Modification of cortical electrical activity in stroke survivors with abnormal subjective visual vertical: An eLORETA...

Area of Science:

• Neuroscience
• Neurology
• Brain Imaging

Background:

• Balance impairment is a common stroke complication, impacting posture and navigation.
• Subjective vertical (SV) perception is crucial for orientation, but its relationship with stroke lesion location is unclear.
• Abnormal visual-vertical perception is frequently observed in stroke patients.

Purpose of the Study:

• To investigate the cortico-cortical network of vertical perception in right hemisphere stroke patients with abnormal visual-vertical perception.
• To compare brain network connectivity between stroke survivors and healthy individuals.

Main Methods:

• Observational cross-sectional study involving 40 right hemisphere stroke patients and 35 healthy controls.
• All stroke patients exhibited abnormal visual-vertical perception.
• Electroencephalography (EEG) connectivity analysis was performed using exact low-resolution brain electromagnetic tomography (eLORETA).

Main Results:

• Stroke survivors showed reduced beta-2 band power in the left hemisphere and increased beta-3 band power in the right hemisphere compared to controls (p < 0.01).
• Lagged-phase synchronization was altered in the vestibular network involved in visual-vertical perception: increased in alpha-1, beta-2, and beta-3 bands, and decreased overall in stroke survivors (p < 0.01).
• Significant differences in power spectral density and functional connectivity were observed between groups.

Conclusions:

• Right hemisphere stroke significantly alters the functional connectivity of cortical areas within the vestibular network.
• These alterations in brain network function are associated with impaired visual-vertical perception and balance deficits post-stroke.
• Findings highlight the vestibular cortex's role in maintaining upright posture and navigation after stroke.