Editorial: Neurological Soft Signs in Neuropsychiatric Conditions

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.

Investigating Gait, Movement, and Coordination in Children with Neurodevelopmental Disorders: Is There a Role for Motor Abnormalities in Atypical Neurodevelopment?

Motor abnormalities have been suggested to play a role in most neuropsychiatric disorders, as a potential generic neurodevelopmental vulnerability. However, they still represent a neglected area, with a paucity of empirical studies, especially in pediatric populations. This case-control study aimed to comprehensively assess motor functioning in children with atypical neurodevelopment and investigate whether any socio-demographic or clinical characteristics would concur with motor difficulties to distinguish children with neurodevelopmental disorders (NDD) from healthy controls. Socio-demographic (age and gender) and clinical (intelligence quotient, gait, movement, and coordination) data were collected on 114 children aged 5-15 (83 with NDD, 31 healthy controls). Male children were at significantly higher risk for NDD (OR: 13.023, p < 0.001). Furthermore, there was a statistically significant interaction between the total intelligence quotient and overall coordination such that increasing levels of total intelligence quotient appeared to protect against the likelihood of being diagnosed with an NDD, but only in the context of a preserved coordination (OR: 0.964, p = 0.038). Collectively, results may have important public health implications, as they point towards the development of new approaches to establish an early prognosis in neurodevelopment, including assessing motor difficulties and mitigating their impact on children's quality of life.

Neurological soft signs (NSS) and gray matter volume (GMV) in first-episode psychosis: An analysis of NSS motor subscores

We aimed to study the correlations between gray matter volume and the motor subscores of NSS in first-episode psychosis patients with both, whole brain and region of interest analyses. The structural MRIs of 81 first-episode psychosis patients were analyzed by using voxel-based morphometry (VBM) for SPM. NSS were assessed using the Heidelberg scale. Significant decreases of gray matter volume were correlated to high NSS total scores and, more specifically, frontal, subcortical and cerebellar areas were significantly correlated with increased scores of the subscores Motor Coordination (MoCo) and Complex Motor Tasks (CMT). When applying a stricter statistical correction, only the frontal gyrus and caudate nucleus survived for MoCo; whereas the precentral and superior frontal gyri survived for CMT. When doing regional analyses, using as masks the structures deemed as significant by the whole brain analyses and applying the FWE-correction, the superior frontal gyrus, thalamus and caudate nucleus correlated negatively with MoCo; and the precentral and superior frontal gyri, thalamus and caudate nucleus showed inverse correlations with CMT. These results suggest that cerebral cortex, subcortical structures (thalamus and striatum) and cerebellum are inversely correlated to both motor NSS subscores, the first time a study describes this relationship for all the relevant structures simultaneously. For its part, ROI proves to be effective demonstrating that subcortical structures (thalamus and caudate) are the most affected by motor NSS.

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.