Fronto-striatal structures related with model-based control as an endophenotype for obsessive–compulsive disorder

Recent theories suggest a shift from model-based goal-directed to model-free habitual decision-making in obsessive-compulsive disorder (OCD). However, it is yet unclear, whether this shift in the decision process is heritable. We investigated 32 patients with OCD, 27 unaffected siblings (SIBs) and 31 healthy controls (HCs) using the two-step task. We computed behavioral and reaction time analyses and fitted a computational model to assess the balance between model-based and model-free control. 80 subjects also underwent structural imaging. We observed a significant ordered effect for the shift towards model-free control in the direction OCD>SIB>HC in our computational parameter of interest. However less directed analyses revealed no shift towards model-free control in OCDs. Nonetheless, we found evidence for reduced model-based control in OCDs compared to HCs and SIBs via 2nd stage reaction time analyses. In this measure SIBs also showed higher levels of model-based control than HCs. Across all subjects these effects were associated with the surface area of the left medial/right dorsolateral prefrontal cortex. Moreover, correlations between bilateral putamen/right caudate volumes and these effects varied as a function of group: they were negative in SIBs and OCDs, but positive in HCs. Associations between fronto-striatal regions and model-based reaction time effects point to a potential endophenotype for OCD

Reactive changes of disc space and foreign body granuloma due to bone wax in lumbar spine

Bone wax is a well-known agent used to prevent bleeding from the bone that can be used in different surgical procedures. Bone wax is a safe agent, but it may rarely lead to significant foreign body reactions. In this report, we present a patient who developed bone wax-related disc space foreign body granuloma following L4 total laminectomy, extremely rare complication

Giant Fusiform Basilar Artery Aneurysm Causing Obstructive Hydrocephalus

A 58-year-old man presented with a sudden onset gait disturbance and urinary incontinence. Magnetic resonance (MR) imaging and MR angiography showed a fusiform basilar artery aneurysm, 2 cm in diameter and 5 cm long. The aneurysm was thrombosed except the ectatic basilar artery flowing through it. Compression of the cerebrospinal fluid (CSF) pathways caused obstructive hydrocephalus with resultant transependymal CSF leakage. Conventional angiography missed the aneurysm. A one-sided ventriculoperitoneal shunt was placed to treat the patient's hydrocephalus. The patient's symptoms improved after surgery. MR imaging and MR angiography were useful noninvasive methods of detecting the aneurysm, defining its relationship with surrounding structures, and determining the cause of the hydrocephalus

Clinical and MRI findings of cerebellar agenesis in two living adult patients

Cerebellar agenesis (CA) is an extremely rare entity. We present two adult patients with CA. The 61-year-old man had ataxia, dysarthria, abnormalities in cerebellar tests, severe cognitive impairment, and moderate mental retardation. The 26-year-old woman had dysmetria, dysdiadochokinesia, and dysarthria as well as mild cognitive impairment and mild mental retardation. Magnetic resonance imaging (MRI) showed complete absence of the cerebellum with small residual vermis. Brainstem was hypoplastic and structures above tentorium were normal. Supratentorial white matter bundles were unaffected in diffusion tensor tractography. Only few adult patients with CA have so far been published. These cases show that patients with CA present with a variety of developmental, clinical, and mental abnormalities; and emphasize the role of the cerebellum in normal motor, language, and mental development

THE ROLE OF THE POPLITEAL LYMPH NODES IMAGING FOR DIFFERENTIATING RHEUMATOID ARTHRITIS FROM OSTEOARTHRITIS

WOS: 000265293000005Objective: We wanted to assess the role of the popliteal lymph nodes for differentiating rheumatoid arthritis (RA) from osteoarthritis (OA) by using three dimensional-fast spoiled gradient echo (3D-FSPGR) MR imaging and colour doppler ultrasonography (CDU). Material and Method: MR examination of the knee of 38 casks, 18 with rheumatoid arthritis (RA) and 20 with ostecarthritis (OA) were analyzed retrospectively. MR images were acquired with a 1.5-Tesla magnet. The MR imaging protocol consisted of 3D-FSPGR sequences in three planes. Images were reviewed to describe the number, size and centrally fatty changes of the popliteal lymph nodes. Additionally, these nodes were examined by CDU. Statistical Package for Social Sciences 11.0 program for Windows was performed for statistical analysis. Results: The popliteal nodes were observed in 88.8% of RA cases and 30% of OA cases. The number of the nodes in the RA and OA group was 53, and 8, respectively. The mean size of the lymph nodes in the RA and OA group was 7.4mm, and 3.6mm, respectively. Central fatty was observed in 100% of OA cases and in 60.4% of RA cases. The hiler vascularization was observed in the only 13% of RA cases. Mean value of the RI was determined as 0.62+/-0.005. Conclusion: Differentiating RA from OA, the criteria of the number sizes and central fatty changes of the popliteal lymph nodes showed statistical significance. Performing 3D-FSPGR sequence in knee MR imaging might useful to describe these nodes. The hiler vascularization with low RIs in CDU is also helpful criteria to differentiating RA from OA

Negative symptoms are associated with modularity and thalamic connectivity in schizophrenia

Negative symptoms, including avolition, anhedonia, asociality, blunted affect and alogia are associated with poor long-term outcome and functioning. However, treatment options for negative symptoms are limited and neurobiological mechanisms underlying negative symptoms in schizophrenia are still poorly understood. Diffusion-weighted magnetic resonance imaging scans were acquired from 64 patients diagnosed with schizophrenia and 35 controls. Global and regional network properties and rich club organization were investigated using graph analytical methods. We found that the schizophrenia group had higher modularity, clustering coefficient and characteristic path length, and lower rich connections compared to controls, suggesting highly connected nodes within modules but less integrated with nodes in other modules in schizophrenia. We also found a lower nodal degree in the left thalamus and left putamen in schizophrenia relative to the control group. Importantly, higher modularity was associated with greater negative symptoms but not with cognitive deficits in patients diagnosed with schizophrenia suggesting an alteration in modularity might be specific to overall negative symptoms. The nodal degree of the left thalamus was associated with both negative and cognitive symptoms. Our findings are important for improving our understanding of abnormal white-matter network topology underlying negative symptoms in schizophrenia

Abnormal white matter integrity and impairment of cognitive abilities in adolescent inhalant abusers

WOS: 000348955000010PubMed ID: 25479538Inhalant abuse represents a major health problem especially among adolescents and young adults. However, less is known about white matter (WM) microstructure in adolescent inhalant abusers. In the present study, we used diffusion tensor imaging (DTI) to study WM changes in adolescent inhalant abusers compared with healthy controls. We also tested whether there was any relationship between WM integrity and neuropsychological measures in adolescent inhalant abusers. The study included 19 adolescent inhalant abusers and 19 healthy control subjects. Whole brain analysis of WM microstructure was performed using tract-based spatial statistics (TBSS) to detect abnormal WM regions between groups. Wisconsin card sorting test (WCST) and Stroop test were used to measure neuropsychological performance. We found that adolescent inhalant abuser group had significantly higher axial diffusivity (AD) values in left parietal, occipital and temporal WM than in healthy control group. Inhalant abuser and control groups did not differ significantly on fractional anisotropy (FA) and radial diffusivity (RD) values. Adolescent inhalant abusers showed worse performance when compared with control group in WCST and Stroop test. There was no significant correlation of AD values in significant clusters with neuropsychological test performances within the two groups. We only found discrete impairments in neuropsychological test performance and WM integrity in adolescent inhalant abusers compared with healthy control subjects and we were not able to demonstrate a direct correlation between WM alterations and neurocognitive performance. Future work is required to longitudinally evaluate brain abnormalities through methods assessing brain structure, function and connectivity. (C) 2014 Elsevier Inc. All rights reserved.Ege University Science and Technology Application and Research CenterEge University [09/EGEBAM/001]This research was funded by Ege University Science and Technology Application and Research Center (grant number 09/EGEBAM/001) which had no role in the design of the study, collection and analysis of data and decision to publish