This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
Detecting problems with motor coordination could be a simple way to predict the long-term severity of psychosis.
The Neurological Evaluation Scale (NES) is a quick and useful tool for examining sensory-motor issues such as restlessness, tremors, and problems with coordination and balance. A new study used the scale to assess patients after their first psychotic episode. It found that patients with more sensory-motor problems when first diagnosed had more severe long-term illness ten years later.
Researchers suggest that the NES could be used when people are experiencing their first psychotic episode. Patients with higher rates of motor coordination problems could then receive targeted, more intensive treatment.
What’s the issue?
People with psychosis lose some contact with reality. They may see or hear things that other people cannot (hallucinations) or believe things that are not true (delusions). The first time this happens, it can be a frightening and distressing experience.
Many people recover after a first episode of psychosis and never have another. Others need ongoing treatment with a combination of antipsychotic medicines, talking therapies and social support. Current assessments do not reliably predict the course of illness for the years after diagnosis which makes it difficult to target treatment and more intensive follow-up to those most likely to experience long-term symptoms.
Sensory-motor problems, or minor neurological signs, are subtle deficits in coordinating movements and processing sensations. These issues appear in the early stages of psychosis and are easy to recognise and assess. They are also seen in some first-degree relatives.
Previous studies have suggested that sensory-motor problems could predict long-term illness outcome. But, before this study, their stability as markers over extended periods of time had not been evaluated.
The research forms part of the Aetiology and Ethnicity in Schizophrenia and Other Psychoses (AESOP-10) study.
Researchers used the NES to evaluate sensory-motor function in 233 patients experiencing their first episode of psychosis. These patients were compared to a control group of 172 people without psychosis.
Ten years later, the course of psychosis was assessed. Researchers found that patients who initially presented with more sensory-motor problems went on to have a more severe illness and experience fewer periods of remission (when psychotic symptoms gradually disappear).
In a subgroup of 56 patients, researchers looked for changes in sensory-motor problems over time. They found that sensory problems (such as processing sights and sounds) increased, regardless of whether the illness progressed. Motor coordination problems (such as balance) remained constant. These problems were worse in people who went on to have ongoing psychosis than in those who recovered or who never had psychosis (healthy controls). They were also quick and easy to detect.
This suggests that, when someone is first diagnosed with psychosis, a test of motor coordination may predict whether psychosis will be severe and ongoing.
The level of sensory-motor problems was not linked to the type or amount of antipsychotic medication. Nor was it linked to the use of psychotropic drugs like cannabis or amphetamines. This suggests that differences in sensory-motor problems are linked directly to the illness and are not caused by antipsychotics or drug use.
Why is this important?
The extent of patients’ motor coordination problems at the onset of psychosis can inform clinicians on the likely long-term severity of the illness.
People with psychosis undergo extensive assessments involving multiple mental health professionals, blood tests and sometimes scans when they enter care. But evaluating sensory-motor function using the NES is quick, easy, and cheap. It could provide clinicians with a tool for predicting long-term outcomes. Its use could help identify the most vulnerable patients for targeted and more intensive treatment.
More comprehensive follow-up with these patients could ensure they are receiving appropriate treatment. Extra support could check for issues such as effectiveness of treatment, side-effects, and adherence. These patients could receive more support in the community and benefit from occupational interventions.
Sensory-motor problems could also influence the choice of antipsychotics. Doctors could consider not prescribing certain medications to patients with more pronounced sensory-motor problems.
This study is the first to report on long-term neurological changes following the first psychotic episode. This work now needs to be evaluated in larger groups of patients and follow how other measures of psychosis change over time.
A more in-depth understanding of the relationship between sensory-motor problems and the progression of psychosis could help identify the most vulnerable patients who may need more intensive treatment over the longer term.
You may be interested to read
The full paper: Ferruccio NP, and others. Neurological Signs at the First Psychotic Episode as Correlates of Long-Term Outcome: Results From the AESOP-10 Study. Schizophrenia Bulletin. 2020. doi: 10.1093/schbul/sbaa089
First episode psychosis: an information guide, Centre for Addiction and Mental Health 2015
Another paper exploring neurological signs as predictors of outcome: Cuesta MJ, and others. Motor abnormalities in first-episode psychosis patients and long-term psychosocial functioning. Schizophr Res. 2018;200:97-103
Review of the links between motor abnormalities and psychosis: van Harten PN, and others. The clinical and prognostic value of motor abnormalities in psychosis, and the importance of instrumental assessment. Neurosci Biobehav Rev. 2017;80:476-487
Paper which used the Neurological Evaluation Scale in schizophrenia: Emsley R, and others. Neurological soft signs in first-episode schizophrenia: State- and trait-related relationships to psychopathology, cognition and antipsychotic medication effect. Schizophr Res. 2017;188:144-150
Funding: This research was supported by the UK Medical Research Council and the NIHR Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London.
Conflicts of Interest: The study authors declare no conflicts of interest.
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