Impaired spatial dynamic functional network connectivity and neurophysiological correlates in functional hemiparesis

Area of Science:

• Neuroscience
• Functional Neuroimaging
• Neurology

Background:

• Functional hemiparesis, often mimicking stroke (functional stroke mimics, FSM), presents diagnostic challenges.
• Understanding the underlying neural dynamics in FSM is crucial for developing targeted interventions.

Purpose of the Study:

• To investigate spatial dynamic functional network connectivity (dFNC) in patients with FSM.
• To assess alterations in brain states and their relationship with neurotransmission.

Main Methods:

• Resting-state fMRI data were acquired from 15 FSM patients and 52 healthy controls (HC).
• Spatial dFNC was evaluated across the somatomotor network (SMN), default mode network (DMN), and salience network (SN).
• Transcranial magnetic stimulation was used to assess GABAergic and glutamatergic transmission.

Main Results:

• FSM patients showed significantly reduced dwell time in a specific state of the SMN compared to HC.
• FSM patients spent more time in specific states of the DMN and SN.
• Impaired SMN dwell time correlated with increased GABAergic inhibition.

Conclusions:

• FSM is associated with distinct alterations in dynamic functional brain network connectivity.
• These dFNC changes are linked to GABAergic neurotransmission, indicating a potential neurochemical basis.
• dFNC and GABAergic function represent promising targets for future therapeutic strategies in FSM.