Rebecca McCourt1, Ehsan Misaghi2, Wei Tu3, Mahesh Kate4, Laura Gioia5, Sarah Treit6, Christian Beaulieu6, Ken S Butcher7. 1. Neuroscience and Mental Health Institute, University of Alberta, Canada; Division of Neurology, Faculty of Medicine and Dentistry, University of Alberta, Canada. 2. Neuroscience and Mental Health Institute, University of Alberta, Canada; Department of Rehabilitation Medicine, Institute of Stuttering Treatment and Research, University of Alberta, Canada. 3. Department of Mathematical and Statistical Sciences, University of Alberta, Canada. 4. Department of Neurology, Christian Medical College & Hospital, India. 5. Division of Neurology, Department of Medicine, CHUM-Université de Montréal, Canada. 6. Department of Biomedical Engineering, University of Alberta, Canada. 7. Prince of Wales Clinical School, University of New South Wales, Australia. Electronic address: ken.butcher@unsw.edu.au.
Abstract
BACKGROUND: The impact of perihematoma edema in Intracerebral Hemorrhage (ICH) on white matter integrity is uncertain. Fractional Anisotropy (FA), as measured with Diffusion Tensor Imaging (DTI), can be used to assess white matter microstructure. We tested the hypotheses that sections of the Corticospinal Tract (CST) passing through perihematoma edema would 1) have low FA relative to the contralateral CST and 2) would predict NIHSS motor score in ICH patients. METHODS: Patients were prospectively imaged with DTI at 48 h and 7 days after onset. Edema volume/extent was measured on CT at baseline and 24 h. FA, mean, axial and radial diffusivity were measured in the perihematoma edema, contralateral CST and sections of CST passing through the edema ('edematous CST'). RESULTS: Patients (n = 27, mean age 67 ± 13) were scanned with DTI at a median (IQR) of 42.3 (24.5) hours and 7.7 (1.8) days from onset. Median acute ICH volume was 8.8 (22) ml. FA in edematous CST at 72 h was decreased (0.37 ± 0.03) relative to contralateral CST (0.52 ± 0.06; p < 0.0001). Day 7 FA in edematous CST (0.35 ± 0.08) was also decreased compared to contralateral CST (0.54 ± 0.06; p < 0.0001). FA remained stable between 72 h (0.37 ± 0.03) and day 7 (0.35 ± 0.07; p = 0.350). FA at 72 h (ρ = -0.22, p = 0.420) and day 7 (ρ = -0.14, p = 0.624) was unrelated to 90-day motor score. CONCLUSIONS: FA is decreased in the CST where it passes through the edema. Decreased FA in the edematous CST remained stable over time, was unrelated to motor score, and may represent water infiltration into the tracts rather than axonal injury.
BACKGROUND: The impact of perihematoma edema in Intracerebral Hemorrhage (ICH) on white matter integrity is uncertain. Fractional Anisotropy (FA), as measured with Diffusion Tensor Imaging (DTI), can be used to assess white matter microstructure. We tested the hypotheses that sections of the Corticospinal Tract (CST) passing through perihematoma edema would 1) have low FA relative to the contralateral CST and 2) would predict NIHSS motor score in ICHpatients. METHODS:Patients were prospectively imaged with DTI at 48 h and 7 days after onset. Edema volume/extent was measured on CT at baseline and 24 h. FA, mean, axial and radial diffusivity were measured in the perihematoma edema, contralateral CST and sections of CST passing through the edema ('edematous CST'). RESULTS:Patients (n = 27, mean age 67 ± 13) were scanned with DTI at a median (IQR) of 42.3 (24.5) hours and 7.7 (1.8) days from onset. Median acute ICH volume was 8.8 (22) ml. FA in edematous CST at 72 h was decreased (0.37 ± 0.03) relative to contralateral CST (0.52 ± 0.06; p < 0.0001). Day 7 FA in edematous CST (0.35 ± 0.08) was also decreased compared to contralateral CST (0.54 ± 0.06; p < 0.0001). FA remained stable between 72 h (0.37 ± 0.03) and day 7 (0.35 ± 0.07; p = 0.350). FA at 72 h (ρ = -0.22, p = 0.420) and day 7 (ρ = -0.14, p = 0.624) was unrelated to 90-day motor score. CONCLUSIONS: FA is decreased in the CST where it passes through the edema. Decreased FA in the edematous CST remained stable over time, was unrelated to motor score, and may represent water infiltration into the tracts rather than axonal injury.
Authors: Muhammad E Haque; Seth B Boren; Octavio D Arevalo; Reshmi Gupta; Sarah George; Maria A Parekh; Xiurong Zhao; Jaraslow Aronowski; Sean I Savitz Journal: Front Neurol Date: 2021-11-30 Impact factor: 4.003