Recovery of slow-5 oscillations in a longitudinal study of ischemic stroke patients

In this study, we characterized longitudinally the changes in the slow-5 oscillations in stroke patients across two different time-points. We followed a group of ischemic stroke patients (n =20) and another group of healthy older adults (n =14) over two visits separated by a minimum of three months (average of 9months). For the stroke patients, one visit occurred in their subacute window (10days to 6months after stroke onset), the other took place in their chronic window (>6months after stroke). Using a mid-order group ICA method on 10-minutes eyes-closed resting-state fMRI data, we assessed the frequency distributions of a component's representative time-courses for differences in regards to slow-5 spectral power. First, our stroke patients, in their subacute stage, exhibited lower amplitude slow-5 oscillations in comparison to their healthy counterparts. Second, over time in their chronic stage, those same patients showed a recovery of those oscillations, reaching near equivalence to the healthy older adult group. Our results indicate the possibility of an eventual recovery of those initially disrupted network oscillations to a near-normal level, providing potentially a biomarker for stroke recovery of the cortical system. This finding opens new avenues in infra-slow oscillation research and could serve as a useful biomarker in future treatments aimed at recovery.
Source: NeuroImage: Clinical - Category: Radiology Source Type: research