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

Sex-dependent effects of rat maternal immune activation on motor function in offspring of poly I:C treated rats

A majority of people with schizophrenia will experience motor symptoms such as impairments to coordination, balance and motor sequencing. These neurological soft signs are associated with negative social and functional outcomes, and poor disease prognosis. They occur prior to medication exposure, suggesting they are an intrinsic feature of schizophrenia. Despite the need to better understand this dysfunction, relatively few studies have provided a detailed focus on motor capability in animal models of schizophrenia. Here we investigate motor coordination in a rat maternal immune activation (MIA) model of schizophrenia risk. The female and male offspring of Polyinosinic:polycytidylic acid (Poly I:C), and vehicle-treated, pregnant dams were tested in a horizontal ladder rung task using regular and irregular rung configurations. We extracted information about limb positions from video, and measured faults and gait coordination in the task. We found that adult male MIA rats were more likely to slip from the ladder rungs than control animals, and they were more likely to have multiple limbs slip simultaneously. MIA rats also exhibited more variability in stride length, a result that correlated with slips and mirrored disease-related changes in human gait. In contrast, female MIA rats displayed minimal alterations in motor performance. Our findings show that the ladder task uncovers sex-dependent effects on motor coordination in MIA rats and highlights the potential usefulness of the MIA model for investigating motor dysfunction in an animal model of schizophrenia risk.

Neurological soft signs and olfactory dysfunction in patients with borderline personality disorder

BACKGROUND

Borderline personality disorder (BPD) is a serious disorder with a lifetime prevalence of 2.7-5.9% and is thought to correlate with altered neuroplasticity. The aim of the present study is to investigate possible associations of BPD (-severity) and alterations in neurological soft signs (NSS) and olfactory function.

METHODS

For the monocentric observational study, 39 female subjects with a BPD diagnosis and 19 female healthy control subjects were recruited. The groups were matched by age. Olfactory functions were examined using Sniffin' Sticks. NSS were assessed by a standardized test with 50 items.

RESULTS

BPD subjects have higher NSS scores in group comparison. By contrast, there are no alterations in the total score of olfactory function, while the BPD subjects scored higher in smell identification. Within the BPD group, the total NSS score was discovered to have a negative correlation with olfactory function. BPD subjects taking antipsychotics show more NSS than those without. We found no significant influence of posttraumatic stress disorder on the NSS or olfactory function. The BPD-severity correlates with NSS.

LIMITATIONS

Due to the cross-sectional design, we did not have a follow up examination. The sample size was small, and all patients had psychiatric comorbidities. Additionally, we did not perform MRI to connect our findings with possible structural abnormalities.

CONCLUSIONS

Our study confirmed altered NSS in BPD patients, whereas no impairment in the olfactory function was found. Further research is required to establish NSS and smell tests as clinical screening tools in BPD patients and to uncover the disorder's impact on neuroplasticity.

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.

A Study of Neurological Soft Signs and Cognition in Schizophrenia

INTRODUCTION

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.

METHODS

 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 tests and Spearman rank correlation along with mean and standard deviation.

RESULTS

 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.

CONCLUSION

 A significant association was observed between cognitive deficits, negative symptoms, and NSS in Schizophrenia. NSS and cognitive dysfunctions are integral parts of Schizophrenia symptom domains 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.