Restriction spectrum imaging reveals decreased neurite density in patients with temporal lobe epilepsy

Autor: Donald J. Hagler, Brianna M. Paul, Anders M. Dale, Richard Q. Loi, Carrie R. McDonald, Nathan S. White, Kelly M. Leyden, Vedang S. Uttarwar, Akshara R. Balachandra
Rok vydání: 2016
Předmět:
Male
Image Processing
Restricted diffusion
Nerve Fibers
Myelinated
Functional Laterality
030218 nuclear medicine & medical imaging
Epilepsy
Nerve Fibers
Computer-Assisted
0302 clinical medicine
Image Processing
Computer-Assisted
Medicine
Cingulum (brain)
Fornix
Electroencephalography
Anatomy
Middle Aged
Magnetic Resonance Imaging
White Matter
Temporal Lobe
Diffusion Tensor Imaging
Diffusion tensor imaging
medicine.anatomical_structure
Neurology
Female
Adult
Clinical Sciences
Uncinate fasciculus
behavioral disciplines and activities
Article
Temporal lobe
White matter
Young Adult
03 medical and health sciences
Fractional anisotropy
Humans
Crossing fibers
Intracellular diffusion
Neurology & Neurosurgery
business.industry
Neurosciences
medicine.disease
Epilepsy
Temporal Lobe
nervous system
Case-Control Studies
Myelinated
Anisotropy
Neurology (clinical)
business
Neuroscience
030217 neurology & neurosurgery
Diffusion MRI
Zdroj: Epilepsia, vol 57, iss 11
Loi, RQ; Leyden, KM; Balachandra, A; Uttarwar, V; Jr, HDJ; Paul, BM; et al.(2016). Restriction spectrum imaging reveals decreased neurite density in patients with temporal lobe epilepsy. EPILEPSIA, 57(11), 1897-1906. doi: 10.1111/epi.13570. UC San Diego: Retrieved from: http://www.escholarship.org/uc/item/5989m562
ISSN: 0013-9580
DOI: 10.1111/epi.13570
Popis: Author(s): Loi, Richard Q; Leyden, Kelly M; Balachandra, Akshara; Uttarwar, Vedang; Hagler, Donald J; Paul, Brianna M; Dale, Anders M; White, Nathan S; McDonald, Carrie R | Abstract: ObjectiveDiffusion tensor imaging (DTI) has become a popular tool for delineating the location and extent of white matter injury in temporal lobe epilepsy (TLE). However, DTI yields nonspecific measures that are confounded by changes occurring within both the intracellular and extracellular environments. This study investigated whether an advanced diffusion method, restriction spectrum imaging (RSI) could provide a more robust measure of white matter injury in TLE relative to DTI due to RSI's ability to separate intraaxonal diffusion (i.e., neurite density; ND) from diffusion associated with extraaxonal factors (e.g., inflammation; crossing fibers).MethodsRSI and DTI scans were obtained on 21 patients with TLE and 11 age-matched controls. RSI-derived maps of ND, isotropic-hindered (IH) and isotropic-free (IF) water, and crossing fibers (CFs) were compared to DTI-derived fractional anisotropy (FA) maps. Voxelwise and tract-based analyses were performed comparing patients with TLE to controls on each diffusion metric.ResultsReductions in FA were seen primarily in frontotemporal white matter in TLE, and they were most pronounced proximal to the seizure focus. Reductions in ND corresponded to those seen in the FA maps; however, ND reductions were greater in magnitude, more lateralized to the epileptogenic hemisphere, and showed a broader pattern. Increases in IF/IH and effects from CFs also contributed to reduced FA in the ipsilateral parahippocampal cingulum and fornix, with decreases in IH extending into extratemporal regions. Reduced ND of the uncinate fasciculus was associated with longer disease duration, whereas FA was not associated with any clinical variables.SignificanceRSI may provide a more specific measure of white matter pathology in TLE, distinguishing regions primarily affected by axonal/myelin loss from those where CFs and increases in extracellular water also play a role. By providing a more specific measure of axonal/myelin loss, RSI-derived ND may better reflect overall white matter burden in epilepsy.
Databáze: OpenAIRE
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