Higher Neurological Soft Signs Scores Research Articles

Neurological soft signs as trait markers of a subset of patients with obsessive-compulsive disorder with low insight and altered cognitive abilities

Neurological soft signs (NSS) are subtle motor control impairments that include involuntary movements and abnormalities of motor coordination, sensory integration and lateralization. They engage different brain networks, including the prefrontal networks that support the higher cognitive functions that are dysfunctional in obsessive-compulsive disorder (OCD). This study investigated the relationships between the presence of NSS and patients' severity of OCD symptoms, insight, and treatment resistance in a sample of 63 patients. Treatment-resistance was assessed considering all the treatments the patients received during the course of their disease. The four dimensions of OCD defined in the dimensional obsessive-compulsive scale were considered. Links between the patients’ cognitive abilities and NSS were assessed using tests targeting specifically the core components of executive functions.As expected, OCD patients displayed more NSS than individually matched control participants. In OCD patients, high NSS scores were associated with poor insight and lower cognitive abilities. Multiple regression analysis identified worse visuospatial working memory, attentional control, and verbal fluency as predictive factors of high NSS scores among cognitive functions. Unexpectedly, the patients displaying symptoms in the contamination/washing dimension displayed less NSS than the other patients. In contrast, neither the severity of OCD symptoms nor long-range treatment resistance was significantly related to patients’ NSS scores. Altogether, our findings suggest that high NSS scores may be a trait marker of a subset of OCD patients with low insight and particularly altered cognitive abilities who would not express the contamination/washing dimension of the pathology.

A Study of Neurological Soft Signs and Cognition in Schizophrenia.

Neurological soft signs (NSS) are delicate neurological abnormalities that comprise deficits in motor coordination, problems with the sequencing of complex motor acts, and sensory integration difficulties. These are nonspecific with no specific localization in the brain. NSS are found in many patients with Schizophrenia. Cognitive dysfunctions are also present in more than two-thirds of patients with Schizophrenia. This study aims at assessing the NSS and its association with cognitive impairment in patients with Schizophrenia. A total of 100 Schizophrenia patients were included in the study. The Heidelberg scale was used for assessing the NSS. The Montreal Cognitive Assessment Scale(MoCA) for cognitive impairment, the Positive and Negative Syndrome Scale(PANSS) for Schizophrenia, and the Brief Psychiatric Rating Scale (BPRS) were used to assess the severity. Statistical analysis was performed by Pearson's Chi-square test, Kruskal-Wallis test, Wilcoxon rank testsand Spearman rank correlation along with mean and standard deviation. NSS were present in 68% (N=68) of the patients with motor coordination being maximally affected. Cognitive impairment was found in 73% (N=73) of patients with a MoCA score <26. Patients with predominant negative symptoms had higher NSS scores and lower MoCA scores. A "statistically significant" correlation was observed between cognitive impairment and NSS. Most patients with NSS and impaired cognition were in the "markedly ill" category of BPRS. A significant association was observed between cognitive deficits, negative symptoms, and NSS in Schizophrenia.NSS and cognitive dysfunctions are integral parts of Schizophrenia symptomdomains and need to be assessed as the negative symptoms and severity of illness are associated with NSS, especially problems with motor coordination and cognitive dysfunctions.

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.

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.

Neurological soft signs and grey matter abnormalities in individuals with ultra-high risk for psychosis.

Neurological soft signs (NSSs), conventionally defined as subtle neurological abnormalities, are frequently found in individuals with schizophrenia. Many neuroimaging studies have also reported that NSSs are associated with grey matter changes in patients with schizophrenia at different stages of the illness. However, these findings may be confounded by the effect of antipsychotic medications, chronicity, and duration of untreated psychosis. Examining NSSs in individuals with ultra-high risk (UHR) for psychosis may help to identify the neuroanatomical substrates of NSSs related to the illness itself and to avoid these potential confounding effects. A sample of 21 individuals with UHR were included in the present study. NSSs were rated using the abridged version of the Cambridge Neurological Inventory. Grey matter volume was assessed using optimized voxel-based morphometry on images acquired by a high-resolution 3-T magnetic resonance imaging scanner. We found that higher NSS scores in individuals with UHR were associated with decreased grey matter volume at the superior and medial frontal cortex, the rectal cortex, the pre- and post-central cortex, the insula, the caudate, and the cerebellum. Our results suggest that these brain structural characteristics may represent the neuroanatomical substrate of NSSs in individuals with UHR. These findings contribute to the understanding of the intrinsic features of psychosis associated with NSSs and may provide insights into pre-schizophrenia pathophysiology.

Saccadic eye movements as markers of schizophrenia spectrum: Exploration in at-risk mental states

Schizophrenia is a neurodevelopmental disease with cognitive and motor impairments. Motor dysfunctions, such as eye movements or Neurological Soft Signs (NSS), are proposed as endophenotypic markers. Antisaccade (AS) and memory-guided saccades (MGS), two markers of inhibitory control mechanism, are altered in both patients with schizophrenia and their relatives, although these tools may have different sensitivities. Recently, emphasis has been put on identifying markers predictive of psychosis transition in subjects with ultra-high-risk psychosis in order to develop targeted prevention. This study investigates AS and MGS in 46 patients with schizophrenia, 23 ultra-high-risk subjects, and 39 full siblings compared to 47 healthy volunteers. NSS were assessed as a marker of abnormal neurodevelopment. The results revealed more errors in MGS in patients, ultra-high-risk subjects and siblings, than in controls, and more specifically ultra-high-risk subjects with high NSS scores. By contrast, the error rate in AS was significantly higher only in patients with schizophrenia compared to controls. These findings suggest that MGS could be more accurate to detect deficient inhibitory processes as a marker of vulnerability before the onset of schizophrenia. The use of the different paradigms (AS, MGS) revealed distinct profiles depending on the stage of the disease, indicating that some alterations could be pure endophenotypic markers of vulnerability for schizophrenia, while others could be markers of the disease progression.

Association between neurological soft signs, temperament and character in patients with schizophrenia and non-psychotic relatives.

The heritability of schizophrenia and most personality traits has been well established, but the role of personality in susceptibility to schizophrenia remains uncertain. The aim of this study was to test for an association between personality traits and Neurological Soft Signs (NSS), a well-known biological marker of schizophrenia, in non-psychotic relatives of patients with schizophrenia. For this purpose, we evaluated the NSS scale and personality measured by the Temperament and Character inventory (TCI-R) in three groups of subjects: 29 patients with schizophrenia, 24 unaffected relatives and 37 controls. The results showed that patients with schizophrenia were more asocial (higher harm avoidance and lower reward dependence), more perseverative (higher persistence), and more schizotypal (lower self-directedness and cooperativeness, higher self-transcendence). The unaffected relatives showed higher harm avoidance, lower self-directedness and cooperativeness than the healthy controls. Higher NSS scores and sub-scores were found in patients and non-psychotic relatives compared with the controls. Among all the patients, total NSS scores were positively correlated with harm avoidance but negatively correlated with novelty seeking and persistence. Total NSS were also correlated with low scores on self-directedness and cooperativeness, which are indicators of personality disorder. Our results show that susceptibility to NSS and to schizophrenia are both related to individual differences in the temperament and character features in non-psychotic relatives of patients with schizophrenia. High harm avoidance, low persistence, low self-directedness and low cooperativeness contribute to both the risk of NSS and schizophrenia. These findings highlight the value of using both assessments to study high risk populations.

Association between implicit motor learning and neurological soft signs in schizophrenia

IntroductionSchizophrenia (SZ) patients present subtle motor deficits known as Neurological Soft Signs (NSS). Those deficits encompass impairments of motor coordination, sequencing of complex motor acts and sensory integration. It has been shown that SZ patients present also deficits of higher motor functions as implicit motor learning. Growing number of studies indicate that both NSS and implicit motor learning deficits are associated with impairments of common cortico-cerebellar pathways, however relationship between these two deficits has not been evaluated yet.ObjectivesTo assess NSS and implicit motor learning in SZ patients.AimsTo evaluate associations between NSS and implicit motor learning scores in SZ patients.MethodsTwenty schizophrenia patients and 20 healthy controls were examined. Patients were under olanzapine, clozapine or quetiapine treatment. NSS were assessed with Neurological Evaluation Scale (NES). Implicit motor learning were assessed with a use of Serial Reaction Time Task.ResultsSZ patients presented statistically higher NSS scores than healthy controls (P &lt; 0.001) and presented no signs of implicit motor learning. There was statistically significant negative correlation between implicit motor learning score and total score of neurological soft signs (r = −0.44), sequence of motor acts subscore (r = −0.54) and sensory integration subscore (r = −0.47) in SZ patients group (P &lt; 0.05).ConclusionsThere is association between implicit motor learning deficits and neurological soft signs in SZ patients.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Local brain gyrification as a marker of neurological soft signs in schizophrenia

Patients with psychiatric disorders of significant neurodevelopmental origin, such as schizophrenia and autism frequently experience genuine motor abnormalities, such as neurological soft signs (NSS). Previous MRI studies in patients with schizophrenia have shown that NSS are associated with abnormal cortical, thalamic and cerebellar structure and function. So far, however, no neuroimaging study focused on the role of the local gyrification index (LGI) in the pathophysiology of NSS. This study sought to explore the relationship between NSS and folding patterns of the cerebral cortex that are thought to be established during early brain development. In this study, whole brain high-resolution magnetic resonance imaging (MRI) at 3 Tesla was used to investigate the LGI in 33 patients with recent-onset schizophrenia. Cortical reconstruction was performed with the Freesurfer image analysis suite. NSS were examined on the Heidelberg Scale and related to LGI. Age, gender, years of education and medication were considered as potential confounding variables. In summary, higher NSS scores were positively associated with morphological changes of LGI predominantly in parietal and occipital areas. Our results confirm the hypothesis of a significant relationship between LGI changes and the NSS expression in schizophrenia. Investigation of LGI may help to explain subtle motor symptoms such as NSS in schizophrenia.

Neurological soft signs and prepulse inhibition of the startle reflex in psychosis: A pilot study

Objective. Prepulse inhibition (PPI) of the startle reflex deficit and neurological soft signs (NSS) are two markers of vulnerability to psychosis. This study investigated the possibility of a PPI–NSS relation due to a putative common biological substrate, hypothesizing that patients with higher NSS scores also show higher PPI deficits. Moreover, we examined the possibility of an association of PPI deficits and NSS with negative symptoms. Methods. Fifteen subjects with psychosis and fifteen healthy controls underwent PPI and NSS evaluations. Results. Patients did not exhibit higher PPI deficits but only higher NSS rates (p < 0.01), as compared with healthy controls. Higher NSS rates were not associated with PPI deficits, and NSS sensory integration signs correlated positively with negative symptoms (p < 0.01). Conclusion. Our study supported the hypothesis that NSS are trait markers whereas PPI deficits state markers and that their putative common biological substrate is not sufficient to determinate an association between them. The study hypothesis, however, needs further investigation.

Multiparametric mapping of neurological soft signs in healthy adults.

Minor motor and sensory deficits or neurological soft signs (NSS) are frequently found in patients with schizophrenia at any stage of their illness. Although previous studies have reported that NSS are associated with altered structure and function within fronto-parietal areas, it remains unclear whether the neuroanatomical basis of NSS may be confounded by underlying pathological processes, and by antipsychotic treatment. Morphological brain correlates of NSS in healthy subjects have seldom been investigated. This study evaluated the relationship between NSS levels and abnormalities of subcortical and cortical structures in healthy individuals. High-resolution MRI data at 3 Tesla were obtained from 68 healthy individuals. Automated segmentation of caudate nucleus, putamen, globus pallidus, thalamus, and brainstem was performed using both FSL-FIRST and Freesurfer. The surface-based analysis via Freesurfer enabled calculation of cortical thickness, area and folding (local gyrification index). NSS were examined on the Heidelberg Scale and related to both subcortical and cortical measurements. Using two fully automated brain segmentations methods, we found no significant association between NSS levels and morphological changes in subcortical structures. Higher NSS scores were associated with morphological changes of cortical thickness, area and folding in multiple areas comprising superior frontal, middle temporal, insular and postcentral regions. Our findings demonstrate the benefit of surface-based approaches when investigating brain correlates of NSS. The data lend further support to the hypothesis that NSS in healthy individuals involve multiple cortical rather than subcortical brain regions.

Cortical Signature of Neurological Soft Signs in Recent Onset Schizophrenia

Motor symptoms such as neurological soft signs (NSS) are characteristic phenomena of schizophrenia at any stage of the illness. Neuroimaging studies in schizophrenia patients have shown regional thinning of the cortical mantle, but it is unknown at present whether NSS are related to cortical thickness changes. Whole brain high-resolution magnetic resonance imaging at 3 Tesla was used to investigate cortical thickness in 28 patients with recent-onset schizophrenia. Cortical reconstruction was performed with the Freesurfer image analysis suite. NSS were examined on the Heidelberg Scale and related to cortical thickness. Age, education, and medication were considered as potential confounders. Higher NSS scores were associated with morphological changes of cortical thickness in multiple areas comprising paracentral gyrus, postcentral lobule, precuneus, inferior parietal lobule and temporal lobe. Our results confirm the hypothesis of a significant relationship between cortical thickness changes and the extent of NSS in schizophrenia. Investigation of cortical thickness may help to explain subtle motor symptoms such as NSS in schizophrenia.

Neurological Soft Signs and Their Relationship with Measures of Executive Function in Chinese Adolescents

To examine the prevalence of neurological soft signs (NSS) in Chinese adolescents and their associations with sex, age, and executive function. A total of 3892 14- to 19-year-old adolescents were recruited from 7 big cities in China. NSS were assessed using the soft sign subscales of the Cambridge Neurological Inventory. Executive functions were tested using the arrows task (AT) and the Stroop color-word test (SCWT). The prevalence of individual signs of NSS in Chinese adolescents varied from 1.3% to 24.6%. Boys obtained higher NSS scores than girls. Both boys and girls showed age-related reduction in prevalence of NSS. Adolescents with high NSS scores exhibited significantly higher scores in AT and SCWT reaction time and AT and SCWT interference and lower scores in AT and SCWT accuracy than adolescents with low NSS score. The current study indicated that boys have significantly higher rate of NSS than girls, and this difference in NSS rate between genders decreased with increasing age. Adolescents with high NSS scores exhibited more severe impairment in executive functions.

Anomalies neurologiques et physiques mineures chez des patients présentant un premier épisode psychotique

Over the last several decades, there has been an increasing number of neuroanatomical, neuroimaging, neurophysiological, and neuropsychological studies in search of structural, functional, and cognitive correlates of brain insult(s) that could ultimately lead to unravelling the pathophysiology of schizophrenia. A direct, easily administered, and inexpensive way of investigating brain dysfunction in schizophrenia is the study of neurological soft signs and minor physical anomalies, two putative indices of developmental abnormality. The study of these neurodevelopmental markers in the first-episode psychosis allows the detection of the neurodevelopmental abnormalities at the onset of psychosis. The objectives of our study were to determinate the prevalence, the scores, and the nature of neurological soft signs (NSS) and minor physical anomalies (MPA) in patients with first-episode psychosis and to explore the correlations between these neurodevelopmental markers and the demographic, clinical and therapeutic features. A cross-sectional study was carried-out on 61 patients (mean age: 28.9±9.4years; 86.9% were males), hospitalized for first-episode psychosis (DSM-IV-TR diagnosis of schizophrenia, schizophreniform disorder, brief psychotic disorder, delusional disorder, and psychotic disorder not otherwise specified). The evaluation procedure consisted of a retrospective assessment of the premorbid functioning by the Premorbid Functioning Scale (PAS) and the following clinical scales: Positive and Negative Symptoms Scale (PANSS), Clinical Global Impression (CGI) and Global Assessment of Functioning (GAF), the NSS scale of Krebs et al. (23 items exploring motor coordination, motor integrative function, sensory integration, involuntary movements or posture, quality of lateralization) and the MPA scale of Gourion et al. (41 items, exploring anomalies of face, eyes, ears, mouth, hands and feet). The prevalence of NSS was 83.6% (cut-off point=9.5), with a mean total score of 15.3±6.7. The highest score was for the motor coordination. The prevalence of MPA was 62.7% (cut-off point=5), with a mean total score of 5.8±3.2. The most common MPA were the fine hair (50.8%), adherent earlobes (49.2%) and clinodactyly (31.1%). Correlations were found between the NSS total score and the Poor Premorbid Functioning (r=0.32, P=0.04), the PANSS total score (r=0.36, P=0.005), and the negative (r=0.45, P<0.001) and disorganization sub-scores (r=0.41, P=0.001), the CGI-severity of (r=0.30, P=0.02), the impairment functioning in the GAF (r=-0.26, P=0.04) and with extrapyramidal symptoms (r=0.52, P<0.001). However, no correlation was found between the NSS total scores, age, gender, the PANSS positive sub-score, the daily dosage of antipsychotics, the CGI-improvement score and the MPA total score. There was no correlation between MPA total score and demographic, clinical and therapeutic features of patients. Moreover, there was no correlation between the NSS or MPA scores and the short-term evolution (6months to 1year) towards schizophrenia. These results confirm the data in the literature relating high NSS and MPA scores in patients with a first-episode psychosis. The NSS appear to characterize severe psychotic disorders with more negative and disorganization symptoms and poor social functioning and may be a prognostic indicator.

Impaired saccadic adaptation in schizophrenic patients with high neurological soft sign scores

Many motor and cognitive alterations in schizophrenia suggest the involvement of the cerebellum. Neurological soft signs (NSS) are frequent in patients with schizophrenia and reductions in cerebellar volume have been associated with high NSS scores. In this study, we tested saccadic adaptation, a well-characterised oculomotor paradigm involving the cerebellum, in schizophrenic patients with high NSS scores. We used a backward reactive saccade adaptation task, in which the target moves intrasaccadically toward initial fixation, causing the saccade to complete with an endpoint error. A group of 12 schizophrenic patients (SZ; DSM IV) with high NSS scores was compared to a group of 13 matched healthy controls (HC). SZ patients showed lower saccade adaptation than HC. Nevertheless, the time course of adaptation was similar for both groups. This study indicates cerebellar dysfunction in patients with schizophrenia and high NSS scores. Part of the deficit seen in schizophrenia may have a cerebellar origin.

P-787 - Cortical signature of neurological soft signs in recent onset schizophrenia

Minor motor and sensory deficits or neurological soft signs (NSS) are frequently found in patients with schizophrenia at any stage of their illness. Numerous structural magnetic resonance imaging (MRI) studies repeatedly revealed accentuated thinning of cortical mantle in schizophrenia. However, whether NSS are related to alterations of cortical thickness has so far remained mostly unexplored. Whole brain high-resolution MRI at 3 Tesla was used to investigate cortical thickness in twenty five patients with recent-onset schizophrenia. Cortical reconstruction was performed with the Freesurfer image analysis suite. NSS were examined on the Heidelberg Scale after remission of acute symptoms and related to cortical thickness. Age, education, medication and duration of illness were considered as potential confounders. Higher NSS scores were associated with decreased cortical thickness in multiple areas. Significant correlations were found in somatosensory and primary motor cortex, pre-motor area and temporal lobe. Our results confirm the hypothesis of significant relationship between alterations of cortical thickness and the extent of NSS in schizophrenia. Our findings provide new insights into the association of NSS with brain morphometric alterations and an involvement of cortical thickness in schizophrenia.

Cerebellar substructures and neurological soft signs in first-episode schizophrenia

A subtle impairment of motor coordination and sensory integration functions is frequently found in schizophrenia. Clinically these deficits present as neurological soft signs (NSS). Because of its crucial role in motor function, control of muscle tone and equilibrium, the cerebellum is likely to be involved in the appearance of NSS. Magnetic resonance imaging (MRI) was performed in 30 patients with first-episode schizophrenia – all treated with atypical neuroleptics – and 21 healthy controls. NSS were rated on the Heidelberg Scale. By manual tracing, the cerebellum was divided into the following subregions bilaterally: anterior lobe, superior posterior lobe, inferior posterior lobe, and corpus medullare, respectively. Volumetric measures were compared between the two groups and related to NSS scores. NSS scores were significantly higher in patients than in controls. Cerebella of patients were significantly smaller with atrophy pronounced in the corpus medullare bilaterally. In the patients' group, higher NSS scores were found to be related to reduced volumes of the posterior lobes of the cerebellum. In contrast, no significant associations between NSS scores and cerebellar subregions in healthy subjects arose. Our findings support the hypothesis of cerebellar involvement in schizophrenia and indicate that alterations in distinct cerebellar regions are related to NSS.

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.

Neurological Soft Signs as the Stroke Risk in Sickle Cell Disease

Sickle cell disease (SCD) is a common form of hemoglobinopathy and is highly prevalent worldwide. Silent cerebral infarction, which represents infarction without clinical signs, is a risk factor for clinical stroke in patients with SCD. It is well known that silent infarction predisposes patients with SCD to overt stroke. The aim of the present study is to investigate the effect of silent infarction on neurological soft signs (NSS), which demonstrate subtle impairments in sensory integration, motor coordination and the sequencing of complex motor acts and to evaluate whether NSS can be used in clinical practice to evaluate the patients at risk of stroke in SCD patients with silent infarction. Fifty-nine SCD patients without any documented history of cerebrovascular accident and 28 healthy controls were included in this study. All the patients with SCD were evaluated with cerebral magnetic resonance imaging. We found that the NSS scores were significantly higher in patients with silent cerebral infarction than those in patients without silent infarction and control subjects (p < 0.05). Importantly, there was no significant difference in the NSS scores between the patients without silent infarction and control subjects. These results indicate that high NSS scores represnt an important finding for diagnosis of silent infarction in SCD patients. As silent infarction increases the risk for stroke in patients with SCD, NSS can be used to provide additional information in diagnosis of the patients with possible stroke risk during the course of SCD.

Nonresponding schizophrenia: differentiation by neurological soft signs and neuropsychological tests.

Schizophrenia patients have higher scores on neurological soft-signs (NSS) and show greater deficits on a variety of neuropsychological tests than normal control subjects and mixed groups of psychiatric patients. Among chronic schizophrenia patients it is unclear which of these types of deficits most strongly differentiates patients who remain consistently symptomatic in spite of treatment with several conventional neuroleptics (nonresponders) as compared with relapsing chronic schizophrenia patients who improve substantially with treatment (relative responders). In this study, 25 nonresponders and 20 relative responders to conventional neuroleptics were compared on an NSS battery and a limited number of neuropsychological tests, which evaluated deficits influenced by functioning of frontal and nonfrontal brain areas. NSS scores showed the largest difference between relative responders and nonresponders, and statistical analyses suggested that NSS scores were the strongest differentiator between the two groups of chronic schizophrenia patients. Scores differentiating the two groups involved deficits influenced by both frontal and nonfrontal functioning. A predominance of negative symptoms in the current clinical picture was highly correlated with high NSS scores.