Artificial neural networks can be effectively used to model changes of intracranial pressure (ICP) during spinal surgery using different noninvasive ICP surrogate estimators.

BACKGROUND: Artificial intelligence (AI) techniques play a major role in anesthesiology, even though their importance is often overlooked. In the extant literature, AI approaches, such as artificial neural networks (ANNs), have been underutilized, being used mainly to model patient's consciousness state, to predict the precise number of anesthetic gases, the level of analgesia, or the need of anesthesiological blocks, among others. In the field of neurosurgery, ANNs have been effectively applied to the diagnosis and prognosis of cerebral tumors, seizures, low back pain, and also to the monitoring of intracranial pressure (ICP). METHODS: A multilayer perceptron (MLP), which is a feedforward ANN, with hyperbolic tangent as activation function in the input/hidden layers, softmax as activation function in the output layer, and cross-entropy as error function, was used to model the impact of prone versus supine position and the use of positive end expiratory pressure (PEEP) on ICP in a sample of 30 patients undergoing spinal surgery. Different noninvasive surrogate estimations of ICP have been used and compared: namely, mean optic nerve sheath diameter (ONSD), noninvasive estimated cerebral perfusion pressure (NCPP), Pulsatility Index (PI), ICP derived from PI (ICP-PI), and flow velocity diastolic formula (FVDICP). RESULTS: ONSD proved to be a more robust surrogate estimation of ICP, with a predictive power of 75%, whilst the power of NCPP, ICP-PI, PI, and FVDICP were 60.5%, 54.8%, 53.1%, and 47.7%, respectively. CONCLUSIONS: Our MLP analysis confirmed our findings previously obtained with regression, correlation, multivariate receiving operator curve (multi-ROC) analyses. ANNs can be successfully used to predict the effects of prone versus supine position and PEEP on ICP in patients undergoing spinal surgery using different noninvasive surrogate estimators of ICP.

Erdheim-Chester disease (ECD): Case report, clinical and basic investigations, and review of literature.

BACKGROUND: Erdheim-Chester disease (ECD) is an uncommon aggressive, multisystem form of non-Langerhans' cell histocytosis, which was firstly reported by Jakob Erdheim and William chester in 1930. The disease pathological features encompass an aberrant multiplication, overproduction and accumulation of white blood cells called histiocytes within multiple tissues and organs. Herein, we present a case of ECD owing to the rarity of this disease (roughly 550 cases have been described in the literature to date). METHODS: We discussed the clinical course, diagnostic evaluations, and the possible treatments. Our case was encountered in an Arab male in his 30's who has suffered from an ongoing bones pain for years. RESULTS: At our rheumatologic department we compiled his recent medical history, which consisted of diagnosis of central diabetes insipidus, hyperprolactinemia and secondary hypogonadism along with the previously conducted laboratory evaluations and imaging which brought to our mind the possibility of an infiltrative disease such as ECD. The diagnosis of ECD was done based on the combinations of pathognomonic radiographic osteosclerosis, neuroimaging, bones biopsies along with a careful clinical evaluation. Given the protean clinical manifestations, interferon-α was considered as our first line treatment of ECD, consequently our patient improved noticeably. CONCLUSION: Clinical presentation, imaging studies, distinctive pathological findings, followed by bone biopsy showed a non-Langerhans cell histiocytosis, supported by immunohistochemistry exams are essential for the diagnosis. Radiation therapy and Bisphosphonates in addition to cladribine, anakinra, infliximab and vemurafenib (BRAF Inhibitors) are currently advocated as promising second line treatment for patients whose response to interferon-α is unsatisfactory.

Effects of carnitine on oxidative stress response to intravenous iron administration to patients with CKD: impact of haptoglobin phenotype.

BACKGROUND: Anemia is a common disorder in CKD patients. It is largely attributed to decreased erythropoietin (EPO) production and iron deficiency. Therefore, besides EPO, therapy includes iron replenishment. However, the latter induces oxidative stress. Haptoglobin (Hp) protein is the main line of defense against the oxidative effects of Hemoglobin/Iron. There are 3 genotypes: 1-1, 2-1 and 2-2. Hp 2-2 protein is inferior to Hp 1-1 as antioxidant. So far, there is no evidence whether haptoglobin phenotype affects iron-induced oxidative stress in CKD patients. Therefore, the present study examines the influence of carnitine treatment on the intravenous iron administration (IVIR)-induced oxidative stress in CKD patients, and whether Hp phenotype affects this response. TRIAL REGISTRATION: Current Controlled Trials ISRCTN5700858. This study included 26 anemic (Hb = 10.23 ± 0.28) CKD patients (stages 3-4) that were given a weekly IVIR (Sodium ferric gluconate, [125 mg/100 ml] for 8 weeks, and during weeks 5-8 also received Carnitine (20 mg/kg, IV) prior to IVIR. Weekly blood samples were drawn before and after each IVIR for Hp phenotype, C-reactive protein (CRP), advanced oxidative protein products (AOPP), neutrophil gelatinase-associated lipocalin (NGAL), besides complete blood count and biochemical analyses. RESULTS: Eight percent of CKD patients were Hp1-1, 19 % Hp2-1, and 73 % Hp2-2. IVIR for 4 weeks did not increase hemoglobin levels, yet worsened the oxidative burden as was evident by elevated plasma levels of AOPP. The highest increase in AOPP was observed in Hp2-2 patients. Simultaneous administration of Carnitine with IVIR abolished the IVIR-induced oxidative stress as evident by preventing the elevations in AOPP and NGAL, preferentially in patients with Hp2-2 phenotype. CONCLUSIONS: This study demonstrates that Hp2-2 is a significant risk factor for IVIR-induced oxidative stress in CKD patients. Our finding, that co-administration of Carnitine with IVIR preferentially attenuates the adverse consequences of IVIR, suggests a role for Carnitine therapy in these patients.