional neuroimaging studies, activation abnormalities were observed in the temporal lobes and amygdala, which are involved in language and social cognition. An increase in visual activity cortex was also reported.

CONCLUSION

Clinical observations and results from neuroimaging studies were gathered to hypothize and explain the pathophysiology of autism. Yet, it is still very early to conclude with certainty the neurobiological process responsible for autism.

[Evoked potentials and regional cerebral blood flow changes in conversion disorder: a case report and review]

Conversion disorder is defined as the presence of functional impairment in motor, sensory or neurovegetative systems which cannot be explained by a general medical condition. Although the diagnostic systems emphasize the absence of an organic basis for the dysfunction in conversion disorder, there has been a growing interest in the specific functional brain correlates of conversion symptoms in recent years, particularly by examining neuroimaging and neurophysiological measures. In this case report, regional cerebral blood flow changes and evoked potentials of a patient with conversion symptoms are presented. Somatosensory evoked potentials (SEP) of this patient with conversion disorder who had signs of movement disorder revealed that the latency to N20, P 25 waves were in normal limits while the amplitudes of the P25 and N33 components were extremely high (giant SEP). Regional cerebral blood flow assessment revealed hypoperfusion in the left parietal and temporal lobes of the brain. Three months after the first assessment, the control scans showed that the left parietal hypoperfusion disappeared while the left temporal hypoperfusion was still present. The following SEP evaluations which were repeated twice in three months intervals after the initial recordings, showed the persistence of the abnormalities in somatosensorial measures. The neurophysiological and neuroimaging findings in conversion disorder were reviewed and the results of the evaluations of this case were discussed in this article.

Obsessive compulsive symptoms associated with quetiapine treatment in a schizophrenic patient: a case report

PURPOSE

Atypical antipsychotics (AAPs) are used as adjunct therapy in the treatment of resistant obsessive-compulsive symptoms (OCSs). Paradoxically other reports suggest that AAPs, particularly clozapine, risperidone, and olanzapine can induce de novo emergence or exacerbation of OCSs in psychotic patients. The authors present here the first report suggesting an association between de novo appearance of OCSs and quetiapine treatment in a schizophrenic patient.

CASE

The patient was a 33-year-old woman with the diagnosis of paranoid schizophrenia, who displayed OCSs for the first time during treatment with quetiapine. The symptoms reduced remarkably when fluoxetine was added to her treatment regimen while keeping the quetiapine dosage unchanged.

CONCLUSION

AAP-induced OCSs merit consideration and early identification, as these drugs are now widely in use in clinical practice. This rare but disabling side effect should also be monitored in quetiapine treated schizophrenic patients.

[Creutzfeldt-Jakob disease: a case that initiated with psychiatric symptoms]

Creutzfeldt-Jakob disease (CJD) is a rapidly progressive prion disease that causes deficits involving movement, cognition, and mental status. The clinical heterogeneity of the disease can make diagnosis difficult. Thorough neurologic, cognitive, and psychiatric examinations are necessary for observing its clinical features. In this case report we describe a 62-year-old male patient who was initially followed with a diagnosis of depression and later was diagnosed with CJD. The patient had a one-year history of anhedonia, loss of interest, social withdrawal, anxiety and decrease in speech and was given paroxetin 20 mg/day with a diagnosis of depression. During follow up, neurological symptoms including ataxia and rigidity became evident and dementia and akinetic mutism developed in a rapidly progressive course. Although electroencephalography (EEG) and magnetic resonance imaging (MRI) revealed nonspecific findings initially, typical findings for CJD were seen during the follow up. The positive 14-3-3 protein in CSF supported the diagnosis. The aim of this report is to emphasize the fact that CJD may present with different psychiatric symptoms and can be initially misdiagnosed. CJD should be considered in the differential diagnosis of patients who have focal neurological signs in addition to psychiatric symptoms. Repeated neurological examinations, EEG and cranial MRI may help in the diagnosis of these patients.

[The neurobiology of hallucinations]

OBJECTIVE

Although hallucinations are among the cardinal features of schizophrenia, the mechanisms underlying these symptoms have not been fully understood yet. In this review our objective is to summarize the studies about the neurobiology of auditory hallucinations in schizophrenia and discuss their significance for understanding schizophrenia.

METHOD

This is a retrospective literature review and the relevant studies within the last 10 years are included. For this purpose Pubmed search engine and 'hallucination, schizophrenia, neurobiology' key words are used.

RESULTS

Hallucinations cause sensory modality specific activation in cerebral areas involved in normal sensation. A disturbance in perception of speech seems to have a central role in occurrence of auditory hallucinations. Anatomically, auditory hallucinations appear to involve primary and association cortices, Broca's and Wernicke's areas, subcortical, paralimbic, limbic regions, ventral striatum and thalamus. Furthermore they are suggested to be associated with the dysmodulation of the information flow from ventral striatum to thalamus and cortex caused by increased dopaminergic activity in mesolimbic pathway.

CONCLUSION

The validity of the models which are proposed to explain neurobiology of hallucinations in schizophrenia should be tested by new studies. The difficulties regarding the assessment and measurement of subjective mental phenomena are important impacts in studying and understanding the neural correlates of hallucinations. Functional neuroimaging, cognitive and molecular biological studies will hopefully enhance our knowledge about this disease.

A double-blind controlled study of adjunctive treatment with risperidone in schizophrenic patients partially responsive to clozapine: efficacy and safety

BACKGROUND

Several open trials and case studies have reported beneficial effects following the addition of risperidone for partial responders to clozapine. The purpose of this study was to carry out a placebo-controlled, randomized, double-blind trial of the efficacy, safety, and tolerability of adjunctive treatment with risperidone in patients with schizophrenia partially responsive to clozapine.

METHOD

In this 6-week double-blind study, 30 patients with DSM-IV schizophrenia who had partial response to clozapine despite being treated for a mean of 32 months were randomly assigned to risperidone (N = 16) up to 6 mg/day or placebo (N = 14). Efficacy assessments included the Positive and Negative Syndrome Scale (PANSS), the Calgary Depression Scale, the Clinical Global Impressions-Severity of Illness scale, the Global Assessment of Functioning scale, and the Quality of Life Scale. A variety of safety and tolerability measures were also obtained. Data were collected between November 2001 and July 2003.

RESULTS

Significant improvement was noted in both groups on a variety of measures of psychopathology, but there was significantly greater improvement in the placebo-treated patients on the primary outcome measure, the PANSS positive symptom subscale. There were no significant differences between the treatment groups regarding extrapyramidal symptoms, weight gain, vital signs, serum clozapine levels, and QTc interval. The only side effect significantly more severe in risperidone-treated compared to placebo-treated patients was sedation. The patients treated with risperidone developed significant increases in plasma prolactin levels.

CONCLUSION

Adjunctive risperidone treatment in schizophrenia patients partially responsive to clozapine does not significantly improve psychopathology or quality of life compared to placebo in a 6-week period.

[The neurobiology of sleep and its influence on memory]

OBJECTIVE

Recent developments in neuroscience have increased our knowledge of the physiology of sleep and dreaming, and thus the number of studies about the influence of sleep on learning and memory have increased rapidly. In this review the objective is to assess the relationship between sleep and memory considering the evidence regarding the neurobiology of sleep and dreaming.

METHOD

This is a retrospective literature review and the relevant studies from the last 10 years are included. For this purpose the PubMed search engine and the key words "sleep, neurobiology, synaptic plasticity, memory" were used.

RESULTS

Sleep-wake and NREM-REM cycles are accompanied by neuromodulatory influences on forebrain structures that affect behavior, consciousness and cognition. Animal and human studies in which learning paradigms are used to assess the influence of sleep deprivation on memory show the influence of sleep on memory consolidation. Different sleep stages have different effects on memory processes. Some investigators claim that NREM improves declarative memory while REM improves procedural and implicit memory. Other investigators suggest that NREM and REM affect memory in a complementary and sequential way. Molecular and electrophysiological evidence suggests that the influence of sleep on memory is through synaptic plasticity.

CONCLUSION

Studies about the physiology of sleep and dreaming will help us to understand consciousness and memory better. The reverse is also true: understanding the contribution of sleep stages to memory will help us to determine the advantages of sleep and dreaming in an evolutionary perspective.

The influence of neurocognitive deficits and symptoms on disability in schizophrenia

OBJECTIVE

The purpose of the present study was to examine the relationship of disability with neurocognitive deficits and symptoms in schizophrenia.

METHOD

Sixty patients with schizophrenia and 30 healthy controls matched for age, sex and level of education were included in the study. Neurocognitive tests measuring attention, visual memory and executive functions were given. Severity of symptomatology was assessed by the Positive and Negative Syndrome Scale (PANSS). Disability level of the subjects was assessed by World Health Organisation-Disability Assessment Schedule 2 (WHO-DAS-2).

RESULTS

PANSS total score and the subscores were all correlated with DAS scores at a significant level. Neurocognitive test scores were not significantly associated with disability level. Regression analysis furthermore showed that symptom severity was predictive of the disability level.

CONCLUSION

These results suggest that, rather than neurocognitive deficits, symptoms appear to have direct impact on the functioning of patients with schizophrenia in many domains of life.

Alteration of epidermal growth factor receptor expression following ischaemia of renal tissue

This study was aimed to investigate Epidermal Growth Factor Receptor (EGF-R) expression after ischaemic injury in renal tissue and the effects of calcium channel blockers in the prevention of damage due to ischaemic insult. Simple nephrectomy was performed in a group of Sprague-Dawley rats, and kidneys were grouped according to cold ischaemia time (1, 6, 12, 24 and 48 hours, respectively) and to the type of calcium channel blockers (diltiazem and verapamil) used. EGF-R expression status was investigated in each group by immunohistochemistry on paraffin sections. Overall expression of EGF-receptor was detected in 8 (22.8%) kidneys. In terms of localization of EGF-receptor expression cortical tubular staining was detected in 8 (100%) kidneys, medullar tubular staining in (62.5%) kidneys and glomerular mesangial staining in 5 (62.5%) kidneys. There was no difference between various ischaemia times and different calcium channel blockers used. It has been concluded that hypoxia and cold ischaemia causes widespread down-regulation of EGF-receptor expression in renal tissue regardless of treatment with calcium channel blockers.

Use of double J stent in a case of spontaneous ureteral extravasation of urine

OBJECTIVES

Although there are numerous case reports of spontaneous rupture of the collecting system, especially including the calyceal fornix or the renal pelvis, spontaneous rupture of the ureter is a rare condition.

METHODS

Herein, we present a case of a patient who suffered symptoms of acute abdomen due to rupture of the proximal ureter. Extensive assessment revealed no etiological factor as to the extravasation.

RESULTS/CONCLUSIONS

The condition was managed conservatively by insertion of a double-J catheter. The double-J ureteral stent was removed on the first postoperative month under local anesthesia uneventfully. One year after the spontaneous ureteral extravasation, the patient remained without clinical problems. The diagnosis, pathogenesis and complications of this unusual condition are reviewed.

Comparative efficacy of cefixime and ampicillin-sulbactam in shigellosis in children

Shigellosis is still an important health problem in developing and underdeveloped countries as it is resistance to commonly used antibiotics including ampicillin, trimethoprim-sulfamethoxazole, chloramphenicol and tetracycline. Between May 1996 and October 1996, in a prospective randomized double-blind trial, cefixime was compared with ampicillin-sulbactam, both given orally for a period of 5 days, for the treatment of 80 children with acute bloody diarrhea. Forty patients were treated with a single-dose (8 mg/kg per day) of cefixime and the other 40 patients were given three doses of 100 mg/kg per day of ampicillin-sulbactam. After identification of Shigella organisms in stool specimens, nine patients in the cefixime receiving group and six patients in the ampicillin-sulbactam receiving group were excluded from the study. Differences in average age, sex and weight between the cefixime and ampicillin-sulbactam group were statistically meaningless (P > 0.05). Fever and bloody diarrhea were universal features. The efficacy of cefixime was found to be better than ampicillin-sulbactam. Patients given cefixime had a shorter duration of fever (P < 0.01), shorter duration to disappearance of blood in the stool (P < 0.01), reduced time with diarrhea (P < 0.01) and reduced hospitalization time during the 5 study days (P < 0.01) than patients given ampicillin-sulbactam. No adverse effects were observed in the two study groups. This controlled trial showed good efficacy with cefixime compared to ampicillin-sulbactam in the treatment of shigellosis. Single-dose daily oral therapy with cefixime also showed good tolerability. Cefixime should be considered as an alternative drug of choice for shigellosis in children.