Dr. Barbara A.K. Kreilkamp

Fiber ball white matter modeling in focal epilepsy

DOI

Lorna Bryant, Emilie T. McKinnon, James A. Taylor, Jens H. Jensen, Leonardo Bonilha, Christophe de Bezenac, Barbara A. K. Kreilkamp, Guleed Adan, Udo C. Wieshmann, Shubhabrata Biswas, Anthony G. Marson, Simon S. Keller

February 2021 Human Brain Mapping

Highlights

We estimated intra- and extra-axonal diffusion characteristics in patients with longstanding focal epilepsy.
Fiber ball imaging (FBI) and fiber ball white matter modeling parameters were calculated along tracts.
Patients with refractory epilepsy had significantly greater markers of extra‐axonal diffusivity compared to those with non-refractory epilepsy.
These could be markers of neuroinflammatory processes or a reflection of reduced axonal density.
FBI is a clinically feasible MRI approach that provides the basis for more interpretive conclusions about brain microstructure.

Altered structural connectome in non-lesional newly diagnosed focal epilepsy: Relation to pharmacoresistance

DOI

Barbara A.K. Kreilkamp, Andrea McKavanagh, Batil Alonazi, Lorna Bryant, Kumar Das, Udo C. Wieshmann, Anthony G. Marson, Peter N. Taylor, Simon S. Keller

January 2021 Neuroimage:Clincal

Highlights

Patients showed showed widespread connectome alterations relative to controls.
Relative to controls, patients /w seizure-freedom (SF) had increased diffusivity.
Patients /w persistent seizures (PS) had increased diffusivity relative to controls.
Subgroup-specific connectomes were found for both patient groups (SF vs PS).
Patients with generalized seizures and those without had altered connectomes.

Comparison of manual and automated fiber quantification tractography in patients with temporal lobe epilepsy

DOI

Barbara A.K. Kreilkamp, Lucy Lisanti, G. Russell Glenn, Udo C. Wieshmann, Kumar Das, Anthony G. Marson, Simon S. Keller

September 2019 NeuroImage:Clinical

Highlights

Tractography approaches showed moderate to good agreement for tract morphology.
Along- and whole-tract diffusivity was significantly correlated across approaches.
Whole-tract AFQ but not manual tract diffusivity correlated with clinical variables.
Absence of excellent agreement between approaches warrants caution.

Neuroradiological findings in patients with “non-lesional” focal epilepsy revealed by research protocol

DOI

Barbara A.K. Kreilkamp, Kumar Das, Udo C. Wieshmann, Shubhabrata Biswas, Anthony G. Marson, Simon S. Keller

August 2018 Clinical Radiology

Highlights

Patients with focal refractory epilepsy with previous ‘non-lesional’ clinical MRI.
A dedicated epilepsy research protocol with expert image re-evaluation.
33% patients were found to have potentially epileptogenic brain lesions.
Dedicated epilepsy protocol with artifact-free MRI may increase lesion pick-up-rate.

Hippocampal subfield segmentation in temporal lobe epilepsy: Relation to outcomes

DOI

Barbara A.K. Kreilkamp, Bernd Weber, Samia B. Elkommos, Mark P. Richardson, Simon S. Keller

March 2018 Acta Neurologica Scandinavica

Highlights

Patients with left TLE had smaller volumes of the contralateral presubiculum and hippocampus‐amygdala transition area compared to those with right TLE.
No significant differences in hippocampal subfield volumes between patients who were rendered seizure free and those with persistent postoperative seizures.
Ipsilateral hippocampal subfield volumes are not related to the chronicity/severity of TLE.
In patients with TLE and HS, MRI analysis of hippocampal architecture may have limited value for prediction of postoperative outcomes.

Automated tractography in patients with temporal lobe epilepsy using TRActs Constrained by UnderLying Anatomy (TRACULA)

DOI

Barbara A.K. Kreilkamp, Bernd Weber, Mark P. Richardson, Simon S. Keller

January 2017 NeuroImage:Clinical

Highlights

We investigated white matter tract alterations in TLE using an automated tool.
Patients showed bilateral tract alterations but were more prominent ipsilaterally.
Along-the-tract analyses revealed the exact location of tract diffusion alterations.
Alterations correlated with chronicity/severity of TLE but not hippocampal atrophy.

Preoperative automated fibre quantification predicts postoperative seizure outcome in temporal lobe epilepsy

DOI

Simon S. Keller, G. Russell Glenn, Bernd Weber, Barbara A.K. Kreilkamp, Jens H. Jensen, Joseph A. Helpern, Jan Wagner, Gareth J. Barker, Mark P. Richardson, Leonardo Bonilha

November 2016 Brain

Highlights

We investigated regional tissue characteristics of preoperative temporal lobe white matter tracts.
Relative to controls, both patient groups exhibited strong and significant diffusion abnormalities along tracts.
Only patients with persistent postoperative seizures showed evidence of pathology in the ipsilateral dorsal fornix and in the contralateral parahippocampal white matter bundle.
Diffusion characteristics of these regions could classify individual patients according to outcome with 84% sensitivity and 89% specificity.

Investigating conceptions of intentional action by analyzing participant generated scenarios

DOI

Alexander Skulmowski, Andreas Bunge, Bret R. Cohen, Barbara A. K. Kreilkamp, Nicole Troxler

November 2015 Frontiers in Psychology

Highlights

We asked our participants to come up with their own scenarios and to explain why these are examples of intentional or unintentional actions.
We employed content analysis to extract contexts and components that people associated with these action types.
Unintentional actions were predominantly associated with bad outcomes while intentional actions were more strongly linked to positive outcomes.
People’s conceptions of intentional action seem to involve more aspects than previously reported, such as decisions and thoughts about the action.

Retrospective Head Motion Correction Approaches for Diffusion Tensor Imaging: Effects of Preprocessing Choices on Biases and Reproducibility of Scalar Diffusion Metrics

DOI

Barbara A.K. Kreilkamp, Domenico Zaca, Nico Papinutto, Jorge Jovicich

May 2015 Journal of Magnetic Resonance Imaging

Highlights

Goal: To evaluate how retrospective head motion correction strategies affect the estimation of scalar metrics.
Preprocessing choices affected DTI measures and their reproducibility.
The DTIPrep pipeline showed significantly higher reproducibility (P<0.001) relative to the other pipelines.
The use of an iteratively averaged b0 image as motion correction reference (as performed by DTIPrep) affects both scalar values and improves test–retest reliability.

Thalamotemporal Alteration and Postoperative Seizures in Temporal Lobe Epilepsy

DOI

Simon S. Keller, Mark P. Richardson, Jan-Christoph Schoene-Bake, Jonathan O’Muircheartaigh, Samia Elkommos, Barbara A.K. Kreilkamp, Yee Yen Goh, Anthony G. Marson, Christian Elger, Bernd Weber

January 2015 Annals of Neurology

Highlights

Goal: To Identify common brain structural and connectivity alteration in patients with persistent postoperative seizures
Patients with persistent seizures had significant atrophy of bilateral dorsomedial and pulvinar thalamic regions.
Patients with persistent seizures had significant alterations of DTI‐derived thalamotemporal probabilistic paths bilaterally.
Patients with bihemispheric alterations of thalamotemporal structural networks may represent a subtype of mTLE that is resistant to surgery.