Botulinum toxin injection changes resting state cerebellar connectivity in cervical dystonia

Area of Science:

• Neuroscience
• Neurology
• Medical Imaging

Background:

• Cervical dystonia involves altered brain resting state networks.
• The cerebellum's role in dystonia is increasingly recognized.
• Botulinum neurotoxin A (BoNT) is a common treatment for cervical dystonia.

Purpose of the Study:

• To investigate changes in cerebello-cortical connectivity before and after BoNT treatment in cervical dystonia patients.
• To correlate functional connectivity alterations with clinical improvement post-treatment.

Main Methods:

• Seventeen cervical dystonia patients underwent fMRI scans before and 4 weeks after BoNT injection.
• Seed-based functional connectivity analysis focused on atlas-defined cerebellar regions.
• Clinical severity was assessed using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS).

Main Results:

• BoNT treatment led to a significant decrease in connectivity between the cerebellar vermis lobule VIIIa and the left dorsal mesial frontal cortex.
• Connectivity changes in specific cerebellar regions (lobule VI, crus II, vermis VIIIb, lobule IX) positively correlated with clinical improvement.
• Functional MRI data indicated successful modulation of cerebello-cortical networks by BoNT therapy.

Conclusions:

• BoNT treatment effectively modulates cerebello-cortical functional connectivity in cervical dystonia.
• Observed connectivity changes are linked to therapeutic outcomes and clinical symptom reduction.
• This study highlights the cerebellum's involvement and the impact of BoNT on brain networks in cervical dystonia.