Kerim Aslan

Increased Laterality of the Thalamus in Children and Adolescents with Asperger's Disorder: An MRI and Proton Spectroscopy Study

Objective Thalamic abnormalities have been reported in people with pervasive developmental disorders (PDD) including Aspergers Disorder (ASP). The aim of the present study was to compare the volume and volume fraction of the thalamus and the metabolite concentrations in children and adolescents with ASP using the magnetic resonance imaging and proton magnetic resonance spectroscopy. Additionally, the relationships between thalamic abnormalities and clinical features were examined. Methods Volume and volume fractional and metabolic measurements of bilateral thalamus were collected from 15 boys with ASP with a total IQ over 70 (age range 7-18 years, mean age 11.6±3.79 years), and 15 healthy controls matching age, sex and IQ. The thalamic volumes, hemisphere volumes and total brain volumes (TBV) were estimated using the stereological methods on magnetic resonance images. Chemical metabolites of thalamus were evaluated by 1H spectroscopy. Results No differences in thalamic volumes, volume fractions and metabolites were observed between the groups. There were significant correlation between thalamic volume and total brain volume in both groups. The ASP group showed a significant left-minus-right thalamus difference as well as a significantly greater laterality index. In addition, a significant correlation between the laterality index and Autism Behavior Checklist language scores was observed. Conclusion Findings from this investigation point to a significant increase in laterality of the thalamus and a relationship with language problems in individuals with ASP. Our findings suggest that thalamic abnormalities may be related to mild language problems observed in ASP.

Structural brain alterations of Down's syndrome in early childhood evaluation by DTI and volumetric analyses.

AbstractObjectivesTo provide an initial assessment of white matter (WM) integrity with diffusion tensor imaging (DTI) and the accompanying volumetric changes in WM and grey matter (GM) through volumetric analyses of young children with Down’s syndrome (DS).MethodsTen children with DS and eight healthy control subjects were included in the study. Tract-based spatial statistics (TBSS) were used in the DTI study for whole-brain voxelwise analysis of fractional anisotropy (FA) and mean diffusivity (MD) of WM. Volumetric analyses were performed with an automated segmentation method to obtain regional measurements of cortical volumes.ResultsChildren with DS showed significantly reduced FA in association tracts of the fronto-temporo-occipital regions as well as the corpus callosum (CC) and anterior limb of the internal capsule (p < 0.05). Volumetric reductions included total cortical GM, cerebellar GM and WM volume, basal ganglia, thalamus, brainstem and CC in DS compared with controls (p < 0.05).ConclusionThese preliminary results suggest that DTI and volumetric analyses may reflect the earliest complementary changes of the neurodevelopmental delay in children with DS and can serve as surrogate biomarkers of the specific elements of WM and GM integrity for cognitive development.Key Points• DS is the most common genetic cause of intellectual disability. • WM and GM structural alterations represent the neurological features of DS. • DTI may identify the earliest aging process changes. • DTI-volumetric analyses can serve as surrogate biomarkers of neurodevelopment in DS.

Normal pressure hydrocephalus versus atrophic dilatation to distinguish and predict the benefits of surgical intervention with a phase-contrast MRI technique.

AIM To compare mean cerebrospinal fluid (CSF) volume in the aqueduct by using phase-contrast magnetic resonance imaging for the patients with idiopathic normal pressure hydrocephalus (INPH) and atrophic dilation (AD) to investigate the efficacy of this technique in predicting surgery. MATERIAL AND METHODS The MR images of a total of 80 individuals, consisting of 30 patients considered to have INPH, 20 patients with AD not proportional with cerebral sulci, and 30 control cases without a hydrocephalus clinical picture, were evaluated retrospectively. The minute mean aqueductal CSF flow rates of the three groups were compared using the Kruskall-Wallis analysis of variance, and the inter-group statistical comparisons were made using the Mann-Whitney U test. RESULTS The mean aqueductal flow rates were 46.56 ± 25.06 ml/min for the INPH group, 9.28 ± 4.68 ml/min for the AD group, and 8.68 ± 3.40 ml/min for the control group. The mean flow rate of the INPH group was significantly higher than those of the control and ADH groups (p < 0.001). CONCLUSION The mean CSF flow rate may be useful in the diagnosis and differential diagnosis, and the prediction of the potential benefits of surgical intervention for patients considered to have INPH.

Primary malignant mucosal melanoma of the nasopharynx: an unusual cause of unilateral hearing loss.

There are many causes of unilateral hearing loss, and making the correct differential diagnosis, especially in elderly patients, is difficult. A primary malignant mucosal melanoma of the nasopharynx is extremely rare and can cause a variety of symptoms. Hearing loss, as a presenting symptom of mucosal malignant melanoma of the nasopharynx, has not yet been defined in the literature. Herein, we report a case of primary mucosal malignant melanoma of the nasopharynx presented with unilateral hearing loss in a 70-year-old man.

Efficiency of B-mode Ultrasound and Strain Elastography in Differentiating Between Benign and Malignant Cervical Lymph Nodes

Purpose The purpose of this study was to evaluate the diagnostic accuracy and efficiency of ultrasonography (US), especially when combined with strain elastography (SE), in differentiating between benign and malignant cervical lymph nodes (LNs). Methods Forty-one LNs were examined by B-mode US, power Doppler US, and SE. The following imaging features were analyzed: shape, echogenicity, echogenic hilum, calcification, intranodal vascular pattern, elasticity scores (5 categories), and strain ratio. The average strain ratio was calculated as the mean strain of the adjacent sternocleidomastoid muscle divided by the mean strain of the target LN. The results of the US and SE features were compared with the histopathologic findings. Results The imaging features that were significantly associated with malignant LNs were an increased short-to-long axis diameter ratio, abnormal or absence of hilum, microcalcification, type 2-3-4 vascularity, 3-4-5 elasticity scores, and a high level of strain ratio (P < 0.05). The cutoff value of the strain index was detected as 1.18. According to this, there was a significant difference (P = 0.004) in the strain index between benign and malignant LNs. Conclusions Strain elastography is useful in differentiating between benign and malignant cervical LNs, thereby informing decisions to perform a biopsy and/or surgery, and facilitating follow-up.

Effects of short and long term electromagnetic fields exposure on the human hippocampus

The increasing use of mobile phones may have a number of physiological and psychological effects on human health. Many animal and human studies have reported various effects on the central nervous system and cognitive performance from of exposure to electromagnetic fields (EMF) emitted by mobile phones. The aim of the present study was to evaluate the effects of mobile phones on the morphology of the human brain and on cognitive performance using stereological and spectroscopic methods and neurocognitive tests. Sixty healthy female medical school students aged 18–25 years were divided into a low exposure group (30 subjects, <30 min daily use by the head) and high exposure group (30 subjects, >90 min daily use by the head). Magnetic resonance images (MRI) of the brain analysed on OsiriX 3.2.1 workstation. Neuropsychological tests were performed for each subject. In addition, three dominant specific metabolites were analysed, choline at 3.21 ppm, creatine at 3.04 ppm and N-acetyl aspartate at 2.02 ppm. Analysis of the spectroscopic results revealed no significant difference in specific metabolites between the groups (p > 0.05). There was also no significant difference in terms of hippocampal volume between the groups (p > 0.05). In contrast, the results of the stroop and digit span (backward) neurocognitive tests of high exposure group for evaluating attention were significantly poorer from low exposure group (p < 0.05). Based on these results, we conclude that a lack of attention and concentration may occur in subjects who talk on mobile phones for longer times, compared to those who use phones relatively less.

Limbic-Auditory Interactions of Tinnitus: An Evaluation Using Diffusion Tensor Imaging

ObjectiveTinnitus is defined as an imaginary subjective perception in the absence of an external sound. Convergent evidence proposes that tinnitus perception includes auditory, attentional and emotional components. The aim of this study was to investigate the thalamic, auditory and limbic interactions associated with tinnitus-related distress by Diffusion Tensor Imaging (DTI).MethodsA total of 36 tinnitus patients, 20 healthy controls underwent an audiological examination, as well as a magnetic resonance imaging protocol including structural and DTI sequences. All participants completed the Tinnitus Handicap Inventory (THI) and Visual Analog Scales (VAS) related with tinnitus. The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were obtained for the auditory cortex (AC), inferior colliculus (IC), lateral lemniscus (LL), medial geniculate body (MGB), thalamic reticular nucleus (TRN), amygdala (AMG), hippocampus (HIP), parahippocampus (PHIP) and prefrontal cortex (PFC).ResultsIn tinnitus patients the FA values of IC, MGB, TRN, AMG, HIP decreased and the ADC values of IC, MGB, TRN, AMG, PHIP increased significantly. The contralateral IC-LL and bilateral MGB FA values correlated negatively with hearing loss. A negative relation was found between the AMG-HIP FA values and THI and VAS scores. Bilateral ADC values of PHIP and PFC significantly correlated with the attention deficiency—VAS scores.ConclusionIn conclusion, this is the first DTI study to investigate the grey matter structures related to tinnitus perception and the significant correlation of FA and ADC with clinical parameters suggests that DTI can provide helpful information for tinnitus. Magnifying the microstructures in DTI can help evaluate the three faces of tinnitus nature: hearing, emotion and attention.

Imaging of unilateral adrenal hemorrhages in patients after blunt abdominal trauma: Report of two cases

Adrenal hemorrhage following blunt abdominal trauma is extremely rare. Most of the lesions are unilateral and right sided. Although often asymptomatic, life-threatening adrenal insufficiency may develop in the bilateral adrenal gland hemorrhage. Isolated adrenal injuries are very rare. They are often associated with other organ injuries. The mortality rates of patients range from 7% to 32%. In this report, we present the computed tomography and magnetic resonance imaging findings of unilateral adrenal hemorrhages in two patients with a history of fall from a height.

Magnetic Resonance Imaging Evidence of Varicella Zoster Virus Polyneuropathy: Involvement of the Glossopharyngeal and Vagus Nerves Associated With Ramsay Hunt Syndrome.

The involvement of lower cranial nerve palsies is less frequent in Ramsay Hunt syndrome caused by varicella zoster virus (VZV). The authors report 1 of extremely rare patients of radiologically proven polyneuropathy of VZV infection with magnetic resonance imaging findings of VII, IX, and X cranial nerve involvement is a 62-year-old female patient, who initially presented with Ramsay Hunt syndrome. Varicella zoster virus infection should be considered even in patients who show unilateral palsy of the lower cranial nerves associated with laryngeal paralysis. Thin-section T2W and T1W images with a contrast agent should be added to the imaging protocol to show the subtle involvement.

Diagnostic performance of diffusion-weighted MRI in the diagnosis of ovarian torsion: comparison of torsed and nonaffected ovaries

INTRODUCTION The aim of this study was to evaluate the role of diffusion-weighted magnetic resonance imaging (MRI) in the diagnosis of ovarian torsion. METHODS We retrospectively identified 84 patients with surgically confirmed ovarian torsion. Seventeen patients with unclear ultrasound findings underwent MRI examination with two different magnetic resonance (MR) systems. RESULTS In ovarian torsion, the mean apparent diffusion coefficient (ADC) value of the torsed ovary was significantly lower than that of the nonaffected ovary in both MR systems (n=17; 0.898±0.539 vs. 1.615±0.469×10(-3)mm(2)/s; P<.001). CONCLUSIONS ADC comparisons were useful for detecting ovarian torsion.