I completed my MD at the University of Saskatchewan in 2008. I subsequently undertook my Neurology Residency training at the University of Alberta and obtained my FRCPC in 2015. Following this, I completed a 1-year fellowship in Epilepsy and electroencephalography at the University of Alberta. I completed a PhD in experimental medicine in 2018. I am currently an Assistant Professor in the Division of Neurology, Department of Medicine at the University of Alberta. My clinical interests are in general neurology, urgent neurology, Epilepsy and electroencephalography.
I am currently the course coordinator for Off-Service Residents rotating through the Neurology service at the University of Alberta. I also lecture on a number of topics throughout the year, especially on seizures and epilepsy.
I am currently recruiting MSc and PhD students.
My research focuses on brain mapping, the process by which specific brain regions are distinguished from each other. In particular, I am interested in cytoarchitectural and myeloarchitectural definitions of brain regions - and how these can be applied to MRI. The methodology I current employ involves coregistration of ex vivo MRI with histology. We have published an initial proof-of-concept study using this method:
Steve TA, Yasuda CL, Coras R, Lail M, Blumcke I, Livy DJ, Malykhin N, Gross DW. Development of a histologically validated segmentation protocol for the hippocampal body NeuroImage 2017;157:219-232
Our current project aims to expand this work to include the remainder of the temporal lobe and to apply this in patients with neurological disorders. Our work is translational as we design tools which are applicable to in vivo MRI. We have active projects in which we apply our techniques in patients with temporal lobe epilepsy. The primary clinical purpose of this application is the prediction of outcomes from epilepsy surgery. We are also actively developing potential MRI-based biomarkers for Alzheimer's Disease using the ADNI database.
ex vivo MRI, in vivo MRI
Dr. Donald Gross (Neurology)
Dr. Richard Camicioli (Neurology)
Dr. Christian Beaulieu (Biomedical Engineering)
Dr. Dan Livy (Anatomy)
1 Steve, T.A., Yasuda, C.L., Coras, R., Lail, M., Blumcke, I., Livy, D.J., Malykhin, N. and Gross, D.W. Development of a histologically validated segmentation protocol for the hippocampal body NeuroImage 157:219-232 (2017)
In this paper, we developed a new method for subfield segmentation of the hippocampal body - using ex vivo MRI and histology of cadaveric hippocampi. We found that our method had improved accuracy (relative to gold standard histology) in comparison to previous techniques.
2 Steve, T.A., GARGULA, J., Misaghi, E., Nowacki, T.A., Schmitt, L.M., Wheatley, B.M., Gross, D.W Hippocampal subfield measurement and ILAE hippocampal sclerosis subtype classification with in vivo 4.7 tesla MRI Epilepsy Research (Available online January 16 2020) https://doi.org/10.1016/j.eplepsyres.2020.106279
Here we applied this method to in vivo MR Images from patients with epilepsy. We found that our method had excellent intra- and inter- rater reliability when applied in vivo and detected distinct changes across patients with epilepsy.
3 Gross, D.W., Misaghi, E., Steve, T.A., Wilman, A.H., and Beaulieu, C. Curved multiplanar reformatting provides improved visualization of hippocampal anatomy Hippocampus https://doi.org/10.1002/hipo.23177 (EPub November 2019) PMID 31743546
We have recently shown that it is possible to visualize the hippocampal subfields throughout the head, body, and tail using a reformatting technique called Curved MultiPlanar Reformatting (CMPR). This finding suggests that it might be possible to expand our in vivo volumetric analyses (described in paper 2 above) throughout the entire hippocampal long axis (head, body, and tail).
4 Treit, S., Steve, T.A., Gross, D.W., and Beaulieu, C. High resolution in-vivo diffusion imaging of the human hippocampus NeuroImage 182:479-487 (2018)
In this paper, we performed subfield segmentation directly on diffusion images (1 mm isotropic voxels) in order to directly measure diffusion parameters in hippocampal subfields from healthy control subjects.
5 Treit, S., Little, G., Steve, T.A., Nowacki, T., Schmitt, L., Wheatley, B.M., Beaulieu, C., and Gross, D.W. Regional hippocampal diffusion abnormalities associated with subfield‐specific pathology in temporal lobe epilepsy Epilepsia Open 4:544-554 (2019)
Furthermore, in this paper we demonstrated that high resolution diffusion images (Ref 4 above) reveal diffusion abnormalities in patients with TLE that correlated with subfield-specific pathological findings.
Temporal Lobe Epilepsy, drug resistant epilepsy, surface EEG, stereo-encephalography (depth electrode recordings), epilepsy surgery
I am an early-career investigator at the University of Alberta (appointed July 1, 2017). I have over seven years of continuous hands-on experience measuring hippocampal subfields with MRI. In 2012, I began my PhD research applying existing in vivo MRI protocols in patients with temporal lobe epilepsy. However, as our research question required separate measures for CA1, CA2, and CA3, I began to experiment with a number of the other available protocols from the literature. Eventually we endeavoured to develop our own protocol using ex vivo MRI and histology of cadaveric hippocampal specimens, which we recently published (Steve et al. NeuroImage 2017;157:219-232). We have subsequently applied our protocol to in vivo MRI and demonstrated excellent intra- and inter- rater reliability in patients with TLE (Steve et al. Epilepsy Research - Epub January 2020 https://doi.org/10.1016/j.eplepsyres.2020.106279). I maintain an active interest in hippocampal subfield research, including: 1) ex vivo MRI – we have recently applied curved multiplanar reconstruction to enable visualization of hippocampal anatomy throughout the head, body, and tail (Gross et al. Hippocampus 2020;30:156–161); and 2) in vivo MRI – we have performed subfield segmentation directly on diffusion images (1 mm isotropic voxels) in order to measure diffusion parameters in hippocampal subfields from healthy control subjects (Treit et al. NeuroImage 2018;182:479-487). Finally, we have demonstrated that these high resolution images detect diffusion abnormalities in patients with TLE that are correlated with subfield-specific pathological findings (Treit et al. Epilepsia Open 2019;4:544-554). Application of our methods to predict surgical outcomes in TLE and to develop biomarkers for Alzheimer’s Disease represent potential clinical applications of this work.
Doctor of Philosophy
- University of Alberta
- University Of Saskatchewan