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

Stride-level analysis of mouse open field behavior using deep-learning-based pose estimation

Gait and posture are often perturbed in many neurological, neuromuscular, and neuropsychiatric conditions. Rodents provide a tractable model for elucidating disease mechanisms and interventions. Here, we develop a neural-network-based assay that adopts the commonly used open field apparatus for mouse gait and posture analysis. We quantitate both with high precision across 62 strains of mice. We characterize four mutants with known gait deficits and demonstrate that multiple autism spectrum disorder (ASD) models show gait and posture deficits, implying this is a general feature of ASD. Mouse gait and posture measures are highly heritable and fall into three distinct classes. We conduct a genome-wide association study to define the genetic architecture of stride-level mouse movement in the open field. We provide a method for gait and posture extraction from the open field and one of the largest laboratory mouse gait and posture data resources for the research community.

Sheppard et al. present a method for gait and posture analysis in the common open field apparatus using neural-network-based pose estimation. They apply this high-throughput method to dissect the genetic architecture of mouse movement.

Gait Alterations in the Prediction of Metabolic Syndrome in Patients With Schizophrenia: A Pilot Study With PODOSmart ® Insoles

BACKGROUND

Second-generation antipsychotics (APs) are associated with metabolic syndrome (MetS), characterized by abnormal pro-inflammatory cytokine production and oxidative stress due to the reduced antioxidant systems, and neurological effects, including mobility impairment. This pilot study investigated relationships between inflammatory-metabolic biomarkers, MetS and gait alterations in patients with psychosis treated with APs.

METHODS

Patients with psychosis treated with APs, 20 with MetS (MPS group) and 20 without MetS (PS group) were studied, usinganthropometric data, blood measurements and gait analysis performed with the PODOSmart ® gait analysis device.

RESULTS AND DISCUSSION

The MPS group had significantly higher mean body mass index (BMI) and arterial blood pressure (BP) than the PS group. PODOSmart ® gait analysis recorded significant differences between groups in pronation-supination at Heel Off (HO), gaitline HO and gaitline Toe Off (TO). Multifactorial elastic net regression models demonstrated significant association with MetS of inflammatory markers, specific AP2 treatment, gender, age; BMI; BP and smoking (accuracy λ = 0.08), and in relation to gait parameters (accuracy λ = 0.750), the three pronation- supination variables, i.e., at HO, flat foot in (AP2 related) and TO, and propulsion speed. The gait parameters were at the edges of the model, thus indicating a more significant role of these parameters compared to the other clinical variables. Early diagnosis of MetS in patients with schizophrenia via identification of gait alterations can be a screening measure for serious cardiovascular complications related to psychosis and APs, to enable timely dietary intervention that can control the pro-inflammatory state and reduce oxidative stress.

Effects of different types of sensory signals on reaching performance in persons with chronic schizophrenia

Previous studies have reported movement abnormalities in persons with schizophrenia. This study aimed to examine the differences between persons with chronic schizophrenia and healthy control participants in reaching movement and the effects of sensory signals on reaching performance in persons with chronic schizophrenia. A counter-balanced repeated-measures design was employed. Twenty persons with schizophrenia and 20 age- and gender-matched control participants were recruited in this study. Reaching performance was measured in three types of sensory signal conditions (visual, auditory, and no signal), i.e., two externally triggered and one self-initiated movement were assessed in reaction time/inter-response interval, movement time, peak velocity, percentage of time in which peak velocity occurred, and movement units. The results revealed significant main effects of group in reaction time/inter-response interval (p = 0.003), movement time (p < 0.001), peak velocity (p < 0.001), and movement units (p < 0.001). The persons with chronic schizophrenia demonstrated slower response to signals and in self-initiated movement, increased movement time, and less forceful and less smooth movement compared to healthy control participants when performing the reaching task. The interaction effect between group and signal in reaction time/inter-response interval was also significant (p < 0.001). The inter-response interval for self-initiated reaching was the shortest in healthy controls. Conversely, the inter-response interval for self-initiated reaching was the longest in persons with schizophrenia. The main effect of the signal on movement time was significant (p < 0.001). The movement time of reaching was longer in response to the auditory signal than in response to visual or self-initiated. The differences in percentages of time in which peak velocity occurred between persons with schizophrenia and healthy controls (p > 0.01) and across the three conditions (p > 0.01) were non-significant. Neither duration of illness nor antipsychotic dosage was significantly associated with reaching performance (all p > 0.01). In conclusion, these findings indicate that reaching movement in persons with chronic schizophrenia is slower, less forceful, and less coordinated compared to healthy control participants. In addition, persons with chronic schizophrenia also had shorter inter-response interval for self-initiated movement and shorter movement time in auditory signal condition, independent of duration of illness and antipsychotic dosage.

Antipsychotics Do Not Influence Neurological Soft Signs in Children and Adolescents at Ultra-High Risk for Psychosis: A Pilot Study

OBJECTIVE

Ultra-high risk for psychosis (UHR) is considered as the condition that temporally precedes the onset of psychotic symptoms. In addition to the core symptoms, patients with schizophrenia show motor abnormalities, also known as neurological soft signs (NSS), that are considered an endophenotype for psychotic disorders and particularly for schizophrenia. Antipsychotic medications do not appear to influence NSS in individuals with schizophrenia. However, NSS in UHR subjects have been poorly studied and, to date, we do not know what effects antipsychotics have in early treated UHR subjects. Therefore, we evaluated NSS in treated UHR subjects in comparison with drug-naive UHR subjects and a group of healthy control subjects and the effect of pharmacological treatment on early treated UHR children and adolescents.

PATIENTS AND METHODS

Fifteen UHR subjects receiving pharmacological treatment, 15 drug-naive UHR subjects, and 25 healthy control subjects were evaluated for NSS to analyze any differences between clinical subjects and healthy controls and to evaluate the effect of antipsychotic medications in early treated UHR subjects.

RESULTS

Both clinical groups showed a greater number of NSS compared with the healthy control subjects. However, no significant differences in NSS were found between treated and drug-naive UHR subjects.

CONCLUSIONS

Consistent with what has been observed in the population of patients with a first psychotic episode and/or with schizophrenia, our results support the conclusion that antipsychotic medications do not influence NSS in children and adolescents who are at high risk for psychosis.

Distinct Associations of Motor Domains in Relatives of Schizophrenia Patients-Different Pathways to Motor Abnormalities in Schizophrenia?

INTRODUCTION

Aberrant motor function is an integral part of schizophrenia. In fact, abnormalities are frequently found in patients, in populations at risk, and in unaffected relatives. Motor abnormalities are suspected to be relevant for the clinical outcome and could probably predict the conversion from at-risk individuals to schizophrenia. Furthermore, motor function has been argued as endophenotype of the disorder. Yet, which particular motor domain may classify as a potential endophenotype is unknown. We aimed to compare schizophrenia patients, unaffected first-degree relatives and healthy controls for different motor domains. We expected impairments in all domains in patients and in some domains in relatives.

METHOD

We included 43 schizophrenia patients, 34 unaffected first-degree relatives of schizophrenia patients, and 29 healthy control subjects, matched for age, gender, and education level. We compared motor function of four motor domains between the groups. The domains comprise neurological soft signs (NSS), abnormal involuntary movements (dyskinesia), Parkinsonism, and fine motor function including simple [finger tapping (FT)] and complex fine motor function, (i.e., dexterity as measured with the coin rotation test). Furthermore, we tested the association of motor function of the four domains with working memory, frontal lobe function, and nonverbal intelligence for each group separately using within-group bivariate correlations.

RESULTS

Schizophrenia patients showed poorer motor function in all tested domains compared to healthy controls. First-degree relatives had intermediate ratings with aberrant function in two motor domains. In detail, relatives had significantly more NSS and performed poorer in the FT task than controls. In contrast, complex fine motor function was intact in relatives. Relatives did not differ from controls in dyskinesia or Parkinsonism severity.

DISCUSSION

Taken together, schizophrenia patients have motor abnormalities in all tested domains. Thus, motor abnormalities are a key element of the disorder. Likewise, first-degree relatives presented motor deficits in two domains. A clear difference between relatives and healthy controls was found for NSS and FT. Thus, NSS and FT may be potential markers of vulnerability for schizophrenia. The lack of association between genetic risk and dyskinesia or Parkinsonism suggests distinct pathobiological mechanisms in the various motor abnormalities in schizophrenia.

Aberrant Force Processing in Schizophrenia

Initially considered as mere side effects of antipsychotic medication, there is now evidence that motor and somatosensory disturbances precede the onset of the illness and can be found in drug-naive patients. However, research on the topic is scarce. Here, we were interested in assessing the accuracy of the neural signal in detecting parametric variations of force linked to a voluntary motor act and a received tactile sensation, either self-generated or externally generated. Patients with a diagnosis of schizophrenia and healthy controls underwent functional magnetic resonance imaging while asked to press, or abstain from pressing, a lever in order to match a visual target force. Forces, exerted and received, varied on 10 levels from 0.5 N to 5 N in 0.5 N increments. Healthy participants revealed a positive correlation between force and activity in contralateral primary somatosensory area (S1) when performing a movement as well as when receiving a tactile sensation but only when this was externally, and not self-, generated. Patients showed evidence of altered force signaling in both motor and tactile conditions, as well as increased correlation with force when tactile sensation was self-generated. Findings are interpreted in line with accounts of predictive and sensory integration mechanisms and point toward alterations in the encoding of parametric forces in the motor and somatosensory domain in patients affected by schizophrenia.

Manual Dexterity in Schizophrenia-A Neglected Clinical Marker?

Impaired manual dexterity is commonly observed in schizophrenia. However, a quantitative description of key sensorimotor components contributing to impaired dexterity is lacking. Whether the key components of dexterity are differentially affected and how they relate to clinical characteristics also remains unclear. We quantified the degree of dexterity in 35 stabilized patients with schizophrenia and in 20 age-matched control subjects using four visuomotor tasks: (i) force tracking to quantify visuomotor precision, (ii) sequential finger tapping to measure motor sequence recall, (iii) single-finger tapping to assess temporal regularity, and (iv) multi-finger tapping to measure independence of finger movements. Diverse clinical and neuropsychological tests were also applied. A patient subgroup (N = 15) participated in a 14-week cognitive remediation protocol and was assessed before and after remediation. Compared to control subjects, patients with schizophrenia showed greater error in force tracking, poorer recall of tapping sequences, decreased tapping regularity, and reduced degree of finger individuation. A composite performance measure discriminated patients from controls with sensitivity = 0.79 and specificity = 0.9. Aside from force-tracking error, no other dexterity components correlated with antipsychotic medication. In patients, some dexterity components correlated with neurological soft signs, Positive and Negative Syndrome Scale (PANSS), or neuropsychological scores. This suggests differential cognitive contributions to these components. Cognitive remediation lead to significant improvement in PANSS, tracking error, and sequence recall (without change in medication). These findings show that multiple aspects of sensorimotor control contribute to impaired manual dexterity in schizophrenia. Only visuomotor precision was related to antipsychotic medication. Good diagnostic accuracy and responsiveness to treatment suggest that manual dexterity may represent a useful clinical marker in schizophrenia.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Childhood pegboard task predicts adult-onset psychosis-spectrum disorder among a genetic high-risk sample

Motor abnormalities have been established as a core aspect of psychosis-spectrum disorders, with numerous studies identifying deficits prior to clinical symptom presentation. Additional research is needed to pinpoint standardized motor assessments associated with psychosis-spectrum disorders prior to illness onset to enhance prediction and understanding of etiology. With a long history of findings among people with diagnosable psychosis-spectrum disorders, but little research conducted during the premorbid phase, pegboard tasks are a viable and understudied measure of premorbid for psychosis motor functioning. In the current study, examining data from the Copenhagen Perinatal Cohort, the Simultaneous Pegs Test was performed with children (n=244, aged 10-13) at genetic high risk for psychosis (n=94) and controls (n=150). Findings suggest that children who eventually developed a psychosis-spectrum disorder (n=33) were less likely to successfully complete the task within time limit relative to controls (χ²(2, N=244)=6.94, p=0.03, ϕ=0.17). Additionally, children who eventually developed a psychosis-spectrum disorder took significantly longer to complete the task relative to controls (χ²(2, N=244)=7.06, p=0.03, ϕ=0.17). As pegboard performance is thought to tap both diffuse and specific brain networks, findings suggest that pegboard tests may be useful premorbid measures of motor functioning among those on a trajectory towards a psychosis-spectrum disorder.

A clinical study of neurological soft signs in patients with schizophrenia

BACKGROUND AND AIM

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

SUBJECTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Dysfluent Handwriting in Schizophrenic Outpatients

Taking into account findings in the literature, the author aimed to test whether specific graphical characteristics of handwriting can distinguish patients diagnosed with schizophrenic disorders from healthy controls. Handwriting samples (one sample from each person) from 60 outpatients (29 women, 31 men; age M = 28.5, SD = 5.4) with paranoid schizophrenia were analyzed by three documents examiners and were compared to samples from 60 controls (30 men, 30 women, age M = 28.0, SD = 3.0) without psychiatric disorders. Document examiners assessed 32 graphical features potentially related to schizophrenia. The comparisons between groups revealed that only 7 out of 32 handwriting properties were significantly different in the handwriting of schizophrenic outpatients from controls: the calligraphic forms of letters, loops in ovals, lacking of dots, tremor, sinusoidal baseline, and irregularities size of lower zone. These findings are discussed in terms of motor disturbances in schizophrenia and in relation to the previous research on handwriting of other mental disorders. Similarities between the graphical patterns of handwriting of schizophrenic patients and those of other mental disorders and/or other mental states have been demonstrated.

Neurological soft signs in children with attention deficit hyperactivity disorder: Their relationship to executive function and parental neurological soft signs

The correlations between neurological soft signs (NSS) in children with attention deficit hyperactivity disorder (ADHD) and their executive function, symptoms of inattention, and hyperactivity-impulsivity and the NSS of their parents remain unclear. This study aimed to examine: (1) the prevalence of NSS in children with ADHD and their parents; (2) the correlation between the NSS of children with ADHD and the NSS of their parents; and (3) the correlation between the NSS of children with ADHD and their executive function and symptoms. NSS were assessed with the Cambridge Neurological Inventory (CNI) in 57 children with ADHD (and 80 parents) and 60 healthy children (and 75 parents). Executive function was measured with the Behavioral Rating Inventory of Executive Function (BRIEF). Children with ADHD and their parents had significantly higher NSS than normal children and their parents, respectively, and the NSS of children with ADHD were correlated more strongly with the NSS of their fathers than their mothers. No correlation was found between NSS and BRIEF executive function, but Disinhibition in children with ADHD was significantly correlated with hyperactivity-impulsivity symptoms. Paternal and maternal NSS provided different predictions for child NSS. It may be that NSS are more likely to be genetically transmitted by fathers.

Study protocol: The Whitehall II imaging sub-study

BACKGROUND

The Whitehall II (WHII) study of British civil servants provides a unique source of longitudinal data to investigate key factors hypothesized to affect brain health and cognitive ageing. This paper introduces the multi-modal magnetic resonance imaging (MRI) protocol and cognitive assessment designed to investigate brain health in a random sample of 800 members of the WHII study.

METHODS/DESIGN

A total of 6035 civil servants participated in the WHII Phase 11 clinical examination in 2012-2013. A random sample of these participants was included in a sub-study comprising an MRI brain scan, a detailed clinical and cognitive assessment, and collection of blood and buccal mucosal samples for the characterisation of immune function and associated measures. Data collection for this sub-study started in 2012 and will be completed by 2016. The participants, for whom social and health records have been collected since 1985, were between 60-85 years of age at the time the MRI study started. Here, we describe the pre-specified clinical and cognitive assessment protocols, the state-of-the-art MRI sequences and latest pipelines for analyses of this sub-study.

DISCUSSION

The integration of cutting-edge MRI techniques, clinical and cognitive tests in combination with retrospective data on social, behavioural and biological variables during the preceding 25 years from a well-established longitudinal epidemiological study (WHII cohort) will provide a unique opportunity to examine brain structure and function in relation to age-related diseases and the modifiable and non-modifiable factors affecting resilience against and vulnerability to adverse brain changes.

Effects of object size on unimanual and bimanual movements in patients with schizophrenia

Schizophrenia affects not only mental function but also movement. We compared the movement of patients with mild schizophrenia and healthy control participants during a bimanual assembly task and examined whether changes in object size affected unimanual and bimanual movements. Fifteen patients with schizophrenia and 15 age- and gender-matched control participants were instructed to bimanually reach for and assemble objects. We manipulated the object size for the left hand (large vs. small) and measured movement time, peak velocity, and bimanual synchronization to represent movement speed, forcefulness, and bimanual coordination. Patients with schizophrenia showed slower and less forceful unimanual movements and less coordinated bimanual movements than control participants. Increasing the object size elicited faster and more forceful unimanual movements and more coordinated bimanual movements in patients. The results suggest the need for movement rehabilitation in patients with schizophrenia and the possibility of manipulating object size to optimize patients' movements. These results benefit the practice of evidence-based therapy.

First rank symptoms and neurological soft signs in schizophrenia

The aim of the study was to compare the neurological soft signs (NSS) in schizophrenia patients with and without first rank symptoms (FRS), their first degree relatives (FDR), and normal controls. The study was conducted on 60 schizophrenia patients diagnosed according to ICD 10 DCR and categorized into groups with and without FRS using Schedules for Clinical Assessment in Neuropsychiatry, 30 FDRs of the study sample, and 30 normal controls matched for age, education, and handedness. All the subjects gave written informed consent. Scale for the Assessment of Positive Symptoms and Scale for the Assessment of Negative Symptoms were applied to have a comprehensive assessment of the symptoms. NSS were assessed using Extended Standard Neurological Assessment Instrument. The correlations between NSS and clinical symptoms were relatively modest but significant. There was a weak relation between NSS and positive symptom severity. The FDR of schizophrenia patients had significantly lower NSS scores than schizophrenia patients, but only FDR of schizophrenia patients without FRS had significantly higher scores than normal controls. Our results indicate that NSS are more prominent in schizophrenia patients with negative symptoms and support the theory of NSS being a trait marker of schizophrenia particularly in those without FRS.

Sensory and motor secondary symptoms as indicators of brain vulnerability

In addition to the primary symptoms that distinguish one disorder from the next, clinicians have identified, yet largely overlooked, another set of symptoms that appear across many disorders, termed secondary symptoms. In the emerging era of systems neuroscience, which highlights that many disorders share common deficits in global network features, the nonspecific nature of secondary symptoms should attract attention. Herein we provide a scholarly review of the literature on a subset of secondary symptoms––sensory and motor. We demonstrate that their pattern of appearance––across a wide range of psychopathologies, much before the full-blown disorder appears, and in healthy individuals who display a variety of negative symptoms––resembles the pattern of appearance of network abnormalities. We propose that sensory and motor secondary symptoms can be important indicators of underlying network aberrations and thus of vulnerable brain states putting individuals at risk for psychopathology following extreme circumstances.

A fast-moving target in the Valpar assembly task improved unimanual and bimanual movements in patients with schizophrenia

PURPOSE

To investigate the effects of target speed on unimanual and bimanual movements during a bimanual prehension and assembly task in patients with mild schizophrenia and healthy controls.

METHOD

Fifteen patients with schizophrenia and 15 age- and gender-matched healthy controls were instructed to reach and assemble spacers with both hands for a target that moved at two speeds: fast or slow. Dependent variables were movement kinematics: movement time, number of movement units and timing intervals between both hands.

RESULTS

A fast-moving target induced shorter movement times, fewer movement units and shorter timing intervals than did a slow-moving target for patients. Under the slow-target condition, patients had longer movement times and a longer timing interval during prehension, as well as longer movement times, more movement units and a longer timing interval during assembly than did controls. Under the fast-target condition, patients still had slower and less-synchronized prehension than did controls, but their assembly improved to a level similar to that of controls.

CONCLUSIONS

A fast-moving target induced faster, smoother and more synchronized movements than did a slow-moving target for patients with schizophrenia, especially during assembly.

IMPLICATIONS FOR REHABILITATION

A fast-moving target might elicit faster, smoother, and more synchronized movements than might a slow-moving target during a bimanual assembly task for patients with mild schizophrenia. The findings of impaired movement kinematics under the slow-target condition suggest that patients with schizophrenia need movement training.

Dynamics of neurological soft signs and its relationship to clinical course in patients with first-episode schizophrenia

The aim of the study was to assess the dynamics of neurological soft signs (NSS) over four years from the clinical onset of schizophrenia, depending on the clinical course of the disease, and to evaluate the relationship of NSS to symptomatic dimensions in patients with first-episode schizophrenia. Sixty-eight patients with first-episode schizophrenia were included in the trial. The clinical status was assessed using Positive and Negative Syndrome Scale (PANSS) at the same time as the neurological examination, at admission to the hospital for first-episode schizophrenia and at a check-up examination four years later. The assessment of NSS using the Neurological Evaluation Scale (NES) coincided with the assessment of the clinical condition of the patients. According to the Andreasen remission criterion of schizophrenia, after four years we found that 57% of patients' were remitters and 43% were non-remitters. During the monitoring period, in remitters total NES score and sensory integration/sequencing of motor acts items of the NES decreased. In non-remitters, increase in the total NES score and the 'others' item of the NES was observed. A connection between the dynamics of NSS and the clinical course of schizophrenia, over the period of four years, and a relationship between NSS and negative schizophrenia symptoms was found.

Premorbid multivariate markers of neurodevelopmental instability in the prediction of adult schizophrenia-spectrum disorder: a high-risk prospective investigation

The authors examined whether multiple childhood indicators of neurodevelopmental instability known to relate to schizophrenia-spectrum disorders could predict later schizophrenia-spectrum outcomes. A standardized battery of neurological and intellectual assessments was administered to a sample of 265 Danish children in 1972, when participants were 10-13 years old. Parent psychiatric diagnoses were also obtained in order to evaluate the predictive strength of neurodevelopmental factors in combination with genetic risk. Adult diagnostic information was available for 244 members of the sample. Participants were grouped into three categories indicating level of genetic risk: children with a parent with schizophrenia (n=94); children with a parent with a non-psychotic mental health diagnosis (n=84); and children with a parent with no records of psychiatric hospitalization (n=66). Variables measured included minor physical anomalies (MPAs), coordination, ocular alignment, laterality, and IQ. Adult diagnoses were assessed through psychiatric interviews in 1992, as well as through a scan of the national psychiatric registry through 2007. Through a combination of multiple childhood predictors, the model correctly classified 73% (24 of 33) of the participants who eventually developed a schizophrenia-spectrum outcome in adulthood. Results suggest that, with replication, multivariate premorbid prediction could potentially be a useful complementary approach to identifying individuals at risk for developing a schizophrenia-spectrum disorder. Genetic risk, MPAs, and other markers of neurodevelopmental instability may be useful for comprehensive prediction models.

Treatment response of neurological soft signs in drug-naïve patients with a first psychotic episode

BACKGROUND

Neurological soft signs (NSS) are intrinsic features of psychosis that appear years before beginning a drug treatment. However, whether NSS respond to antipsychotics and whether these changes are clinically reliable and significant remains to be seen.

OBJECTIVE

We sought to determine the effect of antipsychotics on NSS in a first-episode psychosis (FEP) sample who had never exposed to antipsychotics.

METHODS

We included 100 antipsychotic-naïve patients with FEP in this study. 77 patients completed the study assessments at baseline, 1 month and 6 months. The Neurological Evaluation Scale (NES) evaluated NSS. Patients were alternatively selected to receive risperidone or olanzapine treatments and continued participation in their mental health setting during follow-up with one of four treatment groups: risperidone, olanzapine, mixed antipsychotics or no medication. We also included a control group of 28 healthy volunteers.

RESULTS

Treatment groups showed a statistically significant improvement on total NES scores and most NES subscales except for 'frontal signs', regardless of antipsychotic allocation. NSS changes were reliable; however, there was great variation in the total NES scores between treatment groups, ranging from 4% to 24%. Clinically meaningful changes (CMCs) on total NES scores ranged from 25% to 50%. Six patients (7.8%) demonstrated a reliable change (RC) and CMC on total NES scores.

CONCLUSIONS

NSS improved significantly over follow up regardless of the treatment regimen assigned to antipsychotic-naïve patients with a FEP. However, only 6 (7.8%) achieved a reliable and clinically meaningful improvement. The pattern of response of NSS to antipsychotic drugs evidenced both state and trait characteristics.

Abnormal functional motor lateralization in healthy siblings of patients with schizophrenia

Earlier neuroimaging studies of motor function in schizophrenia have demonstrated reduced functional lateralization in the motor network during motor tasks. Here, we used event-related functional magnetic resonance imaging during a visually guided motor task in 18 clinically unaffected siblings of patients with schizophrenia and 24 matched controls to investigate if abnormal functional lateralization is related to genetic risk for this brain disorder. Whereas activity associated with motor task performance was mainly contralateral with only a marginal ipsilateral component in healthy participants, unaffected siblings had strong bilateral activity with significantly greater response in ipsilateral and contralateral premotor areas as well as in contralateral subcortical motor regions relative to controls. Reduced lateralization in siblings was also identified with a measure of laterality quotient. These findings suggest that abnormal functional lateralization of motor circuitry is related to genetic risk of schizophrenia.

More than just tapping: index finger-tapping measures procedural learning in schizophrenia

BACKGROUND

Finger-tapping has been widely studied using behavioral and neuroimaging paradigms. Evidence supports the use of finger-tapping as an endophenotype in schizophrenia, but its relationship with motor procedural learning remains unexplored. To our knowledge, this study presents the first use of index finger-tapping to study procedural learning in individuals with schizophrenia or schizoaffective disorder (SCZ/SZA) as compared to healthy controls.

METHODS

A computerized index finger-tapping test was administered to 1169 SCZ/SZA patients (62% male, 88% right-handed), and 689 healthy controls (40% male, 93% right-handed). Number of taps per trial and learning slopes across trials for the dominant and non-dominant hands were examined for motor speed and procedural learning, respectively.

RESULTS

Both healthy controls and SCZ/SZA patients demonstrated procedural learning for their dominant hand but not for their non-dominant hand. In addition, patients showed a greater capacity for procedural learning even though they demonstrated more variability in procedural learning compared to healthy controls. Left-handers of both groups performed better than right-handers and had less variability in mean number of taps between non-dominant and dominant hands. Males also had less variability in mean tap count between dominant and non-dominant hands than females. As expected, patients had a lower mean number of taps than healthy controls, males outperformed females and dominant-hand trials had more mean taps than non-dominant hand trials in both groups.

CONCLUSIONS

The index finger-tapping test can measure both motor speed and procedural learning, and motor procedural learning may be intact in SCZ/SZA patients.

Neurological soft signs in schizophrenia: a meta-analysis

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Dyskinesia and parkinsonism in antipsychotic-naive patients with schizophrenia, first-degree relatives and healthy controls: a meta-analysis

BACKGROUND

Several studies have reported the presence of dyskinesia and parkinsonism in antipsychotic-naive patients with schizophrenia as well as in their first-degree relatives. These movement disorders may therefore form an integral part of the illness and its (genetic) liability.

METHOD

A systematic search was conducted in the Medline, EMBASE, and PsychINFO databases to identify studies reporting on dyskinesia and parkinsonism assessed in antipsychotic-naive patients with schizophrenia (n = 213) and controls (n = 242) and separately in nonill first-degree relatives (n = 395) and controls (n = 379). Effect sizes were pooled using random-effect models to calculate odds ratios (ORs) to compare the risk of these movement disorders among patients and healthy relatives each with matched controls.

RESULTS

Antipsychotic-naive schizophrenia was found to be strongly associated with dyskinesia (OR: 3.59, 95% confidence interval [CI]: 1.53-8.41) and parkinsonism (OR: 5.32, 95% CI: 1.75-16.23) compared with controls. Dyskinesia and parkinsonism were also significantly more prevalent in healthy first-degree relatives of patients with schizophrenia as compared with healthy controls (OR: 1.38, 95% CI: 1.06-1.81, and OR: 1.37, 95% CI: 1.05-1.79, respectively).

CONCLUSION

The results suggest that movement disorders, and by inference abnormalities in the nigrostriatal pathway, are not only associated with schizophrenia itself but may also be related to the (genetic) risk of developing the disease.

Neurological soft signs in non-psychotic first-degree relatives of patients with schizophrenia: a systematic review and meta-analysis

BACKGROUND

Neurological soft signs (NSS) have been associated with the neuropsychopathology of schizophrenia, and have been proposed as candidate endophenotypes for this clinical group. However, the prevalence rate of NSS in non-psychotic first-degree relatives is not fully known. The authors systematically and quantitatively reviewed the literature to determine the magnitude of difference between: (1) first-degree non-psychotic relatives of schizophrenia patients and healthy controls, and (2) between schizophrenia patients and their non-psychotic relatives.

METHODS

An article search and meta-analysis was conducted using the Comprehensive Meta-Analysis software package to quantify group differences. Mean effect sizes (standardized group mean differences) and associated confidence intervals along with homogeneity and publication bias tests and statistics were calculated.

RESULTS

Search procedures identified 11 independent studies that met the inclusion criteria. Quantification of NSS differences yielded a mean effect size of 0.81 for schizophrenia patients and their non-psychotic relatives and 0.97 for non-psychotic relatives of schizophrenia patients and healthy controls.

CONCLUSIONS

The current findings show that there are large group differences in NSS prevalence between patients with schizophrenia, non-psychotic relatives, and healthy controls. These results are consistent with the argument that NSS are familial in nature, segregate with the illness and may be valid and useful endophenotypes.

Objectively measured motor activity in schizophrenia challenges the validity of expert ratings

Motor symptoms are frequent in schizophrenia and relevant to diagnosis. They are usually assessed by clinical observation and ratings based on psychometric scales. However, investigations with quantitative measurements are rare. To understand the relationship between the objective parameters of a quantitative motor activity measurement and the items related to motor symptoms of the Positive and Negative Syndrome Scale (PANSS), 55 schizophrenia patients were studied with 24-h continuous wrist actigraphy. Activity level, movement index, and mean duration of uninterrupted immobility periods were analyzed for wakeful periods. Actigraphic parameters were strongly inter-correlated. High PANSS negative syndrome subscale scores predicted low activity levels. Single PANSS items, such as suspiciousness, hallucinatory behavior, and emotional withdrawal, contributed largely to the variance in activity level and movement index. Age, gender, medication, and duration of illness had no significant impact on the actigraphic parameters. Interestingly, correlations between the specific motor symptoms of the PANSS and the actigraphic parameters were only found as a non-significant trend. We conclude that the objectively measured quantity of movement is related to the clinically assessed negative syndrome in schizophrenia. In contrast, PANSS items related to psychomotor behavior imprecisely reflect real quantitative motor activity.

Psychomotor performance in relation to acute oral administration of Delta9-tetrahydrocannabinol and standardized cannabis extract in healthy human subjects

Abnormalities in psychomotor performance are a consistent finding in schizophrenic patients as well as in chronic cannabis users. The high levels of central cannabinoid (CB(1)) receptors in the basal ganglia, the cerebral cortex and the cerebellum indicate their implication in the regulation of motor activity. Based on the close relationship between cannabis use, the endogenous cannabinoid system and motor disturbances found in schizophrenia, we expected that administration of cannabinoids may change pattern of psychomotor activity like in schizophrenic patients. This prospective, double-blind, placebo-controlled cross-over study investigated the acute effects of cannabinoids on psychomotor performance in 24 healthy right-handed volunteers (age 27.9 +/- 2.9 years, 12 male) by comparing Delta(9)-tetrahydrocannabinol (Delta(9)-THC) and standardized cannabis extract containing Delta(9)-THC and cannabidiol. Psychomotor performance was assessed by using a finger tapping test series. Cannabis extract, but not Delta(9)-THC, revealed a significant reduction of right-hand tapping frequencies that was also found in schizophrenia. As to the pure Delta(9)-THC condition, left-hand tapping frequencies were correlated with the plasma concentrations of the Delta(9)-THC metabolite 11-OH-THC. These effects are thought to be related to cannabinoid actions on CB(1) receptors in the basal ganglia, the cerebral cortex and the cerebellum. Our data further demonstrate that acute CB(1) receptor activation under the cannabis extract condition may also affect intermanual coordination (IMC) as an index of interhemispheric transfer. AIR-Scale scores as a measure of subjective perception of intoxication were dose-dependently related to IMC which was shown by an inverted U-curve. This result may be due to functional changes involving GABAergic and glutamatergic neurotransmission within the corpus callosum.

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

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

Potential Endophenotype for Schizophrenia: Neurological Soft Signs

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Relation of neurological soft signs to psychiatric symptoms in schizophrenia

INTRODUCTION

Although several studies have identified abnormal rates of neurological soft signs (NSS) as a manifestation of CNS dysfunction in schizophrenia, differences in sample populations have contributed to a discrepancy in empirical findings. Furthermore, little is known about the potential of NSS to predict a clinical response to antipsychotic medications. The present study tests the associations between NSS and schizophrenia symptomatology and examines NSS as a potential marker for predicting treatment response.

METHODS

Nineteen unmedicated male schizophrenia patients were treated prospectively with haloperidol for six weeks. The subjects were assessed for pre and post-treatment NSS and schizophrenia symptomatology (Brief Psychiatric Rating Scale, BPRS).

RESULTS

NSS at baseline were significantly associated with baseline symptoms on the Positive, Negative, and Psychological Discomfort BPRS subscales. NSS showed a strong trend toward improvement during six weeks of a prospective haloperidol trial. Hierarchical linear regression analyses indicated that more severe baseline NSS predicted poorer response to haloperidol treatment as measured by post-treatment BPRS Total subscale scores.

DISCUSSION

NSS at untreated baseline are associated with baseline symptom severity, and elevated NSS are predictive of a smaller degree of improvement in symptoms after antipsychotic treatment. These findings are consistent with the hypothesis that NSS are linked to the neuropathology that underlies schizophrenia symptomatology and course.

Transcranial Magnetic Stimulation at M1 disrupts cognitive networks in schizophrenia

Transcranial Magnetic Stimulation (TMS) is rapidly gaining acceptance as a non-invasive probe into brain functionality. We utilize TMS to study the connectivity of a simple motor network in patients of schizophrenia (N=19), and in healthy control subjects (N=9). TMS was used in an externally paced finger tapping task, perturbing the internal network oscillations invoked by the finger motion as it keeps pace with a metronome. TMS perturbations were synchronized to the metronome and applied to the network at the level of the primary motor cortex (M1). Contrary to initial expectations, TMS did not affect the sensorimotor synchronization of subjects with schizophrenia or their tapping accuracy. TMS did cause extreme deviations in the finger's trajectory, and altered the timing perceptions of subjects with schizophrenia. Additionally, it invoked high-level deficiencies related to attention and volition in the form of lapses, implying that the connectivity between modules in the brain that underlie motor control, sensorimotor synchronization, timing perception and awareness of action, can be disrupted by TMS in subjects with schizophrenia, but not in healthy subjects. The ability to disrupt high level network functions with perturbations to the lower level of M1 supports models describing deficits in connectivity of distributed networks in the brains of schizophrenia patients. It also demonstrates the use of TMS to probe connectivity between components of such networks.

Psychomotor slowing in schizophrenia

Psychomotor slowing (PS) is a cluster of symptoms that was already recognized in schizophrenia by its earliest investigators. Nevertheless, few studies have been dedicated to the clarification of the nature and the role of the phenomenon in this illness. Moreover, slowed psychomotor functioning is often not clearly delineated from reduced processing speed. The current, first review of all existing literature on the subject discusses the key findings. Firstly, PS is a clinically observable feature that is most frequently established by neuropsychological measures assessing speed of fine movements such as writing or tasks that require rapid fingertip manipulations or the maintenance of maximal speed over brief periods of time in manual activities. Moreover, the slowed performance on the various psychomotor measures has been demonstrated independent of medication and has also been found to be associated with negative symptoms and, to a lesser extent, with positive and depressive symptoms. Importantly, performance on the psychomotor tasks proved related to the patients' social, clinical, and functional outcomes. Several imaging studies showed slowed performance to coincide with dopaminergic striatal activity. Finally, conventional neuroleptics do not improve the patients' PS symptoms, in contrast to the atypical agents that do seem to produce modestly improving effects.

Associations between schizotypal features and indicators of neurological and morphological abnormalities

OBJECTIVE

Limited research suggests that subtle neurological and morphological abnormalities that have been documented in patients with schizophrenia also may be associated with schizotypal traits in non-psychiatric samples. Based on the notion that neurological soft signs (NSS) may mark a genetic diathesis, this study hypothesized that NSS scores would be related to the level of schizotypy in relatives of schizophrenia patients and in controls. Additionally, associations between MPA scores and schizotypy were explored in these two groups.

METHOD

Twenty-six first-degree relatives of schizophrenia patients and 38 controls with no personal or family history of psychosis were assessed for schizotypy using the Structured Clinical Interview for DSM-IV Axis II Disorders schizotypal personality disorder module, as well as the self-administered Schizotypal Personality Questionnaire. The Neurological Evaluation Scale and a structured examination for MPAs also were administered.

RESULTS

Mean schizotypy scores did not differ between relatives and controls. Both NSS and MPAs were associated with the level of interviewer-assessed schizotypal features in controls but not in relatives of patients with schizophrenia. NSS and MPAs were not associated with self-reported schizotypy in either group.

CONCLUSIONS

These findings demonstrate that both NSS and MPAs are associated with interview-based schizotypal traits, at least in non-psychiatric participants. Future research should seek to replicate these results in other samples of relatives and controls.

Comparative study of neurological soft signs in schizophrenia with onset in childhood, adolescence and adulthood

OBJECTIVE

To compare neurological soft signs (NSS) in patients of schizophrenia with onset in childhood (COS), adolescence (AdOS) and adulthood (AOS).

METHOD

Assessment of NSS in 15 patients of COS and 20 patients each of AdOS and AOS was made using condensed neuropsychiatric examination for NSS.

RESULTS

NSS were significantly more frequent in COS (100%) and AdOS (90%) when compared with AOS (55%) patients. COS patients showed significantly higher scores on temporal and frontal lobe NSS, of which differences between the three groups in temporal lobe NSS disappeared on ancova. Parietal lobe dependent NSS were seen in a few COS patients. The NSS were more in those with lesser IQ, lower education and higher Positive and Negative Syndrome Scale scores.

CONCLUSION

Findings indicate that earlier onset types may be more strongly associated with a generalized disruption of brain function. Non-suppression of primitive reflexes with cortical maturation in COS point towards disordered neurodevelopment. Preponderance of fronto-temporal and a relative lack of parietal lobe NSS point towards differential lobar involvement. Neurodevelopmental abnormalities leading to NSS also lead to lower IQ and lower educational level.

The presence of neurological soft signs along the psychosis proneness continuum

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

Quantitative analysis of motor disturbances in schizophrenic patients

The presence of neurological signs and disturbed psychomotor performance have been consistently confirmed by clinical studies in schizophrenic patients. These parameters are mainly assessed by using clinical rating scales. In recent years, new approaches such as ultrasonic movement analysis systems have been introduced in order to objectively evaluate motor disturbances in schizophrenic patients. Ultrasonic movement analysis systems calculate the three-dimensional positions of tiny markers, which are attached to moving body parts, with high spatial and temporal resolution. Thus, key parameters of gait and hand movements can be determined precisely. This article summarizes and discusses several studies using these new methods. Results indicate that schizophrenia causes a specific motor deficit pattern, with a predominant disturbance of spatial parameters. Conventional antipsychotic treatment usually worsens these deficits, whereas the effects of atypical antipsychotic treatments are less pronounced. Disturbed motor performance can be normalized by external sensory stimuli, but only when no major attentional processes are required, and it can be enhanced by an attentional strategy, but not to the extent that motor parameters are normalized.

Factor structure of the Neurological Evaluation Scale in a predominantly African American sample of patients with schizophrenia, unaffected relatives, and non-psychiatric controls

OBJECTIVE

This study aimed to identify latent factors of the most widely used scale to measure neurological soft signs, the Neurological Evaluation Scale (NES), in a sample of schizophrenia patients, their relatives, and non-psychiatric controls.

METHOD

The NES was administered following the format and instructions of the original scale [Buchanan, R.W., Heinrichs, D.W., 1989. The Neurological Evaluation Scale (NES): a structured instrument for the assessment of neurological signs in schizophrenia. Psychiatry Res. 27, 335-350]. Three factor analyses were conducted using: (1) 23 items of the scale, (2) these 23 items in a sample restricted to African American participants, and (3) 12 items previously recommended based on adequate inter-rater reliability [Sanders, R.D., Forman, S.D., Pierri, J.N., Baker, R.W., Kelley, M.E., van Kammen, D.P., Keshavan, M.S., 1998. Inter-rater reliability of the neurological examination in schizophrenia. Schizophr. Res. 29, 287-292].

RESULTS

Exploratory factor analysis in the overall sample (n = 110) revealed three factors of interest: a "coordination/Romberg" factor (which included the fist-edge-palm test, finger-thumb opposition, rapid alternating movements, and the Romberg test), a "sensory integration" factor (which included synkinesis, extinction, stereognosis, and audio-visual integration), and an "eye movements/tandem walk/overflow movements" factor (which included convergence, gaze impersistence, tandem walk, and adventitious overflow). Minimal differences were apparent when comparing these results with those obtained from an analysis including only African American participants (n = 99). Restricting the analysis to only 12 items resulted in two factors (with poor discriminant validity and internal consistency), which showed few similarities with previously reported exploratory factor analysis results.

CONCLUSIONS

This study shows that results of empirically-derived factors of the NES vary substantially across study samples and research groups, though there appear to be at least two consistent latent variables, one related to the repetition of motor tasks and another tapping the processing of sensory stimuli. The factors demonstrated in the present study are more consistent with the original conceptually-derived subscales than prior factor analyses. Thus, until further research replicates consistent subscales of subtle neurological impairment in a variety of settings and samples, the total NES score may be more useful when comparing results across studies. Further research on latent neurological factors is needed.

Neurological soft signs, clinical symptoms and treatment reactivity in patients suffering from first episode schizophrenia

OBJECTIVE

(a) To investigate the correlation between clinical symptoms and neurological soft signs in patients suffering from their first episode of schizophrenia and (b) to examine the relationship between soft signs and the reactivity of first episode treatment.

METHODS

The trial included 92 male patients undergoing a first episode of schizophrenia. The clinical symptoms of the patients were rated on the positive and negative syndrome scale (PANSS). The PANSS scale was used to provide a measure for three syndromes: psychomotor poverty, disorganisation, and reality distortion. Neurological soft signs were assessed with the help of the neurological evaluation scale.

RESULTS

The findings corroborated significant positive correlations between soft neurological signs on the one hand and negative symptoms and reduced treatment response on the other.

CONCLUSION

Our study of the population of patients with first episode schizophrenia has corroborated the findings of those trials that found a correlation between neurological soft signs and the negative symptomatic dimension of schizophrenia. Another finding of the trial is that neurological soft signs were associated with poorer response to treatment of the first episode of schizophrenia.

Neurological abnormalities in schizophrenic twins

BACKGROUND

Neurological abnormalities (NAs) are well recognized in schizophrenia, though their genetic and environmental determinants, and pathophysiological significance, are poorly understood.

METHODS

Sixty-three twin pairs, varying in their zygosity and concordance for schizophrenia, and 73 unaffected control twin pairs were examined for total, primary and integrative NAs using the Neurological Evaluation Scale.

RESULTS

NAs were increased in probands with schizophrenia compared to nonschizophrenic co-twins and to healthy control twins but there were no significant differences between patients from the concordant and discordant pairs. NAs in the nonpsychotic co-twins from discordant pairs were increased compared to control twins. There were no significant differences in NAs between the nonschizophrenic co-twins from monozygotic (MZ) and dizygotic (DZ) discordant pairs, but the within pair correlations were greater in the MZ compared to DZ pairs. NAs were modified in all groups by pre-morbid schizotypal traits, and in patients by anti-psychotic medication.

CONCLUSIONS

NAs in schizophrenia are determined in part by genetic risk for the illness but the presence of premorbid schizotypal traits, and anti-psychotic medication confer additional risk for NAs.

Spontaneous dyskinesia and familial liability to schizophrenia

Several factors suggest that spontaneous dyskinesia may be a useful supplemental phenotype for further elucidating the specific nature of the genetic contribution to schizophrenia. For example, involuntary movement abnormalities have been observed in both medicated and unmedicated schizophrenia patients, in individuals with schizotypal personality disorder, and sometimes in siblings of schizophrenia patients. However, there are many inconsistencies present in the literature to date. The current study thus sought to investigate the existence of spontaneous dyskinesia in schizophrenia patient probands, their non-psychotic siblings, and healthy controls in order to clarify its potential value as an "endophenotype" in genetic studies of schizophrenia. Videotaped interviews were coded for the presence of spontaneous, involuntary movement abnormalities by a trained and reliable rater using computer assisted technology who was blind to group and family status. The results of this study indicated that siblings of schizophrenia patients did not display significantly more involuntary movements compared to controls, although tremor was observed in a few siblings. In contrast, schizophrenia patients did display significantly more involuntary movements compared to controls as well as their non-psychotic siblings. The lack of significant differences between siblings and controls argues against a strong association between spontaneous dyskinesia and an "unexpressed" genetic liability to schizophrenia. Thus, it appears that involuntary movement abnormalities may be limited in their utility as endophenotypes in genetic studies of schizophrenia, despite being associated with, and perhaps predictive of, schizophrenia itself.

The European First Episode Schizophrenia Trial (EUFEST): rationale and design of the trial

BACKGROUND

Most studies comparing second generation antipsychotics with classical neuroleptics have been conducted in more or less chronic schizophrenia patients. Such studies were usually conducted in highly selected samples, and were generally designed and financed by the manufacturer of the drug tested. These and other facts have stimulated discussions regarding the effectiveness of the new generation of antipsychotics.

AIMS

The aim of the European First Episode Schizophrenia Trial (EUFEST) is to compare treatment with amisulpride, quetiapine, olanzapine and ziprasidone to a low dose of haloperidol in an unselected sample of first episode schizophrenia patients with minimal prior exposure to antipsychotics.

METHODS

500 patients between the ages of 18-40 meeting DSM-IV criteria for schizophrenia, schizoaffective disorder or schizophreniform disorder are randomly allocated to one year of treatment with one of the drugs under study. The primary outcome measure is retention in treatment, defined as time to discontinuation of study drug. Loss of retention can be the result of insufficient clinical effect, or lack of tolerability or acceptance. Secondary measures include changes in different dimensions of psychopathology, side effects, compliance, social needs, quality of life, substance abuse and cognitive functions.

CONCLUSIONS

At present, more than 400 patients have been recruited and randomized in the following countries: Austria, Belgium, Bulgaria, Czech Republic, Germany, France, Israel, Italy, the Netherlands, Poland, Rumania, Spain, Sweden and Switzerland: The study should be finished by the end of 2006 and it is expected that results will yield relevant clinical information with regard to the effectiveness of the second generation antipsychotics. This effort represents the first independently designed trans-European schizophrenia treatment trial.

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

A 3-year prospective study of neurological soft signs in first-episode schizophrenia

Neurological soft signs are biological traits that underlie schizophrenia and are found to occur at higher levels in at-risk individuals. The expression of neurological soft signs may be modifiable during the onset of the first psychotic episode and the subsequent evolution of the illness and its treatment. This study investigates neurological soft signs in 138 patients with first-episode schizophrenia and tracks the expression of motor soft signs in the following 3 years. For the 93 patients who have completed the 3-year follow-up, we find that neurological soft signs are stable in the 3 years that follow the first psychotic episode, and that neurological soft signs are already elevated at the presentation of first-episode psychosis in medication-naive subjects. The level of neurological soft signs at clinical stabilization is lower for patients with a shorter duration of untreated psychosis. Although the quantity of neurological soft signs does not significantly change in the 3 years that follow the first episode, the relationship between neurological soft signs and negative symptoms does not become apparent until 1 year after the initial episode. A higher level of neurological soft signs is related to a lower educational level and an older age at onset, but the level of neurological soft signs does not predict the outcome in terms of relapse or occupational functioning.

Cortical release signs in psychiatry

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSIONS

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