Reduced readiness potential and post-movement beta synchronization reflect self-disorders in early course schizophrenia.
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ABSTRACT:
SUBMITTER: Donati FL
PROVIDER: S-EPMC8298598 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Schizophrenia patients exhibit well-documented visual processing deficits. One area of disruption is visual integration, the ability to form global objects from local elements. However, most studies of visual integration in schizophrenia have been conducted in the context of an active attention task, which may influence the findings. In this study we examined visual integration using electroencephalography (EEG) in a passive task to elucidate neural mechanisms associated with poor visual integration. Forty-six schizophrenia patients and 30 healthy controls had EEG recorded while passively viewing figures comprised of real, illusory, or no contours. We examined visual P100, N100, and P200 event-related potential (ERP) components, as well as neural synchronization in the gamma (30-60 Hz) band assessed by the EEG phase locking factor (PLF). The N100 was significantly larger to illusory vs. no contour, and illusory vs. real contour stimuli while the P200 was larger only to real vs. illusory stimuli; there were no significant interactions with group. Compared to controls, patients failed to show increased phase locking to illusory versus no contours between 40-60 Hz. Also, controls, but not patients, had larger PLF between 30-40 Hz when viewing real vs. illusory contours. Finally, the positive symptom factor of the BPRS was negatively correlated with PLF values between 40-60 Hz to illusory stimuli, and with PLF between 30-40 Hz to real contour stimuli. These results suggest that the pattern of results across visual processing conditions is similar in patients and controls. However, patients have deficits in neural synchronization in the gamma range during basic processing of illusory contours when attentional demand is limited.
| S-EPMC4364708 | biostudies-literature
Project description:BACKGROUND:Symptoms of psychosis in schizophrenia reflect disturbances in sense of agency-difficulty distinguishing internally from externally generated sensory and perceptual experiences. One theory attributes these anomalies to a disruption in corollary discharge (CD), an internal copy of generated motor commands used to distinguish self-movement-generated sensations from externally generated stimulation. METHODS:We used a transsaccadic shift detection paradigm to examine possible deficits in CD and sense of agency based on the ability to perceive visual changes in 31 schizophrenia patients (SZPs) and 31 healthy control subjects. We derived perceptual measures based on manual responses indicating the transsaccadic target shift direction. We also developed a distance-from-unity-line measure to quantify use of CD versus purely sensory (visual) information in evaluating visual changes in the environment after an eye movement. RESULTS:SZPs had higher perceptual thresholds in detecting shift of target location than healthy control subjects, regardless of movement direction or amplitude. Despite producing similar hypometric saccades, healthy control subjects overestimated target location, whereas SZPs relied more on the experienced visual error and consequently underestimated the target position. We show that in SZPs the postsaccadic judgment of the initial target location was largely aligned with the measure based only on visual error, suggesting a deficit in the use of CD. This CD deficit also correlated with positive schizophrenia symptoms and disturbances in sense of agency. CONCLUSIONS:These results provide a novel approach in quantifying abnormal use of CD in SZPs and provide a framework to distinguish deficits in sensory processing versus defects in the internal CD-based monitoring of movement.
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Project description:Temporal cues are important for discerning word boundaries and syllable segments in speech; their perception facilitates language acquisition and development. Beat synchronization and neural encoding of speech reflect precision in processing temporal cues and have been linked to reading skills. In poor readers, diminished neural precision may contribute to rhythmic and phonological deficits. Here we establish links between beat synchronization and speech processing in children who have not yet begun to read: preschoolers who can entrain to an external beat have more faithful neural encoding of temporal modulations in speech and score higher on tests of early language skills. In summary, we propose precise neural encoding of temporal modulations as a key mechanism underlying reading acquisition. Because beat synchronization abilities emerge at an early age, these findings may inform strategies for early detection of and intervention for language-based learning disabilities.
| S-EPMC4210020 | biostudies-literature
Project description:Understanding whether and how the schizophrenia polygenic risk score (SZ PRS) predicts course of illness could improve diagnosis and prognostication in psychotic disorders. We tested whether the SZ PRS predicts symptoms, cognition, illness severity, and diagnostic changes over the 20 years following first admission. The Suffolk County Mental Health Project is an inception cohort study of first-admission patients with psychosis. Patients were assessed six times over 20 years, and 249 provided DNA. Geographically- and demographically-matched never psychotic adults were recruited at year 20, and 205 provided DNA. Symptoms were rated using the Schedule for the Assessment of Positive Symptoms and Schedule for the Assessment of Negative Symptoms. Cognition was evaluated with a comprehensive neuropsychological battery. Illness severity and diagnosis were determined by consensus of study psychiatrists. SZ PRS was significantly higher in first-admission than never psychotic groups. Within the psychosis cohort, the SZ PRS predicted more severe negative symptoms (??=?0.21), greater illness severity (??=?0.28), and worse cognition (??=?-0.35), across the follow-up. The SZ PRS was the strongest predictor of diagnostic shifts from affective to non-affective psychosis over the 20 years (AUC?=?0.62). The SZ PRS predicts persistent differences in cognition and negative symptoms. The SZ PRS also predicts who among those who appear to have a mood disorder with psychosis at first admission will ultimately be diagnosed with a schizophrenia spectrum disorder. These findings show potential for the SZ PRS to become a tool for diagnosis and treatment planning.
| S-EPMC6856168 | biostudies-literature
Project description:IntroductionBasic self-disorders on the one hand and motor symptoms on the other hand are discussed as endophenotypes of schizophrenia psychopathology. However, the systematic interaction between motor symptoms and the self-experience of patients is rarely studied.MethodsIn a previous study we defined motor markers of schizophrenia via a data-driven analysis of patients' gait patterns. In this study, we related the movement markers to measures of basic self-disorder obtained with EASE interviews. We substantiated the correlations with a qualitative content analysis of the interviews of a subset of four patients. We related qualitative and quantitative data on an intra- and interpersonal level.ResultsOur results suggest an association between the previously defined, theory-independent movement markers and basic self-disorders, specifically in the domain of cognition, self-experience and bodily experiences. While movement marker manifestation was not precisely reflected in the individuals' descriptions of anomalous self- and body experience, we found clear trends of more and more intense descriptions with increasing movement marker scores, when looking at specific experiences, such as hyper reflexivity.DiscussionThese results foster an integrated view of the patient and could stimulate therapeutic approaches aiming at an improvement of self- and body-experience of patients with schizophrenia.
| S-EPMC10319999 | biostudies-literature
Project description:ObjectiveThis proof-of-concept feasibility trial examined the potential of the Cognitive Orientation to daily Occupational Performance Approach (CO-OP) to augment deep brain stimulation (DBS) outcomes in childhood-onset hyperkinetic movement disorders (HMD) including dystonia and dyskinetic cerebral palsy.MethodsThis is a single case experimental design using multiple baseline as n-of-1 trial comprising 10 intervention sessions, with replications across participants (n = 10). Treatment focused on 3 participant-selected goals. Transfer was assessed on 2 additional untreated goals. Individuals enrolled were 6-21 years of age and had DBS in situ and sufficient manual ability. Primary outcome was functional performance change on the Performance Quality Rating Scale-Individualized (PQRS-i) measured before, during, and posttreatment, and at 3-month follow-up. Assessors of outcome were blinded to time of assessment, number of intervention session, and treatment allocation. To measure effect size, a nonoverlapping index, Tau-U, was used. Feasibility measures were captured.ResultsOne participant withdrew before baseline assessment. Effect sizes of at least 0.66 were seen at both posttreatment and follow-up with all participants showing improvements in at least one trained goal in PQRS-i. Six participants improved on all 3 goals and 2 improved on 2 trained goals. Two children showed deterioration in one trained goal each. Transfer to untrained goals was observed in 3 participants for a total of 5 goals. CO-OP was feasible and acceptable to all participants.ConclusionA cognitive-based, task-oriented approach to support performance of personally relevant functional skills enabling participation is acceptable in childhood-onset HMD post-DBS. Further, preliminary efficacy to improve outcomes and proof of concept with CO-OP has been established in this population.Classification of evidenceThis study provides Class IV evidence that for children with HMD who had undergone DBS, CO-OP improves performance of personally relevant functional skills.
| S-EPMC6511104 | biostudies-literature
Project description:For years, phenomenological psychiatry has proposed that distortions of the temporal structure of consciousness contribute to the abnormal experiences described before schizophrenia emerges, and may relate to basic disturbances in consciousness of the self. However, considering that temporality refers mainly to an implicit aspect of our relationship with the world, disturbances in the temporal structure of consciousness remain difficult to access. Nonetheless, previous studies have shown a correlation between self disorders and the automatic ability to expect an event in time, suggesting timing is a key issue for the psychopathology of schizophrenia. Timing disorders may represent a target for cognitive remediation, but this requires that disorders can be demonstrated at an individual level. Since cognitive impairments in patients with schizophrenia are discrete, and there is no standardized timing exploration, we focused on timing impairments suggested to be related to self disorders. We present the case report of AF, a 22 year old man suffering from schizophrenia, with no antipsychotic intake. Although AF shows few positive and negative symptoms and has a normal neurocognitive assessment, he shows a high level of disturbance of Minimal Self Disorders (SDs) (assessed with the EASE scale). Moreover, AF has a rare ability to describe his self and time difficulties. An objective assessment of timing ability (variable foreperiod task) confirmed that AF had temporal impairments similar to those previously described in patients, i.e., a preserved ability to distinguish time intervals, but a difficulty to benefit from the passage of time to expect a visual stimulus. He presents additional difficulties in benefitting from temporal cues and adapting to changes in time delays. The impairments were ample enough to yield significant effects with analyses at the individual level. Although causal relationships between subjective and objective impairments cannot be established, the results show that exploring timing deficits at the individual level is possible in patients with schizophrenia. Besides, the results are consistent with hypotheses relating minimal self disorders (SDs) to timing difficulties. They suggest that both subjective and objective timing investigations should be developed further so that their use at an individual level can be generalized in clinical practice.
| S-EPMC5900747 | biostudies-literature
Project description:ObjectiveTo investigate the neural mechanisms underlying impaired self-agency in patients with functional movement disorders using resting-state functional MRI (fMRI).MethodsWe obtained resting-state fMRI on 35 patients with clinically definite functional movement disorders and 35 age- and sex-matched healthy controls. Between-group differences in functional connectivity from the right temporo-parietal junction (TPJ), a region previously demonstrated to play a critical role in self-agency by comparing internal predictions of movement with actual external events, were assessed using t tests. All participants were screened for psychiatric diagnoses using a structured clinical interview and completed the Beck Depression Inventory and Childhood Trauma Questionnaire.ResultsCompared to the healthy controls, patients with functional movement disorders showed decreased functional connectivity between the right TPJ and the right sensorimotor cortex, cerebellar vermis, bilateral supplementary motor area, and right insula. These findings were independent of depression, anxiety, and childhood trauma scores included in our assessment as covariates.ConclusionsThe decreased functional connectivity between the right TPJ and bilateral sensorimotor regions observed in patients with functional movement disorders supports a model whereby impaired motor feed-forward together with altered sensory feedback from sensorimotor regions and areas of sensorimotor integration to the right TPJ contributes to patients' impaired sense of self-agency.
| S-EPMC4977370 | biostudies-literature
Project description:Peripheral trauma may be a trigger for the development of various movement disorders though the pathophysiology remains controversial and some of these patients have a functional (psychogenic) disorder. We report 3 cases of shoulder movement disorders following trauma to the shoulder region. Physiology was done in all the patients to extend the physical examination. Two patients had history of recurrent shoulder dislocation and were diagnosed with Ehlers-Danlos syndrome. One patient had shoulder injury following repeated falls while performing as a cheerleader. In two patients there were some clinical features suggesting a functional etiology, but physiological studies in all three failed to produce objective evidence of a functional nature. Shoulder movement following trauma is uncommon. Diagnosis in such cases is challenging considering the complex pathophysiology. The movements can be associated with prolonged pain and handicap, and once established they appear resistant to treatment.
| S-EPMC4151852 | biostudies-literature
Project description:ADCY5 mutations have been recently identified as an important cause of early-onset hyperkinetic movement disorders. The phenotypic spectrum associated with mutations in this gene is expanding. However, the ADCY5 mutational frequency in cohorts of paediatric patients with hyperkinetic movement disorders has not been evaluated.We performed a screening of the entire ADCY5 coding sequence in 44 unrelated subjects with genetically undiagnosed childhood-onset hyperkinetic movement disorders, featuring chorea alone or in combination with myoclonus and dystonia. All patients had normal CSF analysis and brain imaging and were regularly followed-up in tertiary centers for paediatric movement disorders.We identified five unrelated subjects with ADCY5 mutations (11% of the cohort). Three carried the p. R418W mutation, one the p. R418Q and one the p. R418G mutation. Mutations arose de novo in four cases, while one patient inherited the mutation from his similarly affected father. All patients had delayed motor and/or language milestones with or without axial hypotonia and showed generalized chorea and dystonia, with prominent myoclonic jerks in one case. Episodic exacerbations of the baseline movement disorder were observed in most cases, being the first disease manifestation in two patients. The disease course was variable, from stability to spontaneous improvement during adolescence.Mutations in ADCY5 are responsible for a hyperkinetic movement disorder that can be preceded by episodic attacks before the movement disorder becomes persistent and is frequently misdiagnosed as dyskinetic cerebral palsy. A residual degree of neck hypotonia and a myopathy-like facial appearance are frequently observed in patients with ADCY5 mutations.
| S-EPMC5549507 | biostudies-literature