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

Clinical and Sociodemographic Correlations with Neurological Soft Signs in Hospitalized Patients with Schizophrenia: A Preliminary Longitudinal Study

Schizophrenia is a severe, chronic neuropsychiatric disorder characterized by symptoms that profoundly impact behavior, cognition, perception, and emotions, leading to a reduced quality of life and physical impairment. Given the complexity of schizophrenia, there is a pressing need for clinical markers and tools to predict its course, enhance disease staging, facilitate early intervention, improve differential diagnosis, and tailor individualized treatment approaches. Previous studies focused on the relationship between neurological soft signs (NSS) and factors such as age, illness duration, and symptomatology, indicating NSS as state markers improving in parallel with psychotic symptom remission or predicting treatment resistance. However, there is a lack of consensus on NSS assessment tools, hindering routine clinical monitoring despite diagnostic and prognostic potential. The present longitudinal study involved 81 psychiatric inpatients diagnosed with schizophrenia. Patients were assessed at three time points: baseline, 1 month, and 6 months. The examination included the use of scales to evaluate psychotic and neurological symptoms, as well as the identification of adverse extrapyramidal reactions caused by neuroleptic treatment. The progression of NSS was correlated to both the symptomatology and the sociodemographic data of the patients. The main findings from the present investigation revealed a statistical correlation between NSS and psychopathological symptoms, especially with negative symptoms of schizophrenia. However, it is important to note that neuroleptic side effects only had a limited impact on NSS. Therefore, instead of being linked to extrapyramidal symptoms caused by neuroleptics, NSS appears to be more frequently related with symptoms of schizophrenia. Our findings provide further support for their strong association with the course of schizophrenia, independent of treatment side effects, thus emphasizing their potential as reliable assessment tools in both research and clinical settings.

Deciphering the interplay between psychopathological symptoms, sensorimotor, cognitive and global functioning: a transdiagnostic network analysis

BACKGROUND

Understanding the relationship between psychopathology and major domains of human neurobehavioral functioning may identify new transdiagnostic treatment targets. However, studies examining the interrelationship between psychopathological symptoms, sensorimotor, cognitive, and global functioning in a transdiagnostic sample are lacking. We hypothesized a close relationship between sensorimotor and cognitive functioning in a transdiagnostic patient sample.

METHODS

We applied network analysis and community detection methods to examine the interplay and centrality [expected influence (EI) and strength] between psychopathological symptoms, sensorimotor, cognitive, and global functioning in a transdiagnostic sample consisting of 174 schizophrenia spectrum (SSD) and 38 mood disorder (MOD) patients. All patients (n = 212) were examined with the Positive and Negative Syndrome Scale (PANSS), the Heidelberg Neurological Soft Signs Scale (NSS), the Global Assessment of Functioning (GAF), and the Brief Cognitive Assessment Tool for Schizophrenia consisted of trail making test B (TMT-B), category fluency (CF) and digit symbol substitution test (DSST).

RESULTS

NSS showed closer connections with TMT-B, CF, and DSST than with GAF and PANSS. DSST, PANSS general, and NSS motor coordination scores showed the highest EI. Sensory integration, DSST, and CF showed the highest strength.

CONCLUSIONS

The close connection between sensorimotor and cognitive impairment as well as the high centrality of sensorimotor symptoms suggests that both domains share aspects of SSD and MOD pathophysiology. But, because the majority of the study population was diagnosed with SSD, the question as to whether sensorimotor symptoms are really a transdiagnostic therapeutic target needs to be examined in future studies including more balanced diagnostic groups.

Rare genetic brain disorders with overlapping neurological and psychiatric phenotypes

Understanding rare genetic brain disorders with overlapping neurological and psychiatric phenotypes is of increasing importance given the potential for developing disease models that could help to understand more common, polygenic disorders. However, the traditional clinical boundaries between neurology and psychiatry result in frequent segregation of these disorders into distinct silos, limiting cross-specialty understanding that could facilitate clinical and biological advances. In this Review, we highlight multiple genetic brain disorders in which neurological and psychiatric phenotypes are observed, but for which in-depth, cross-spectrum clinical phenotyping is rarely undertaken. We describe the combined phenotypes observed in association with genetic variants linked to epilepsy, dystonia, autism spectrum disorder and schizophrenia. We also consider common underlying mechanisms that centre on synaptic plasticity, including changes to synaptic and neuronal structure, calcium handling and the balance of excitatory and inhibitory neuronal activity. Further investigation is needed to better define and replicate these phenotypes in larger cohorts, which would help to gain greater understanding of the pathophysiological mechanisms and identify common therapeutic targets.

Neurological soft signs and schizophrenia

Neurological soft signs (NSS) are likely to represent abnormal neurodevelopment and aberration in neural maturation and connectivity. They may not be unique to schizophrenia, but they appear to be a trait characteristic in psychosis and therefore could serve as an objective measure for the assessment of serious psychiatric disorder in the prodromal phase, at onset, and along the course of the disease. Evidence so far proposes that NSS are independent of antipsychotic treatment and therefore constitute a trait symptom, independent of the illness stage and medication. Somatomotor and somatosensory regions, spatial orientation, and visual processing areas, cerebellum, and basal ganglia are implicated as possible structural substrates of NSS. Several studies have examined the relationship between NSS and schizophrenia positive, negative symptoms and deficit syndrome; however, results have been so far ambiguous. Neurocognitive symptoms have been moderately related to NSS suggesting that neurocognitive deficits may contribute to the construct of NSS. Regardless of the fact that NSS are not unique to schizophrenia but extend across to the schizotypy continuum, they may help identify individuals at risk of developing schizophrenia later in life.

Neurological soft signs and cognition among inpatients with schizophrenia

Introduction: Evidence has shown that neurological soft signs are strongly associated with neurocognitive dysfunction. Therefore, the primary objective of this study was to assess the association between NSS and cognitive impairments in a sample of inpatients with schizophrenia. The secondary objective was to explore the association between NSS total scores and functioning.Methods: The study enrolled 95 inpatients diagnosed with schizophrenia disorders and 45 healthy controls. The neurological evaluation scale (NES) was used to assess neurological soft sign while the Brief Assessment of Cognition in Schizophrenia (BACS) was used to evaluate cognitive functioning in patients with schizophrenia.Results: Patients with schizophrenia had significantly higher mean scores on the NES total test and subtests than the control group. Higher cognition was significantly associated with lower NES total and subtest scores. Higher functional independence was significantly associated with a lower NES total score (Beta = -.25), lower motor coordination subtest score (Beta = -.04), and lower others subtest (Beta = -.12). When taking the functional independence scale as the dependent variable, a higher NES total score was significantly associated with lower functioning (Beta = -0.03).Conclusion: NSS were associated to neurocognitive impairments in almost every domain among patients with schizophrenia. Further prospective research is still needed to confirm this role.

Movement initiation and preparation in subjects with schizophrenia - The amplitude of the readiness potential as a biological marker for negative symptom severity

OBJECTIVE

Despite extensive research, the etiology of negative symptoms is not well understood. Preliminary findings are linking motor disturbances to negative symptom severity. We aimed to further the understanding to what extent motor movement preparation influences negative symptom severity.

METHODS

In a cohort of 31 subjects with schizophrenia and 20 control subjects we recorded the readiness potential amplitude over Cz during spontaneous movements of the right and left thumb. We further assessed negative and positive symptom severity (scale for the assessment of negative and positive symptoms) as well as neurological soft signs (NSS).

RESULTS

In subjects with schizophrenia the severity of negative symptoms was best predicted by the readiness potential amplitude and the NSS subdomain motor coordination. The correlation between deficits in motor coordination and negative symptom severity was partially mediated by the readiness potential amplitude in subjects with schizophrenia.

CONCLUSIONS

Deficits in motor processing are linked to negative symptom severity in schizophrenia. The readiness potential may represent a biological marker of these basal deficits. In combination with the assessment of NSS, the readiness potential may be a marker of the course of negative symptom severity and help clarifying interdependencies between (pre)frontal networks for action initiation and coordination, as well as negative symptoms.

Motor function in early onset schizophrenia-A 2-year follow-up study

AIM

Motor symptoms primarily assessed by clinical rating are documented across the schizophrenia spectrum, but no studies have examined the longitudinal course of these symptoms in adolescents using tests that control for the natural maturational process. The aim is therefore to compare fine and gross motor function using age-adjusted tests in adolescents with schizophrenia and controls across a 2-year period, and examine if clinical correlates contribute to changes in motor function in adolescents with schizophrenia.

METHOD

Motor function assessed by two age-adjusted tests was compared in 25 adolescents with schizophrenia and age- and sex-matched controls over a 2-year period using t-tests, Cohen's D and χ2 tests. Linear mixed models with a random intercept at patient level were used to assess changes between baseline and follow-up. The latter approach was adopted to assess the association between changes and potential predictors as age, sex, complications during labour/delivery, childhood motor function, symptoms severity, executive function and antipsychotics.

RESULT

All measures of motor function but one significantly differentiated adolescents with schizophrenia from controls with large effect sizes at 2-year follow-up. The overall scores did not change during follow-up, whereas two resembling motor areas of the tests significantly improved in adolescents with schizophrenia. The severity of schizophrenia, sex and IQ revealed association with the changes.

CONCLUSION

The finding of both stability and improvements from diagnosis to follow-up in adolescents with schizophrenia and the differences between adolescents with and without schizophrenia argue in favour of the neurodevelopment hypothesis and highlights the need for assessing motor function.

Relating movement markers of schizophrenia to self-experience-a mixed-methods study

Introduction

Basic self-disorders on the one hand and motor symptoms on the other hand are discussed as endophenotypes of schizophrenia psychopathology. However, the systematic interaction between motor symptoms and the self-experience of patients is rarely studied.

Methods

In a previous study we defined motor markers of schizophrenia via a data-driven analysis of patients' gait patterns. In this study, we related the movement markers to measures of basic self-disorder obtained with EASE interviews. We substantiated the correlations with a qualitative content analysis of the interviews of a subset of four patients. We related qualitative and quantitative data on an intra- and interpersonal level.

Results

Our results suggest an association between the previously defined, theory-independent movement markers and basic self-disorders, specifically in the domain of cognition, self-experience and bodily experiences. While movement marker manifestation was not precisely reflected in the individuals' descriptions of anomalous self- and body experience, we found clear trends of more and more intense descriptions with increasing movement marker scores, when looking at specific experiences, such as hyper reflexivity.

Discussion

These results foster an integrated view of the patient and could stimulate therapeutic approaches aiming at an improvement of self- and body-experience of patients with schizophrenia.

Neurological Soft Signs in Schizophrenia, a Picture of the Knowledge in the Last Decade: A Scoping Review

(1) Background: Neurological Soft Signs (NSS) are subtle neurological abnormalities that are more common in schizophrenia patients than in healthy individuals and have been regularly observed in neuroleptic-naive first-episode patients, supporting the hypothesis that they are an intrinsic component of schizophrenia. (2) Methods: a review of articles published in the last ten years (from January 2013 to January 2023) was carried out on articles published in ScienceDirect and PubMed, by following the PRISMA Statement extension for scoping reviews (PRISMA-ScR), which evaluated the impact of NSS in correlation with the symptomatology, neuroleptic treatment, and the cerebral structural changes of patients with schizophrenia. (3) Results: thirty articles were included, among them twelve included MRI structural evaluation and four studies with a longitudinal design. (4) Conclusions: interest in researching NSS has increased in recent years, but questions remain about their origin and relationship to schizophrenia symptoms, thus this study aims to fill in information gaps in the hope that future research will help provide individualized treatment. It is suggested that NSS in schizophrenia might have an inherited genetic relationship pattern, thus being in line with a trait viewpoint. Most of the research revealed that schizophrenia patients had higher NSS scores than healthy controls, however, they were rather similar to their first-degree relatives, thus, also arguing in favor of a trait perspective. The greatest improvement in scores is seen in those with a remitting course, as shown by declining NSS ratings concurrent with symptomatology.

Correlates of neurological soft signs in bipolar disorder

Recent research has focused on neurological soft signs (NSS) in bipolar disorder (BD), but there is still scarce evidence on their correlates with other relevant variables. The aim of this study was to explore the association between NSS and clinical demographic, neurocognitive, and functional variables. Eighty-eight euthymic BD patients were included in whom NSS were assessed using the Neurological Evaluation Scale. All subjects performed an extensive neurocognitive battery selected to assess premorbid IQ, attention, language, verbal memory, and executive functions. Psychosocial outcomes were assessed by means of the Functioning Assessment Short Test. Among the demographical variables, NSS tended to be negatively associated with years of education and increased with age. Likewise, NSS were higher in BD type I than in BD type II, but independent of age at illness onset and number of previous affective episodes. There was a negative correlation between NSS and premorbid IQ, as well as with performance in attention, language, and executive functions. Results tended to be unchanged when controlled for potential confounders. Although NSS were associated with poor psychosocial functioning in the bivariate analysis, when added to a multiple regression model including neurocognition, these neurological features did not significantly contribute to the variance of the functional outcome. Our findings contribute to a better characterization of NSS in BD; their potential clinical and theoretical implications are discussed in the manuscript.

Cognitive Optimisation and Schizophrenia: Assembling Heterogeneity, Overcoming the Precariousness of Life, and Challenging Public Health Policies in Psychiatry in France

Cognitive remediation therapy (CRT) aims to optimise cognitive abilities of people who suffer from schizophrenia in order to improve their social adaptation. This therapeutic orientation was developed in psychiatry in the 1980s and 1990s, at a time when the disorder was being redefined as a neurocognitive deficit disorder. In this article, I describe CRT as an assemblage that lies at the intersection of multiple, overlapping theories and spaces of mental disorders and psychiatric care. To do so, I draw on 18 months of ethnographic research conducted in a French hospital unit dedicated to the development of CRT. I argue that the focus on cognitive health and cognitive abilities (or deficits) is not only redefining the logics of care and reshaping medical conceptualisations of schizophrenia, but it is also opening up to a new understanding of people's precarious life conditions, where emotional, biological, and cognitive fragility is intertwined with social and economic uncertainty. I then examine the extent to which psychiatrists have extended the goals of CRT to include psychosocial rehabilitation in order to mitigate not only the effects of cognitive deficits, but also the effects of limited social and professional integration encountered by patients. Finally, I conclude with a consideration of how CRT has become, for its proponents in France, a means to develop a policy and organisational project for French psychiatry.

Neurological soft signs in adolescents are associated with brain structure

Neurological soft signs (NSS) are minor deviations in motor performance. During childhood and adolescence, NSS are examined for functional motor phenotyping to describe development, to screen for comorbidities, and to identify developmental vulnerabilities. Here, we investigate underlying brain structure alterations in association with NSS in physically trained adolescents. Male adolescent athletes (n = 136, 13–16 years) underwent a standardized neurological examination including 28 tests grouped into 6 functional clusters. Non-optimal performance in at least 1 cluster was rated as NSS (NSS+ group). Participants underwent T1- and diffusion-weighted magnetic resonance imaging. Cortical volume, thickness, and local gyrification were calculated using Freesurfer. Measures of white matter microstructure (Free-water (FW), FW-corrected fractional anisotropy (FAt), axial and radial diffusivity (ADt, RDt)) were calculated using tract-based spatial statistics. General linear models with age and handedness as covariates were applied to assess differences between NSS+ and NSS− group. We found higher gyrification in a large cluster spanning the left superior frontal and parietal areas, and widespread lower FAt and higher RDt compared with the NSS− group. This study shows that NSS in adolescents are associated with brain structure alterations. Underlying mechanisms may include alterations in synaptic pruning and axon myelination, which are hallmark processes of brain maturation.

The Impact of Antipsychotic Treatment on Neurological Soft Signs in Patients with Predominantly Negative Symptoms of Schizophrenia

Schizophrenia is a complex and incompletely elucidated pathology that affects sensorimotor function and also produces numerous therapeutic challenges. The aims of this cross-sectional study were to identify the profile of neurological soft signs (NSS) in patients with predominantly negative symptoms of schizophrenia (PNS) compared with patients with schizophrenia who do not present a predominance of negative symptoms (NPNS) and also to objectify the impact of treatment on the neurological function of these patients. Ninety-nine (n = 99; 56 females and 43 males) patients diagnosed with schizophrenia according to DSM-V were included; these patients were undergoing antipsychotic (4 typical antipsychotics, 86 atypical antipsychotics, and 9 combinations of two atypical antipsychotics) or anticholinergic treatment (24 out of 99) at the time of evaluation, and the PANSS was used to identify the patients with predominantly negative symptoms (n = 39), the Neurological Evaluation Scale (NES) was used for the evaluation of neurological soft signs (NSS), and the SAS was used for the objectification of the extrapyramidal side effects induced by the neuroleptic treatment, which was converted to chlorpromazine equivalents (CPZE). The study's main finding was that, although the daily dose of CPZE did not represent a statistically significant variable, in terms of neurological soft signs, patients with PNS had higher rates of NSS.

Structural network alterations and their association with neurological soft signs in schizophrenia: Evidence from clinical patients and unaffected siblings

BACKGROUND

Grey matter abnormalities and neurological soft signs (NSS) have been found in schizophrenia patients and their unaffected relatives. Evidence suggested that NSS are associated with grey matter morphometrical alterations in multiple regions in schizophrenia. However, the association between NSS and structural abnormalities at network level remains largely unexplored, especially in the schizophrenia and unaffected siblings.

METHOD

We used source-based morphometry (SBM) to examine the association of structural brain network characteristics with NSS in 62 schizophrenia patients, 25 unaffected siblings, and 60 healthy controls.

RESULTS

Two components, namely the IC-5 (superior temporal gyrus, inferior frontal gyrus and insula network) and the IC-10 (parahippocampal gyrus, fusiform, thalamus and insula network) showed significant grey matter reductions in schizophrenia patients compared to healthy controls and unaffected siblings. Further association analysis demonstrated separate NSS-related grey matter covarying patterns in schizophrenia, unaffected siblings and healthy controls. Specifically, NSS were negatively associated with IC-1 (hippocampus, caudate and thalamus network) and IC-5 in schizophrenia, but with IC-3 (caudate, superior and middle frontal cortices network) in unaffected siblings and with IC-5 in healthy controls.

CONCLUSION

Our results confirmed the key cortical and subcortical network abnormalities and NSS-related grey matter covarying patterns in the schizophrenia and unaffected siblings. Our findings suggest that brain regions implicating genetic liability to schizophrenia are partly separated from brain regions implicating neural abnormalities.

Using dynamic point light display stimuli to assess gesture deficits in schizophrenia

Background

Gesture deficits are ubiquitous in schizophrenia patients contributing to poor social communication and functional outcome. Given the dynamic nature of social communications, the current study aimed to explore the underlying socio-cognitive processes associated with point-light-displays (PLDs) of communicative gestures in the absence of any other confounding visual characteristics, and compare them to other well-established stimuli of gestures such as pictures by examining their association with symptom severity and motor-cognitive modalities.

Methods

We included 39-stable schizophrenia outpatients and 27-age-gender matched controls and assessed gesture processing using two tasks. The first task used static stimuli of pictures of a person performing a gesture. The limbs executing the gesture were missing and participants' task was to choose the correct gesture from three-options provided. The second task included videos of dynamic PLDs interacting with each other. One PLD performed communicative gestures, while the other PLD imitated/followed these performed gestures. Participants had to indicate, which of the two PLDs was imitating/following the other. Additionally, we evaluated symptom severity, as well as, motor and cognitive parameters.

Results

Patients underperformed in both gesture tasks compared to controls. Task performance for static stimuli was associated with blunted affect, motor coordination and sequencing domains, while PLD performance was associated with expressive gestures and sensory integration processes.

Discussion

Gesture representations of static and dynamic stimuli are associated with distinct processes contributing to poor social communication in schizophrenia, requiring novel therapeutic interventions. Such stimuli can easily be applied remotely for screening socio-cognitive deficits in schizophrenia.

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.

The neural substrates of neurological soft signs in schizophrenia: a systematic review

Neurological soft signs (NSS) are common in patients with schizophrenia. However, the neural substrates of NSS remain poorly understood. Using legacy PubMed, we performed a systematic review and included studies that assessed NSS and obtained neuroimaging data in patients with a schizophrenia spectrum disorder published up to June 2020. We systematically reviewed 35 relevant articles. Studies consistently implicate the basal ganglia and cerebellum as structural substrates of NSS and suggest that somatomotor and somatosensory regions as well as areas involved in visual processing and spatial orientation may underlie NSS in psychosis spectrum disorders. Additionally, dysfunction of frontoparietal and cerebellar networks has been implicated in the pathophysiology of NSS. The current literature outlines several structural and functional brain signatures that are relevant for NSS in schizophrenia spectrum disorder. The majority of studies assessed gray matter structure, but only a few studies leveraged other imaging methods such as diffusion weighted imaging, or molecular imaging. Due to this, it remains unclear if white matter integrity deficits or neurometabolic alterations contribute to NSS in the illness. While a substantial portion of the literature has been conducted in patients in the early illness stages, mitigating confounds of illness chronicity, few studies have been conducted in antipsychotic medication-naïve patients, which is a clear limitation. Furthermore, only little is known about the temporal evolution of NSS and associated brain signatures. Future studies addressing these pivotal gaps in our mechanistic understanding of NSS will be important.

Neurological soft signs and brain morphology in people living with HIV

Neurological soft signs (NSS) are a common feature of severe psychiatric disorders such as schizophrenia but are also prevalent in organic brain diseases like HIV-associated neurocognitive disorder (HAND) or Alzheimer’s disease. While distinct associations between NSS, neurocognition, and cerebral regions were demonstrated in schizophrenia, these associations still have to be elucidated in HIV. Therefore, we investigated 36 persons with HIV of whom 16 were neurocognitively healthy and 20 were diagnosed with HAND. NSS were assessed using the Heidelberg scale. NSS scores were correlated with gray matter (GM) using whole brain voxel-based morphometry. Results showed significantly elevated NSS in the HAND group when compared to the neurocognitively healthy with respect to NSS total score and the subscores “orientation” and “complex motor tasks”. While the two groups showed only minor, non-significant GM differences, higher NSS scores (subscales “motor coordination”, “orientation”) were significantly correlated with GM reduction in the right insula and cerebellum (FWE-corrected). Our results corroborate elevated NSS in HIV+ patients with HAND in contrast to cognitively unimpaired patients. In addition, cerebral correlates of NSS with GM reductions in insula and cerebellum were revealed. Taken together, NSS in this patient group could be considered a marker of cerebral damage and neurocognitive deficits.

Treatment-resistant schizophrenia: Addressing white matter integrity, intracortical glutamate levels, clinical and cognitive profiles between early- and adult-onset patients

BACKGROUND

Treatment-resistance in schizophrenia is 30-40%. Its neurobiology remains unclear; to explore it, we conducted a combined spectrometry/tractography/cognitive battery and psychopathological rating study on patients with treatment-resistant schizophrenia (TRS), dividing the sample into early-onset (N = 21) and adult-onset TRS (N = 20). Previous studies did not differentiate between early- (onset 13-18 years) and adult-onset (>18 years at formal diagnosis of schizophrenia) TRS.

METHODS

We evaluated cross-sectionally 41 TRS patients (26 male and 15 female) and 20 matched healthy controls (HCs) with psychopathological and cognitive testing prior to participating in brain imaging scanning using magnetic resonance spectroscopy and diffusion tensor imaging to determine the relationship between their symptoms and their glutamate levels and white matter integrity.

RESULTS

TRS patients scored lower than HCs on all cognitive domains; early-onset patients performed better than adult-onset patients only on the Symbol Coding domain. TRS correlated with symptom severity, especially negative symptoms. Glutamate levels and glutamate/creatine were increased in anterior cingulate cortex. Diffusion tensor imaging showed low fractional anisotropy in TRS patients in specific white matter tracts compared to HCs (bilateral anterior thalamic radiation, cortico-spinal tract, forceps minor, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, superior longitudinal fasciculus, and right uncinate fasciculus).

CONCLUSIONS

We identified specific magnetic resonance spectroscopy and diffusion tensor imaging alterations in TRS patients. Adult-onset TRS differed little from early-onset TRS on most measures; this points to alterations being present since the outset of schizophrenia and may constitute a biological signature of treatment-resistance.

Characterizing the sensorimotor domain in schizophrenia spectrum disorders

The rapidly evolving field of sensorimotor neuroscience reflects the scientific and clinical relevance of sensorimotor abnormalities as an intrinsic component of the disease process, e.g., in patients with schizophrenia spectrum disorders (SSD). Despite previous efforts, however, prevalence rates and relationships between different categories of sensorimotor abnormalities in SSD patients are still subject of ongoing debate. In this study, we examined five different categories of the sensorimotor domain (Neurological soft signs (NSS), parkinsonism, catatonia, akathisia, and tardive dyskinesia) according to well-established clinical ratings scales and the respective cut-off criteria in a sample of 131 SSD patients. We used a collection of statistical methods to better understand prevalence, overlap and heterogeneity, as well as psychopathological and cognitive correlates of sensorimotor abnormalities. 97.7% of the SSD patients considered by this study exhibited at least one categorically defined sensorimotor abnormality that tended to co-vary within three different sensorimotor subgroups (moderate, hyperkinetic and hypokinetic). Finally, hyperkinetic and hypokinetic groups differed significantly in their neurocognitive performance compared with the moderate group. The results suggest different patterns of clinical overlap, highlight the relationship between sensorimotor and cognitive domain and provide clues for further neurobiological studies.

Movement markers of schizophrenia: a detailed analysis of patients' gait patterns

Motor abnormalities occur in the majority of persons with schizophrenia but are generally neglected in clinical care. Psychiatric diagnostics fail to include quantifiable motor variables and few assessment tools examine full-body movement. We assessed full-body movement during gait of 20 patients and 20 controls with motion capture technology, symptom load (PANSS, BPRS) and Neurological Soft Signs (NSS). In a data-driven analysis, participants' motion patterns were quantified and compared between groups. Resulting movement markers (MM) were correlated with the clinical assessment. We identified 16 quantifiable MM of schizophrenia. While walking, patients and controls display significant differences in movement patterns related to posture, velocity, regularity of gait as well as sway, flexibility and integration of body parts. Specifically, the adjustment of body sides, limbs and movement direction were affected. The MM remain significant when controlling for medication load. They are systematically related to NSS. Results add assessment tools, analysis methods as well as theory-independent MM to the growing body of research on motor abnormalities in schizophrenia.

Investigation of structural brain correlates of neurological soft signs in individuals at ultra-high risk for psychosis

Increased severity of neurological soft signs (NSS) in schizophrenia have been associated with abnormal brain morphology in cerebello-thalamo-cortical structures, but it is unclear whether similar structures underlie NSS prior to the onset of psychosis. The present study investigated the relationship between severity of NSS and grey matter volume (GMV) in individuals at ultra-high risk for psychosis (UHR) stratified for later conversion to psychosis. Structural T1-weighted MRI scans were obtained from 56 antipsychotic-naïve UHR individuals and 35 healthy controls (HC). The UHR individuals had follow-up data (mean follow-up: 5.2 years) to ascertain clinical outcome. Using whole-brain voxel-based morphometry, the relationship between NSS and GMV at baseline was assessed in UHR, HC, as well as individuals who later transitioned (UHR-P, n = 25) and did not transition (UHR-NP, n = 31) to psychosis. NSS total and subscale scores except motor coordination were significantly higher in UHR compared to HC. Higher signs were also found in UHR-P, but not UHR-NP. Total NSS was not associated with GMV in the whole sample or in each group. However, in UHR-P individuals, greater deficits in sensory integration was associated with lower GMV in the left cerebellum, right insula, and right middle frontal gyrus. In conclusion, NSS are present in UHR individuals, particularly those who later transitioned to a psychotic disorder. While these signs show little overall variation with GMV, the association of sensory integration deficits with lower GMV in UHR-P suggests that certain brain areas may be implicated in the development of specific neurological abnormalities in the psychosis prodrome.

Dyslexia: Links with schizotypy and neurological soft signs

Abnormalities in language processing, psychological distress, and subtle neurodevelopmental features called neurological soft signs (NSS) are expressed by people with dyslexia and those scoring highly on schizotypy. We investigated whether the expression of NSS, distress, and schizotypy predicted dyslexia status. Participants (N = 96, 48 dyslexic) selected to be age and sex matched, completed the Schizotypal Personality Questionnaire, General Health Questionnaire, Neurological Evaluation Scale, and the National Adult Reading Test (NART; a measure of verbal intelligence). Dyslexia status was predicted by higher total NSS and disorganized schizotypy scores in the absence of NART. However, even with the inclusion of NART, disorganized schizotypy remained a significant predictor. The findings suggest that disorganized features of schizotypy could be a significant factor for those with dyslexia. Conversely, more attention needs to be given to developmental language disorders in those who score highly on schizotypy.

Neurological Soft Signs (NSS) in Census-Based, Decade-Adjusted Healthy Adults, 20 to >70 Years of Age

Neurological soft signs (NSS) represent minor neurological features and have been widely studied in psychiatric disease. The assessment is easily performed. Quantity and quality may provide useful information concerning the disease course. Mostly, NSS scores differ significantly between patients and controls. However, literature does not give reference values. In this pilot study, we recruited 120 healthy women and men to build a cross-sectional, census-based sample of healthy individuals, aged 20 to >70 years, subdivided in 10-year blocks for a close approach to the human lifeline. Testing for NSS and neurocognitive functioning was performed following the exclusion of mental and severe physical illness. NSS scores increased significantly between ages 50+ and 60+, which was primarily accountable to motor signs. Gender and cognitive functioning were not related to changes of scores. Although the number of individuals is small, study results may lay a foundation for further validation of NSS in healthy individuals.

Different trajectories of neurological soft signs progression between treatment-responsive and treatment-resistant schizophrenia patients

Schizophrenia patients exhibit subtle and non-localizing neurological abnormalities, known as neurological soft signs (NSS). Life-span evidence suggests that NSS vary along the course of schizophrenia. An association between NSS and treatment response has been proposed, suggesting that NSS reflect the underlying neuropathology development in schizophrenia. However, few studies have investigated the relationship between NSS and treatment resistance in first-episode schizophrenia patients. We conducted a longitudinal study on 52 first-episode schizophrenia patients, who were assessed at baseline, the sixth month, and the fifth year using the abridged version of the Cambridge Neurological Inventory. The trajectories of NSS between 29 treatment-responsive patients (with full symptomatic remission) and 23 treatment-resistant patients (who received clozapine) were compared using mixed model ANOVA. We also controlled for the effect of age and estimated IQ, using a mixed ANCOVA model. Although the two schizophrenia groups had comparable NSS at the baseline, their trajectories of NSS differed significantly. Compared with their treatment-responsive counterparts, treatment-resistant schizophrenia patients had worsening of NSS over time. Our findings support the potential utility of NSS in identifying treatment resistance in first-episode schizophrenia. Progressive worsening of NSS in treatment-resistant schizophrenia patients may reflect the development of underlying neuropathology. Further studies using large samples of treatment-resistant schizophrenia patients are needed.

Neurological soft signs and cognition in the late course of chronic schizophrenia: a longitudinal study

Neurological soft signs (NSS) are minor ('soft') neurological abnormalities in sensory and motor performances, which are frequently reported in patients with schizophrenia at any stage of their illness. It has been demonstrated that NSS vary in the clinical course of the disorder: longitudinally NSS decrease in parallel with remission of psychopathological symptoms, an effect which mainly applies to patients with a remitting course. These findings are primarily based on patients with a first episode of the disorder, while the course of NSS in patients with chronic schizophrenia and persisting symptoms is rather unknown. Therefore, we investigated NSS twice in 21 patients with chronic schizophrenia (initial mean duration of illness: 23 ± 11 years) with a mean follow-up interval of 7 years. NSS were evaluated by the Heidelberg Scale, established instruments were used to rate neuropsychological performance and psychopathological symptoms. NSS showed significant increases on the subscales "motor coordination" and "integrative functions", while positive and negative symptoms, including apathy, showed only minor, non-significant changes. Verbal memory, verbal fluency, and cognitive flexibility along with severity of global cognitive deficits demonstrated a significant deterioration. Regression analyses identified executive dysfunction (cognitive flexibility and verbal fluency) at baseline as significant predictors of NSS increase at follow-up. Our findings indicate that NSS deteriorate in the long-term course of chronic schizophrenia. This effect may be accounted for by a decrease of executive functions and logical memory, which can be attributed to premature brain aging.

Neurological Soft Signs and Brain Abnormalities in Schizophrenia: A Literature Review

Neurological soft signs (NSS) are subtle neurological impairments in sensory integration, motor coordination, balance, and sequencing of complex motor acts. The prevalence of NSS is well over 50% in schizophrenic patients compared to about 5% in healthy controls. About 30% of schizophrenia patients are resistant to treatment. The main reason for not finding better pharmaceutical agents is the inability to elicit the underlying neurophysiological and neuroanatomical basis of schizophrenia. The most common NSS can be divided into three domains: motor coordination, sequencing of complex motor acts, and sensory integration. Here, the neuroimaging correlates of the abovementioned NSS are reviewed. Most of the studies found a negative correlation of NSS subs cores motor coordination and complex motor tasks with the cerebellum, inferior frontal gyrus, and postcentral gyrus. There was a negative correlation between cortical thickness and NSS total scores in the left paracentral lobule, precuneus, middle frontal cortex, right inferior temporal cortex, left/right superior parietal cortex. Instead of considering NSS as a mere trait or state markers, its active inclusion in patient management is required to improve patients' quality of life. Future studies on larger cohorts, combining different imaging modalities are needed to elucidate how these factors might relate to each other and contribute to NSS. 

Nonverbal communication remains untouched: No beneficial effect of symptomatic improvement on poor gesture performance in schizophrenia

BACKGROUND

Gestures are an important part of communication. Patients with schizophrenia present gesture deficits that tend to deteriorate in the course of the disease and hamper functional outcome. This gesture deficit has been associated with motor abnormalities, cognitive impairment, and psychotic symptoms. Unaffected, first-degree relatives of schizophrenia patients share some subclinical motor and cognitive abnormalities. We aimed to investigate, whether gesture performance changes with symptomatic improvement in patients, and to test the longitudinal performance in unaffected, first-degree relatives.

METHODS

In this study, we measured gesture performance using a validated test in 33 patients, 29 first-degree relatives and 38 healthy controls. Measurements were completed shortly after admission and before discharge in patients. Performance was rated blindly by experts using video recordings of the gesture task. Additionally, we evaluated cognitive function and psychotic symptoms at both visits.

RESULTS

Gesture performance was poorer in relatives compared to controls and poorer in patients compared to both relatives and controls. Patients showed an improvement in psychopathology but a significant decrease in gesture performance at follow-up, while performance in the other groups remained stable. Proportional change of gesture performance correlated with change of cognitive function in patients, whereas there were no correlations with change of cognitive function in the other groups.

CONCLUSION

While symptom severity was reduced, the gesture deficit further deteriorated in schizophrenia. The finding argues for distinct processes contributing to poor nonverbal communication skills in patients, requiring novel alternative treatment efforts.

Trajectory of neurological examination abnormalities in antipsychotic-naïve first-episode psychosis population: a 1 year follow-up study

BACKGROUND

Neurological Examination Abnormalities (NES) are quantified by measuring subtle, partially localizable (cerebello-thalamo-prefrontal cortical circuit) and heritable neurological signs comprising sensory integration, motor coordination and complex motor sequencing that are associated with first-episode psychosis (FEP). A few studies have evaluated NES longitudinally and as a predictor for diagnostic and response classification, but these studies have been confounded, underpowered and divergent. We examined (1) baseline and longitudinal NES differences between diagnostic and year 1 response groups; (2) if NES predicts diagnostic and response groups and (3) relationships between clinical variables and NES measures in antipsychotic-naïve FEP.

METHODS

NES and clinical measures were obtained for FEP-schizophrenia (FEP-SZ, n = 232), FEP non-schizophrenia (FEP-NSZ, n = 117) and healthy controls (HC, n = 204). Response groups with >25% improvement in average year 1 positive and negative symptomatology scores were classified as responsive (n = 97) and <25% improvement as non-responsive (n = 95). Analysis of covariance, NES trajectory analysis and logistic regression models assessed diagnostic and response group differences. Baseline and longitudinal NES relationships with clinical variables were performed with Spearman correlations. Data were adjusted for age, sex, race, socioeconomic status and handedness.

RESULTS

Cognitive perceptual (COGPER) score was better than repetitive motor (REPMOT) at differentiating FEP-SZ from FEP-NSZ and distinguishing responders from non-responders. We identified significant group-specific associations between COGPER and worse GAF, positive and negative symptomatology and some of these findings persisted at 1-year assessment.

CONCLUSION

NES are an easy to administer, bedside-elicited, endophenotypic measure and could be a cost-effective clinical tool in antipsychotic-naïve FEP.

Neurological Signs at the First Psychotic Episode as Correlates of Long-Term Outcome: Results From the AESOP-10 Study

Minor neurological signs are subtle deficits in sensory integration, motor coordination, and sequencing of complex motor acts present in excess in the early stages of psychosis. Still, it remains unclear whether at least some of these signs represent trait or state markers for psychosis and whether they are markers of long-term disease outcome of clinical utility. We examined the relationship between neurological function at illness onset assessed with the Neurological Evaluation Scale and subsequent illness course in 233 patients from AESOP-10 (Aetiology and Ethnicity in Schizophrenia and Other Psychoses), a 10-year follow-up study of a population-based cohort of individuals recruited at the time of their first episode of psychosis in the United Kingdom. In 56 of these patients, we also explored changes in neurological function over time. We included a group of 172 individuals without psychosis as controls. After 10 years, 147 (63%) patients had developed a non-remitting course of illness, and 86 (37%) a remitting course. Already at first presentation, patients who developed a non-remitting course had significantly more primary, motor coordination, and total signs than both remitting patients and healthy controls. While Motor Coordination signs did not change over time, rates of Primary, Sensory Integration, and Total signs increased, independently of illness course type. These findings suggest that motor coordination problems could be a useful early, quick, and easily detectable marker of subsequent clinical outcome. With other motor abnormalities, a measure of motor incoordination could contribute to the identification of the most vulnerable individuals, who could benefit from targeted and more assertive treatment approaches.

Moving forward: distinct sensorimotor abnormalities predict clinical outcome after 6 months in patients with schizophrenia

Despite substantial efforts in the last decades, objective measures that can predict clinical outcome in patients with schizophrenia (SZ) after an acute psychotic episode are still lacking. Here, we introduced a comprehensive assessment of sensorimotor function to predict mid-term clinical outcome following an acute psychotic episode. This naturalistic follow-up of 43 patients with DSM-IV-TR diagnosis of SZ examined sensorimotor abnormalities (i.e. Neurological Soft Signs (NSS), parkinsonism, akathisia, catatonia and acute dyskinesia), psychopathology, cognition and psychosocial functioning using well-established instruments. A collection of statistical methods was used to examine the relationship between sensorimotor domain, psychopathology, cognition and psychosocial functioning. We also tested the clinical feasibility of this relationship when predicting clinical outcome after an acute psychotic episode. Longitudinal data were collected on 43 individuals after a follow-up period of >6 months. At follow-up, patients showed significantly reduced general symptom severity, as well as decreased levels of NSS, parkinsonism and catatonia. Further, NSS scores at baseline predicted PANSS negative scores and cognitive functioning at baseline. Finally, NSS scores at baseline predicted symptom change (reduction of PANSS positive and negative scores) at follow-up. In conclusion, our results suggest that NSS are significant predictors of poor clinical outcome in SZ at baseline and >6 months after an acute psychotic episode. These findings propose sensorimotor domain as state biomarker of SZ and support its predictive power with respect to treatment outcome.

Neurological soft signs (NSS) and cognitive deficits in HIV associated neurocognitive disorder

Neurological soft signs (NSS) are frequently found in severe mental disorders, such as Alzheimer's disease, schizophrenia or HIV associated neurocognitive disorder (HAND) which includes asymptomatic neurocognitive impairment (ANI), mild neurocognitive disorder (MND) and HIV-associated dementia. To characterize NSS in patients with HIV we examined them with respect to neuropsychological deficits typically found in the disorder. 67 HIV + patients without a history of head trauma, opportunistic infections, severe psychiatric disorders or acute confounding comorbidities of the Central nervous system (CNS) were recruited. NSS and neuropsychological deficits were examined on the Heidelberg scale and the Cambridge Neuropsychological Test Automated Battery (CANTAB), respectively. Semantic and phonemic verbal fluency were additionally established. According to NIMH and NINDS criteria, 18 patients were diagnosed with ANI and 21 with MND, 28 showed no cognitive deficits. NSS total scores were significantly correlated with several cognitive domains and NSS subscales. These correlations were confirmed when motor performance was entered as a covariate. According to our findings, NSS in HIV positive patients are significantly correlated with deficits in a broad range of neuropsychological domains. Similar findings were reported in schizophrenia, emphasizing the transdiagnostic character of NSS and supporting NSS examination in screening HIV patients for HAND.

Neurological soft signs (NSS) and brain morphology in patients with chronic schizophrenia and healthy controls

Subtle abnormalities in sensory integration, motor coordination and sequencing of complex motor acts or neurological soft signs (NSS) are characteristic phenomena in patients with schizophrenia at any stage of the illness. Previous MRI studies in schizophrenia found NSS to be associated with cortical, thalamic and cerebellar changes. Since these studies mainly focused on first-episode or recent onset schizophrenia, the cerebral correlates of NSS in chronic schizophrenia remained rather unclear. 49 middle-aged patients with chronic schizophrenia with a mean duration of illness of 20.3 ± 14.0 years and 29 healthy subjects matched for age and sex were included. NSS were examined on the Heidelberg Scale and correlated to grey matter (GM) by using whole brain high resolution magnetic resonance imaging (3 Tesla) with SPM12/CAT12 analyses. As expected, NSS in patients were significantly (p≤0.001) elevated in contrast to healthy controls, a finding, which not only applied to NSS total score, but also to the respective subscales "motor coordination", "sensory integration", "complex motor tasks", "right/left and spatial orientation" and "hard signs". Within the patient group NSS total scores were significantly correlated to reduced GM in right lingual gyrus, left parahippocampal gyrus, left superior temporal gyrus, left thalamus (medial dorsal nucleus) and left posterior lobe of the cerebellum (declive). Respective negative associations could also be revealed for the subscales "motor coordination", "complex motor tasks" and "right/left and spatial orientation". These findings remained significant after FWE-correction for multiple comparisons and were confirmed when years of education, chlorpromazine-equivalents or variables indicating the severity of psychopathology were introduced as additional covariates. According to our results lingual, parahippocampal, superior temporal, inferior and middle frontal gyri, thalamus and cerebellum have to be considered as important sites of NSS in chronic schizophrenia. That these findings only applied for patients but not healthy controls may indicate a different pathogenesis of NSS.

Neurological soft signs and neurocognitive deficits in remitted patients with schizophrenia, their first-degree unaffected relatives, and healthy controls

Neurological soft signs (NSS) and neurocognitive deficits (ND) are highly prevalent in schizophrenia, and have been separately proposed as candidate endophenotypes of schizophrenia. However, few relevant studies focus on remitted patients with schizophrenia (RP) and integrate NSS and ND as a composite endophenotype. This study aimed to explore the NSS and ND and examine the comparative relationship between them in RP, their first-degree unaffected relatives (FDR), and healthy controls, furthermore, to seek potential endophenotypes subitems of NSS and ND and create a composite endophenotype. 86 RP, 86 FDR, and 86 healthy controls were included. NSS and ND were independently assessed with Cambridge Neurological Inventory and MATRICS^TM Consensus Cognitive Battery. RP had more NSS and ND than FDR in all subitems except disinhibition, information processing speed, working memory, and visual memory. Similarly, FDR presented poorer performance than controls in all subscales except disinhibition, sensory integration, working memory, and visual memory. Six subitems of NSS and ND met the criteria of endophenotype and the three groups were most accurately classified (71.2%) with these subitems working as a composite endophenotype. Moreover, information processing speed, attention, and social cognition were associated with sensory integration in RP and FDR. These findings add evidences that certain subitems of NSS and ND might be the endophenotypes of schizophrenia and integrating these endophenotypes may prove useful in identifying schizophrenia and high-risk individuals. Furthermore, sensory integration and specific cognitive domains covary, hence suggesting an overlap of compromised underlying neural systems.

12-Month stability of neurological soft signs in stabilized patients with schizophrenia

Objective: Neurological soft signs (NSS) are a group of minor non-localizable neurological abnormalities found more often in patients with schizophrenia. The aim of the current study was to investigate their temporal stability and relationship to the overall outcome over a 12-month period. Material and methods: The study sample included 133 stabilized patients suffering from schizophrenia (77 males and 56 females; aged 33.55 ± 11.22 years old). The assessment included the application at baseline and after 12 months of the Neurological Evaluation Scale (NES), and a number of scales assessing the clinical symptoms and adverse effects. The statistical analysis included ANOVA, exploratory t-test and Pearson correlation coefficients with Bonferroni correction. Results: In stabilized patients, NSS are stable over a 12-month period with only the subscale of NES-sensory integration manifesting a significant worsening, while, in contrast, most of the clinical variables improved significantly. There was no relationship of NES scores with the magnitude of improvement. The only significant negative correlation was between NES-motor coordination and Positive and Negative Syndrome Scale-GP change at 1 year. Discussion: The results of the current study suggest that after stabilization of patients with schizophrenia, there are probably two separate components, a 'trait' which is stable over a 12-month period, and a 'degenerative' component with a tendency to worsen probably in parallel with the progression of the illness and in correlation with the worsening of negative symptoms. However, the statistical support of the 'degenerative' component is weak. Significant outcomes Neurological softs signs are stable over a 12-month period, with the exception of 'sensory integration' which manifests significant improvement irrespective of treatment response. They do not respond to treatment with antipsychotics. They do not constitute a prognostic factor to predict improvement over a period of 1 year. Neurological soft signs constitute a trait symptom of schizophrenia which is stable though time. Limitations All the subjects have been previously hospitalized which may represent a more severe form of schizophrenia. Also, all patients were under antipsychotic and some also under benzodiazepine medications. Patients with comorbid somatic disorders were excluded which may decrease generalizability of results.

Risk Model Assessment in Early-Onset and Adult-Onset Schizophrenia Using Neurological Soft Signs

Age at onset is one of the most important clinical features of schizophrenia that could indicate greater genetic loadings. Neurological soft signs (NSS) are considered as a potential endophenotype for schizophrenia. However, the association between NSS and different age-onset schizophrenia still remains unclear. We aimed to compare risk model in patients with early-onset schizophrenia (EOS) and adult-onset schizophrenia (AOS) with NSS. This study included 262 schizophrenia patients, 177 unaffected first-degree relatives and 243 healthy controls. We estimated the discriminant abilities of NSS models for early-onset schizophrenia (onset age < 20) and adult-onset schizophrenia (onset age ≥ 20) using three data mining methods: artificial neural networks (ANN), decision trees (DT) and logistic regression (LR). We then assessed the magnitude of NSS performance in EOS and AOS families. For the four NSS subscales, the NSS performance were greater in EOS and AOS families compared with healthy individuals. More interestingly, there were significant differences found between patients' families and control group in the four subscales of NSS. These findings support the potential for neurodevelopmental markers to be used as schizophrenia vulnerability indicators. The NSS models had higher discriminant abilities for EOS than for AOS. NSS were more accurate in distinguishing EOS patients from healthy controls compared to AOS patients. Our results support the neurodevelopmental hypothesis that EOS has poorer performance of NSS than AOS. Hence, poorer NSS performance may be imply trait-related NSS feature in EOS.

Neurological soft signs (NSS) and cognitive impairment in chronic schizophrenia

Recent studies indicate that neurological soft signs (NSS) in schizophrenia are associated with generalized cognitive impairments rather than changes in specific neuropsychological domains. However, the majority of studies solely included first-episode patients or patients with a remitting course and did not consider age, course, education or severity of global cognitive deficits as potential confounding variables. Therefore, we examined NSS with respect to cognitive deficits in chronic schizophrenia, i.e. patients who are particularly vulnerable to both, NSS and cognitive impairments.

Eighty patients with chronic schizophrenia (43.36 ± 15a) and 60 healthy controls (47.52 ± 14.8a) matched for age, sex and years of education were examined on the Heidelberg NSS scale and a broad neuropsychological battery including short term, working, logical and autobiographic memory (AM), theory of mind (ToM), psychomotor speed and cognitive flexibility.

When contrasted with the controls, patients showed significantly higher NSS scores and impairments in all neuropsychological domains but short-term memory. NSS were significantly associated with all neuropsychological domains considered but short-term memory and semantic AM. Except for episodic AM (which was significantly correlated with NSS in patients only) these correlations applied to both groups and were confirmed when age, years of education and severity of global cognitive deficits (Mini Mental State Examination) were controlled for.

Results demonstrate that NSS reflect a rather wide range of cognitive impairments in schizophrenia, which also involves episodic AM and ToM. These associations were not accounted for by age, education or severity of global cognitive deficits and facilitate the clinical usage of NSS as a screening instrument.

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 and Psychopathology in Chronic Schizophrenia: A Cross-Sectional Study in Three Age Groups

As established in a wealth of studies subtle motor and sensory neurological abnormalities or neurological soft signs (NSS) are frequently found in patients with schizophrenia at any stage of their illness. However, the potential impact of chronicity and age on NSS was scarcely investigated. Therefore, we assessed NSS in 90 patients with subchronic (n = 22) or chronic (n = 68) schizophrenia and in 60 healthy controls who were assigned to three age groups (18-29, 30-49, and +50 years). NSS were measured on the Heidelberg Scale, psychopathological symptoms including apathy were rated on established instruments. As demonstrated by analysis of variance, NSS scores in patients were significantly (p < 0.05) increased relative to healthy controls. Significant age effects arose in all NSS subscores, with older subjects scoring well above the younger ones. These age effects were more pronounced in patients than controls, indicating that NSS in chronic schizophrenia exceed age-associated changes. Moreover, the NSS scores in patients were significantly associated with duration of illness, thought disturbance, positive symptoms, and apathy. These results were confirmed after age/duration of illness and years of education were partialed out and via regression analyses. Our findings conform to the hypothesis that NSS are associated with chronicity of the disorder as indicated by the correlations of NSS with both, duration of illness and apathy. The correlations between NSS and positive symptoms/thought disturbance correspond to the fluctuation of positive symptoms during the course of the disorder. The significantly more pronounced age effects on NSS in patients may either point to ongoing cerebral changes or to a greater susceptibility of patients toward physiological age effects, which may be mediated among other factors by a lower cognitive reserve.

Visuospatial and Sensory Integration Tasks in Patients With Schizophrenia or Schizoaffective Disorder: Relationship to Body Mass Index and Smoking

Neurological soft signs (NSSs) are highly prevalent among patients with schizophrenia, but their pathophysiological significance remains unclear. The present study employed perceptual-motor and visuospatial processing tests that have not yet been attempted in this patient population. Patients with schizophrenia or schizoaffective disorder (n = 42) and mentally healthy subjects (n = 10) were administered Copy Figure Test, Detection and Recognition of an Object Test and Road Map Test. As compared to controls, schizophrenic and schizoaffective patients displayed significantly poorer ability to copy three-dimensional figures (namely, Necker- and hidden line elimination cubes) and to orient in space on a road-map test; group differences in copying two-dimensional figures and on objects' recognition against a background noise were not apparent. In the schizophrenia/schizoaffective group, more mistakes on the hidden line elimination cube was associated with greater body mass index and greater severity of nicotine dependence measured via the Fagerstrom Test of Nicotine Dependence. The above findings replicate those of prior reports and extend them to the tasks that do not involve motivational and attentional confounds. Furthermore, the present data support the hypothesis that subtle cerebral cortical abnormalities detected with specific NSSs tests may be related to some aspects of metabolic and motivational function in patients with schizophrenia/schizoaffective disorder.