White matter integrity measured by fractional anisotropy correlates poorly with actual individual fiber anisotropy

AbstractThe goal of this study was to detect abnormalities in white matter integrity connecting the mediodorsal nucleus of the thalamus and the prefrontal cortex using fiber-tracking technique. Diffusion tensor imaging was acquired in 20 patients with schizophrenia and 20 normal comparison subjects. Fiber tracking was performed on the anterior thalamic peduncle, and the tractography was used to determine the cross-sectional area, mean fractional anisotropy, and standard deviation of fractional anisotropy for every step separately in the right and left hemispheres. Compared with normal subjects, patients showed a significant reduction in the cross-sectional area of the left anterior thalamic peduncle. There were no significant differences for the mean fractional anisotropy bilaterally between the two groups, but significant differences for the standard deviation of fractional anisotropy in both hemispheres. Reduction in the cross-sectional area of the left anterior thalamic peduncle suggests the presence of the failure of left-hemisphere lateralization. In schizophrenic patients a significant increase of the standard deviation of fractional anisotropy raise the possibility that the inhomogeneity of white matter integrity, which is densely or sparsely distributed by site. These findings might provide further evidence for disruption of white matter integrity between the thalamus and the prefrontal cortex in schizophrenia.

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Monocyte depletion attenuates the development of posttraumatic hydrocephalus and preserves white matter integrity after traumatic brain injury

10.1101/388793 ◽

2018 ◽

Author(s):

Hadijat M. Makinde ◽

Talia B. Just ◽

Carla M. Cuda ◽

Nicola Bertolino ◽

Daniele Procissi ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

White Matter ◽

Fractional Anisotropy ◽

Diffusion Mri ◽

Lesion Size ◽

White Matter Integrity ◽

Regional Patterns ◽

Software Program ◽

Ventricle Volume

AbstractMonocytes are amongst the first cells recruited into the brain after traumatic brain injury (TBI). We have shown monocyte depletion 24 hours prior to TBI reduces brain edema, decreases neutrophil infiltration and improves behavioral outcomes. Additionally, both lesion and ventricle size correlate with poor neurologic outcome after TBI. Therefore, we aimed to determine the association between monocyte infiltration, lesion size, and ventricle volume. We hypothesized that monocyte depletion would attenuate lesion size, decrease ventricle enlargement, and preserve white matter in mice after TBI. C57BL/6 mice underwent pan monocyte depletion via intravenous injection of liposome-encapsulated clodronate. Control mice were injected with liposome-encapsulated PBS. TBI was induced via an open-head, controlled cortical impact. Mice were imaged using magnetic resonance imaging (MRI) at 1, 7, and 14 days post-injury to evaluate progression of lesion and to detect morphological changes associated with injury (3D T1- weighted MRI) including regional alterations in white matter patterns (multi-direction diffusion MRI). Lesion size and ventricle volume were measured using semi-automatic segmentation and active contour methods with the software program ITK-SNAP. Data was analyzed with the statistical software program PRISM. No significant effect of monocyte depletion on lesion size was detected using MRI following TBI (p=0.4). However, progressive ventricle enlargement following TBI was observed to be attenuated in the monocyte-depleted cohort (5.3 ± 0.9mm3) as compared to the sham-depleted cohort (13.2 ± 3.1mm3; p=0.02). Global white matter integrity and regional patterns were evaluated and quantified for each mouse after extracting fractional anisotropy maps from the multi-direction diffusion-MRI data using Siemens Syngo DTI analysis package. Fractional anisotropy values were preserved in the monocyte-depleted cohort (123.0 ± 4.4mm3) as compared to sham-depleted mice (94.9 ± 4.6mm3; p=0.025) by 14 days post-TBI. The MRI derived data suggests that monocyte depletion at the time of injury may be a novel therapeutic strategy in the treatment of TBI. Furthermore, non-invasive longitudinal imaging allows for the evaluation of both TBI progression as well as therapeutic response over the course of injury.

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Greater Loss of White Matter Integrity in Postural Instability and Gait Difficulty Subtype of Parkinson's Disease

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques ◽

10.1017/cjn.2014.34 ◽

2014 ◽

Vol 41 (6) ◽

pp. 763-768 ◽

Cited By ~ 18

Author(s):

Quanquan Gu ◽

Peiyu Huang ◽

Min Xuan ◽

Xiaojun Xu ◽

Dan Li ◽

...

Keyword(s):

White Matter ◽

Fractional Anisotropy ◽

Diffusion Tensor ◽

Critical Role ◽

Postural Instability ◽

White Matter Integrity ◽

Radial Diffusivity ◽

Superior Longitudinal Fasciculus ◽

Axial Diffusivity ◽

White Matter Abnormalities

ABSTRACTBackground: Patients with the postural instability and gait difficulty (PIGD) subtype of Parkinson disease (PD) are at a higher risk of dysfunction and are less responsive to dopamine replacement therapy. The PIGD subtype was found to largely associate with white matter lesions, but details of the diffusion changes within these lesions have not been fully investigated. Voxel-based analysis for diffusion tensor imaging data is one of the preferred measures to compare diffusion changes in each voxel in any part of the brain. Methods: PD patients with the PIGD (n=12) and non-PIGD subtypes (n=12) were recruited to compare diffusion differences in fractional anisotropy, axial diffusivity, and radial diffusivity with voxel-based analysis. Results: Significantly reduced fractional anisotropy in bilateral superior longitudinal fasciculus, bilateral anterior corona radiata, and the left genu of the corpus callosum were shown in the PIGD subtype compared with the non-PIGD subtype. Increased radial diffusivity in the left superior longitudinal fasciculus was found in the PIGD subtype with no statistical differences in axial diffusivity found. Conclusions: Our study confirms previous findings that white matter abnormalities were greater in the PIGD subtype than in the non-PIGD subtype. Additionally, our findings suggested: (1) compared with the non-PIGD subtype, loss of white matter integrity was greater in the PIGD subtype; (2) bilateral superior longitudinal fasciculus may play a critical role in microstructural white matter abnormalities in the PIGD subtype; and (3) reduced white matter integrity in the PIGD subtype could be mainly attributed to demyelination rather than axonal loss.

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Diffusion tensor imaging of brain white matter in Huntington gene mutation individuals

Arquivos de Neuro-Psiquiatria ◽

10.1590/0004-282x20170085 ◽

2017 ◽

Vol 75 (8) ◽

pp. 503-508 ◽

Cited By ~ 4

Author(s):

Roberta Arb Saba ◽

James H. Yared ◽

Thomas M. Doring ◽

Med Phys ◽

Vanderci Borges ◽

...

Keyword(s):

Diffusion Tensor Imaging ◽

White Matter ◽

Gene Mutation ◽

Fractional Anisotropy ◽

Diffusion Tensor ◽

Brain Magnetic Resonance Imaging ◽

White Matter Integrity ◽

Brain White Matter ◽

Potential Biomarker ◽

Significant Difference

ABSTRACT Objective To evaluate the role of the involvement of white matter tracts in huntingtin gene mutation patients as a potential biomarker of the progression of the disease. Methods We evaluated 34 participants (11 symptomatic huntingtin gene mutation, 12 presymptomatic huntingtin gene mutation, and 11 controls). We performed brain magnetic resonance imaging to assess white matter integrity using diffusion tensor imaging, with measurement of fractional anisotropy. Results We observed a significant decrease of fractional anisotropy in the cortical spinal tracts, corona radiate, corpus callosum, external capsule, thalamic radiations, superior and inferior longitudinal fasciculus, and inferior frontal-occipital fasciculus in the Huntington disease group compared to the control and presymptomatic groups. Reduction of fractional anisotropy is indicative of a degenerative process and axonal loss. There was no statistically significant difference between the presymptomatic and control groups. Conclusion White matter integrity is affected in huntingtin gene mutation symptomatic individuals, but other studies with larger samples are required to assess its usefulness in the progression of the neurodegenerative process.

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Is Manual Drawing of Region of Interest to Measure Fractional Anisotropy a Reliable Method of Determining White Matter Integrity? Medial Temporal Epilepsy Model

Neuroscience Informatics ◽

10.1016/j.neuri.2022.100040 ◽

2022 ◽

pp. 100040

Author(s):

Saman Hazany ◽

Brittany DeClouette

Keyword(s):

White Matter ◽

Fractional Anisotropy ◽

Reliable Method ◽

Region Of Interest ◽

White Matter Integrity ◽

Temporal Epilepsy

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White matter disruption as a cause or consequence of schizophrenia: A Mendelian randomization study

10.1101/2021.08.23.21262451 ◽

2021 ◽

Author(s):

Oskar Hougaard Jefsen ◽

Maria Speed ◽

Karl John Friston ◽

Søren Dinesen Østergaard ◽

Doug Speed

Keyword(s):

White Matter ◽

Fractional Anisotropy ◽

Mendelian Randomization ◽

Functional Integration ◽

White Matter Integrity ◽

Synaptic Dysfunction ◽

White Matter Changes ◽

The Brain

Brief abstractSchizophrenia is hypothesized to be caused by impaired functional integration in the brain, and this could hypothetically be caused by white matter disruptions, synaptic dysfunction, or both. Neuroimaging studies consistently show reduced fractional anisotropy, a measure of white matter integrity, in patients with schizophrenia. Using Mendelian randomization, we show that these white matter changes are likely to be the consequence of a primary synaptopathy in schizophrenia.

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Skewness of Fractional Anisotropy Detects Decreased White Matter Integrity Resulting From Acute Optic Neuritis

Investigative Opthalmology & Visual Science ◽

10.1167/iovs.15-17335 ◽

2015 ◽

Vol 56 (12) ◽

pp. 7597 ◽

Cited By ~ 2

Author(s):

Bradley G. Goodyear ◽

Nourhan M. H. Zayed ◽

Filomeno Cortese ◽

Jessie Trufyn ◽

Fiona Costello

Keyword(s):

White Matter ◽

Optic Neuritis ◽

Fractional Anisotropy ◽

White Matter Integrity ◽

Acute Optic Neuritis

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T123. Decreased Fractional Anisotropy as a Marker of Aberrant White Matter Integrity in Unaffected Offspring of Patients With Bipolar Disorder

Biological Psychiatry ◽

10.1016/j.biopsych.2018.02.459 ◽

2018 ◽

Vol 83 (9) ◽

pp. S176

Author(s):

Tomas Melicher ◽

Benson Mwangi ◽

Mon-Ju Wu ◽

Bo Cao ◽

Cristian Zeni ◽

...

Keyword(s):

Bipolar Disorder ◽

White Matter ◽

Fractional Anisotropy ◽

White Matter Integrity

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Sleep and White Matter in Adults with Down Syndrome

Brain Sciences ◽

10.3390/brainsci11101322 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1322

Author(s):

Victoria Fleming ◽

Brianna Piro-Gambetti ◽

Austin Bazydlo ◽

Matthew Zammit ◽

Andrew L. Alexander ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Down Syndrome ◽

Sleep Apnea ◽

White Matter ◽

Fractional Anisotropy ◽

Brain Aging ◽

White Matter Integrity ◽

Obstructive Sleep ◽

Inferior Longitudinal Fasciculus ◽

The Right

Adults with Down syndrome are at a high risk for disordered sleep. These sleep problems could have marked effects on aging and Alzheimer’s disease, potentially altering white matter integrity. This study examined the associations between disordered sleep assessed via an actigraph accelerometer worn on 7 consecutive nights, presence of diagnosis of obstructive sleep apnea, and diffusion tensor imaging indices of white matter integrity in 29 non-demented adults with Down Syndrome (48% female, aged 33–54 years). Average total sleep time was associated with lower mean diffusivity in the left superior longitudinal fasciculus (r = −0.398, p = 0.040). Average sleep efficiency, length of awakenings, and movement index were related to fractional anisotropy in the right inferior longitudinal fasciculus (r = −0.614 to 0.387, p ≤ 0.050). Diagnosis of obstructive sleep apnea was associated with fractional anisotropy in the right inferior longitudinal fasciculus (r = −0.373 p = 0.050). Findings suggest that more disrupted sleep is associated with lower white matter integrity in the major association tracts in middle-aged adults with Down syndrome. Longitudinal work is needed to confirm the directionally of associations. Sleep interventions could be an important component for promoting optimal brain aging in the Down syndrome population.

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White matter tract integrity in treatment-resistant gambling disorder

The British Journal of Psychiatry ◽

10.1192/bjp.bp.115.165506 ◽

2016 ◽

Vol 208 (6) ◽

pp. 579-584 ◽

Cited By ~ 7

Author(s):

Samuel R. Chamberlain ◽

Katherine Derbyshire ◽

Richard E. Daws ◽

Brian L. Odlaug ◽

Eric W. Leppink ◽

...

Keyword(s):

White Matter ◽

Corpus Callosum ◽

Disease Severity ◽

Fractional Anisotropy ◽

Gambling Disorder ◽

White Matter Integrity ◽

Future Research ◽

Healthy Controls ◽

Treatment Resistant ◽

Addictive Disorders

BackgroundGambling disorder is a relatively common psychiatric disorder recently re-classified within the DSM-5 under the category of ‘substance-related and addictive disorders'.AimsTo compare white matter integrity in patients with gambling disorder with healthy controls; to explore relationships between white matter integrity and disease severity in gambling disorder.MethodIn total, 16 participants with treatment-resistant gambling disorder and 15 healthy controls underwent magnetic resonance imaging (MRI). White matter integrity was analysed using tract-based spatial statistics.ResultsGambling disorder was associated with reduced fractional anisotropy in the corpus callosum and superior longitudinal fasciculus. Fractional anisotropy in distributed white matter tracts elsewhere correlated positively with disease severity.ConclusionsReduced corpus callosum fractional anisotropy is suggestive of disorganised/damaged tracts in patients with gambling disorder, and this may represent a trait/vulnerability marker for the disorder. Future research should explore these measures in a larger sample, ideally incorporating a range of imaging markers (for example functional MRI) and enrolling unaffected first-degree relatives of patients.

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