Szilvia Anett Nagy

Are there any gender differences in the hippocampus volume after head-size correction? A volumetric and voxel-based morphometric study

Previous findings on normal sexual dimorphism in hippocampal volume have not always been consistent. This study investigated gender differences in hippocampal volume using different head-size correction strategies. T1-weighted MR images were collected in 99 healthy, Caucasian, university students (66 female subjects; mean age: 23.1 ± 2.3, range: 19-31 years). Sexual dimorphism in hippocampus was investigated by automated MRI volumetry and voxel-based morphometry (VBM) using both general linear model (GLM) and proportion head-size correction strategies. Absolute hippocampal volumes were larger in men than women. After adjusting for head-size, the proportion method indicated larger hippocampi in women than men, while no gender differences were found using the GLM approach. Investigating absolute hippocampal volumes in 15 head-size matched pairs of males and females indicated no gender differences. We suggest that there is no sexual dimorphism in hippocampal size and the apparent gender differences found by the proportion method may have more to do with head-size than with sex. The GLM and proportion head-size correction strategies are not interchangeable and may yield different results. The importance of the present findings is mostly related to scientific reproducibility across MRI volumetry or VBM studies.

Changes of Migraine‐Related White Matter Hyperintensities After 3 Years: A Longitudinal MRI Study

The aim of this longitudinal study was to investigate changes of migraine‐related brain white matter hyperintensities 3 years after an initial study. Baseline quantitative magnetic resonance imaging (MRI) studies of migraine patients with hemispheric white matter hyperintensities performed in 2009 demonstrated signs of tissue damage within the hyperintensities. The hyperintensities appeared most frequently in the deep white matter of the frontal lobe with a similar average hyperintensity size in all hemispheric lobes. Since in this patient group the repeated migraine attacks were the only known risk factors for the development of white matter hyperintensities, the remeasurements of migraineurs after a 3‐year long follow‐up may show changes in the status of these structural abnormalities as the effects of the repeated headaches.

Quantitative MRI studies of chronic brain white matter hyperintensities in migraine patients.

The aim of this study was to examine chronic brain white matter hyperintensities in migraine and to gain data on the characteristics of the lesions.

Intracranial volume inversely correlates with serum 25(OH)D level in healthy young women

Abstract Objectives Vitamin D is important in normal brain development. In animals low vitamin D level is associated with brain morphological alterations including enlargement of the brain. Whether a similar association exists in humans is unknown. Here we investigated the relationship between vitamin D and total intracranial volume as well as total volume of the cortical grey and cerebral white matter and that of the ventricles in young healthy women. Methods To assess volumes we applied semi-automatic user-independent MR volumetry. For the vitamin D measurements automated electrochemiluminescence immunoassay was used. Results We found a significant negative correlation between vitamin D and total intracranial volume as well as total cortical grey and cerebral white matter volumes. Discussion This association may reflect a trait-like relationship between vitamin D and brain size possibly determined in early development.

Bi-exponential diffusion signal decay in normal appearing white matter of multiple sclerosis.

PURPOSE Our aim was to characterize bi-exponential diffusion signal changes in normal appearing white matter of multiple sclerosis (MS) patients. METHODS Diffusion parameters were measured using mono-exponential (0-1000 s/mm(2)) and bi-exponential (0-5000 s/mm(2)) approaches from 14 relapsing-remitting subtype of MS patients and 14 age- and sex-matched controls after acquiring diffusion-weighted images on a 3T MRI system. The results were analyzed using parametric or nonparametric tests and multiple linear regression models. RESULTS Mono-exponential apparent diffusion coefficient (ADC) slightly increased in controls (P=.09), but decreased significantly in MS as a function of age, nonetheless an elevated ADC was observed with increasing lesion number in patients. Bi-exponential analyses showed that the increased ADC is the result of decreased relative volume fraction of slow diffusing component (f(s)). However, the fast and slow diffusion components (ADC(f), ADC(s)) did not change as a function of either age in controls or lesion number and age in MS patients. CONCLUSIONS These data demonstrated that the myelin content of the white matter affects diffusion in relapsing-remitting subtype of multiple sclerosis that is possibly a consequence of the shift between different water fractions.

Quantitative assessment of brain iron by R2* relaxometry in patients with cervical dystonia

The pathophysiology of cervical dystonia is poorly understood. Increased brain iron deposition has been described in different movement disorders. Our aim was to investigate brain iron content in patients with cervical dystonia, using R2* relaxation rate, a validated MRI marker of brain iron level.

Pilot Study of Cartilage Repair in the Knee Joint with Multiply Incised Chondral Allograft

Background Focal cartilage lesions in the knee joint have limited capacity to heal. Current animal experiments show that incisions of the deep zone of a cartilage allograft allow acceptable integration for the graft. Questions/Purposes We performed this clinical study to determine (1) if the multiply incised cartilage graft is surgically applicable for focal cartilage lesions, (2) whether this allograft has a potential to integrate to the repair site, and (3) if patients show clinical improvement. Patients and Methods Seven patients with 8 chondral lesions were enrolled into the study. Symptomatic lesions between 2 and 8 cm2 were accepted. Additional injuries were allowed but were addressed simultaneously. Grafts were tailored to match and the deep zone of the cartilage was multiply incised to augment the basal integration before securing in place. Rigorous postoperative physiotherapy followed. At 12 and 24 months the patients’ satisfaction were measured and serial magnetic resonance imaging (MRI) was performed in 6 patients. Results Following the implantations no adverse reaction occurred. MRI evaluation postoperatively showed the graft in place in 5 out of 6 patients. In 1 patient, MRI suggested partial delamination at 1 year and graft degeneration at 2 years. Short Form–36 health survey and the Lysholm knee score demonstrated a significant improvement in the first year; however, by 2 years there was a noticeable drop in the scores. Conclusions. Multiply incised pure chondral allograft used for cartilage repair appears to be a relatively safe method. Further studies are necessary to assess its potential in cartilage repair before its clinical use.

Alexithymia is associated with low level of vitamin D in young healthy adults

Abstract Objective Vitamin D plays an important role in brain development and functioning. Low levels of vitamin D have been described in several psychiatric and neurologic conditions including autism spectrum disorder. Alexithymia that shows high comorbidity with autism is also present in the general population as well as hypovitaminosis D. Methods Here we assessed the relation between alexithymia as measured by the Toronto Alexithymia Scale-20 and vitamin D level in healthy young adults. Results We found an inverse correlation between the levels of alexithymia and vitamin D. Discussion These data suggest the association between disturbed emotional processing and low levels of vitamin D to be present in young healthy subjects.

Biexponential diffusion alterations in the normal-appearing white matter of glioma patients might indicate the presence of global vasogenic edema

To investigate normal‐appearing white matter (NAWM) microstructure of glioma patients with biexponential diffusion analysis in order to reveal the nature of diffusion abnormalities and to assess whether they are region‐specific or global.

Differentiating white matter lesions in multiple sclerosis and migraine using monoexponential and biexponential diffusion measurements

To compare the white matter lesions seen in multiple sclerosis and migraine using monoexponential and high b‐value biexponential diffusion measurements.