scholarly journals Dysmature superficial white matter microstructure in developmental focal epilepsy

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Lauren M Ostrowski ◽  
Daniel Y Song ◽  
Emily L Thorn ◽  
Erin E Ross ◽  
Sally M Stoyell ◽  
...  
Keyword(s):  
White Matter ◽  
Fractional Anisotropy ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Fine Motor ◽  
Epilepsy Syndrome ◽  
Healthy Controls ◽  
Deep White Matter ◽  
White Matter Microstructure ◽  
Benign Epilepsy

Abstract Benign epilepsy with centrotemporal spikes is a common childhood epilepsy syndrome that predominantly affects boys, characterized by self-limited focal seizures arising from the perirolandic cortex and fine motor abnormalities. Concurrent with the age-specific presentation of this syndrome, the brain undergoes a developmentally choreographed sequence of white matter microstructural changes, including maturation of association u-fibres abutting the cortex. These short fibres mediate local cortico-cortical communication and provide an age-sensitive structural substrate that could support a focal disease process. To test this hypothesis, we evaluated the microstructural properties of superficial white matter in regions corresponding to u-fibres underlying the perirolandic seizure onset zone in children with this epilepsy syndrome compared with healthy controls. To verify the spatial specificity of these features, we characterized global superficial and deep white matter properties. We further evaluated the characteristics of the perirolandic white matter in relation to performance on a fine motor task, gender and abnormalities observed on EEG. Children with benign epilepsy with centrotemporal spikes (n = 20) and healthy controls (n = 14) underwent multimodal testing with high-resolution MRI including diffusion tensor imaging sequences, sleep EEG recordings and fine motor assessment. We compared white matter microstructural characteristics (axial, radial and mean diffusivity, and fractional anisotropy) between groups in each region. We found distinct abnormalities corresponding to the perirolandic u-fibre region, with increased axial, radial and mean diffusivity and fractional anisotropy values in children with epilepsy (P = 0.039, P = 0.035, P = 0.042 and P = 0.017, respectively). Increased fractional anisotropy in this region, consistent with decreased integrity of crossing sensorimotor u-fibres, correlated with inferior fine motor performance (P = 0.029). There were gender-specific differences in white matter microstructure in the perirolandic region; males and females with epilepsy and healthy males had higher diffusion and fractional anisotropy values than healthy females (P ≤ 0.035 for all measures), suggesting that typical patterns of white matter development disproportionately predispose boys to this developmental epilepsy syndrome. Perirolandic white matter microstructure showed no relationship to epilepsy duration, duration seizure free, or epileptiform burden. There were no group differences in diffusivity or fractional anisotropy in superficial white matter outside of the perirolandic region. Children with epilepsy had increased radial diffusivity (P = 0.022) and decreased fractional anisotropy (P = 0.027) in deep white matter, consistent with a global delay in white matter maturation. These data provide evidence that atypical maturation of white matter microstructure is a basic feature in benign epilepsy with centrotemporal spikes and may contribute to the epilepsy, male predisposition and clinical comorbidities observed in this disorder.

scholarly journals Nicotine Effects on White Matter Microstructure in Young Adults

2019 ◽  
Vol 35 (1) ◽  
pp. 10-21 ◽  
Author(s):  
Megan M Kangiser ◽  
Alicia M Thomas ◽  
Christine M Kaiver ◽  
Krista M Lisdahl
Keyword(s):  
Working Memory ◽  
Young Adults ◽  
White Matter ◽  
Fractional Anisotropy ◽  
Sustained Attention ◽  
Verbal Memory ◽  
Diffusion Tensor ◽  
Memory Performance ◽  
Mean Diffusivity ◽  
White Matter Microstructure

Abstract Objective Nicotine use is widely prevalent among youth, and is associated with white matter microstructural changes as measured by diffusion tensor imaging (DTI). In adults, nicotine use is generally associated with lower fractional anisotropy (FA), but in adolescents/young adults (≤30 years), microstructure appears healthier, indicated by higher FA. This cross-sectional study examined associations between nicotine use and white matter microstructure using fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) in young adults. Methods Fifty-three participants (18 nicotine users [10 female]/35 controls [17 female]) ages 18–25 underwent MRI scan, neuropsychological battery, toxicology screening, and drug use interview. Nicotine group associations with FA and MD were examined in various white matter tracts. In significant tracts, AD and RD were measured. Exploratory correlations were conducted between significant tracts and verbal memory and sustained attention/working memory performance. Results Nicotine users exhibited significantly lower FA than controls in the left anterior thalamic radiation, left inferior longitudinal fasciculus, left superior longitudinal fasciculus—temporal, and left uncinate fasciculus. In these tracts, AD and RD did not differ, nor did MD differ in any tract. White matter quality was positively correlated with sustained attention/working memory performance. Conclusions Cigarette smoking may disrupt white matter microstructure. These results are consistent with adult studies, but inconsistent with adolescent/young adult studies, likely due to methodological and sample age differences. Further studies should examine longitudinal effects of nicotine use on white matter microstructure in a larger sample.

scholarly journals White matter differences between essential tremor and Parkinson disease

Neurology ◽  
2018 ◽  
Vol 92 (1) ◽  
pp. e30-e39 ◽  
Author(s):  
Meher R. Juttukonda ◽  
Giulia Franco ◽  
Dario J. Englot ◽  
Ya-Chen Lin ◽  
Kalen J. Petersen ◽  
...  
Keyword(s):  
White Matter ◽  
Parkinson Disease ◽  
Essential Tremor ◽  
Fractional Anisotropy ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Superior Cerebellar Peduncle ◽  
Radial Diffusivity ◽  
Cerebellar Peduncles ◽  
Cerebellar Peduncle

ObjectiveTo assess white matter integrity in patients with essential tremor (ET) and Parkinson disease (PD) with moderate to severe motor impairment.MethodsSedated participants with ET (n = 57) or PD (n = 99) underwent diffusion tensor imaging (DTI) and fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity values were computed. White matter tracts were defined using 3 well-described atlases. To determine candidate white matter regions that differ between ET and PD groups, a bootstrapping analysis was applied using the least absolute shrinkage and selection operator. Linear regression was applied to assess magnitude and direction of differences in DTI metrics between ET and PD populations in the candidate regions.ResultsFractional anisotropy values that differentiate ET from PD localize primarily to thalamic and visual-related pathways, while diffusivity differences localized to the cerebellar peduncles. Patients with ET exhibited lower fractional anisotropy values than patients with PD in the lateral geniculate body (p < 0.01), sagittal stratum (p = 0.01), forceps major (p = 0.02), pontine crossing tract (p = 0.03), and retrolenticular internal capsule (p = 0.04). Patients with ET exhibited greater radial diffusivity values than patients with PD in the superior cerebellar peduncle (p < 0.01), middle cerebellar peduncle (p = 0.05), and inferior cerebellar peduncle (p = 0.05).ConclusionsRegionally, distinctive white matter microstructural values in patients with ET localize to the cerebellar peduncles and thalamo-cortical visual pathways. These findings complement recent functional imaging studies in ET but also extend our understanding of putative physiologic features that account for distinctions between ET and PD.

scholarly journals Discrimination of epileptogenic lesions and perilesional white matter using diffusion tensor magnetic resonance imaging

2018 ◽  
Vol 32 (1) ◽  
pp. 10-16
Author(s):  
Alexander Rau ◽  
Elias Kellner ◽  
Niels A Foit ◽  
Niklas Lützen ◽  
Dieter H Heiland ◽  
...  
Keyword(s):  
White Matter ◽  
Fractional Anisotropy ◽  
Diffusion Tensor ◽  
Focal Cortical Dysplasia ◽  
Mean Diffusivity ◽  
Area Under The Curve ◽  
P Value ◽  
Radial Diffusivity ◽  
Normal Appearing White Matter ◽  
Diffusion Parameters

The aim of this study was to evaluate whether ganglioglioma (GGL), dysembryoplastic neuroepithelial tumour (DNET) and FCD (focal cortical dysplasia) are distinguishable through diffusion tensor imaging. Additionally, it was investigated whether the diffusion measures differed in the perilesional (pNAWM) and in the contralateral normal appearing white matter (cNAWM). Six GGLs, eight DNETs and seven FCDs were included in this study. Quantitative diffusion measures, that is, axial, radial and mean diffusivity and fractional anisotropy, were determined in the lesion identified on isotropic T2 or FLAIR-weighted images and in pNAWM and cNAWM, respectively. DNET differed from FCD in mean diffusivity, and GGL from FCD in radial diffusivity. Both types of glioneuronal tumours were different from pNAWM in fractional anisotropy and radial diffusivity. For identifying the tumour edges, threshold values for tumour-free tissue were investigated with receiver operating characteristic analyses: tumour could be separated from pNAWM at a threshold ≤ 0.32 (fractional anisotropy) or ≥ 0.56 (radial diffusivity) *10–3 mm2/s (area under the curve 0.995 and 0.990 respectively). While diffusion parameters of FCDs differed from cNAWM (radial diffusivity (*10–3 mm/s2): 0.74 ± 0.19 vs. 0.43 ± 0.05; corrected p-value < 0.001), the pNAWM could not be differentiated from the FCD.

In vivo gradients of thalamic damage in paediatric multiple sclerosis: a window into pathology

Brain ◽  
2020 ◽  
Author(s):  
Ermelinda De Meo ◽  
Loredana Storelli ◽  
Lucia Moiola ◽  
Angelo Ghezzi ◽  
Pierangelo Veggiotti ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Magnetic Resonance ◽  
Fractional Anisotropy ◽  
Mean Diffusivity ◽  
White Matter Lesions ◽  
Healthy Controls ◽  
Paediatric Multiple Sclerosis ◽  
Multiple Sclerosis Patients

Abstract The thalamus represents one of the first structures affected by neurodegenerative processes in multiple sclerosis. A greater thalamic volume reduction over time, on its CSF side, has been described in paediatric multiple sclerosis patients. However, its determinants and the underlying pathological changes, likely occurring before this phenomenon becomes measurable, have never been explored. Using a multiparametric magnetic resonance approach, we quantified, in vivo, the different processes that can involve the thalamus in terms of focal lesions, microstructural damage and atrophy in paediatric multiple sclerosis patients and their distribution according to the distance from CSF/thalamus interface and thalamus/white matter interface. In 70 paediatric multiple sclerosis patients and 26 age- and sex-matched healthy controls, we tested for differences in thalamic volume and quantitative MRI metrics—including fractional anisotropy, mean diffusivity and T1/T2-weighted ratio—in the whole thalamus and in thalamic white matter, globally and within concentric bands originating from CSF/thalamus interface. In paediatric multiple sclerosis patients, the relationship of thalamic abnormalities with cortical thickness and white matter lesions was also investigated. Compared to healthy controls, patients had significantly increased fractional anisotropy in whole thalamus (f2 = 0.145; P = 0.03), reduced fractional anisotropy (f2 = 0.219; P = 0.006) and increased mean diffusivity (f2 = 0.178; P = 0.009) in thalamic white matter and a trend towards a reduced thalamic volume (f2 = 0.027; P = 0.058). By segmenting the whole thalamus and thalamic white matter into concentric bands, in paediatric multiple sclerosis we detected significant fractional anisotropy abnormalities in bands nearest to CSF (f2 = 0.208; P = 0.002) and in those closest to white matter (f2 range = 0.183–0.369; P range = 0.010–0.046), while we found significant mean diffusivity (f2 range = 0.101–0.369; P range = 0.018–0.042) and T1/T2-weighted ratio (f2 = 0.773; P = 0.001) abnormalities in thalamic bands closest to CSF. The increase in fractional anisotropy and decrease in mean diffusivity detected at the CSF/thalamus interface correlated with cortical thickness reduction (r range = −0.27–0.34; P range = 0.004–0.028), whereas the increase in fractional anisotropy detected at the thalamus/white matter interface correlated with white matter lesion volumes (r range = 0.24–0.27; P range = 0.006–0.050). Globally, our results support the hypothesis of heterogeneous pathological processes, including retrograde degeneration from white matter lesions and CSF-mediated damage, leading to thalamic microstructural abnormalities, likely preceding macroscopic tissue loss. Assessing thalamic microstructural changes using a multiparametric magnetic resonance approach may represent a target to monitor the efficacy of neuroprotective strategies early in the disease course.

scholarly journals Alternative Microstructural Measures to Complement Diffusion Tensor Imaging in Migraine Studies with Standard MRI Acquisition

2020 ◽  
Vol 10 (10) ◽  
pp. 711
Author(s):  
Álvaro Planchuelo-Gómez ◽  
David García-Azorín ◽  
Ángel L. Guerrero ◽  
Rodrigo de Luis-García ◽  
Margarita Rodríguez ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Chronic Migraine ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Episodic Migraine ◽  
Healthy Controls ◽  
Axial Diffusivity ◽  
Average Diffusion ◽  
Cerebellar Peduncle

The white matter state in migraine has been investigated using diffusion tensor imaging (DTI) measures, but results using this technique are conflicting. To overcome DTI measures, we employed ensemble average diffusion propagator measures obtained with apparent measures using reduced acquisitions (AMURA). The AMURA measures were return-to-axis (RTAP), return-to-origin (RTOP) and return-to-plane probabilities (RTPP). Tract-based spatial statistics was used to compare fractional anisotropy, mean diffusivity, axial diffusivity and radial diffusivity from DTI, and RTAP, RTOP and RTPP, between healthy controls, episodic migraine and chronic migraine patients. Fifty healthy controls, 54 patients with episodic migraine and 56 with chronic migraine were assessed. Significant differences were found between both types of migraine, with lower axial diffusivity values in 38 white matter regions and higher RTOP values in the middle cerebellar peduncle in patients with a chronic migraine (p < 0.05 family-wise error corrected). Significantly lower RTPP values were found in episodic migraine patients compared to healthy controls in 24 white matter regions (p < 0.05 family-wise error corrected), finding no significant differences using DTI measures. The white matter microstructure is altered in a migraine, and in chronic compared to episodic migraine. AMURA can provide additional results with respect to DTI to uncover white matter alterations in migraine.

Mapping white matter damage distribution in neuromyelitis optica spectrum disorders with a multimodal MRI approach

2020 ◽  
pp. 135245852094149
Author(s):  
Laura Cacciaguerra ◽  
Maria A Rocca ◽  
Loredana Storelli ◽  
Marta Radaelli ◽  
Massimo Filippi
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Fractional Anisotropy ◽  
Neuromyelitis Optica ◽  
Mean Diffusivity ◽  
Healthy Controls ◽  
Neuromyelitis Optica Spectrum Disorders ◽  
White Matter Damage ◽  
Axial Diffusivity ◽  
Spectrum Disorders

Background: The pathogenetic mechanisms sustaining neuroinflammatory disorders may originate from the cerebrospinal fluid. Objective: To evaluate white matter damage with diffusion tensor imaging and T1/T2-weighted ratio at progressive distances from the ventricular system in neuromyelitis optica spectrum disorders and multiple sclerosis. Methods: Fractional anisotropy, mean, axial, and radial diffusivity and T1/T2-weighted ratio maps were obtained from patients with seropositive neuromyelitis optica spectrum disorders, multiple sclerosis, and healthy controls ( n = 20 each group). White matter damage was assessed as function of ventricular distance within progressive concentric bands. Results: Compared to healthy controls, neuromyelitis optica spectrum disorders patients had similar fractional anisotropy, radial and axial diffusivity, increased mean diffusivity ( p = 0.009–0.013) and reduced T1/T2-weighted ratio ( p = 0.024–0.037) in all bands. In multiple sclerosis, gradient of percentage lesion volume and intra-lesional mean and axial diffusivity were higher in periventricular bands. Compared to healthy controls, multiple sclerosis patients had reduced fractional anisotropy ( p = 0.001–0.043) in periventricular bands, increased mean ( p < 0.001), radial ( p < 0.001–0.004), and axial diffusivity ( p = 0.002–0.008) and preserved T1/T2-weighted ratio in all bands. Conclusion: White matter damage is higher at periventricular level in multiple sclerosis and diffuse in neuromyelitis optica spectrum disorders. Fractional anisotropy preservation, associated with increased mean diffusivity and reduced T1/T2-weighted ratio may reflect astrocyte damage.

scholarly journals Perivascular space fluid contributes to diffusion tensor imaging changes in white matter

2018 ◽  
Author(s):  
Farshid Sepehrband ◽  
Ryan P Cabeen ◽  
Jeiran Choupan ◽  
Giuseppe Barisano ◽  
Meng Law ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Fractional Anisotropy ◽  
Diffusion Mri ◽  
Diffusion Tensor ◽  
Diffusion Imaging ◽  
Mean Diffusivity ◽  
Brain Parenchyma ◽  
Perivascular Space ◽  
List Type

AbstractDiffusion tensor imaging (DTI) has been extensively used to map changes in brain tissue related to neurological disorders. Among the most widespread DTI findings are increased mean diffusivity and decreased fractional anisotropy of white matter tissue in neurodegenerative diseases. Here we utilize multi-shell diffusion imaging to separate diffusion signal of the brain parenchyma from fluid within the white matter. We show that unincorporated anisotropic water in perivascular space (PVS) significantly, and systematically, biases DTI measures, casting new light on the biological validity of many previously reported findings. Despite the challenge this poses for interpreting these past findings, our results suggest that multi-shell diffusion MRI provides a new opportunity for incorporating the PVS contribution, ultimately strengthening the clinical and scientific value of diffusion MRI.HighlightsPerivascular space (PVS) fluid significantly contributes to diffusion tensor imaging metricsIncreased PVS fluid results in increased mean diffusivity and decreased fractional anisotropyPVS contribution to diffusion signal is overlooked and demands further investigation

Increased fractional anisotropy in cerebellum in obsessive–compulsive disorder

2015 ◽  
Vol 28 (3) ◽  
pp. 141-148 ◽  
Author(s):  
Tue Hartmann ◽  
Sanne Vandborg ◽  
Raben Rosenberg ◽  
Leif Sørensen ◽  
Poul Videbech
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Fractional Anisotropy ◽  
White Matter Hyperintensities ◽  
Diffusion Tensor ◽  
Healthy Controls ◽  
Obsessive Compulsive ◽  
Compulsive Disorder ◽  
And Diffusion ◽  
Fractional Anisotrophy

BackgroundPrevious morphology and diffusion-imaging studies have suggested that structural changes in white matter is an important part of the pathophysiology of obsessive–compulsive disorder (OCD). However, different methodological approaches and the heterogeneity of patient samples question the validity of the findings.Materials and methodsIn total, 30 patients were matched for age and sex with 30 healthy controls. All participants underwent T1-weighted magnetic resonance imaging, diffusion tensor imaging and T2 fluid-attenuated inversion recovery. Voxel-based morphometry and tract-based spatial statistics were used to compare white matter volumes and diffusion tensor imaging between groups. These data were analysed correcting for the effects of multiple comparisons, age, sex, severity and duration of illness as nuisance covariates. White matter hyperintensities were manually identified.ResultsIncrease in fractional anisotropy in cerebellum was the most prominent result. A decrease in fractional anisotrophy in patients comparable with previous studies was located in forceps minor. There were no differences in the white matter morphology or in the white matter hyperintensities between patients and healthy controls.ConclusionDecrease in fractional anisotrophy in forceps minor and increase in cerebellum were found, and they were not due to neither white matter hyperintensities nor morphology of the white matter. Cerebellar hyperconnectivity could be an important part of OCD pathophysiology.

scholarly journals First application of 7-T ultra–high field diffusion tensor imaging to detect altered microstructure of thalamic-somatosensory anatomy in trigeminal neuralgia

2020 ◽  
Vol 133 (3) ◽  
pp. 839-847 ◽  
Author(s):  
John W. Rutland ◽  
Kuang-Han Huang ◽  
Corey M. Gill ◽  
Dillan F. Villavisanis ◽  
Judy Alper ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Trigeminal Neuralgia ◽  
Fractional Anisotropy ◽  
High Field ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Neurovascular Compression ◽  
Healthy Controls ◽  
Ultra High Field ◽  
Field Diffusion

OBJECTIVETrigeminal neuralgia (TN) is a debilitating neurological disease that commonly results from neurovascular compression of the trigeminal nerve (CN V). Although the CN V has been extensively studied at the site of neurovascular compression, many pathophysiological factors remain obscure. For example, thalamic-somatosensory function is thought to be altered in TN, but the abnormalities are inadequately characterized. Furthermore, there are few studies using 7-T MRI to examine patients with TN. The purpose of the present study was to use 7-T MRI to assess microstructural alteration in the thalamic-somatosensory tracts of patients with TN by using ultra–high field MRI.METHODSTen patients with TN and 10 age- and sex-matched healthy controls underwent scanning using 7-T MRI with diffusion tensor imaging. Structural images were segmented with an automated algorithm to obtain thalamus and primary somatosensory cortex (S1). Probabilistic tractography was performed between the thalamus and S1, and the microstructure of the thalamic-somatosensory tracts was compared between patients with TN and controls.RESULTSFractional anisotropy of the thalamic-somatosensory tract ipsilateral to the site of neurovascular compression was reduced in patients (mean 0.43) compared with side-matched controls (mean 0.47, p = 0.01). The mean diffusivity was increased ipsilaterally in patients (mean 6.58 × 10−4 mm2/second) compared with controls (mean 6.15 × 10−4 mm2/second, p = 0.02). Radial diffusivity was increased ipsilaterally in patients (mean 4.91 × 10−4 mm2/second) compared with controls (mean 4.44 × 10−4 mm2/second, p = 0.01). Topographical analysis revealed fractional anisotropy reduction and diffusivity elevation along the entire anatomical S1 arc in patients with TN.CONCLUSIONSThe present study is the first to examine microstructural properties of the thalamic-somatosensory anatomy in patients with TN and to evaluate quantitative differences compared with healthy controls. The finding of reduced integrity of these white matter fibers provides evidence of microstructural alteration at the level of the thalamus and S1, and furthers the understanding of TN neurobiology.

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