Accelerated rTMS for Psychomotor Slowing

Schizophrenia is a chronic disorder causing tremendous burden to the patients, families, and society. Besides prominent symptoms such as hallucinations, delusions, and thought disorder, the majority of patients also experiences motor abnormalities. Converging evidence links aberrant structure and function of the cerebral motor network to schizophrenia pathology, particularly to motor abnormalities. One of the most frequent motor abnormalities is psychomotor slowing (PS), which may impact both gross and fine motor behaviour. While PS causes significant distress and predicts poor outcome, researchers are just starting to understand its pathobiology. First evidence points to aberrant functional and structural connectivity within the cerebral motor network in schizophrenia patients with PS, particularly in connections between premotor/motor cortex and thalamus, as well as between motor cortex and cerebellum. In addition, severe motor inhibition was linked to increased neural activity in the premotor cortex. Repetitive transcranial magnetic stimulation (rTMS) may temporarily alter brain activity. Data from OCoPS-P (BASEC 2018-02164, clinicaltrials.gov NCT03921450) double-blind RCT indicate that 15 sessions of inhibitory rTMS over three weeks on the supplementary motor area (SMA) alleviate PS. However, three weeks of one daily rTMS session is rather inconvenient for patients and medical professionals. Therefore, this study will aim to optimize the treatment protocol with regard to efficiency and efficacy by using an accelerated rTMS protocol with continuous theta-burst stimulation (cTBS). Inhibitory cTBS will be applied 3 times per day over 5 days, which will increase the session frequency and shorten sessions and treatment duration. Reducing the duration of the treatment phase might increase treatment adherence, shorten inpatient treatment, alleviate PS faster, and will facilitate implementation in clinical practice.