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Electroencephalography Network Indices as Biomarkers of Upper Limb Impairment in Chronic Stroke
Published on: July 14, 2023
Delta dipole density and strength in acute monohemispheric stroke
Filippo Zappasodi1, Mario Tombini, Daniele Milazzo
1Istituto di Scienze e Tecnologie della Cognizione (ISTC), CNR, Roma, Italy. filippo.zappasodi@istc.cnr.it
Neuroscience Letters
|February 27, 2007
Summary
Increased delta activity in both hemispheres after stroke, particularly delta dipole strength (DDS), predicts clinical recovery. This finding offers prognostic insights for stroke patients.
Area of Science:
- Neuroscience
- Clinical Neurology
- Biophysics
Background:
- Electroencephalography and magnetoencephalography studies show increased delta band activity in both perilesional and contralesional hemispheres post-stroke.
- Elevated delta activity in the unaffected hemisphere during the acute phase may offer prognostic value for clinical recovery.
Purpose of the Study:
- To investigate delta activity in perirolandic regions using MEG in stroke patients.
- To correlate delta band power, delta dipole density (DDD), and delta dipole strength (DDS) with lesion characteristics and clinical outcomes.
Main Methods:
- Magnetoencephalography (MEG) was used to assess delta activity in 27 middle cerebral artery stroke patients within the first week of symptom onset.
- Clinical evaluations were conducted in acute and post-acute phases (9 months median).
- Delta band power, DDD, and DDS were analyzed in both hemispheres, considering lesion level (cortical/subcortical), and correlated with lesion volume and clinical status.
Main Results:
- Delta dipole strength (DDS) was elevated in both affected and unaffected hemispheres compared to controls, correlating positively with lesion volume and depending on lesion level.
- While delta dipole density (DDD) did not differ between hemispheres or from controls, DDS showed a significant correlation with clinical recovery in the post-acute phase.
- DDS provided a localized amplitude estimate, independent of the measuring system, aiding inter-laboratory standardization.
Conclusions:
- Delta dipole strength (DDS) in both hemispheres after stroke, particularly in the acute phase, is a potential biomarker for predicting clinical recovery.
- These findings support the use of localized delta activity measures for stroke prognostication and inter-laboratory standardization.
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