Corticospinal tract asymmetry and handedness in right- and left-handers by diffusion tensor tractography

Purpose

Cerebral hemispheres represent both structural and functional asymmetry, which differs among right- and left-handers. The left hemisphere is specialised for language and task execution of the right hand in right-handers. We studied the corticospinal tract in right- and left-handers by diffusion tensor imaging and tractography. The present study aimed at revealing a morphological difference resulting from a region of interest (ROI) obtained by functional MRI (fMRI).

Methods

Twenty-five healthy participants (right-handed: 15, left-handed: 10) were enrolled in our assessment of morphological, functional and diffusion tensor MRI. Assessment of brain fibre reconstruction (tractography) was done using a deterministic algorithm. Fractional anisotropy (FA) and mean diffusivity (MD) were studied on the tractography traces of the reference slices.

Results

We observed a significant difference in number of leftward fibres based on laterality. The significant difference in regard to FA and MD was based on the slices obtained at different levels and the laterality index. We found left-hand asymmetry and right-hand asymmetry, respectively, for the MD and FA.

Conclusions

Our study showed the presence of hemispheric asymmetry based on laterality index in right- and left-handers. These results are inconsistent with some studies and consistent with others. The reported difference in hemispheric asymmetry could be related to dexterity (manual skill).     

Diffusion tensor imaging analysis of optic radiation using readout-segmented echo-planar imaging

Purpose

To investigate the diffusion tensor imaging parameters of the optic radiation and surrounding structures using the high-resolution readout-segmented diffusion tensor imaging method.

Materials and methods

Coronal readout-segmented diffusion tensor images were acquired in 15 healthy volunteers. On three slices of each image, eigenvalue 1, fractional anisotropy, radial diffusivity, apparent diffusion coefficient, and signal intensity on T2-weighted images were measured in the lateral inferior longitudinal fasciculus, external and internal layers of the optic radiation, and the tapetum within regions of interest delineated by two independent observers. Profile curve analysis of regions of interest across the optic radiation and surrounding structures was performed for a representative typical case.

Results

Significant differences in fractional anisotropy, radial diffusivity and apparent diffusion coefficient were observed between external and internal layers of the optic radiation, while there was no significant difference in eigenvalue 1. In fractional anisotropy maps, two low signal bands were observed between the inferior longitudinal fasciculus, the optic radiation and the tapetum. Profile curve analysis showed a minimum on the fractional anisotropy and eigenvalue 1 images and a maximum in the radial diffusivity image.

Conclusion

Readout-segmented diffusion tensor imaging revealed significant differences in the diffusion tensor imaging parameters between internal and external layers of the optic radiation.     

Demonstration of different histological layers of the pachygyria/agyria cortex using diffusion tensor MR imaging

Purpose

Pachygyria/agyria are congenital brain malformations characterized by presence of a few broad, flat gyri with thickened cortex, resulting from arrest of neuronal migration in early gestation. We are hereby describing diffusion tensor imaging findings in different histological layers of lissencephaly cortex in two children.

Method

DTI in addition to conventional MR imaging was performed in two children on a 3 T MRI and post-processed with vendor supplied software to generate the fractional anisotropy, mean diffusivity and trace maps. Tractography was also performed to identify presence of tracts in the thickened cortex.

Results

DTI demonstrated the dysplastic multilayered cortex in cases of pachygyria/agyria; the thickened fourth layer and superficial layer demonstrated high anisotropy on diffusion tensor imaging.

Conclusion

DTI is a useful tool for identifying gross histological features of pachygyria–agyria complex. Superficial layer and thickened fourth layer demonstrate high anisotropy. Identification of anisotropy in the superficial layer has not been described in previous reports.     

Standardized volumetric 3D-analysis of SPECT/CT imaging in orthopaedics: overcoming the limitations of qualitative 2D analysis

Background

Diffusion tensor imaging (DTI) is increasingly used in various diseases as a clinical tool for assessing the integrity of the brain’s white matter. Reduced fractional anisotropy (FA) and an increased apparent diffusion coefficient (ADC) are nonspecific findings in most pathological processes affecting the brain’s parenchyma. At present, there is no gold standard for validating diffusion measures, which are dependent on the scanning protocols, methods of the softwares and observers. Therefore, the normal variation and repeatability effects on commonly-derived measures should be carefully examined.

Methods

Thirty healthy volunteers (mean age 37.8 years, SD 11.4) underwent DTI of the brain with 3T MRI. Region-of-interest (ROI) -based measurements were calculated at eleven anatomical locations in the pyramidal tracts, corpus callosum and frontobasal area. Two ROI-based methods, the circular method (CM) and the freehand method (FM), were compared. Both methods were also compared by performing measurements on a DTI phantom. The intra- and inter-observer variability (coefficient of variation, or CV%) and repeatability (intra-class correlation coefficient, or ICC) were assessed for FA and ADC values obtained using both ROI methods.

Results

The mean FA values for all of the regions were 0.663 with the CM and 0.621 with the FM. For both methods, the FA was highest in the splenium of the corpus callosum. The mean ADC value was 0.727 ×10^-3 mm²/s with the CM and 0.747 ×10^-3 mm²/s with the FM, and both methods found the ADC to be lowest in the corona radiata. The CV percentages of the derived measures were < 13% with the CM and < 10% with the FM. In most of the regions, the ICCs were excellent or moderate for both methods. With the CM, the highest ICC for FA was in the posterior limb of the internal capsule (0.90), and with the FM, it was in the corona radiata (0.86). For ADC, the highest ICC was found in the genu of the corpus callosum (0.93) with the CM and in the uncinate fasciculus (0.92) with FM.

Conclusions

With both ROI-based methods variability was low and repeatability was moderate. The circular method gave higher repeatability, but variation was slightly lower using the freehand method. The circular method can be recommended for the posterior limb of the internal capsule and splenium of the corpus callosum, and the freehand method for the corona radiata.     

Diffusion tensor MR imaging characteristics of cerebral white matter development in fetal pigs

Background

The purpose of this study was to investigate the anisotropic features of fetal pig cerebral white matter (WM) development by magnetic resonance diffusion tensor imaging, and to evaluate the developmental status of cerebral WM in different anatomical sites at different times.

Methods

Fetal pigs were divided into three groups according to gestational age: E69 (n?=?8), E85 (n?=?11), and E114 (n?=?6). All pigs were subjected to conventional magnetic resonance imaging (MRI) and diffusion tensor imaging using a GE Signa 3.0 T MRI system (GE Healthcare, Sunnyvale, CA, USA). Fractional anisotropy (FA) was measured in deep WM structures and peripheral WM regions. After the MRI scans,the animals were sacrificed and pathology sections were prepared for hematoxylin & eosin (HE) staining and luxol fast blue (LFB) staining. Data were statistically analyzed with SPSS version 16.0 (SPSS, Chicago, IL, USA). A P-value?<?0.05 was considered statistically significant. Mean FA values for each subject region of interest (ROI), and deep and peripheral WM at different gestational ages were calculated, respectively, and were plotted against gestational age with linear correlation statistical analyses. The differences of data were analyzed with univariate ANOVA analyses.

Results

There were no significant differences in FAs between the right and left hemispheres. Differences were observed between peripheral WM and deep WM in fetal brains. A significant FA growth with increased gestational age was found when comparing E85 group and E114 group. There was no difference in the FA value of deep WM between the E69 group and E85 group. The HE staining and LFB staining of fetal cerebral WM showed that the development from the E69 group to the E85 group, and the E85 group to the E114 group corresponded with myelin gliosis and myelination, respectively.

Conclusions

FA values can be used to quantify anisotropy of the different cerebral WM areas. FA values did not change significantly between 1/2 way and 3/4 of the way through gestation but was then increased dramatically at term, which could be explained by myelin gliosis and myelination ,respectively.

     

Bispectral index monitoring of sleep in palliative care patients

Purpose

In patients receiving palliative care (PC), sleep is often negatively influenced by pain, anxiety and medication. Because these patients are often too sick to be investigated in a sleep laboratory, it is difficult to obtain objective information concerning their sleep. This study investigates whether bispectral index (BIS) monitoring reflects wakefulness, sleep and the effect of medication and whether it is tolerable for patients.

Methods

In all, 10 patients from an inpatient PC unit participated in the study. They were monitored using a BIS system for one night, while each event was carefully documented by patient care attendants. In addition, participants completed a questionnaire on the evening prior to and on the morning following the recording about their subjective wellbeing and sleep.

Results

On a scale from 0 to 100, BIS measurements covered values ranging from a minimum of 29–40 to a maximum of 74–98. Individual differences between minimum and maximum ranged between 38 and 68. High BIS values are associated with wakefulness, low BIS values with sleep. The administration of sedative and analgesic medication was followed by a long-lasting decrease in BIS measurements. In 3 patients, the measurements were discontinued due to the patient being disturbed or irritation of the skin.

Conclusion

BIS monitoring was well tolerated by most but not all patients. It can be useful in complementing patients’ reports in questionable cases. This might be of special interest in outpatient settings where continuous objective professional observation is not available.     

Cartilage-Hair Hypoplasia: Follow-Up of Immunodeficiency in Two Patients

Purpose

To study the changes in the immunological status in 2 children with cartilage hair hypoplasia (CHH).

Methods

A 4–6 year immunological follow-up from infancy.

Results

In infancy the children presented a combined T cell and B cell immunodeficiency which partly resolved in time. Mitogen-induced T cell proliferation values fluctuated but lymphopenia has remained constant. Both patients had no recent thymic emigrants (TREC). Both children have suffered from a prolonged viral infection. Hypogammaglobulinemia normalized during the first years of life but both children have a specific antibody deficiency (SAD).

Conclusions

The changes in the immunological status in CHH patients emphasize the importance of a regular follow-up. SAD should be searched for in CHH. The absence of TRECs supports combined immunodeficiency and possible need of hematopoietic stem cell transplantion.     

Life Changes in Patients After Out-of-Hospital Cardiac Arrest

Background

Cardiac arrest is a traumatic event that often affects patients’ lives in many ways. Patients after near-death experiences (NDEs) often express strong and permanent change of their values, beliefs and principles.

Purpose

The aim of this study was to determine the association between NDEs and life changes in patients 6 months after out-of-hospital cardiac arrest.

Method

This was a prospective observational study, which included 37 patients (average age 54.0 years, range 22–81 years, 29 males) 6 months after out-of-hospital cardiac arrest. The presence of NDEs was assessed with a self-administered Greyson’s NDE scale. The intensity of life changes was assessed with a self-administered Ring’s life change inventory. Univariate analysis was performed.

Results

NDEs were reported by seven (18.9%) patients. In comparison to the non-NDEs group, patients in the NDEs group expressed significantly stronger changes in the following items: tolerance for others, understanding of myself, appreciation of nature, sense that there is some inner meaning to my life and concern with questions of social justice.

Conclusions

Cardiac arrest survivors do not express extensive life changes. But, the presence of NDEs is significantly associated with the change of interest in some aspects of patients’ lives. Such patients should be prepared for significant life changes that might occur after NDEs by health workers and receive professional help to accommodate to them.     

The Munich Parasomnia Screening in psychiatry

Background

The aim was to investigate the subjective experience of parasomnias and other nocturnal behaviors in depression and schizophrenia.

Materials and methods

Using the Munich Parasomnia Screening (MUPS), 21 parasomnias and other nocturnal behaviors were assessed in 85 participants; 27 were patients with depression, 29 were patients with schizophrenia, and 29 were healthy control participants.

Results

A significant group difference was found for: hypnagogic hallucinations, sleep-related bruxism, sleep talking, sleep-related abnormal swallowing, leg cramps, nightmares, pavor nocturnus, confusional arousals, and sleep paralysis. The highest scores in depression point toward a correlation between depression and the prevalence of parasomnias. Parasomnias did not cluster according to their occurrence.

Conclusion

Although all patients with depression had experienced nocturnal behaviors, none had a previous parasomnia diagnosis or was treated accordingly. Of all participants, 97.6% had experienced nocturnal behaviors. Prevalence in depression was highest, asking for more clinical awareness and thereby better future treatments and outcomes. A screening instrument like the MUPS is essential in filtering out patients who seem to experience parasomnias.     

Inflammatory markers and bariatric surgery: a meta-analysis

Objective

Obesity is a state of chronic low grade inflammation with increased levels of inflammatory markers such as C-reactive protein (CRP), interleukin (IL)-6 and tumor necrosis factor (TNF) α. The changes of some of the above markers after bariatric surgery are not consistent across studies. The objective of this study is to confirm the changes in blood levels of CRP, IL-6 and TNFα after bariatric surgery.

Methods

A Pubmed and EMBASE search was performed for studies measuring the above cytokines in blood before and after bariatric surgery. A meta-analysis was performed for the changes in CRP, TNFα and IL-6 for the maximum follow-up time in each study as well as for discrete follow-up times.

Results

Only observational studies could be retrieved. Bariatric surgery produces about 66 and 27?% reduction in CRP and IL-6 levels, respectively. The change in TNFα after bariatric surgery did not approach statistical significance.

Conclusion

Bariatric surgery decreases the low grade inflammation associated with obesity as measured by CRP and IL-6 levels. The change of TNFα after bariatric surgery should be further investigated with randomized trials.     

Neuroinflammation mediated by IL-1β increases susceptibility of dopamine neurons to degeneration in an animal model of Parkinson's disease

Background

The etiology of Parkinson's disease (PD) remains elusive despite identification of several genetic mutations. It is more likely that multiple factors converge to give rise to PD than any single cause. Here we report that inflammation can trigger degeneration of dopamine (DA) neurons in an animal model of Parkinson's disease.

Methods

We examined the effects of inflammation on the progressive 6-OHDA rat model of Parkinson's disease using immunohistochemistry, multiplex ELISA, and cell counting stereology.

Results

We show that a non-toxic dose of lipopolysaccharide (LPS) induced secretion of cytokines and predisposed DA neurons to be more vulnerable to a subsequent low dose of 6-hydroxydopamine. Alterations in cytokines, prominently an increase in interleukin-1beta (IL-1β), were identified as being potential mediators of this effect that was associated with activation of microglia. Administration of an interleukin-1 receptor antagonist resulted in significant reductions in tumor necrosis factor-α and interferon-γ and attenuated the augmented loss of DA neurons caused by the LPS-induced sensitization to dopaminergic degeneration.

Conclusion

These data provide insight into the etiology of PD and support a role for inflammation as a risk factor for the development of neurodegenerative disease.     

Effect of medial tibial torsion on the sagittal alignment of lower legs in patients with medial knee osteoarthritis

Purpose

The fibular axis (FA) and anterior tibial cortex (ATC) are good determinants of the sagittal mechanical axis (MA) of lower legs during total knee arthroplasty (TKA).When compared with healthy subjects, a significant medial tibial torsion has been reported in patients with medial knee osteoarthritis; this should affect the alignment of lower legs. The purpose of this study was to clarify the effect of the medial torsion on relationship between sagittal MA and intraoperative references (FA and ATC).

Methods

Fifty knees of 50 patients with medial knee osteoarthritis who underwent primary TKA were included in this study. Using preoperative computed tomographic data, the tibial torsion angle was measured in the axial plane. The angle between FA and MA, and the angle between ATC and MA were also measured in the sagittal plane.

Results

The tibial torsion angle was 7.9° ± 7.2° (range ?11.3° to ?24.3°). The angle between MA and FA was ?1.8° ± 0.8° (range ?0.1° to ?4.3°), and the angle between MA and ATC was 4.6° ± 0.5° (range 3.1° to 5.5°). The population variance was significantly larger for the angle between MA and FA than that between MA and ATC (P = 0.0160). There was a significant positive correlation between the tibial torsion angle and the angle between MA and FA (R ² = 0.5111, P < 0.0001).

Conclusion

The angle between FA and MA in the sagittal plane increased in patients with large medial tibial torsion.     

Promoter polymorphism -119C/G in MYG1 (C12orf10) gene is related to vitiligo susceptibility and Arg4Gln affects mitochondrial entrance of Myg1

Background

The gene encoding carboxyl-terminal PDZ ligand of neuronal nitric oxide synthase (NOS1AP) is located on chromosome 1q23.3, a candidate region for schizophrenia, autism spectrum disorders (ASD) and obsessive-compulsive disorder (OCD). Previous genetic and functional studies explored the role of NOS1AP in these psychiatric conditions, but only a limited number explored the sequence variability of NOS1AP.

Methods

We analyzed the coding sequence of NOS1AP in a large population (n = 280), including patients with schizophrenia (n = 72), ASD (n = 81) or OCD (n = 34), and in healthy volunteers controlled for the absence of personal or familial history of psychiatric disorders (n = 93).

Results

Two non-synonymous variations, V37I and D423N were identified in two families, one with two siblings with OCD and the other with two brothers with ASD. These rare variations apparently segregate with the presence of psychiatric conditions.

Conclusions

Coding variations of NOS1AP are relatively rare in patients and controls. Nevertheless, we report the first non-synonymous variations within the human NOS1AP gene that warrant further genetic and functional investigations to ascertain their roles in the susceptibility to psychiatric disorders.     

Schlafbezogene Atmungsstörungen bei Parkinsonsyndromen: Häufigkeit, Art und Behandlungsansätze

Objective

In recent literature the contribution of sleep related breathing disorders [SRBD] to the complex sleep disorder of Parkinson's disease [PD] patients is controversely discussed. In our study we discovered the frequency and kind of SRBD in a group of PD patients with sleep complaints.

Patients and methods

83 patients with different types of parkinsonism were studied polysomnographically. Respiration was measured by means of inductance plethysmography, capnography, and pulse oximetry. Different analysing techniques were used. Besides the evaluation of apneas and hypopneas a visual classification of the respiratory pattern and a breath-to-breath calculation of the laboured breathing index [LBI] was carried out.

Results

More than 50% of the patients showed sleep disordered breathing. Most of them had upper airway obstructions. Central apnea was observed in 5 cases, three of those suffered from a heart disease. In 25% the SRBD should be treated. The LBI calculation revealed hints for short pharyngeal obstructions in each patient. This parameter turned out to be highly sensitive to detect changes in upper airway mechanics and was therefore considered to be useful in testing dopaminergic influences on respiratory movements.

Conclusion

Disturbances of the extrapyramidal motor system may lead to long lasting obstructive hypoventilation of different clinical importance. Specific measurement techniques should be used to identify these disturbances. The laboured breathing index may be useful to detect dopaminergic deficits in respiratory motion. As more than 50% of severe SRBD patients are not able to handle nCPAP it is necessary to develop pharmacological options. Dopaminergic medication as a possible therapeutical alternative to nCPAP should be tested in further studies.     

Functional characterization of the complement receptor type 1 and its circulating ligands in patients with schizophrenia

Background

Whereas the complement system alterations contribute to schizophrenia, complement receptors and regulators are little studied. We investigated complement receptor type 1 (CR1) expression on blood cells, the levels of circulating immune complexes (CIC) containing ligands of CR1, C1q complement protein and fragments of C3 complement protein (C1q-CIC, C3d-CIC), and CR1 C5507G functional polymorphism in schizophrenia patients and controls.

Results

We found an increased C1q-CIC level and CR1 expression on blood cells, elevated number of CR1 positive erythrocytes and reduced number of CR1 positive lymphocytes and monocytes in patients compared to controls. No difference in the levels of C3d-CIC between groups was observed. Higher CR1 expression on erythrocytes in CC genotype versus CG+GG for both groups was detected, whereas no difference was observed for other cell populations. Our results indicated that schizophrenia is associated with the increased CR1 expression and C1q-CIC level.

Conclusions

Our study for the first time indicated that schizophrenia is associated with the increased CR1 expression and C1q-CIC level. Further studies in other ethnic groups are needed to replicate these findings.     

Changes in contractile and elastic properties of the triceps surae muscle induced by neuromuscular electrical stimulation training

Purpose

Neuromuscular electrical stimulation (NMES) training is known to induce improvement in force production capacities and fibre-type transition. The aim of this study was to determine whether NMES training also leads to changes in the mechanical properties of the human triceps surae (TS) muscle.

Methods

Fifteen young male subjects performed a training protocol (4 weeks, 18 sessions, 4–5 sessions per week) based on a high-frequency isometric NMES programme of TS muscle. Quick-release test was used to evaluate Musculo-Tendinous (MT) stiffness index (SI_MT) as the slope of the linear MT stiffness–torque relationships under submaximal contraction. Sinusoidal perturbations allowed the assessment of musculo-articular stiffness index (SI_MA) as well as the calculation of the maximal angular velocity ( \(\varTheta_{\hbox{max} }^{{\prime }}\) ) of TS muscle using an adaptation of Hill’s equation.

Results

After NMES training, Maximal Voluntary Contraction under isometric conditions and \(\varTheta_{\hbox{max} }^{{\prime }}\) increased significantly by 17.5 and 20.6 %, respectively, while SI_MT and SI_MA decreased significantly (?12.7 and ?9.3 %, respectively).

Conclusions

These changes in contractile and elastic properties may lead to functional changes of particular interest in sport-related activities as well as in the elderly.     

The Stigma Scale for Chronic Illnesses 8-Item Version (SSCI-8): Development, Validation and Use Across Neurological Conditions

Background

Although the impact of stigma has been highlighted for epileptic populations, the experiences of people living with other neurological conditions have been less studied.

Purpose

In order to promote research on stigma among people with neurological conditions, we sought to develop and psychometrically validate an eight-item questionnaire measuring internalised and enacted stigma experienced by people with epilepsy, multiple sclerosis (MS), Parkinson’s disease (PD), stroke and amyotrophic lateral sclerosis (ALS).

Method

We used item response theory methodologies to select items and field tested our items with 587 participants from eight academic medical centres across the USA.

Results

We conducted exploratory and confirmatory factor analysis as well as examined the scale’s reliability and validity. In addition, we conducted an analysis of variance test to examine mean total score differences across the five neurological conditions. Data from people across conditions revealed that the shortened instrument conformed to an essentially unidimensional model of multifaceted stigma as a one-factor questionnaire with correlated residuals on a pair of items that distinctly measured internalised stigma.

Conclusion

Preliminary evidence suggests that the Stigma Scale for Chronic Illness 8-item version fits a unidimensional model, which assesses enacted and internalised stigma, and has adequate internal consistency/reliability and validity in relation to psychological distress and patient performance. Our results suggest fairly low stigma for neurological populations. In addition, our results suggest that stigma may be more severe for patients with ALS relative to those with MS and PD. In the future, the SSCI-8 scale could be used practically in clinic settings to examine stigma without the patient burden associated with lengthier scales.