Hemodynamic responses are abnormal in isolated cervical dystonia

Area of Science:

• Neuroscience
• Neuroimaging
• Neurology

Background:

• Functional magnetic resonance imaging (fMRI) is crucial for understanding dystonia pathophysiology.
• Neurobiological disturbances in dystonia may affect neurovascular coupling, potentially impacting fMRI interpretability.

Purpose of the Study:

• To investigate alterations in hemodynamic response patterns during a motor task in isolated cervical dystonia (CD).
• To assess the influence of dystonia on neurovascular coupling during fMRI.

Main Methods:

• Twenty-five CD patients and 25 healthy controls (HCs) underwent fMRI during a paced finger tapping task.
• Constrained principal component analysis (CPCA) was used to analyze task-related functional networks and hemodynamic responses.
• Data from participants with excessive movement were excluded.

Main Results:

• Reduced hemodynamic responses were observed in the sensorimotor network and a cognitive/visual network during task performance in CD patients.
• Lower hemodynamic responses in the sensorimotor network correlated with increased dystonia severity.
• Reduced hemodynamic responses were also noted in a cognitive/visual network during rest.

Conclusions:

• Pathophysiological changes in CD, potentially involving inhibitory signaling and dopaminergic neurotransmission, may alter neurovascular coupling.
• Failure to account for altered hemodynamic responses in fMRI studies of dystonia could lead to misinterpretations.