Schizophrenia and neurological soft signs: gender differences in clinical correlates and antecedent factors

Brain subnetworks most sensitive to alterations of functional connectivity in Schizophrenia: a data-driven approach

Functional connectivity (FC) of the brain changes in various brain disorders. Its complexity, however, makes it difficult to obtain a systematic understanding of these alterations, especially when they are found individually and through hypothesis-based methods. It would be easier if the variety of brain connectivity alterations is extracted through data-driven approaches and expressed as variation modules (subnetworks). In the present study, we modified a blind approach to determine inter-group brain variations at the network level and applied it specifically to schizophrenia (SZ) disorder. The analysis is based on the application of independent component analysis (ICA) over the subject's dimension of the FC matrices, obtained from resting-state functional magnetic resonance imaging (rs-fMRI). The dataset included 27 SZ people and 27 completely matched healthy controls (HC). This hypothesis-free approach led to the finding of three brain subnetworks significantly discriminating SZ from HC. The area associated with these subnetworks mostly covers regions in visual, ventral attention, and somatomotor areas, which are in line with previous studies. Moreover, from the graph perspective, significant differences were observed between SZ and HC for these subnetworks, while there was no significant difference when the same parameters (path length, network strength, global/local efficiency, and clustering coefficient) across the same limited data were calculated for the whole brain network. The increased sensitivity of those subnetworks to SZ-induced alterations of connectivity suggested whether an individual scoring method based on their connectivity values can be applied to classify subjects. A simple scoring classifier was then suggested based on two of these subnetworks and resulted in acceptable sensitivity and specificity with an area under the ROC curve of 77.5%. The third subnetwork was found to be a less specific building block (module) for describing SZ alterations. It projected a wider range of inter-individual variations and, therefore, had a lower chance to be considered as a SZ biomarker. These findings confirmed that investigating brain variations from a modular viewpoint can help to find subnetworks that are more sensitive to SZ-induced alterations. Altogether, our study results illustrated the developed method's ability to systematically find brain alterations caused by SZ disorder from a network perspective.

Motor impairments in early onset schizophrenia

AIM

Motor impairments are frequent both at and before diagnosis. In childhood, impairments in general fine and gross motor function are among others identified using test batteries, and while elements of coordination are assessed in onset schizophrenia, the assessment of general motor functions is absent. Thus, we aimed to assess general motor function including childhood motor function in adolescents with schizophrenia in comparison with healthy controls and examine clinical correlates to general motor function.

METHOD

General fine and gross motor function was assessed using two standardized age-normed test batteries and a questionnaire in 25 adolescents with schizophrenia compared with age and gender-matched controls using t-test and χ² -test. Stepwise linear regression assessed potential developmental predictors on motor function including complications during childbirth, reported childhood motor function, executive function including false discovery rate q-values. Associations with schizophrenia symptom severity, executive function, cognitive function were assessed using Pearson's correlation and the impact of antipsychotic medication using t-test.

RESULT

All measures of motor function but one significantly differentiated adolescents with schizophrenia from healthy controls. The presence of schizophrenia (β =4.41, β = 10.96), explained the main part of the variance however, childhood motor function (β = .08) also added significantly to motor function. Executive function (β = -.45) was important for childhood motor function. Severity of schizophrenia was associated with strength (p < .0011) and manual coordination (p = .0295), and receiving antipsychotics affected manual dexterity (p = .0378).

CONCLUSION

The documentation of significant differences in general motor function in early onset schizophrenia compared with healthy controls highlights the need for general motor assessments and potential interventions.

Sex and gender associations with indicators of neurodevelopmental compromise in schizophrenia spectrum disorders

BACKGROUND

It has been proposed that sex and gender differences described in schizophrenia can be explained from a neurodevelopmental perspective.

AIM

In this study, we examined the associations of biological sex and gender role endorsement with putative indicators of neurodevelopmental compromise.

METHODS

We used the Bem Sex Role Inventory to calculate masculinity scores in 77 patients with a first episode of a schizophrenia spectrum disorder, and selected the following indicators of neurodevelopmental compromise: family history of schizophrenia, obstetric complications, premorbid functioning, neurological soft signs, and cognitive function. Secondary objectives included the moderating effects of age of onset of illness, substance use and negative symptoms on these associations.

RESULTS

There were no significant sex differences across any of the indicators of neurodevelopmental compromise. However, lower masculinity scores correlated significantly with poorer premorbid adjustment, sensory integration deficits and worse overall cognitive performance. Stepwise linear regression identified poorer premorbid adjustment in early adolescence and lower verbal learning scores as independent predictors of lower masculinity scores. In contrast to sex, gender showed several associations with indicators of neurodevelopmental compromise.

CONCLUSIONS

Lower masculinity scores may represent part of a phenotype for a neurodevelopmental anomaly that places some individuals on a pathway to schizophrenia.

The relationship between insight and neurological dysfunction in first-episode psychosis

Purpose

Impaired insight is commonly seen in psychosis and some studies have proposed that is a biologically based deficit. Support for this view comes from the excess of neurological soft signs (NSS) observed in patients with psychoses and their neural correlates which demonstrate a degree of overlap with the regions of interest implicated in neuroimaging studies of insight. The aim was to examine the relationship between NSS and insight in a sample of 241 first-episode psychosis patients.

Method

Total scores and subscale scores from three insight measures and two NSS scales were correlated in addition to factors representing overall insight and NSS which we created using principal component analysis.

Results

There were only four significant associations when we controlled for symptoms. “Softer” Condensed Neurological Evaluation (CNE) signs were associated with our overall insight factor (r = 0.19, P = 0.02), with total Birchwood (r = −0.24, P<0.01), and the Birchwood subscales; recognition of mental illness (r = −0.24, P<0.01) and need for treatment (r = −0.18, P = 0.02). Total Neurological Evaluation Scale (NES) and recognition of the achieved effects of medication were also weakly correlated (r = 0.14, P = 0.04).

Conclusion

This study does not support a direct link between neurological dysfunction and insight in psychosis. Our understanding of insight as a concept remains in its infancy.

Neurological soft signs in schizophrenia spectrum disorders are not confounded by current antipsychotic dosage

Neurological soft signs (NSS) have garnered increasing attention in psychiatric research on motor abnormalities in schizophrenia spectrum disorders (SSD). However, it remains unclear whether the assessment of NSS severity could have been confounded by current antipsychotic dosage. In this study, we recruited 105 patients with SSD that underwent a comprehensive motor assessment evaluating NSS and extrapyramidal motor symptoms (EPMS) by means of standardized instruments. Current antipsychotic dosage equivalence estimates were determined by the classical mean dose method (doses equivalent to 1 mg/d olanzapine). We used multiple regression analyses to describe the relationship between NSS, EPMS and antipsychotic medication. In line with our expectations, current antipsychotic dosage had no significant effects on NSS total score (p = 0.27), abnormal involuntary movements (p = 0.17), akathisia (p = 0.32) and parkinsonism (p = 0.26). Further, NSS total score had a significant effect on akathisia (p = 0.003) and parkinsonism (p = 0.0001, Bonferroni corr.), but only marginal effect on abnormal involuntary movements (p = 0.08). Our results support the notion that NSS are not significantly modulated by current antipsychotic dosage in SSD. The associations between NSS, akathisia and parkinsonism, as revealed by this study, support the genuine rather than medication-dependent origin of particular motor abnormalities in SSD.

Patterns of co-altered brain structure and function underlying neurological soft signs in schizophrenia spectrum disorders

Neurological soft signs (NSS) comprise a broad range of subtle neurological deficits and are considered to represent external markers of sensorimotor dysfunction frequently found in mental disorders of presumed neurodevelopmental origin. Although NSS frequently occur in schizophrenia spectrum disorders (SSD), specific patterns of co-altered brain structure and function underlying NSS in SSD have not been investigated so far. It is unclear whether gray matter volume (GMV) alterations or aberrant brain activity or a combination of both, are associated with NSS in SSD. Here, 37 right-handed SSD patients and 37 matched healthy controls underwent motor assessment and magnetic resonance imaging (MRI) at 3 T. NSS were examined on the Heidelberg NSS scale. We used a multivariate data fusion technique for multimodal MRI data-multiset canonical correlation and joint independent component analysis (mCCA + jICA)-to investigate co-altered patterns of GMV and intrinsic neural fluctuations (INF) in SSD patients exhibiting NSS. The mCCA + jICA model indicated two joint group-discriminating components (temporoparietal/cortical sensorimotor and frontocerebellar/frontoparietal networks) and one modality-specific group-discriminating component (p < .05, FDR corrected). NSS motor score was associated with joint frontocerebellar/frontoparietal networks in SSD patients. This study highlights complex neural pathomechanisms underlying NSS in SSD suggesting aberrant structure and function, predominantly in cortical and cerebellar systems that critically subserve sensorimotor dynamics and psychomotor organization.

Association between neurological soft signs and antioxidant enzyme activity in schizophrenic patients

To determine the relationship between alterations in the activity of the enzymes participating in antioxidative defense system and neurological soft signs (NSS) in schizophrenic patients with the first episode psychosis (S_FE, n = 19), patients in relapse (S_R, n = 46), and healthy controls (HC, n = 20). NSS intensity and enzymatic plasma activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) were compared between S_FE, S_R and HC subjects and a follow-up correlation analyses between the enzyme activities and NSS intensity was performed. NSS intensity was increased four times in schizophrenic patients compared with healthy controls. Activities of SOD and CAT were 40% decreased in S_FE and these reductions were ameliorated by antipsychotic treatment. GPX activity was 20% decreased in both patient groups compared with controls. A negative correlation between NSS intensity and GPX activity was specifically found in the S_FE patients. The data in this report argue that a reduction of GPX activity might be one of the causes for the emergence of NSS at the onset of schizophrenia, and provide the evidence that antipsychotic therapy can attenuate activity reductions of SOD and CAT, but not the activity reduction of GPX and the intensity of NSS.

Neurological Soft Signs in Schizophrenia: An Update on the State- versus Trait-Perspective

BACKGROUND

Neurological soft signs (NSS) represent minor neurological signs, which indicate non-specific cerebral dysfunction. In schizophrenia, their presence has been documented extensively across all stages of the disease. Until recently, NSS were considered an endophenotype or a trait phenomenon. During the past years, however, researchers report fluctuations of the NSS scores.

AIMS

To further clarify the question whether NSS exhibit state or trait components or both, studies that have investigated NSS longitudinally were reviewed.

METHOD

Studies which have assessed NSS longitudinally in adults suffering from schizophrenia, were searched for. The time frame was January 1966 to June 2017. Studies on teenagers were excluded because of interferences between brain maturation and pathology.

RESULTS

Twenty-nine follow-up studies were identified. They included patients during different stages of their illness and mainly used established instruments for NSS assessment. Patients with a first episode or a remitting course predominantly show a decrease of NSS over time, whereas a worsening of NSS can be found in the chronically ill. It was shown that change of NSS total scores over time is predominantly caused by motor system subscales and to a lesser extent by sensory integration scales. With respect to medication, the majority of studies agree on a relationship between medication response and improvement of NSS while the type of antipsychotic does not seem to play a major role. Moreover, where information on side-effects is given, it does not favor a strong relationship with NSS. However, NSS seem to correlate with negative and cognitive symptoms.

CONCLUSION

Studies manifest a conformity regarding the presence of NSS in schizophrenia patients on the one hand. On the other hand, fluctuations of NSS scores have been widely described in subgroups. Taken together results strongly support a state-trait dichotomy of NSS. Thus, the usage of NSS as an endophenotype has to be called into question.

Neurological soft signs in Tunisian patients with first-episode psychosis and relation with cannabis use

BACKGROUND

Neurological soft signs (NSS) are minor non-localizing neurological abnormalities that are conceptualized as neurodevelopmental markers that mediate the biological risk for psychosis. We aimed to explore the relationship between NSS and cannabis use, an environmental risk factor of psychosis.

METHODS

This was a cross-sectional study in consecutively admitted patients hospitalized for first-episode psychosis. NSS were assessed by the NSS scale (23 items exploring motor coordination, motor integrative function, sensory integration, involuntary movements or posture, quality of lateralization). Presence of NSS was defined as a NSS scale total score ≥9.5. Cannabis use was ascertained with the cannabis subsection in the Composite International Diagnostic Interview.

RESULTS

Among 61 first-episode psychosis patients (mean age = 28.9 ± 9.4 years; male = 86.9%, antipsychotic-naïve = 75.4%), the prevalence of current cannabis use was 14.8% (heavy use = 8.2%, occasional use = 6.6%). NSS were present in 83.6% of the sample (cannabis users = 66.7% versus cannabis non-users = 85.5%, p = 0.16). The mean total NSS score was 15.3 ± 6.7, with a significant lower total NSS score in cannabis users (11.2 ± 5.6 versus 16.0 ± 6.7, p = 0.048). Differences were strongest for the "motor coordination" (p = 0.06) and "involuntary movements" (p = 0.07) sub-scores.

CONCLUSIONS

This study demonstrated a negative association between cannabis use and NSS, especially regarding motor discoordination. This finding supports the hypothesis that a strong environmental risk factor, such as cannabis, may contribute to the onset of psychosis even in the presence of lower biological and genetic vulnerability, as reflected indirectly by lower NSS scores. Nevertheless, additional studies are needed that explore this interaction further in larger samples and considering additional neurobiological and environmental risk factors.

A clinical study of neurological soft signs in patients with schizophrenia

BACKGROUND AND AIM

Neurological soft signs (NSSs) are "objectively measured, nonlocalizing abnormalities, not related to impairment of a specific brain region, reflecting improper cortical-subcortical and intercortical connections." The possibility of NSS as an endophenotype in schizophrenia has been studied across the globe. We aimed at finding the prevalence of NSS among patients with schizophrenia as well as the associations of NSS between various sociodemographic and illness variables.

SUBJECTS AND METHODS

One hundred patients between the age group of 16 and 60 years were serially selected from the inpatient department of a tertiary care hospital who have been diagnosed as a case of schizophrenia according to the International Classification of Diseases version 10 during 1 year period. A semi-structured pro forma was used to collect various demographic as well as illness data, and subjects were clinically evaluated for NSS using neurological evaluation scale.

RESULTS

The prevalence of NSSs was found to be 67%, significant association was found between NSS and age, occupation, and duration of illness. A statistically significant correlation was found between NSS and age, NSS and duration of illness.

CONCLUSION

The validity of NSS as an endophenotype lies in the fact that it should be independent of all sociodemographic and illness variables. However, our study evaluated some statistically significant findings between them. Hence, further researches are required with properly adjusted controls to find if the associations obtained between NSS and different variables here are true or whether there are some confounding factors included.

Catatonia as part of the psychomotor syndrome in schizophrenia

Although the prevalence and severity of catatonia may have decreased over time, it is still a highly relevant, frequently occurring symptom cluster that can be observed in schizophrenia patients. Apart from this syndrome, neurological soft signs, psychomotor slowing and extrapyramidal symptoms are other psychomotor symptom clusters that are part of the clinical picture of schizophrenia. In this overview, the relevance of catatonia as a contemporary symptom cluster of the illness as well as its relationship with other psychomotor symptoms of the illness are discussed.

Sex and laterality differences in parkinsonian impairment and transcranial ultrasound in never-treated schizophrenics and their first degree relatives in an Andean population

We tested the hypothesis that loss of substantia nigra neurons in subjects at risk of schizophrenia (1), as reflected by midbrain hyperechogenicity (2) and parkinsonian motor impairment (3), is asymmetric and influenced by sex. We evaluated 62 subjects with never-treated chronic schizophrenia, 80 of their adult, unaffected first degree relatives and 62 healthy controls (matched by sex and age to the cases), part of an Andean population of Northern Argentina. Parkinsonism was scored blindly using UPDRS-3 (Unified Parkinson's Disease Rating Scale) on videotaped exams by 2 independent raters. Transcranial ultrasound was performed by an expert sonographist blind to subject condition with a 2.5 MHz transducer through a temporal bone window. Quantification of echogenic area was carried out on saved images by a different evaluator. We found a significant difference in parkinsonian motor impairment between patients, their relatives as well as controls. All three groups showed worse parkinsonism on the left side than the right, corresponding with increased echogenicity on the right substantia nigra compared with the left. Females had significantly more right echogenicity than males, and patients and unaffected relatives were significantly more echogenic than controls on that side. On the left, only female patients had significant echogenicity. Our data supports the notion that unaffected relatives of schizophrenic subjects have increased parkinsonism and concomitant brainstem abnormalities which may represent a vulnerability to the disease. Both motor and brainstem abnormalities are asymmetric and influenced by sex.

Aberrant cerebellar connectivity in motor and association networks in schizophrenia

Schizophrenia is a devastating illness characterized by disturbances in multiple domains. The cerebellum is involved in both motor and non-motor functions, and the "cognitive dysmetria" and "dysmetria of thought" models propose that abnormalities of the cerebellum may contribute to schizophrenia signs and symptoms. The cerebellum and cerebral cortex are reciprocally connected via a modular, closed-loop network architecture, but few schizophrenia neuroimaging studies have taken into account the topographical and functional heterogeneity of the cerebellum. In this study, using a previously defined 17-network cerebral cortical parcellation system as the basis for our functional connectivity seeds, we systematically investigated connectivity abnormalities within the cerebellum of 44 schizophrenia patients and 28 healthy control participants. We found selective alterations in cerebro-cerebellar functional connectivity. Specifically, schizophrenia patients showed decreased cerebro-cerebellar functional connectivity in higher level association networks (ventral attention, salience, control, and default mode networks) relative to healthy control participants. Schizophrenia patients also showed increased cerebro-cerebellar connectivity in somatomotor and default mode networks, with the latter showing no overlap with the regions found to be hypoconnected within the same default mode network. Finally, we found evidence to suggest that somatomotor and default mode networks may be inappropriately linked in schizophrenia. The relationship of these dysconnectivities to schizophrenia symptoms, such as neurological soft signs and altered sense of agency, is discussed. We conclude that the cerebellum ought to be considered for analysis in all future studies of network abnormalities in SZ, and further suggest the cerebellum as a potential target for further elucidation, and possibly treatment, of the underlying mechanisms and network abnormalities producing symptoms of schizophrenia.

Association Between Age at Onset of Schizophrenia and Age at Menarche

INTRODUCTION

Increasing evidence from clinical practice, as well as from epidemiological and basic research shows that there are gender differences in clinical features of schizophrenia, and this may be related to estrogens. There may be a relationship between earlier puberty and later onset of the disease, because of the protective effects of estrogens in women with schizophrenia. In this study, our aim was to analyze the correlation between age of menarche and age of onset of schizophrenia and to investigate the protective effects of estrogens in schizophrenia.

METHOD

In this study, we included 289 patients who were diagnosed with schizophrenia. Those with mental deficiency or organic brain disorders were excluded from the study. All subjects were given a socio-demographic form to determine their personal information, age at menarche, age at first odd behavior, age at onset of the disease and first hospitalization. Data on factors which may affect the association between age at onset of schizophrenia and age at menarche such as family history, head or birth trauma etc. were recorded on the information form.

RESULTS

We found out that age at menarche was negatively associated with age at first odd behavior and age at first psychotic symptoms.

CONCLUSION

Our study verifies the protective effects of estrogens and shows that the earlier puberty may be the cause of later onset of schizophrenia. A gender-sensitive approach in psychiatry improves our understanding of mental illness and our therapeutic strategies.

[Cortical Release Signs in Patients with Schizophrenia, Depressive Disorders, and Bipolar Affective Disorder]

BACKGROUND AND OBJECTIVES

Determining the presence of cortical release signs associated with white matter damage, is a clinically easy method to perform. The objective of this study is to determine the presence of cortical release signs in patients with mental illnesses and cerebrovascular disease, as well as its clinical usefulness, given that it indicates cortical damage.

MATERIAL AND METHODS

A review was made of cortical release signs in patients hospitalized in clinical psychiatry and general hospitals with bipolar affective disorder (40), depression (37), schizophrenia (33), cardiovascular disease (33) and dementia (37).

RESULTS

The signs of cortical release do not have the same importance as cortical damage. For example, the glabellar reflex was found in all the groups, that of paratonia, particularly in the group with schizophrenia, and others signs in the group of patients with dementia.

CONCLUSIONS

It is suggested that these signs imply subcortical white matter damage. The appearance of these signs shows the need for a follow up of patients diagnosed with bipolar affective disorder, depression and schizophrenia.

Gender difference in age at onset of schizophrenia: a meta-analysis

BACKGROUND

Most studies reporting the gender difference in age at onset of schizophrenia show an earlier onset in males, but vary considerably in their estimates of the difference. This may be due to variations in study design, setting and diagnostic criteria. In particular, several studies conducted in developing countries have found no difference or a reversed effect whereby females have an earlier onset. The aim of the study was to investigate gender differences in age of onset, and the impact of study design and setting on estimates thereof.

METHOD

Study methods were a systematic literature search, meta-analysis and meta-regression.

RESULTS

A total of 46 studies with 29,218 males and 19,402 females fulfilled the inclusion criteria and were entered into a meta-analysis. A random-effects model gave a pooled estimate of the gender difference of 1.07 years (95% confidence interval 0.21-1.93) for age at first admission of schizophrenia, with males having earlier onset. The gender difference in age at onset was not significantly different between developed and developing countries. Studies using diagnostic and statistical manual of mental disorders (DSM) criteria showed a significantly greater gender difference in age at onset than studies using International Classification Of Diseases (ICD) criteria, the latter showing no difference.

CONCLUSIONS

The gender difference in age of onset in schizophrenia is smaller than previously thought, and appears absent in studies using ICD. There is no evidence that the gender difference differs between developed and developing countries.

Obstetric complications and neurological soft signs in male patients with schizophrenia

Bersani G, Clemente R, Gherardelli S, Bersani FS, Manuali G. Obstetric complications and neurological soft signs in male patients with schizophrenia.

Objective: The study investigated the relationship between neurological soft signs (NSS) and obstetric complications (OCs) in patients with schizophrenia.

Methods: Sixty-three male patients with schizophrenia were divided into two subgroups, based on the OCs presence or absence, which were compared in relation to NSS prevalence. After that, a Person's correlation test was performed to explore the correlation between NSS and OCs severity.

Results: The subgroup with OCs showed more NSS, but there were not significant correlations between NSS and OCs severity.

Conclusions: It seems that any OC, without distinction in typology and severity, could unspecifically impair the neurodevelopment and inducing NSS expression. Our findings confirm the hypothesis that neurodevelopment alterations, such as those probably induced by OCs, can contribute to a premorbid brain dysfunctional state expressed by NSS.

Correlations between obstetric complications and neurological soft signs in Tunisian patients with schizophrenia

The objective of this study was to examine the correlations between a history of obstetric complications (OC) and neurological soft signs (NSS) in Tunisian patients with schizophrenia. Forty-six patients were assessed using the Krebs et al. NSS scale. History of OC was obtained from the patients' mothers using the McNeil–Sjöström scale. Although there was no significant difference in NSS between patients with and without OC, there were negative correlations between OC total score and motor coordination and integration sub-scores. These negative correlations suggest that OC could enhance the effects of genetic risk factors for schizophrenia.

Neurological soft signs in schizophrenia: a meta-analysis

BACKGROUND

Neurological soft signs (NSS) are hypothesized as candidate endophenotypes for schizophrenia, but their prevalence and relations with clinical and demographic data are unknown. The authors undertook a quantification (meta-analysis) of the published literature on NSS in patients with schizophrenia and healthy controls. A systematic search was conducted for published articles reporting NSS and related data using standard measures in schizophrenia and healthy comparison groups.

METHOD

A systematic search was conducted for published articles reporting data on the prevalence of NSS in schizophrenia using standard clinical rating scales and healthy comparison groups. Meta-analyses were performed using the Comprehensive Meta-analysis software package. Effect sizes (Cohen d) indexing the difference between schizophrenic patients and the healthy controls were calculated on the basis of reported statistics. Potential moderator variables evaluated included age of patient samples, level of education, sample sex proportions, medication doses, and negative and positive symptoms.

RESULTS

A total of 33 articles met inclusion criteria for the meta-analysis. A large and reliable group difference (Cohen d) indicated that, on average, a majority of patients (73%) perform outside the range of healthy subjects on aggregate NSS measures. Cognitive performance and positive and negative symptoms share 2%-10% of their variance with NSS.

CONCLUSIONS

NSS occur in a majority of the schizophrenia patient population and are largely distinct from symptomatic and cognitive features of the illness.

Neurological soft signs in patients with schizophrenia and their unaffected siblings: frequency and correlates in two ethnic and socioeconomic distinct populations

Recent studies have suggested that ethnicity and socioeconomic status may have an impact on the frequency and significance of neurological soft signs (NSS). However, this impact has not been adequately assessed. The objectives were to determine the NSS scores in patients with schizophrenia and their unaffected siblings and to examine the clinical and therapeutic correlates of NSS in two ethnic and socioeconomic distinct populations. Two independent replicate studies were carried out: (1) a French Caucasian sample of 69 patients with schizophrenia, 43 of their unaffected siblings and 108 control subjects; (2) a Tunisian sample of 66 patients with schizophrenia, 31 of their unaffected siblings and 60 control subjects. NSS were assessed with a multidimensional scale, previously validated in drug-naïve and treated samples of patients with schizophrenia. Both patient groups were assessed with the positive and negative syndrome scale (PANSS), the clinical global impressions (CGI) and the global assessment of functioning. NSS total scores were significantly higher in patients with schizophrenia comparatively to siblings and to controls in both studies. The two sibling groups had also higher NSS scores than controls. In addition, NSS total scores were correlated to the PANSS negative and disorganization sub-scores, to the CGI-severity of illness and to a low educational level in both studies. These studies provide a confirmation in two distinct samples of the high prevalence of NSS in patients with schizophrenia, and in their biological relatives, independently of their respective ethnic and socioeconomic origins.

Potential Endophenotype for Schizophrenia: Neurological Soft Signs

Introduction: Neurological soft signs (NSS) are suggested as a candidate endophenotype for schizophrenia. This article aims to review relevant literature and discuss the role of NSS in understanding schizophrenia. Methods: This is an update on a review article published in 2003. Articles from 2003 onwards were specifically reviewed and discussed with relevance to the role of NSS as endophenotype for schizophrenia. Results: Consistent data suggest an excess of NSS in schizophrenic patients. NSS appear to be related to schizophrenic symptoms, in particular negative symptoms and disorganisation. Information on NSS and demographic correlates is scarce, and the confounding effects between age, education and intelligence on NSS constitute an important gap in current knowledge. Longitudinal data suggest NSS as both a trait and state variable in the course of disease. NSS are not specific with regard to diagnosis, although there are claims that individual sub-components may be more specific. The weight of evidence raises question on the specificity of NSS for schizophrenia. Conclusions: The usefulness and feasibility of NSS as a specific endophenotype target for schizophrenia is unclear. However, NSS remain an important feature and symptom correlate of schizophrenia. Future research should focus on delineating the effects of NSS from those of confounding demographic variables, and the stability of NSS over the course of illness to elucidate its role in schizophrenia. Key words: Diagnostic specificity, Neurological examination abnormalities, Psychotic symptoms, Review, Trait

Neurological signs and involuntary movements in schizophrenia: intrinsic to and informative on systems pathobiology

While it has long been considered whether the pathobiology of schizophrenia extends beyond its defining symptoms to involve diverse domains of abnormality, in the manner of a systemic disease, studies of neuromotor dysfunction have been confounded by treatment with antipsychotic drugs. This challenge has been illuminated by a new generation of studies on first-episode schizophrenia before initiation of antipsychotic treatment and by opportunities in developing countries to study chronically ill patients who have remained antipsychotic naive due to limitations in provision of psychiatric care. Building from studies in antipsychotic-naive patients, this article reviews 2 domains of neuromotor dysfunction in schizophrenia: neurological signs and involuntary movements. The presence and characteristics of neurological signs in untreated vis-à-vis treated psychosis indicate a vulnerability marker for schizophrenia and implicate disruption to neuronal circuits linking the basal ganglia, cerebral cortex, and cerebellum. The presence and characteristics of involuntary movements in untreated vis-à-vis treated psychosis indicate an intrinsic feature of the disease process and implicate dysfunction in cortical-basal ganglia-cortical circuitry. These neuromotor disorders of schizophrenia join other markers of subtle but pervasive cerebral and extracerebral, systemic dysfunction, and complement current concepts of schizophrenia as a disorder of developmentally determined cortical-basal ganglia-thalamo-cortical/cerebellar network disconnectivity.

Fewer neurological soft signs among first episode psychosis patients with heavy cannabis use

BACKGROUND

Although neurological soft signs (NSS) have been consistently associated with schizophrenia and a variety of risk factors, few studies have focused on the association between NSS and environmental factors such as cannabis use, particularly in patients with first episode psychosis.

METHODS

We administered the Neurological Evaluation Scale (NES) to 92 patients during their first episode of functional psychosis. Psychopathology was assessed with the Positive And Negative Syndrome Scale (PANSS) and the family history of psychotic disorder was established on the basis of the Family Interview for Genetic Studies (FIGS). We also assessed lifetime cannabis and cocaine use utilizing that specific section of the Composite International Diagnostic Interview. The outcome variable was the presence of high NSS, defined by a score above the median split of the NES score (>21).

RESULTS

Most patients (80/92, 87%) presented a non-affective psychosis. The presence of high NSS showed a significant independent association with not having been a heavy cannabis user (OR=8.3; 95% CI, 2.4-33.3), family history of psychosis (OR=4.3; 95% CI, 1.2-14.9), male sex (OR=4.0; 95% CI, 1.2-14.0), lower score in verbal fluency and higher score in negative symptoms (both p<0.01).

CONCLUSION

Our cross-sectional results support the hypothesis that potentially different pathways associated with the emergence of first episode psychosis may exist, including neurological premorbid alteration and environmental cannabis abuse.

Region and sex differences in constituent dopamine neurons and immunoreactivity for intracellular estrogen and androgen receptors in mesocortical projections in rats

Many cortical and prefrontal functions show sex differences in their development, adult capacity, and dysfunction in disorders like schizophrenia. Correlations between circulating gonadal hormones and certain prefrontal functions have also been identified in humans and experimental animal models. Although multiple mechanisms may be involved, such hormone sensitivities/sex differences could be related to gonadal steroid actions on another regulator of cortical/prefrontal cortical function, the mesocortical dopamine system. Thus, although it is well known that perturbations in prefrontal dopamine signaling induce behavioral deficits, it is also known that several endpoints of these afferents are sensitive to gonadal steroids and/or are sexually dimorphic. This study explored possible substrates for this in two ways: by comparing the distributions of immunoreactivity for intracellular estrogen (alpha and beta) and androgen receptors among retrogradely labeled dopaminergic and nondopaminergic mesocortical neurons projecting to prefrontal, premotor, and primary motor cortices, areas in which male rat dopamine axons are differentially hormone-sensitive; and by comparing anatomical data in males and females. These analyses revealed region-, cell-, and sex-specific specializations in receptor localization that paralleled established patterns of mesocortical hormone sensitivity, including the androgen sensitivity of dopamine axons and dopamine-dependent functions in prefrontal cortex. It was also found that the proportions of dopamine neurons making up mesocortical projections were approximately 30% in males, whereas in females, significantly more constituent cells were dopaminergic. Together, these features may be part of the neurobiology giving mesocortical afferents their hormone sensitivities and/or sex differences in physiology, function, and dysfunction in disease.

Expanding the schizophrenia phenotype: a composite evaluation of neurodevelopmental markers

Minor physical anomalies (MPAs) and neurologic soft signs (NSSs) have been consistently reported to be more frequent in schizophrenia subjects and their first-degree relatives. We aimed at coassessing both these neurodevelopmental markers in neuroleptic-naive recent-onset schizophrenia (NRS) subjects in comparison to healthy control (HC) subjects to explore the predictive validity of this composite endophenotype. We administered the Modified Waldrop Scale (MWS) and the Neurological Evaluation Scale (NES) to evaluate MPAs and NSSs, respectively, in 40 NRS and 30 matched HC subjects. Schizophrenia subjects had significantly higher frequencies of MPAs and NSSs than HC. Minor physical anomaly total scores were correlated with greater severity of illness, whereas NES scores did not show any relationship with clinical variables. Schizophrenia and HC subjects were most accurately classified (82.9%) when MPAs and NSSs were considered as a composite phenotype rather than independently. Minor physical anomalies and NSSs constitute independent neurodevelopmental markers of schizophrenia and would afford greater predictive validity when used as a composite endophenotype in genetic association studies.

Negative association between a history of obstetric complications and the number of neurological soft signs in first-episode schizophrenic disorder

We examined the relationship between a history of obstetric complications (OCs) and the number of neurological soft signs (NSS) in a group of 132 patients experiencing their first episode of psychosis. We measured NSS by means of a comprehensive standardized assessment and gained information on a selection of nine OCs from the patient's mother. Contrary to our expectations we found significantly more NSS in the group of patients without a history of OCs. This effect was independent of medication in the group of patients with a schizophrenic disorder, but not in the entire group. It is possible that the patients with a history of OCs carry fewer genes for schizophrenia (and NSS) and 'needed' the OCs to develop schizophrenia.

Obstetric complications and neurological abnormalities in neuroleptic-naive psychotic patients

Studies addressing the relationship between a history of obstetric complications (OCs) and neurological abnormalities in schizophrenia have produced contradictory findings. Using a pre-posttreatment design in a neuroleptic-naive sample of psychotic patients, we examined the relationship of a history of OC to primary and drug-induced neurological signs. Fifty neuroleptic-naive non-affective psychotic inpatients were assessed for a history of OC by using the McNeil-Sjöström scale, and for neurological signs including parkinsonism, dyskinesia, akathisia and catatonia, which were rated before and after inception of neuroleptic treatment. A subsample of 28 patients were also examined for neurological soft-signs. Ratings of OCs were related to admission levels of parkinsonism, dyskinesia, akathisia and neurological soft-signs, but not to levels of catatonia. By obstetric period, pregnancy complications were related to levels of parkinsonism, dyskinesia, and neurological soft-signs, and neonatal complications were related to levels of akathisia. Drug-induced neurological signs were not associated with a history of OCs. We argue that the association pattern between a history of OCs and primary neurological signs from several domains suggests a causal link among these variables. Having a history of OCs does not convey a vulnerability for developing drug-induced neurological signs in the short term.

The presence of neurological soft signs along the psychosis proneness continuum

Neurological soft signs have been observed in patients with schizophrenia and their relatives. However, it has not been considered whether the increased rates of neurological soft signs are related to measures of psychosis proneness in the general population. We tested this hypothesis in a group of normal volunteers (n = 28) who scored highly for positive schizotypy when assessed online and a control group (n = 33) who scored below the mean. Compared with the controls, high psychosis-prone individuals showed significantly higher Total and Other Soft Signs subscale scores on the Neurological Evaluation Scale. It appears that soft signs are also associated with psychosis proneness when measured in the general population, which suggests that soft signs are distributed along a continuum of risk for schizophrenia.

Neurologic soft signs in schizophrenic patients treated with conventional and atypical antipsychotics

Neurologic soft signs (NSS) are considered a somatic feature associated with schizophrenia (DSM-IV) that are present in neuroleptic-treated, as well as untreated or first-episode patients. The aim of this study was to determine the incidence and severity of NSS in groups of schizophrenic patients treated with either a conventional neuroleptic medication, haloperidol (n = 37), or atypical antipsychotic medications, risperidone (n = 19), clozapine (n = 34), and olanzapine (n = 18). NSS were assessed with the Neurological Evaluation Scale (NES), whereas extrapyramidal symptoms (EPS), which occur more commonly with conventional neuroleptic treatment, were evaluated using the Simpson-Angus Scale. NES scores were not significantly different between groups. Slight differences were found for 2 items only. The haloperidol group showed higher scores for the "Romberg test," whereas the clozapine group showed higher scores for "short-term memory." There were significant correlations between EPS and NES total score in the haloperidol and risperidone groups. These results demonstrate an overall overlapping of NSS among the groups, confirming their substantial independence from neurologic implications of neuroleptic treatment.

Neurological abnormalities in first-episode schizophrenia: temporal stability and clinical and outcome correlates

OBJECTIVE

Neurological abnormalities in subjects with schizophrenia have been regarded as diagnostically non-specific and non-localising. This study assessed the temporal stability of neurological abnormalities in subjects with first-episode schizophrenia over the course of 12 months. We also examined their relationships with psychiatric symptoms, medication effects and treatment outcome.

METHOD

The sample comprised 66 largely medication-naive subjects who were treated according to a fixed protocol. We performed a factor analysis of the Neurological Evaluation Scale (NES) items, and relationships between the NES factors and various clinical and outcome measures were explored.

RESULTS

Five NES factors were identified, explaining 68.4% of the variance. While the NES total scores did not change significantly over time, poor performance on motor sequencing tests was related to longer duration of untreated psychosis, and showed a tendency to improve as psychiatric symptoms resolved. The most interesting finding was that high scores on the motor sequencing factor predicted the emergence of persistent dyskinesia at 24 months (ANCOVAR F(1, 20) = 19.287, p = 0.0002).

CONCLUSIONS

Two NES factors (motor sequencing and attention) are reasonably replicable across samples, and have potential relevance for the further exploration of the pathogenesis of schizophrenia, as well as possible clinical applications.

Cortical release signs in psychiatry

OBJECTIVE

To review the role of cortical release signs (CRS) in neuropsychiatry.

METHOD

A thorough literature review was conducted using Medline and Psychlit databases, and other relevant references available to the authors.

RESULTS

A number of neurological abnormalities are reported at elevated rates in neuropsychiatric conditions. CRS are a group of primitive reflexes that are present in the neonate but become inhibited as the infant central nervous system (CNS) develops, only to later re-emerge in the context of CNS disease. The clinical elicitation and interpretation of each CRS is described with reference to its neurobiology. The prevalence of CRS in schizophrenia, affective disorder, obsessive-compulsive disorder, Alzheimer's disease, vascular dementia, frontotemporal dementia and other neuropsychiatric illness allows for their use in the clinical management of these patients, including diagnostic assessment, treatment monitoring and prognosis.

CONCLUSIONS

A number of issues complicate their interpretation in neuropsychiatric illness, including the apparent high base rate of some CRS in non-clinical populations, their increasing prevalence with age, lack of specificity and uncertainty over what constitutes an 'abnormal' response. In some circumstances, CRS may assist in diagnostic differentiation and illness staging.

Abnormal neurological signs at the onset of psychosis

INTRODUCTION

The objective of this investigation was to determine whether abnormal neurological signs (ANS) are present at the onset of psychosis, prior to the initiation of antipsychotic treatment, and to examine the effect of 6 weeks of antipsychotic treatment on these signs.

METHODS

We examined 29 first-episode schizophrenic patients admitted at an Army Medical Center within 10 days of psychosis onset, using the Neurological Evaluation Scale and the 18-item Brief Psychiatric Rating Scale (BPRS) and compared them to controls.

RESULTS

All of the subjects had neurological signs indicating problems in sensory integration, motor coordination, and sequencing of complex motor acts. No psychotic subject had fewer than two abnormal neurological signs. When compared to age and sex matched groups of normal controls and nonpsychotic psychiatric controls, the psychotic group had a significantly higher incidence of neurological signs. At baseline, the severity of neurological signs was associated with elevated BPRS total, positive, and negative symptom scores. The change in clinical symptoms was positively correlated with a change in neurological signs.

DISCUSSION

These findings indicate that some neurological signs are present at the onset of psychosis, and that these signs may be altered by treatment. These abnormal neurological signs reflect an underlying brain function abnormality and may be useful in differential diagnosis, prognosis, and treatment selection.

Neurological soft-signs and minor physical anomalies in schizophrenia: differential transmission within families

Markers of vulnerability have been identified in schizophrenia, and among them, neurological soft-signs (NSS) and minor physical anomalies (MPAs) also seem to occur in biological relatives. The similarities of these developmental markers within families may depend on either genetic or non-genetic factors. The aim of the study was to investigate the intra-familial similarities of NSS and MPAs within 18 nuclear families (18 probands with schizophrenia and 36 of their non-psychotic parents). A general linear model showed similarities within families for NSS (intra-class coefficient [ICC] = 0.64; F = 2.6; df = 17.17; p = 0.02) but not for MPAs (ICC = -0.10; F = 0.7; df = 17.17; ns). We thus found a direct evidence for the intra-familial transmission of NSS but not of MPAs, suggesting that this morphological phenotypic trait could be more dependent on epigenetic influences.

Neurological soft signs in first-episode psychosis: a systematic review

BACKGROUND

Neurological soft signs (NSS) are minor neurological signs indicating non-specific cerebral dysfunction. Their presence has been documented extensively in schizophrenia but not during the first psychotic episode.

AIMS

To review studies that have specifically investigated NSS at the time of the first psychotic episode.

METHOD

A review of studies investigating neurological function in first-episode psychosis, using a clinical examination.

RESULTS

Patients with first-episode psychosis show an excess of NSS, particularly in the areas of motor coordination and sequencing, sensory integration and in developmental reflexes. Furthermore, NSS may be associated with a specific laterality pattern.

CONCLUSIONS

More studies on first-onset schizophrenia are needed, evaluating both sensory and motor neurological domains (scoring separately for the two sides of the body), integrating this knowledge with neuroimaging findings and clarifying the role of NSS as markers of cognitive dysfunction.

A risk factor screening and assessment protocol for schizophrenia and related psychosis

OBJECTIVE

The Psychological Assistance Service (PAS) opened in Newcastle, New South Wales in 1997 as a clinical service for the assessment and treatment of young people at high risk of psychosis and those experiencing a first psychotic episode. The aim of this paper is to describe the assessment protocol of PAS, which is strongly influenced by the neurodevelopmental perspective on early onset psychosis.

METHOD

The systematic assessment of patients referred to PAS using a protocol over a 2 week period is described. The protocol includes a narrative history, structured diagnostic interview, quantitative assessment of symptoms and other clinical features, a neurological examination and comprehensive neuropsychological test battery.

RESULTS

The clinic has received over 250 referrals in a 2 year period and accepted 116 patients for a full assessment, of whom 60 were deemed to be 'at-risk' of psychosis and 56 were experiencing their first psychotic episode. Both groups were similar with respect to gender and there were minor age differences. The first-episode group experienced more reality distortion, schizotypal and negative symptoms. While both groups showed some neuropsychological and neurological impairment, there were no statistically significant differences between the groups on these variables except for a test of executive functioning in which the first-episode group was more impaired than the 'at-risk' group. A low rate of conversion to psychosis occurred in the 'at-risk' group.

CONCLUSIONS

The minor differences between the two groups may have been related to relatively small sample sizes, although some similarities between the groups were to be expected. The low rate of conversion to psychosis in the 'at-risk' group is discussed. Further analyses using larger samples are necessary to determine the validity of the various 'at-risk' categories and this will involve following a sufficiently large sample over an adequate time. The most efficient way of doing this would be to pool data across centres with comparable early intervention programs.

Long-term adaptive life functioning in relation to initiation of treatment with antipsychotics over the lifetime trajectory of schizophrenia

BACKGROUND

There is evidence that the stage of illness at which antipsychotic treatment is initiated in schizophrenia may have consequences for its subsequent course. How this might relate to impaired adaptive life functioning in the long-term is poorly understood.

METHODS

Thirty-eight inpatients, many of whom had been admitted in the preneuroleptic era, were assessed using the Social-Adaptive Functioning Evaluation (SAFE); constituent clinical and medication phases of the lifetime trajectory of their illnesses were then analyzed to identify predictors of SAFE score using multiple regression modeling.

RESULTS

The primary, independent predictor of SAFE score was duration of initially unmedicated psychosis, which accounted for 22% of variance (p<.001) therein. Conversely, duration of subsequently treated illness, although decades longer, failed to predict SAFE score.

CONCLUSIONS

These findings are consistent with some form of "progressive" process, particularly over the first several years following the emergence of psychosis, which is associated with accrual of deficits in adaptive life functioning.

The specificity of neurological signs in schizophrenia: a review

This review examines the extent to which neurological signs are more prevalent in schizophrenia patients, compared to mood-disorder patients and healthy subjects, and whether there is a pattern in any of the differences that may be found. We included 17 studies and calculated the weighted mean prevalence of 30 neurological signs. The prevalence of most signs appears to be significantly different between schizophrenia patients and normal controls, but there are fewer differences between schizophrenia and mood-disorder patients. Several signs - poor stereognosis and rhythm tapping - are even more prevalent in mood-disorder patients than in schizophrenia patients. Only lack of extinction, dysdiadochokinesia, poor tandem walk, finger-thumb-opposition and articulation are significantly more prevalent in schizophrenia compared to mood-disorder patients. Impaired motor coordination seems most specific to schizophrenia. The discriminating power of motor sequencing still needs to be studied. So far, there is no evidence of a clearly interpretable pattern of neurological signs distinguishing schizophrenia patients from mood-disorder patients.

Soft neurological signs in schizophrenic patients and their nonpsychotic siblings

This study examined neurological signs as familial vulnerability factors to schizophrenia. Fifteen Chinese schizophrenic patients, 21 of their nonpsychotic siblings, and 26 healthy volunteers, matched for age, sex, and education, were assessed by using the Cambridge Neurological Inventory. Results showed that patients and their siblings had significantly higher global neurological impairment than controls. The severity of motor coordination impairment of the siblings was in between patients and controls. This may suggest either patients have higher genetic vulnerability for the neurological abnormality and schizophrenia than their nonpsychotic siblings or the disease can further worsen the preexisting neurological deficit. Disinhibition signs were similar in patients and siblings, but significantly less in controls indicating its familial nature. Extrapyramidal and sensory integration signs were similar in siblings and controls, but significantly more severe in patients, suggesting nonfamilial abnormalities. In conclusion, these findings may imply different etiological origins for different subgroups of neurological signs.

Neurological soft signs in adolescents with poor performance on the continous performance test: markers of liability for schizophrenia spectrum disorders?

There is much evidence that neurological soft signs (NSS) are highly prevalent in both adults and children with schizophrenia. In addition, they have been detected as early precursors of a schizophrenic outcome in at-risk subjects. Such findings point to the possible value of NSS as neurointegrative markers in schizophrenia which has been hypothesized to be a neurodevelopmental disease. In our study we used a biobehavioral criterion to select the 'at-risk' group, a sustained attentional deficit as measured by the continuous performance test (CPT). We compared 140 normal adolescents with 162 'CPT-linked vulnerable' adolescents (index subjects) on a battery for the assessment of NSS (including laterality), IQ, frontal lobe function and schizotypy. An association was found between NSS and attentional deficit. Furthermore, index subjects with NSS were characterized by lower IQ scores, poorer performance on frontal lobe tests and greater problems with social interaction. There was also a trend for an association between male sex and both left-handedness and NSS.

Neurological signs and psychomotor performance in patients with schizophrenia, their relatives and healthy controls

Schizophrenic patients (DSM-III-R) were consecutively recruited and 39 were included. Twenty-one were first-episode and 18 were chronic schizophrenic patients. Thirty of the patients were on neuroleptic medication. Thirty-three parents were included, of whom nine were classified as 'family history positive' and 22 as 'family history negative' of a disposition to psychosis. Fifty-five healthy controls volunteered. The subjects were investigated according to a protocol divided into neurological signs and psychomotor performance (finger-tapping rate, Purdue pegboard test, pronation-supination test, gait and hand-grasp strength). Seventy-eight percent of the patients and 7% of the controls were classified as globally aberrant in signs. The patients and their parents, classified as 'family history positive', exhibited a similar laterality pattern in a finger-tapping test improving performance with the preferred hand, significantly different from the performance of the 'family history negative' parents and normal subjects. Duration of illness, neuroleptic medication and negative symptoms were not related to the occurrence of neurological signs and psychomotor performance. These findings indicate that neurological aberrations are present at the onset of illness and that hereditary factors are associated with motor laterality.

Precursors to schizophrenia: do biological markers have specificity?

This review addresses childhood antecedents and biological markers of schizophrenia within a neurodevelopmental framework. General-population birth-cohort studies illustrate delays in developmental milestones, abnormalities in social functioning, and cognitive deficits throughout childhood, adolescence, and early adulthood. Abnormal neurology and motor dysfunction have been measured in children prior to the onset of schizophrenia, at first onset of disease, and in those with chronic schizophrenia. Minor physical anomalies, a static marker of developmental disturbance, are also increased in schizophrenia. None of these factors has high specificity for this disorder. This review examines the associations between these precursors and some etiological factors for schizophrenia, comments on their lack of complete specificity to this psychotic syndrome, and considers their usefulness as predictors of risk.