Characterization of spontaneous Parkinsonism in drug-naive patients with nonaffective psychotic disorders

Manual dexterity and grip force are distinctly linked to domains of neurological soft signs in schizophrenia spectrum disorders

Motor abnormalities are highly prevalent among patients with schizophrenia spectrum disorders. Very likely, motor control processes, such as dexterity and grip force (GF), are impaired in schizophrenia. We aimed to explore associations between various motor abnormalities and motor control processes and to investigate whether specific motor abnormalities predict the performance of fine motor movements and GF. Our analyses included 198 patients with schizophrenia spectrum disorders. We applied well-established standardized motor rating scales to assess five different motor abnormalities: psychomotor slowing (PS), neurological soft signs (NSS), parkinsonism, catatonia, and dyskinesia. As a measure of manual dexterity, we used the coin rotation (CR) task, requiring patients to rotate a coin between their thumb, index, and middle finger. Maximal grip strength was measured with the GF task. Correlation analyses revealed that both CR and GF performances were associated with different motor abnormalities, most strongly with NSS (CR: tau = -0.263, p < 0.001; GF: tau = -0.208, p < 0.001). Hierarchical regression showed that NSS predicted performance on the CR and GF task better compared to PS, parkinsonism, and catatonia alone (CR: ∆R2 = 0.09, F = 22.26, p < 0.001; GF: ∆R2 = 0.02, F = 6.61, p < 0.001). When looking within the NSS domains, CR performance was predicted better by motor coordination and sequencing of motor acts, whereas GF was predicted better by sensory integration. Motor control processes are influenced by different motor abnormalities, especially NSS. Our results suggest that distinct aspects of NSS affect fine motor movements and GF. This knowledge is important for designing specific novel interventions aimed at improving specific motor control processes.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

From one to many: Hypertonia in schizophrenia spectrum psychosis an integrative review and adversarial collaboration report

Different types of resistance to passive movement, i.e. hypertonia, were described in schizophrenia spectrum disorders (SSD) long before the introduction of antipsychotics. While these have been rediscovered in antipsychotic-naïve patients and their non-affected relatives, the existence of intrinsic hypertonia vs drug-induced parkinsonism (DIP) in treated SSD remains controversial. This integrative review seeks to develop a commonly accepted framework to specify the putative clinical phenomena, highlight conflicting issues and discuss ways to challenge each hypothesis and model through adversarial collaboration. The authors agreed on a common framework inspired from systems neuroscience. Specification of DIP, locomotor paratonia (LMP) and psychomotor paratonia (PMP) identified points of disagreement. Some viewed parkinsonian rigidity to be sufficient for diagnosing DIP, while others viewed DIP as a syndrome that should include bradykinesia. Sensitivity of DIP to anticholinergic drugs and the nature of LPM and PMP were the most debated issues. It was agreed that treated SSD should be investigated first. Clinical features of the phenomena at issue could be confirmed by torque, EMG and joint angle measures that could help in challenging the selectivity of DIP to anticholinergics. LMP was modeled as the release of the reticular formation from the control of the supplementary motor area (SMA), which could be challenged by the tonic vibration reflex or acoustic startle. PMP was modeled as the release of primary motor cortex from the control of the SMA and may be informed by subclinical echopraxia. If these challenges are not met, this would put new constraints on the models and have clinical and therapeutic implications.

The Behavioral Mapping of Psychomotor Slowing in Psychosis Demonstrates Heterogeneity Among Patients Suggesting Distinct Pathobiology

OBJECTIVES

Psychomotor slowing (PS) occurs in up to half of schizophrenia patients and is linked to poorer outcomes. As standard treatment fails to improve PS, novel approaches are needed. Here, we applied the RDoC framework using 3 units of analysis, ie, behavior, self-report, and physiology to test, whether patients with PS are different from patients without PS and controls.

METHODS

Motor behavior was compared between 71 schizophrenia patients with PS, 25 without PS, and 42 healthy controls (HC) using 5 different measures: (1) for behavior, an expert rating scale: Motor score of the Salpêtrière Retardation Rating Scale, (2) for self-report, the International Physical Activity Questionnaire; and for physiology, (3) Actigraphy, which accounts for gross motor behavior, (4) Gait velocity, and (5) coin rotation task to assess manual dexterity.

RESULTS

The ANCOVAs comparing the 3 groups revealed differences between patients with PS and HC in expert ratings, self-report, and instrumental measures (all P ≤ .001). Patients with PS also scored higher in expert ratings and had lower instrumental activity levels compared to patients without PS (all P ≤ .045). Instrumental activity levels correlated with an expert rating of PS (rho = -0.51, P-fdr corrected <.001) and classified similarly at 72% accuracy.

CONCLUSIONS

PS is characterized by slower gait, lower activity levels, and slower finger movements compared to HC. However, only actigraphy and observer ratings enable to clearly disentangle PS from non-PS patients. Actigraphy may become the standard assessment of PS in neuroimaging studies and clinical trials.

Low physical activity is associated with two hypokinetic motor abnormalities in psychosis

Individuals with schizophrenia engage in more sedentary behavior than healthy controls, which is thought to contribute to multiple health adversities. Age, medication side effects and environment are critical determinants of physical activity in psychosis. While motor abnormalities are frequently observed in psychosis, their association with low physical activity has received little interest. Here, we aimed to explore the association of actigraphy as an objective measure of physical activity with clinician assessed hypokinetic movement disorders such as parkinsonism and catatonia. Furthermore, we studied whether patients with current catatonia would differ on motor rating scales and actigraphy from patients without catatonia. In 52 patients with schizophrenia spectrum disorders, we cross-sectionally assessed physical activity using wrist actigraphy and ratings of catatonia, parkinsonism, and negative syndrome. The sample was enriched with subjects with severe psychomotor slowing. Lower activity levels correlated with increased age and severity of catatonia and parkinsonism. The 22 patients with catatonia had lower activity as well as higher scores on parkinsonism, involuntary movements, and negative symptoms compared to the 30 patients without catatonia. Collectively, these results suggest that various hypokinetic motor abnormalities are linked to lower physical activity. Therefore, future research should determine the direction of the associations between hypokinetic motor abnormalities and physical activity using longitudinal assessments and interventional trials.

Characterizing the sensorimotor domain in schizophrenia spectrum disorders

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

Structural alterations in brainstem, basal ganglia and thalamus associated with parkinsonism in schizophrenia spectrum disorders

The relative roles of brainstem, thalamus and striatum in parkinsonism in schizophrenia spectrum disorder (SSD) patients are largely unknown. To determine whether topographical alterations of the brainstem, thalamus and striatum contribute to parkinsonism in SSD patients, we conducted structural magnetic resonance imaging (MRI) of SSD patients with (SSD-P, n = 35) and without (SSD-nonP, n = 64) parkinsonism, as defined by a Simpson and Angus Scale (SAS) total score of ≥ 4 and < 4, respectively, in comparison with healthy controls (n = 20). FreeSurfer v6.0 was used for segmentation of four brainstem regions (medulla oblongata, pons, superior cerebellar peduncle and midbrain), caudate nucleus, putamen and thalamus. Patients with parkinsonism had significantly smaller medulla oblongata (p = 0.01, false discovery rate (FDR)-corrected) and putamen (p = 0.02, FDR-corrected) volumes when compared to patients without parkinsonism. Across the entire patient sample (n = 99), significant negative correlations were identified between (a) medulla oblongata volumes and both SAS total (p = 0.034) and glabella-salivation (p = 0.007) scores, and (b) thalamic volumes and both SAS total (p = 0.033) and glabella-salivation (p = 0.007) scores. These results indicate that brainstem and thalamic structures as well as basal ganglia-based motor circuits play a crucial role in the pathogenesis of parkinsonism in SSD.

White matter microstructure alterations in cortico-striatal networks are associated with parkinsonism in schizophrenia spectrum disorders

The specific role of white matter (WM) microstructure in parkinsonism among patients with schizophrenia spectrum disorders (SSD) is largely unknown. To determine whether topographical alterations of WM microstructure contribute to parkinsonism in SSD patients, we examined healthy controls (HC, n=16) and SSD patients with and without parkinsonism, as defined by Simpson-Angus Scale total score of ≥4 (SSD-P, n=33) or <4 (SSD-nonP, n=62). We used whole brain tract-based spatial statistics (TBSS), tractometry (along tract statistics using TractSeg) and graph analytics (clustering coefficient (CCO), local betweenness centrality (BC)) to provide a framework of specific WM microstructural changes underlying parkinsonism in SSD. Using these methods, post hoc analyses showed (a) decreased fractional anisotrophy (FA), as measured via tractometry, in the corpus callosum, corticospinal tract and striato-fronto-orbital tract, and (b) increased CCO, as derived by graph analytics, in the left orbitofrontal cortex (OFC) and left superior frontal gyrus (SFG), in SSD-P patients when compared to SSD-nonP patients. Increased CCO in the left OFC and SFG was associated with SAS scores. These findings indicate the prominence of OFC alterations and aberrant connectivity with fronto-parietal regions and striatum in the pathogenesis of parkinsonism in SSD. This study further supports the notion of altered "bottom-up modulation" between basal ganglia and fronto-parietal regions in the pathobiology of parkinsonism, which may reflect an interaction between movement disorder intrinsic to SSD and antipsychotic drug-induced sensorimotor dysfunction.

Emerging concepts on bradykinesia in non-parkinsonian conditions

BACKGROUND AND PURPOSE

Bradykinesia is one of the cardinal motor symptoms of Parkinson's disease. However, clinical and experimental studies indicate that bradykinesia may also be observed in various neurological diseases not primarily characterized by parkinsonism. These conditions include hyperkinetic movement disorders, such as dystonia, chorea, and essential tremor. Bradykinesia may also be observed in patients with neurological conditions that are not seen as "movement disorders," including those characterized by the involvement of the cerebellum and corticospinal system, dementia, multiple sclerosis, and psychiatric disorders.

METHODS

We reviewed clinical reports and experimental studies on bradykinesia in non-parkinsonian conditions and discussed the major findings.

RESULTS

Bradykinesia is a common motor abnormality in non-parkinsonian conditions. From a pathophysiological standpoint, bradykinesia in neurological conditions not primarily characterized by parkinsonism may be explained by brain network dysfunction.

CONCLUSION

In addition to the pathophysiological implications, the present paper highlights important terminological issues and the need for a new, more accurate, and more widely used definition of bradykinesia in the context of movement disorders and other neurological conditions.

Stability of Action and Kinesthetic Perception in Parkinson's Disease

We present a review of action and perception stability within the theoretical framework based on the idea of control with spatial referent coordinates for the effectors at a number of hierarchical levels. Stability of salient variables is ensured by synergies, neurophysiological structures that act in multi-dimensional spaces of elemental variables and limit variance to the uncontrolled manifold during action and iso-perceptual manifold during perception. Patients with Parkinson’s disease show impaired synergic control reflected in poor stability (low synergy indices) and poor agility (low indices of anticipatory synergy adjustments prior to planned quick actions). They also show impaired perception across modalities, including kinesthetic perception. We suggest that poor stability at the level of referent coordinates can be the dominant factor leading to poor stability of percepts.

A Neural Signature of Parkinsonism in Patients With Schizophrenia Spectrum Disorders: A Multimodal MRI Study Using Parallel ICA

Motor abnormalities in schizophrenia spectrum disorders (SSD) have increasingly attracted scientific interest in the past years. However, the neural mechanisms underlying parkinsonism in SSD are unclear. The present multimodal magnetic resonance imaging (MRI) study examined SSD patients with and without parkinsonism, as defined by a Simpson and Angus Scale (SAS) total score of ≥4 (SAS group, n = 22) or <4 (non-SAS group, n = 22). Parallel independent component analysis (p-ICA) was used to examine the covarying components among gray matter volume maps computed from structural MRI (sMRI) and fractional amplitude of low-frequency fluctuations (fALFF) maps computed from resting-state functional MRI (rs-fMRI) patient data. We found a significant correlation (P = .020, false discovery rate [FDR] corrected) between an sMRI component and an rs-fMRI component, which also significantly differed between the SAS and non-SAS group (P = .042, z = -2.04). The rs-fMRI component comprised the cortical sensorimotor network, and the sMRI component included predominantly a frontothalamic/cerebellar network. Across the patient sample, correlations adjusted for the Positive and Negative Syndrome Scale (PANSS) total scores showed a significant relationship between tremor score and loadings of the cortical sensorimotor network, as well as between glabella-salivation score, frontothalamic/cerebellar and cortical sensorimotor network loadings. These data provide novel insights into neural mechanisms of parkinsonism in SSD. Aberrant bottom-up modulation of cortical motor regions may account for these specific motor symptoms, at least in patients with SSD.

Neurological Soft Signs, Spontaneous and Treatment Emergent Extrapyramidal Syndromes in Black Africans With First Episode Schizophrenia

Background: Very little is known about the relationship between spontaneous and treatment-induced motor syndromes in Africans with first episode schizophrenia. Objective: We investigated the association between spontaneous NSS and EPS, with treatment-induced EPS in a homogenous sample of Black Africans with first episode schizophrenia. Methods: We examined Xhosa (South Africa) and Yoruba (Nigeria) patients, using the Neurological Evaluation Scale and extrapyramidal symptoms scale before and at 3 months after exposure to low dose flupenthixol decanoate. Pearson's correlations and Linear regression models, controlling for duration of untreated psychosis (D.U.P) and premorbid adjustments, were used in examining associations. Results: Among 99 participants in the baseline sample, 91 (91.8%) and 20 (20.2%) had at least one definite NSS and EPS, respectively, before exposure to antipsychotics. Treatment-induced EPS were recorded in 34 (38.6%). Spontaneous EPS was associated with treatment-emergent Akathisia in participants with a longer D.U.P (r = 0.75, β = 0.70, p = 0.008). This association was specific for Parkinsonism (r = 0.75, β = 0.85, p = 0.008) and dyskinesia (r = 0.75, β = 1.70, p = 0.008). Conclusion: Similar to previous findings for tardive dyskinesia in studies implementing longer-term follow-up, spontaneous EPS may also predict short-term antipsychotic-induced EPS such as akathisia. These results may be important for early identification of patients at risk of treatment-induced Akathisia-linked psychomotor agitation in first episode schizophrenia.

Evaluating subjective domains of antipsychotic-induced adverse effects using heart rate variability

AIMS

Antipsychotic-induced autonomic dysregulation may lead to a wide range of subjective side-effects in schizophrenia patients. Using heart rate variability (HRV) measures, we prospectively examined the relationship between subjective side-effects and cardiac autonomic regulation in unmedicated schizophrenia patients.

METHODS

Forty-five unmedicated schizophrenia patients were assessed for antipsychotic-associated side-effects and HRV parameters at baseline and after 6 weeks of treatment. Psychiatric symptoms and subjective side-effects were assessed using the Positive and Negative Syndrome Scale (PANSS) and the Liverpool University Neuroleptic Side-effect Rating Scale (LUNSERS).

RESULTS

Correlations between subjective adverse effects and HRV measures at baseline and at week 6 varied. Nonetheless, the changes in the psychic side-effects domain were significantly correlated with the changes in time-domain HRV measures and sample entropy (SampEn). In addition, the change in SampEn was significantly associated with that in the scores of extrapyramidal, anticholinergic, miscellaneous, and red herring domains as well as the mean total LUNSERS score.

CONCLUSION

Baseline HRV measures may predict clinical response and adverse events associated with treatment adherence. Also, subjective side-effects may correspond well with the changes in neurocardiac dynamics, and the changes in SampEn may effectively reflect subjective discomfort in patients receiving antipsychotic treatment.

Spontaneous parkinsonism is associated with cognitive impairment in antipsychotic-naive patients with first-episode psychosis: a 6-month follow-up study

There is now growing evidence that parkinsonism and other extrapyramidal signs are highly prevalent in patients with first-episode psychosis who have never been exposed to antipsychotic drugs. However, the neurocognitive correlates of parkinsonism in this population remained to be clarified. A sample comprising 100 consecutive drug-naive patients with first-episode psychosis were enrolled on the study and followed up for 6 months. Seventy-seven completed assessments at 3 time points (baseline, 1 mo, and 6 mo), involving clinical and cognitive examinations and a specific assessment of motor abnormalities. The Simpson-Angus Scale (SAS) was used for the assessment of extrapyramidal signs, and each motor domain was evaluated with a standard assessment scale. Linear mixed models were built to explore the longitudinal relationships between parkinsonism scores and cognitive impairment. Parkinsonism scores showed significant strong longitudinal associations with deficits in memory, executive functioning, and attention. Spontaneous parkinsonism (total SAS score and hypokinesia and rigidity subscores at baseline) showed high 6-month predictive values for cognitive impairment. In addition, they also had high predictive values for neurologic soft-sign abnormalities but not for dyskinesia, akathisia, and pure catatonic abnormalities. No predictive value was found for glabella-salivation or tremor subscores on the SAS scale. These results emphasize the relevance of the assessment of parkinsonism signs prior to starting to administer antipsychotic drugs, as core manifestations of psychotic illness with a high predictive value for cognitive impairment.

[First-episodes psychosis: clinical and epidemiological news]

In the context of the development of early intervention for first-episode psychosis, this manuscript reviews new data with respect to its incidence, risk factors and evolution. Annual incidence of non-affective psychosis appeared to be between 14 and 30/100,000 in people aged 18-64. Incidence decreases with age and is twice higher in men than in women. There is an interaction between age and gender; the risk of psychosis decreases with age faster in men than in women. Thus, for schizophrenia, incidence rate is twice higher in men under 45 year-old and similar in both genders after. There is evidence that genetic and environmental factors may cause enduring liability to psychotic disorder, and, in addition, that genes and environment may interact synergistically. Some environmental factors have been identified; they concern foetal life, childhood or adolescence and may be conceptualized at the individual or the contextual level. The definition of recent onset psychosis may be based on duration of psychosis, between two and five years. Its development is identified through the occurrence of major psychotic symptoms, such as positive, negative symptomatology or disorganization, and impairment of social functioning. The types and patterns of occurrence and of evolution of psychotic symptoms have a prognostic impact. A long duration of untreated psychosis impacts symptomatology. It is associated with less severe positive symptoms at baseline and more severe after three years, insidious onset, male gender, early onset, and diagnosis of schizophrenia. Recent onset psychosis is often associated with comorbidities, such as depression, anxiety disorders, suicidal behaviours, and addiction. Symptomatic remission rates are found between 25 and 60%. Symptomatic and functional remissions favour each other. A third to half of patients is active, employed or students. Symptoms and evolution are various in studies, probably corresponding to various patho-physiological mechanisms.

[Minor neurological and physical anomalies in patients with first-episode psychosis]

INTRODUCTION

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.

AIMS OF THE STUDY

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.

METHOD

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).

RESULTS

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.

CONCLUSION

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.