# Mapping neurological symptoms and muscle tension representations in impaired gray matter volume of Wilson disease

## TL;DR

This study maps how brain volume changes in Wilson disease relate to neurological symptoms and muscle tension, highlighting the role of the CSTC circuit.

## Contribution

The study identifies specific gray matter volume changes linked to neurological symptoms and muscle tension in Wilson disease patients.

## Key findings

- WD patients showed gray matter loss in the caudate nucleus, putamen, and cerebellum compared to healthy controls.
- Gray matter volume in the CSTC circuit correlated with neurological symptom severity and muscle tension in WD patients.
- Altered gray matter volume, especially in the basal ganglia, may serve as a biomarker for WD severity and dystonia mechanisms.

## Abstract

Neurodegenerative changes are key manifestations of Wilson disease (WD), causing neurological symptoms including parkinsonism, tremors, and dystonia. However, the neuroimaging correlates of specific neurological manifestations (especially dystonia) in WD remain poorly characterized.

37 WD patients and 37 healthy controls (HC) were recruited. All subjects underwent structural magnetic resonance scanning, muscle biomechanical measurements, and the Unified Wilson Disease Rating Scale for Neurology (UWDRS-N) assessment. Neurodegenerative changes, identified as gray matter volume (GV) changes, were analyzed via voxel-based morphometry (VBM) in WD compared to HC. Clinical symptoms were linked to GV changes in WD patients’ brains.

Compared with HC, WD patients had GV loss in the bilateral caudate nucleus, putamen, cerebellum (Crus1), left amygdala, right posterior insular lobe, and right parahippocampal gyrus and increased GV in the bilateral anterior insular lobes. In cortical areas, UWDRS-N significantly negatively correlated with GV in the bilateral posterior insula lobes, part of temporal lobe, optic cortex, frontal lobe, and cingulate cortex, while positively correlated with that in bilateral anterior insular lobes and putamen. Moreover, the GV from the left parahippocampal gyrus, bilateral hippocampus, and bilateral caudate nucleus showed a strong positive correlation with the F value of the right gastrocnemius medial head.

In WD patients with neurological symptoms, obvious abnormal GV values in the cortico-striatal-thalamo-cortical (CSTC) circuit were noted. These GV changes were linked to UWDRS-N and correlated with muscle tension. The study mapped UWDRS-N and muscle biomechanics in GV-impaired areas, suggesting altered GV (especially in basal ganglia) as a key imaging sign of WD severity. This indicates that the CSTC circuit could act as a biomarker for WD neurological symptoms and affect WD dystonia mechanisms. Additionally, it shows that muscle-related biological parameters can assess WD dystonia severity and neurological damage.

clinicaltrials.gov, identifier NCT05305872.