Patterns of Brain Structural Changes in First-Contact, Antipsychotic Drug-Naïve Patients with Schizophrenia

BACKGROUND AND PURPOSE: Previous studies have suggested that structural changes do occur in the brain of patients with schizophrenia compared with healthy control participants. However, findings from such studies are inconclusive, probably because of the different methodologic approaches, the clinical heterogeneity of patient samples, and also the fact that patients enrolled were treated with antipsychotic drugs. The aim of this study was to investigate brain GM volumes and intrinsic structural WM changes in first-contact, antipsychotic drug-naive patients with schizophrenia. MATERIALS AND METHODS: A total of 43 first-contact, drug-naive, patients with schizophrenia and 17 age-matched control participants were studied. All participants underwent T1-weighted MR imaging and DTI scans. Voxel-based morphometry and tract-based spatial statistics were used to compare GM volumes and WM DTI metrics between groups. MR imaging measures were correlated with the duration of the untreated psychosis and the clinical positive and negative symptoms. RESULTS: Compared with control participants, patients with schizophrenia showed smaller volumes of the temporal, parietal, and occipital GM, and a pattern of decreased mean diffusivity and increased fractional anisotropy in the brain stem and cerebellum bilaterally, interhemispheric and cortico-cortical connections bilaterally, and right anterior and posterior limb of the internal capsule. In patients, decreased mean diffusivity and increased fractional anisotropy in several brain regions were related to a longer duration of the untreated psychosis and the severity of positive symptoms. CONCLUSIONS: First-contact, drug-naive, patients with schizophrenia present with volumetric and DTI changes, which correlated with their clinical features. This study increases our knowledge on the neural networks involved in the pathophysiologic mechanisms of schizophrenia

Prognostic Factors for Surgical Failure in Malignant Bowel Obstruction and Peritoneal Carcinomatosis

Introduction: Patients with peritoneal metastasis frequently develop malignant bowel obstruction (MBO). Medical palliative management is preferred but often fails. Conversely, the role of palliative surgery remains unclear and debated. This study aims to identify patients who could benefit from invasive surgical interventions and factors associated with successful surgical palliation. Materials and Methods: In this retrospective study, 98 consecutive patients who underwent palliative surgery for MBO over 5 years were reviewed. We evaluate as the primary outcome surgical failure to select patients who could benefit from palliative surgery, avoiding unnecessary surgery. A prognostic score was developed based on a logistic regression model to identify patients at risk of surgical failure. The score was evaluated for overall accuracy by receiver operating characteristic curve analysis. Results: Palliative surgery was achieved in 76 (77.5%) patients. The variables that were found to be significant factors for surgical failure are recurrent disease (P = 0.015), absence of bowel obstruction (P < 0.001), absence of bowel distension (P < 0.001), and mesenteric involvement (P = 0.001) and retraction (P < 0.001). The absence of bowel distension (P = 0.046) and bowel obstruction (P = 0.012) emerged as independent predictors of surgical failure. Carcinomatosis level assessment for peritoneum score, based on these factors, was built to evaluate the risk of surgical failure. Conclusion: Our proposed scoring system might help select patients most likely to benefit from palliative surgery

Diffusion Tensor Imaging and Tractography ofTraumatic Brachial Plexus Palsies: PreliminaryExperience

PURPOSE In traumatic injuries of the brachial plexus the preoperative assessment of nerve root avulsions is essential for surgical planning. In the diagnostic workup MR myelography has almost completely replaced CT myelography as the first choice examination. To our knowledge there are no reports on the application of diffusion tensor Imaging to the study of traumatic brachial plexus palsies. Evaluation of the clinical feasibility of diffusion tensor tractography of the brachial plexus in a selected population of patients with traumatic brachial plexus injuries. MATERIALS & METHODS Ten patients (8 males, 2 females, mean age 27.4 years, range 16-52 years) with traumatic brachial plexus palsies (6 left, 4 right) have been examined with 1.5 T scanner (Siemens, Avanto) with the following imaging protocol: a) 3D MR myelography (3DMRM) with multiplanar reconstructions along the course of cervical nerve roots (3D T2 fast spin echo sequences, 0.7 mm isotropic voxel), b) 3D T2 STIR SPACE sequences (TR 2000, TE 149, TI 160, 1 mm isotropic voxel), C) DTI (64 contiguous axial sections from C3 to T2, TR 9200 TE 90, 12 directions, 2.2 mm isotropic voxel, 5 runs, peripheral triggering, FOV 250 mm). Diffusion tensor imaging data were preprocessed coregistering every single direction of each run with the first b0 and corrected for eddy currents with FSL (FMRIB Software Library; Oxford, UK) FDT tool. Tractography of the brachial plexus and cervical spinal cord was obtained placing multiple 3D ROIs along the extraforaminal course of C5-T1 nerve roots on MPR reformatted b0 coronal images. Nerve root avulsions were defined on MR tractography on the basis of a loss of continuity with the spinal cord fibers. Brachial plexus tractography diagnostic accuracy was assessed comparing it with 3DMRM findings on a per root basis on 100 nerve roots. RESULTS Three-dimensional MRM detected 18 avulsed nerve roots and 32 intact roots on the injured side. Brachial plexus tractography had 94% sensitivity, 87% specificity, 60% PPV and 98% NPV compared to 3DMRM, with 1 false negative and 12 false positives. The relatively elevated false positive rate is mainly related to the evaluation of C8-T1 nerve roots, which are displayed in a suboptimal way, due to their anatomical course adjacent to bone. CONCLUSION Diffusion tensor tractography is a cutting-edge technique for studying peripheral nerves, which cannot be performed as readily and reliably in the spinal cord and brachial plexus for technical and anatomical reasons such as pulsation artifacts, motion of organs in the thorax and large number of longitudinal fibers. Compared to 3DMRM brachial plexus tractography is characterized by an elevated diagnostic accuracy in the assessment of nerve root avulsions, which can be displayed easily as loss of continuity with spinal cord fibers. Although DTI of the brachial plexus is still an experimental technique which needs further testing in order to produce meaningful clinical results, our preliminary experience suggests its promising role in the assessment of nerve continuity in traumatic injuries of the brachial plexus

A constructivist approach in designing an e-learning system identification course

This paper describes the design philosophy and the realization of a basic course on dynamic system identification that relies on constructivist methodologies and on the use of e-learning environments. It reports also some of the opinions formulated by the users on the effectiveness of the available tools and on their role in acquiring proficiency in the application of identification techniques in modelling real processes

Feasibility of diffusion tensor tractography of brachial plexus injuries at 1.5 T.

OBJECTIVE: The objective of this study was to examine the feasibility of diffusion tensor imaging and diffusion tensor tractography (DTT) at 1.5 T for the detection of nerve root avulsions in patients with brachial plexus injuries (BPI). MATERIALS AND METHODS: We performed a 1.5-T magnetic resonance imaging on 28 patients (mean [SD] age, 25 [9.1]) with BPI using the following imaging protocol: (a) magnetic resonance myelography (MRM), (b) magnetic resonance neurography, and (c) diffusion tensor imaging. A reproducible tractography approach was developed to assess the myeloradicular continuity, which consists of multiple regions of interests placed on each hemicord, including the ventral and dorsal rootlets from C4 to T2 nerve roots. Two independent observers blindly evaluated DTT and MRM studies. The degree of agreement between DTT and MRM findings was estimated on a per-root basis on the 140 nerve roots (C5-T1) on the injured side by calculation of the κ coefficient (K value) and the Bland-Altman plot analysis. The diagnostic accuracy of DTT was assessed by comparing it with the MRM findings of the 140 nerve roots on the injured side on a per-root basis. RESULTS: Diffusion tensor tractography allowed a complete visualization of the C5-T1 intact nerve roots on the normal side in 100% of studies.Complete nerve root avulsions were recognized on DTT either as a total loss of fibers or as a very short segment of incoherent fibers in apparent continuity with the spinal cord.The MRM identified 88 intact nerve roots (62.9%), 44 completely avulsed nerve roots (31.4%), and 8 partially avulsed nerve roots (5.7%). The DTT and MRM were concordant in 127 of the 140 nerve roots (90.7%) and exhibited an excellent overall agreement (K value, 80.8). The brachial plexus DTT had an 88.1% sensitivity, 98.1% positive predictive value, 98.8% specificity, 92.6 negative predictive value, and a 94.5% overall accuracy for detecting the presence of a nerve root avulsion. The κ coefficients for the interobserver reliability of DTT and MRM were 0.85 and 0.80, respectively. CONCLUSIONS: Our results suggest that cervical nerve root avulsions can be successfully visualized at 1.5 T in patients with BPI despite the anatomical complexity and susceptibility and motion artifacts. We propose that DTT is a reliable and reproducible method for the investigation of BPI because it provides a successful anatomical and functional display of neural structures that are not otherwise attainable with conventional studies

Leptomeningeal dissemination of anaplastic medullary cone astrocytoma: An unexpected findings in a patient with leptomeningeal enhancement and clinical history of multiple myeloma

We report a challenging autopsy case with an insidious clinical presentation with diffuse lepto- and pachymeningeal enhancement in a context of a complex clinical history. Clinical features, neuroradiological and anamnestic data were consistent with central nervous system (CNS) dissemination of a previously known lambda restricted multiple myeloma. Autoptic findings allowed to discard this hypothesis. Unexpectedly, CNS sampling revealed an atypical glial cell proliferation within the sacral meningeal layers. No primary intraparenchymal CNS glial lesion was found. Findings supported the final diagnosis of anaplastic astrocytoma IDH1-wild type of the medullary cone with diffuse leptomeningeal and cerebrospinal fluid (CSF) dissemination. This occurrence represents an extremely rare condition itself, further complicated by the clinical history of the patient that led to formulate the most probable diagnosis of localization of the primary known disease. This autopsy case underlines that patients previously diagnosed with a primary tumor are not only at risk of recurrences or progression of the original disease, but they must be always accurately checked for eventual onset of a second tumor, including rare conditions such as gliomatosis

Patterns of Brain Structural Changes in First-Contact, Antipsychotic Drug-Naive Patients with Schizophrenia.

BACKGROUND AND PURPOSE: Previous studies have suggested that structural changes do occur in the brain of patients with schizophrenia compared with healthy control participants. However, findings from such studies are inconclusive, probably because of the different methodologic approaches, the clinical heterogeneity of patient samples, and also the fact that patients enrolled were treated with antipsychotic drugs. The aim of this study was to investigate brain GM volumes and intrinsic structuralWMchanges in first-contact, antipsychotic drug-naı ¨ve patients with schizophrenia. MATERIALS AND METHODS: A total of 43 first-contact, drug-naı ¨ve, patients with schizophrenia and 17 age-matched control participants were studied. All participants underwent T1-weighted MR imaging and DTI scans. Voxel-based morphometry and tract-based spatial statistics were used to compare GM volumes and WM DTI metrics between groups. MR imaging measures were correlated with the duration of the untreated psychosis and the clinical positive and negative symptoms. RESULTS: Compared with control participants, patients with schizophrenia showed smaller volumes of the temporal, parietal, and occipital GM, and a pattern of decreased mean diffusivity and increased fractional anisotropy in the brain stem and cerebellum bilaterally, interhemispheric and cortico-cortical connections bilaterally, and right anterior and posterior limb of the internal capsule. In patients, decreased mean diffusivity and increased fractional anisotropy in several brain regions were related to a longer duration of the untreated psychosis and the severity of positive symptoms. CONCLUSIONS: First-contact, drug-naı ¨ve, patients with schizophrenia present with volumetric and DTI changes, which correlated with their clinical features. This study increases our knowledge on the neural networks involved in the pathophysiologic mechanisms of schizophrenia

Laparoscopic approach to recurrent incisional hernia repair. A 3-year experience

Background: Incisional hernias are one of the most frequent complications of open abdominal surgery. The incidence of relapses after a conventional repair procedure is higher in recurrent than in primary cases (30%-50% vs. 11%-20%). The laparoscopic approach can prevent the complications associated with the conventional approach when dealing with recurrent incisional hernias. The aim of this study was to evaluate the efficacy of laparoscopic treatment in such cases. Materials and Methods: We prospectively analyzed data from 41 consecutive patients with recurrent incisional hernias, who submitted to a laparoscopic repair procedure with an expanded polytetrafluoroethylene Dual Mesh (Gore-Tex® Dual Mesh® Plus Biomaterial; W.L. Gore 8 Associates) from December 2001 to December 2004. All of the patients underwent clinical follow-up at 1, 6, and 12 months and then yearly. An ultrasound scan of the abdominal wall was performed at 6 and 12 months after the procedure. The parameters considered for the analysis were: mesh size, operating time, hospital stay, postoperative complications, and recurrences. Results: The defects were usually localized along midline laparotomies. The mean mesh size was 400 cm2, the mean operating time was 68 minutes, and the mean length of hospital stay was 2.7 days. Complications were encountered in 17% of patients. The mean follow-up was 38 months (range, 18-54). Recurrence was reported in 1 case only (2.4%), which occurred within the first 6 months after the operation. Conclusions: The laparoscopic repair of recurrent incisional hernia seems to be an effective alternative to the conventional approach, as it can give lower recurrence and complication rates

Patterns of Brain Structural Changes in First-Contact, Antipsychotic Drug-Naïve Patients with Schizophrenia

BACKGROUND AND PURPOSE: Previous studies have suggested that structural changes do occur in the brain of patients with schizophrenia compared with healthy control participants. However, findings from such studies are inconclusive, probably because of the different methodologic approaches, the clinical heterogeneity of patient samples, and also the fact that patients enrolled were treated with antipsychotic drugs. The aim of this study was to investigate brain GM volumes and intrinsic structural WM changes in first-contact, antipsychotic drug-naive patients with schizophrenia. MATERIALS AND METHODS: A total of 43 first-contact, drug-naive, patients with schizophrenia and 17 age-matched control participants were studied. All participants underwent T1-weighted MR imaging and DTI scans. Voxel-based morphometry and tract-based spatial statistics were used to compare GM volumes and WM DTI metrics between groups. MR imaging measures were correlated with the duration of the untreated psychosis and the clinical positive and negative symptoms. RESULTS: Compared with control participants, patients with schizophrenia showed smaller volumes of the temporal, parietal, and occipital GM, and a pattern of decreased mean diffusivity and increased fractional anisotropy in the brain stem and cerebellum bilaterally, interhemispheric and cortico-cortical connections bilaterally, and right anterior and posterior limb of the internal capsule. In patients, decreased mean diffusivity and increased fractional anisotropy in several brain regions were related to a longer duration of the untreated psychosis and the severity of positive symptoms. CONCLUSIONS: First-contact, drug-naive, patients with schizophrenia present with volumetric and DTI changes, which correlated with their clinical features. This study increases our knowledge on the neural networks involved in the pathophysiologic mechanisms of schizophrenia