Omer Kitis

Association of the brain-derived neurotrophic factor Val66Met polymorphism with hippocampus volumes in drug-free depressed patients.

Abstract Objectives. Val66Met BDNF gene polymorphism is shown to affect the function of mature BDNF and mature BDNF plays an important role in the hippocampal neurogenesis and neuronal survival. Methods. A relationship of Val66Met BDNF gene polymorphism and hippocampal volumes in 33 MDD patients and 40 healthy controls is investigated. Region of interest analysis was conducted on the images acquired via MRI. Results. Depressed patients had smaller left hippocampal volumes compared to healthy controls. The diagnosis of MDD was not significantly related to hippocampal volumes among Met carriers; however, among Val homozygotes depressed patients had significantly smaller left hippocampal volumes compared to controls. Although both right and left hippocampal volumes showed nearly significant correlation with the duration of illness, this correlation reached (negative) significant levels only in the right hippocampal volume of the Val homozygotes. Conclusions. Val homozygote genotype may serve as a vulnerability factor in MDD regarding hippocampal volume loss. This finding can be considered as a supportive evidence for the neurotrophic factor hypothesis of depression.

Reduced left uncinate fasciculus fractional anisotropy in deficit schizophrenia but not in non-deficit schizophrenia

Aims:  Schizophrenia is a psychiatric disorder manifesting with heterogeneous symptom clusters and clinical presentations. The deficit syndrome is the condition defined by the existence of primarily negative symptoms, and patients with the deficit syndrome differ from non‐deficit patients on measures of brain structure and function. In the current study, by using diffusion tensor imaging (DTI), we investigated the frontotemporal connectivity that is hypothesized to differ between deficit and non‐deficit schizophrenia.

Cerebral cortical and deep venous thrombosis without sinus thrombosis: clinical MRI correlates

Background –  Cortical and/or deep vein thrombosis (CDVT) without dural sinus involvement is uncommon and presents diagnostic difficulty for many reasons. Our aim is to determine the relationship between magnetic resonance imaging (MRI) findings and clinical findings in patients with CDVT.

Diffusion-weighted MR imaging of viral encephalitis

IntroductionThe aim of this study was to evaluate the role of diffusion-weighted imaging (DWI) in the diagnosis of viral encephalitis and its relationship with the stage of the illness.MethodsWe performed conventional magnetic resonance imaging (MRI) including T1-W, T2-W and fluid attenuated inversion recovery (FLAIR) sequences and DWI in 18 patients with viral encephalitis diagnosed on the basis of laboratory, clinical and radiologic findings. Based on the qualitative and quantitative comparison of the conventional MRI and DWI, the patients were divided into three groups. Apparent diffusion coefficient (ADC) values of the involved and contralateral normal brain tissues were computed and compared for each group. The degree of correlation between the time (TI) from the onset of neurologic symptoms to the MR examination and ADC values was determined.ResultsIn group I (n=11) DWI was superior to conventional MRI in detecting the encephalitic involved sites and in depicting the borders of the encephalitic lesions. In group II (n=4) DWI was similar to conventional MRI. In group III (n=3) conventional MRI was superior to DWI. Mean ADC values of affected versus contralateral normal brain tissues were 0.458±0.161×10−3 versus 0.86±0.08×10−3 in group I, 0.670±0.142×10−3 versus 0.93±0.07×10−3 in group II, and 1.413±0.211×10−3 versus 1.05±0.06×10−3 in group III. Patients in group I had significantly lower ADC values than those in group II, while patients in group III had the highest ADC values (P<0.05). The ADC values were significantly lower in the affected sites than in the unaffected sites of patients in groups I and II, but were significantly higher in the affected sites than in the unaffected sites of patients in group III (P<0.05). There was an excellent correlation between ADC values and duration of the disease (r=0.874, P=0.01).ConclusionDWI is superior to other conventional diagnostic MR sequences in the detection of early viral encephalitic lesions and depiction of the lesion borders and, in combination with other sequences, DWI may contribute to the determination of the disease phase.

Correlative value of magnetic resonance imaging for neurodevelopmental outcome in periventricular leukomalacia

The aim of this study was to evaluate the correlative value of magnetic resonance imaging (MRI) in children with periventricular leukomalacia (PVL) for neurodevelopmental outcome. MRI examinations of 89 children (46 males, 43 females) with PVL (median age 4y, range 1 to 14y) were reevaluated. PVL was graded as follows: grade I, unilateral or bilateral areas of periventricular hyperintensity (1–3); grade II, hyperintensity more than 3; grade III, hyperintense lesions more than 3 and ventricular wall irregularity; grade IV, diffuse PVL and ventricular dilatation. Localizations of PVL and brain abnormalities associated with PVL were also noted. Assignment to PVL grades on MRI was as follows: PVL I (n=22), PVL II (n=18), PVL III (n=30), and PVL IV (n=19). Cerebral palsy was slightly less common in children with PVL I and II compared with PVL III to IV. Motor function was normal in 50% of children with PVL grade I, but severely impaired in 73.7% of children with PVL grade IV. Results of visual function were normal in all with PVL I, but pathological in 42.1% of patients with PVL IV. Developmental tests were appropriate for age in 75% of patients with PVL I, but significantly delayed in all patients with PVL IV. Thinning of the corpus callosum and presence of cortical atrophy were also correlated with neurological outcome. Significant risk factors associated with developmental delay were asphyxia at birth (odds ratio [OR] 4.3), PVL localization numbers over 3 (OR 4.4), PVL III to IV (OR 15), thinning of corpus callosum, and cortical atrophy.

Intracerebral metastasis showing restricted diffusion: correlation with histopathologic findings.

OBJECTIVE We aimed to detect the frequency of restricted diffusion in intracerebral metastases and to find whether there is correlation between the primary tumor pathology and diffusion-weighted MR imaging (DWI) findings of these metastases. MATERIAL AND METHODS 87 patients with intracerebral metastases were examined with routine MR imaging and DWI. 11 hemorrhagic metastatic lesions were excluded. The routine MR imaging included three plans before and after contrast enhancement. The DWI was performed with spin-echo EPI sequence with three b values (0, 500 and 1000), and ADC maps were calculated. 76 patients with metastases were grouped according to primary tumor histology and the ratios of restricted diffusion were calculated according to these groups. ADCmin values were measured within the solid components of the tumors and the ratio of metastases with restricted diffusion to that which do not show restricted diffusion were calculated. Fishers exact and Mann-Whitney U tests were used for the statistical analysis. RESULTS Restricted diffusion was observed in a total of 15 metastatic lesions (19, 7%). Primary malignancy was lung carcinoma in 10 of these cases (66, 6%) (5 small cell carcinoma, 5 non-small cell carcinoma), and breast carcinoma in three cases (20%). Colon carcinoma and testicular teratocarcinoma were the other two primary tumors in which restricted diffusion in metastasis was detected. There was no statistical significant difference between the primary pathology groups which showed restricted diffusion (p>0.05). ADCmin values of solid components of the metastasis with restricted diffusion and other metastasis without restricted diffusion also showed no significant statistical difference (0.72+/-0.16x10(-3)mm(2)/s and 0.78+/-21x10(-3)mm(2)/s respectively) (p=0.325). CONCLUSION Detection of restricted diffusion on DWI in intracerebral metastasis is not rare, particularly if the primary tumor is lung or breast cancer. However we found that there is no correlation between the metastasis showing restricted diffusion and primary pathology. Prospective studies with larger groups and more information are necessary regarding the correlation between the primary tumor histopathology and the ADC values of metastasis with restricted diffusion.

Smaller Hippocampus Volume Is Associated with Short Variant of 5-HTTLPR Polymorphism in Medication-Free Major Depressive Disorder Patients

Aim: Serotonin is known for its importance in the pathophysiology of major depressive disorder. Although the hippocampus is one of the key regions in which neurogenesis occurs, and serotonin plays an important role in neurogenesis, results of studies that investigate effect of the 5-HTTLPR polymorphism on hippocampal volumes in major depressive disorder are inconclusive. Method: We looked for a relationship between the 5-HTTLPR polymorphism and hippocampal volumes in 44 depressed patients (mean age ± SD 33.6 ± 9.5 years) and 43 healthy controls (30.4 ± 6.7 years). Region of interest analysis was conducted on the images acquired via MRI. Results: Although hippocampal volumes were similar in healthy and patient groups, there was a significant interaction between genotype and diagnosis on hippocampus volumes. Post-hoc ANCOVA showed that hippocampal volumes of S/S homozygous depressed patients were smaller compared to healthy controls in both hemispheres. Conclusion: The 5-HTTLPR polymorphism has an effect on hippocampal volumes of depressed patients, which is apparent only in S/S genotype. It seems that decreased neurogenesis by effects of reduced serotoninergic transmission may be responsible for smaller hippocampal volumes observed in S/S homozygous depressed patients.

The clinical spectrum of intracerebral hematoma, hemorrhagic infarct, non‐hemorrhagic infarct, and non‐lesional venous stroke in patients with cerebral sinus–venous thrombosis

Background and purpose:  The clinical spectrum of different neuroradiological features of cerebral sinus–venous thrombosis (CSVT) varies considerably. We sought the relationship between different neuroradiological aspects and clinical presentations in these patients.

Brain regions associated with risk and resistance for bipolar I disorder: a voxel‐based MRI study of patients with bipolar disorder and their healthy siblings

Bipolar I disorder is a highly heritable disorder but not all siblings manifest with the illness, even though they may share similar genetic and environmental risk factors. Thus, sibling studies may help to identify brain structural endophenotypes associated with risk and resistance for the disorder.

Brucellar spondylodiscitis: magnetic resonance imaging features with conventional sequences and diffusion-weighted imaging

PurposeIn this retrospective study, we evaluated the contribution and role of diffusion-weighted imaging (DWI) in differentiating acute and chronic forms of brucellar spondylodiscitis. We also describe the characteristics and some indistinguishable features of brucellar spondylodiscitis on magnetic resonance imaging (MRI) to emphasise the importance and limitations of MRI.Materials and methodsMRI examinations of 25 patients with brucellar spondylodiscitis were retrospectively reviewed and analysed by two experienced radiologists. Signal and morphological changes were assessed. The imaging characteristics of acute and chronic forms of spondylodiscitis were compared. Both discriminative imaging findings of brucellar spondylodiscitis and some uncommon findings were interpreted.ResultsOf 25 patients with spinal brucellosis, eight had thoracic, ten had lumbar, five had both thoracic and lumbar and two had both lumbar and sacral vertebral involvement. We detected posterior longitudinal ligament elevation in 11 patients, epidural abscess formation in 11 and paravertebral abscess formation in nine. Ten patients had cord compression and eight had root compression. Three patients had facet-joint involvement, and one had erector spinae muscle involvement. Eight patients (32%) were in the acute stage, six (24%) in the subacute stage and 11 (44%) in the chronic stage. Vertebral bodies, vertebral end plates and intervertebral disc spaces were hypointense and hyperintense in the acute stage, whereas they were hypointense and heterogeneous in the subacute and chronic stages on T1- and T2-weighted images, respectively. In the acute stage on the DWI series, vertebral bodies, end plates and discs were all hyperintense but hypointense in the chronic stage.ConclusionsAlthough conventional MRI has several advantages over other imaging modalities and is very useful in the differential diagnosis between brucellar spondylodiscitis and other spinal pathologies, it has some difficulties in discriminating acute and chronic forms of spondylodiscitis. DWI is a sensitive, fast sequence that has the potential for differentiating acute and chronic forms of spondylodiscitis, which makes it crucial in spinal imaging.AbstractObiettivoIn questo studio retrospettivo abbiamo valutato il contributo e il ruolo della sequenza pesata in diffusione nella diagnosi differenziale tra forme acute e croniche di spondilodiscite brucellare. Abbiamo inoltre descritto le caratteristiche e alcuni aspetti patognomonici della spondilodiscite brucellare nell’imaging di Risonanza Magnetica (RM) per sottolineare l’importanza e i limiti della RM.Materiali e MetodiLe indagini RM di 25 Pazienti con spondilodiscite brucellare sono state rivalutate e analizzate retrospettivamente da due radiologi esperti. Sono state valutate le alterazioni morfologiche e del segnale. Sono state inoltre messe a confronto le caratteristiche di immagine delle forme acute e croniche. Infine sono stati interpretati sia alcuni aspetti di immagine discriminativi della spondilodiscite brucellare che alcuni reperti rari.RisultatiDei 25 Pazienti con brucellosi spinale, 8 presentavano un interessamento toracico, 10 lombare, 5 sia toracico che lombare e 2 sia lombare che sacrale. Abbiano rilevato sollevamento del legamento longitudinale posteriore in 11 Pazienti, formazione di ascessi epidurali in 11 e presenza di ascessi paravertebrali in 9. Dieci Pazienti avevano compressione del midollo e 8 compressione radicolare. Tre Pazienti presentavano coinvolgimento delle faccette articolari e uno del muscolo erettore spinale. Otto Pazienti (32%) erano in fase acuta, 6 (24%) in fase subacuta e 11 (44%) in fase cronica. I corpi vertebrali, i piatti vertebrali e i dischi intervertebrali erano ipointensi e iperintensi nello stadio acuto, mentre erano ipointensi e eterogenei negli stadi subacuto e cronico, rispettivamente nelle sequenze T1- e T2 dipendenti. In fase acuta, nella sequenza pesata in diffusione, i corpi vertebrali, i piatti e i dischi erano tutti iperintensi mentre erano ipointensi in fase cronica.ConclusioniNonostante la RM convenzionale abbia parecchi vantaggi rispetto ad altre metodiche di immagine e sia molto utile nella diagnosi differenziale tra la spondilodiscite brucellare e altre patologie spinali, tale metodica presenta delle difficoltànel differenziare le forme acute e croniche della spondilodiscite. L’imaging pesato in diffusione è una sequenza sensibile e veloce che possiede il potenziale per differenziare le forme acute e croniche di spondilodiscite rendendola pertanto fondamentale nella diagnostica per immagini spinale.