scholarly journals Effect of high-potency cannabis on corpus callosum microstructure

2015 ◽  
Vol 46 (4) ◽  
pp. 841-854 ◽  
Author(s):  
S. Rigucci ◽  
T. R. Marques ◽  
M. Di Forti ◽  
H. Taylor ◽  
F. Dell'Acqua ◽  
...  
Keyword(s):  
Corpus Callosum ◽  
Diffusion Tensor ◽  
Group Analysis ◽  
Mean Diffusivity ◽  
Brain Morphology ◽  
First Episode ◽  
High Potency ◽  
Frequent Use ◽  
Raising Awareness ◽  
Frequency Of Use

BackgroundThe use of cannabis with higher Δ9-tetrahydrocannabinol content has been associated with greater risk, and earlier onset, of psychosis. However, the effect of cannabis potency on brain morphology has never been explored. Here, we investigated whether cannabis potency and pattern of use are associated with changes in corpus callosum (CC) microstructural organization, in patients with first-episode psychosis (FEP) and individuals without psychosis, cannabis users and non-users.MethodThe CC of 56 FEP (37 cannabis users) and 43 individuals without psychosis (22 cannabis users) was virtually dissected and segmented using diffusion tensor imaging tractography. The diffusion index of fractional anisotropy, mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity was calculated for each segment.ResultsAcross the whole sample, users of high-potency cannabis had higher total CC MD and higher total CC AD than both low-potency users and those who never used (p = 0.005 and p = 0.004, respectively). Daily users also had higher total CC MD and higher total CC AD than both occasional users and those who never used (p = 0.001 and p < 0.001, respectively). However, there was no effect of group (patient/individuals without psychosis) or group x potency interaction for either potency or frequency of use. The within-group analysis showed in fact that the effects of potency and frequency were similar in FEP users and in users without psychosis.ConclusionsFrequent use of high-potency cannabis is associated with disturbed callosal microstructural organization in individuals with and without psychosis. Since high-potency preparations are now replacing traditional herbal drugs in many European countries, raising awareness about the risks of high-potency cannabis is crucial.

scholarly journals Relationship of Corpus Callosum Integrity with Working Memory, Planning, and Speed of Processing in Patients with First-Episode and Chronic Schizophrenia

2021 ◽  
Vol 10 (14) ◽  
pp. 3158
Author(s):  
Ernest Tyburski ◽  
Piotr Podwalski ◽  
Katarzyna Waszczuk ◽  
Katarzyna Rek-Owodziń ◽  
Monika Mak ◽  
...  
Keyword(s):  
Working Memory ◽  
Corpus Callosum ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Verbal Working Memory ◽  
Chronic Schizophrenia ◽  
First Episode ◽  
Speed Of Processing ◽  
Treatment Research ◽  
Relationship Of

There is a paucity of reports examining the relationship between the integrity of the corpus callosum (CC) and different aspects of cognitive functioning in patients with first-episode (FES) and chronic schizophrenia (CS) simultaneously; furthermore, what results exist are inconclusive. We used diffusion tensor imaging tractography to investigate differences in integrity in five regions of the CC between FES, CS, and healthy controls (HC). Additionally, we analyzed correlations between these regions’ integrity and working memory, planning, and speed of processing. Eighteen patients with FES, 55 patients with CS, and 30 HC took part in the study. We assessed cognitive functions with four tasks from Measurement and Treatment Research to Improve Cognition in Schizophrenia. Patients with CS showed lower fractional anisotropy (FA) in Region 5 (statistical trend) and higher mean diffusivity (MD) in Regions 4 and 5 than HC, and patients with FES had higher MD in Region 3 (statistical trend) than HC. Both clinical groups performed worse on working memory and speed of processing tasks than HC, and patients with CS scored worse than HC on independent planning, and worse than FES and HC on dependent planning. Moreover, in patients with CS, MD in Region 3 was correlated with verbal working memory. Our results suggest that patients with FES and CS are characterized by impaired integrity of the middle and posterior CC, respectively. We confirmed that both clinical groups have cognitive impairments. Moreover, the integrity of the middle CC may influence planning in patients with CS.

scholarly journals White matter abnormalities in the corpus callosum with cognitive impairment in Parkinson disease

Neurology ◽  
2018 ◽  
Vol 91 (24) ◽  
pp. e2244-e2255 ◽  
Author(s):  
Ian O. Bledsoe ◽  
Glenn T. Stebbins ◽  
Doug Merkitch ◽  
Jennifer G. Goldman
Keyword(s):  
Cognitive Impairment ◽  
White Matter ◽  
Corpus Callosum ◽  
Parkinson Disease ◽  
Information Transfer ◽  
Diffusion Tensor ◽  
Anterior Segment ◽  
Mean Diffusivity ◽  
Cognitive Domain ◽  
White Matter Abnormalities

ObjectiveTo evaluate microstructural characteristics of the corpus callosum using diffusion tensor imaging (DTI) and their relationships to cognitive impairment in Parkinson disease (PD).MethodsSeventy-five participants with PD and 24 healthy control (HC) participants underwent structural MRI brain scans including DTI sequences and clinical and neuropsychological evaluations. Using Movement Disorder Society criteria, PD participants were classified as having normal cognition (PD-NC, n = 23), mild cognitive impairment (PD-MCI, n = 35), or dementia (PDD, n = 17). Cognitive domain (attention/working memory, executive function, language, memory, visuospatial function) z scores were calculated. DTI scalar values, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD), were established for 5 callosal segments on a midsagittal plane, single slice using a topographically derived parcellation method. Scalar values were compared among participant groups. Regression analyses were performed on cognitive domain z scores and DTI metrics.ResultsParticipants with PD showed increased AD values in the anterior 3 callosal segments compared to healthy controls. Participants with PDD had significantly increased AD, MD, and RD in the anterior 2 segments compared to participants with PD-NC and most anterior segment compared to participants with PD-MCI. FA values did not differ significantly between participants with PD and participants with HC or among PD cognitive groups. The strongest associations for the DTI metrics and cognitive performance occurred in the most anterior and most posterior callosal segments, and also reflected fronto-striatal and posterior cortical type cognitive deficits, respectively.ConclusionsMicrostructural white matter abnormalities of the corpus callosum, as measured by DTI, may contribute to PD cognitive impairment by disrupting information transfer across interhemispheric and callosal–cortical projections.

scholarly journals Non-local means based Rician noise filtering for diffusion tensor and kurtosis imaging in human brain and spinal cord

2020 ◽  
Author(s):  
Zhongping Zhang ◽  
Dhanashree Vernekar ◽  
Wenshu Qian ◽  
Mina Kim
Keyword(s):  
Spinal Cord ◽  
Corpus Callosum ◽  
Human Brain ◽  
Healthy Subjects ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Chi Square ◽  
Lateral Column ◽  
Diffusion Weighted Images ◽  
The Brain

Abstract Background: To investigate the effect of using an Rician nonlocal means (NLM) filter on quantification of diffusion tensor (DT)- and diffusion kurtosis (DK)-derived metrics in various anatomical regions of the human brain and the spinal cord, when combined with a constrained linear least squares (CLLS) approach.Methods: Prospective brain data from 9 healthy subjects and retrospective spinal cord data from 5 healthy subjects from a 3T MRI scanner were included in the study. Prior to tensor estimation, registered diffusion weighted images were denoised by an optimized blockwise NLM filter with CLLS. Mean kurtosis (MK), radial kurtosis (RK), axial kurtosis (AK), mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD) and fractional anisotropy (FA), were determined in anatomical structures of the brain and the spinal cord. DTI and DKI metrics, signal-to-noise ratio (SNR) and Chi-square values were quantified in distinct anatomical regions for all subjects, with and without Rician denoising. Results: The averaged SNR significantly increased with Rician denoising by a factor of 2 while the averaged Chi-square values significantly decreased up to 61 % in the brain and up to 43% in the spinal cord after Rician NLM filtering. In the brain, the mean MK varied from 0.70 (putamen) to 1.27 (internal capsule) while AK and RK varied from 0.58 (corpus callosum) to 0.92 (cingulum) and from 0.70 (putamen) to 1.98 (corpus callosum), respectively. In the spinal cord, FA varied from 0.78 in lateral column to 0.81 in dorsal column while MD varied from 0.91 × 10−3 mm2/s (lateral) to 0.93 × 10−3 mm2/s (dorsal). RD varied from 0.34 × 10−3 mm2/s (dorsal) to 0.38 × 10−3 mm2/s (lateral) and AD varied from 1.96 × 10−3 mm2/s (lateral) to 2.11 × 10−3 mm2/s (dorsal).Conclusions: Our results show Rician denoising NLM filter incorporated with CLLS significantly increases SNR and reduces estimation errors of DT- and KT-derived metrics, providing the reliable metrics estimation with adequate SNR levels.

scholarly journals A diffusion tensor imaging study of structural dysconnectivity in never-medicated, first-episode schizophrenia

2007 ◽  
Vol 38 (6) ◽  
pp. 877-885 ◽  
Author(s):  
V. Cheung ◽  
C. Cheung ◽  
G. M. McAlonan ◽  
Y. Deng ◽  
J. G. Wong ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Corpus Callosum ◽  
Diffusion Tensor ◽  
Structural Connectivity ◽  
First Episode ◽  
Cerebral Peduncle ◽  
Healthy Controls ◽  
Subcortical Region ◽  
First Episode Schizophrenia

BackgroundDiffusion tensor imaging (DTI) can be used to investigate cerebral structural connectivity in never-medicated individuals with first-episode schizophrenia.MethodSubjects with first-episode schizophrenia according to DSM-IV-R who had never been exposed to antipsychotic medication (n=25) and healthy controls (n=26) were recruited. Groups were matched for age, gender, best parental socio-economic status and ethnicity. All subjects underwent DTI and structural magnetic resonance imaging (MRI) scans. Voxel-based analysis was performed to investigate brain regions where fractional anisotropy (FA) values differed significantly between groups. A confirmatory region-of-interest (ROI) analysis of FA scores was performed in which regions were placed blind to group membership.ResultsIn patients, FA values significantly lower than those in healthy controls were located in the left fronto-occipital fasciculus, left inferior longitudinal fasciculus, white matter adjacent to right precuneus, splenium of corpus callosum, right posterior limb of internal capsule, white matter adjacent to right substantia nigra, and left cerebral peduncle. ROI analysis of the corpus callosum confirmed that the patient group had significantly lower mean FA values than the controls in the splenium but not in the genu. The intra-class correlation coefficient (ICC) for independent ROI measurements was 0.90 (genu) and 0.90 (splenium). There were no regions where FA values were significantly higher in the patients than in the healthy controls.ConclusionsWidespread structural dysconnectivity, including the subcortical region, is already present in neuroleptic-naive patients in their first episode of illness.

scholarly journals Maturation of Corpus Callosum Anterior Midbody Is Associated with Neonatal Motor Function in Eight Preterm-Born Infants

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Preethi Mathew ◽  
Kerstin Pannek ◽  
Pamela Snow ◽  
M. Giulia D'Acunto ◽  
Andrea Guzzetta ◽  
...  
Keyword(s):  
Corpus Callosum ◽  
Preterm Infants ◽  
Motor Function ◽  
Gestational Age ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Motor Impairments ◽  
Very Preterm Infants ◽  
Very Preterm ◽  
Preterm Born

Background. The etiology of motor impairments in preterm infants is multifactorial and incompletely understood. Whether corpus callosum development is related to impaired motor function is unclear. Potential associations between motor-related measures and diffusion tensor imaging (DTI) of the corpus callosum in preterm infants were explored.Methods. Eight very preterm infants (gestational age of 28–32 weeks) underwent the Hammersmith neonatal neurological examination and DTI assessments at gestational age of 42 weeks. The total Hammersmith score and a motor-specific score (sum of Hammersmith motor subcategories) were calculated. Six corpus callosum regions of interest were defined on the mid-sagittal DTI slice—genu, rostral body, anterior midbody, posterior midbody, isthmus, and splenium. The fractional anisotropy (FA) and mean diffusivity (MD) of these regions were computed, and correlations between these and Hammersmith measures were sought.Results. Anterior midbody FA measures correlated positively with total Hammersmith (rho=0.929,P=0.001) and motor-specific scores (rho=0.857,P=0.007). Total Hammersmith scores also negatively correlated with anterior midbody MD measures (rho=−0.714,P=0.047).Discussion. These results suggest the integrity of corpus callosum axons, particularly anterior midbody axons, is important in mediating neurological functions. Greater callosal maturation was associated with greater motor function. Corpus callosum DTI may prove to be a valuable screening or prognostic marker.

Motor abnormalities and basal ganglia in first-episode psychosis (FEP)

2020 ◽  
pp. 1-12 ◽  
Author(s):  
Manuel J. Cuesta ◽  
Pablo Lecumberri ◽  
Lucia Moreno-Izco ◽  
Jose M. López-Ilundain ◽  
María Ribeiro ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Fractional Anisotropy ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
First Episode Psychosis ◽  
First Episode ◽  
Iron Load ◽  
Episode Psychosis ◽  
Extrapyramidal Signs ◽  
Motor Abnormalities

Abstract Background Motor abnormalities (MAs) are the primary manifestations of schizophrenia. However, the extent to which MAs are related to alterations of subcortical structures remains understudied. Methods We aimed to investigate the associations of MAs and basal ganglia abnormalities in first-episode psychosis (FEP) and healthy controls. Magnetic resonance imaging was performed on 48 right-handed FEP and 23 age-, gender-, handedness-, and educational attainment-matched controls, to obtain basal ganglia shape analysis, diffusion tensor imaging techniques (fractional anisotropy and mean diffusivity), and relaxometry (R2*) to estimate iron load. A comprehensive motor battery was applied including the assessment of parkinsonism, catatonic signs, and neurological soft signs (NSS). A fully automated model-based segmentation algorithm on 1.5T MRI anatomical images and accurate corregistration of diffusion and T2* volumes and R2* was used. Results FEP patients showed significant local atrophic changes in left globus pallidus nucleus regarding controls. Hypertrophic changes in left-side caudate were associated with higher scores in sensory integration, and in right accumbens with tremor subscale. FEP patients showed lower fractional anisotropy measures than controls but no significant differences regarding mean diffusivity and iron load of basal ganglia. However, iron load in left basal ganglia and right accumbens correlated significantly with higher extrapyramidal and motor coordination signs in FEP patients. Conclusions Taken together, iron load in left basal ganglia may have a role in the emergence of extrapyramidal signs and NSS of FEP patients and in consequence in the pathophysiology of psychosis.

scholarly journals Corpus Callosum and Cingulum Tractography in Parkinson's Disease

2010 ◽  
Vol 37 (5) ◽  
pp. 595-600 ◽  
Author(s):  
Katie Wiltshire ◽  
Luis Concha ◽  
Myrlene Gee ◽  
Thomas Bouchard ◽  
Christian Beaulieu ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cognitive Impairment ◽  
White Matter ◽  
Corpus Callosum ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Method ◽  
Motor Symptoms ◽  
Mri Scans

Background:In Parkinson's disease (PD) cell loss in the substantia nigra is known to result in motor symptoms; however widespread pathological changes occur and may be associated with non-motor symptoms such as cognitive impairment. Diffusion tensor imaging is a quantitative imaging method sensitive to the micro-structure of white matter tracts.Objective:To measure fractional anisotropy (FA) and mean diffusivity (MD) values in the corpus callosum and cingulum pathways, defined by diffusion tensor tractography, in patients with PD, PD with dementia (PDD) and controls and to determine if these measures correlate with Mini-Mental Status Examination (MMSE) scores in parkinsonian patients.Methods:Patients with PD (17 Males [M], 12 Females [F]), mild PDD (5 M, 1F) and controls (8 M, 7F) underwent cognitive testing and MRI scans. The corpus callosum was divided into four regions and the cingulum into two regions bilaterally to define tracts using the program DTIstudio (Johns Hopkins University) using the fiber assignment by continuous tracking algorithm. Volumetric MRI scans were used to measure white and gray matter volumes.Results:Groups did not differ in age or education. There were no overall FA or MD differences between groups in either the corpus callosum or cingulum pathways. In PD subjects the MMSE score correlated with MD within the corpus callosum. These findings were independent of age, sex and total white matter volume.Conclusions:The data suggest that the corpus callosum or its cortical connections are associated with cognitive impairment in PD patients.

scholarly journals The impact of susceptibility correction on diffusion metrics in adolescents

2021 ◽  
Author(s):  
Katri Lahti ◽  
◽  
Riitta Parkkola ◽  
Päivi Jääsaari ◽  
Leena Haataja ◽  
...  
Keyword(s):  
Corpus Callosum ◽  
Fractional Anisotropy ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Length Distribution ◽  
Mean Diffusivity ◽  
Imaging Method ◽  
Brain White Matter ◽  
Significant Difference ◽  
The Impact

Abstract Background Diffusion tensor imaging is a widely used imaging method of brain white matter, but it is prone to imaging artifacts. The data corrections can affect the measured values. Objective To explore the impact of susceptibility correction on diffusion metrics. Materials and methods A cohort of 27 healthy adolescents (18 boys, 9 girls, mean age 12.7 years) underwent 3-T MRI, and we collected two diffusion data sets (anterior–posterior). The data were processed both with and without susceptibility artifact correction. We derived fractional anisotropy, mean diffusivity and histogram data of fiber length distribution from both the corrected and uncorrected data, which were collected from the corpus callosum, corticospinal tract and cingulum bilaterally. Results Fractional anisotropy and mean diffusivity values significantly differed when comparing the pathways in all measured tracts. The fractional anisotropy values were lower and the mean diffusivity values higher in the susceptibility-corrected data than in the uncorrected data. We found a significant difference in total tract length in the corpus callosum and the corticospinal tract. Conclusion This study indicates that susceptibility correction has a significant effect on measured fractional anisotropy, and on mean diffusivity values and tract lengths. To receive reliable and comparable results, the correction should be used systematically.

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