Symptom-severity-related brain connectivity alterations in functional movement disorders

Multi-centre classification of functional neurological disorders based on resting-state functional connectivity

“…Abnormal interaction between the TPJ and sensorimotor regions has been repeatedly found in FND patient and is thought to be associated with their impaired sensory prediction signal (i.e., the sense of agency) ( Perez et al, 2012 , Voon et al, 2010 ). Similarly, RS-fMRI study in FND identified decreased connectivity from the TPJ to sensorimotor regions ( Maurer et al, 2016 ), to the precuneus ( Mueller et al, 2022 ), and between the TPJ, motor regions, cingulate cortex and insula ( Diez et al, 2019 ), as well as decreased connectivity between the right inferior parietal cortex to the dlPFC and the anterior cingulate cortex ( Baek et al, 2017 ) supporting the theory of impaired sensorimotor integration and impaired sense of agency. On the other hand, the cingular- and insular cortex, and hippocampal regions belong – amongst others - to the limbic network and are considered to be part of the emotion-cognition integrative system ( Pessoa, 2008 ).…”

“…Data were collected retrospectively from four different European University Neurology Departments: i) Geneva (Switzerland, previously published in ( Wegrzyk et al, 2018 )), ii) Bern (Switzerland), iii) Prague (Czech Republic, previously published in ( Mueller et al, 2022 )) and iv) Groningen (The Netherlands, previously reported in ( Marapin et al, 2021 , 2020)). Board-certified neurologists confirmed the diagnosis of FND according to DSM-5 ( World Health Organization, 1993 ) and using positive signs ( Stone and Carson, 2015 ).We included FND patients with motor and sensory symptoms (F44.4 and 44.6), with functional seizures (F44.5), and mixed symptom type (F44.7).…”

“…Even though task-based fMRI studies are predominant in FND, RS studies in FND were able to confirm findings from task-based studies and identified consistent results. Amongst the existing RS studies, (1) increased limbic connectivity to motor control areas ( Baek et al, 2017 , Maurer et al, 2016 , van der Kruijs et al, 2012 ), (2) aberrant connectivity from the right temporoparietal junction (TPJ) to sensorimotor regions ( Diez et al, 2019 , Hassa et al, 2017 , Maurer et al, 2016 , Mueller et al, 2022 , Wegrzyk et al, 2018 ), as well as (3) altered connectivity from memory-related temporal structures ( Longarzo et al, 2020 , Monsa et al, 2018 , Szaflarski et al, 2018 ) were identified.…”

Altered brain connectivity in hyperkinetic movement disorders: A review of resting-state fMRI

“…( Marapin et al, 2020 , Marapin et al, 2021 ) Two studies reported a positive relationship between motor severity and: 1) FC between left and right insula and temporoparietal junction (TPJ); 2) connectivity in the precuneus and bilateral temporoparietal junction. ( Mueller et al, 2022 , Diez et al, 2019 ) On the other hand, a negative correlation was reported for motor severity and FC between the right amygdala and right middle frontal gyrus. ( Spagnolo et al, 2020 ) One study described a positive relationship between disease duration and FC between the ventromedial prefrontal cortex and thalamus.…”

“…Eleven articles on FMD patients were included in this review. ( Canu et al, 2020 , Marapin et al, 2020 , Mueller et al, 2022 , Marapin et al, 2021 , Wegrzyk et al, 2018 , Diez et al, 2019 , Morris et al, 2017 , Baek et al, 2017 , Maurer et al, 2016 , Spagnolo et al, 2020 , Piramide et al, 2022 ) Patients were diagnosed with several FMD phenotypes, including functional tremor, functional jerks, functional dystonia, and functional weakness. All studies compared patient groups with age- and gender-matched healthy participants.…”