Comparison between VII-to-VII and XII-to-VII coaptation techniques for early facial nerve reanimation after surgical intra-cranial injuries: a systematic review and pooled analysis of the functional outcomes

Neurosurgical Review - The surgical injury of the intracranial portion of the facial nerve (FN) is a severe complication of many skull base procedures, and it represents a relevant issue in terms...     

Remote cerebellar hemorrhage after spinal procedures (part 2): a systematic review

A remote cerebellar hemorrhage (RCH) is a spontaneous bleeding in the posterior fossa, which can be rarely observed as a complication of spine surgery. As well as for RCH reported after supratentorial procedures, it shows a characteristic bleeding pattern defined “zebra sign”. Nowadays, RCH pathophysiology still remains unknown. We performed a comprehensive review, collecting all cases of RCH after spine surgery reported in literature in order to identify the procedures most frequently associated with RCH and the possible risk factors. We assessed percentages of incidence and 95 % confidence interval of all demographic, neuroradiological, and clinical features. Univariate and multivariate analyses were used to evaluate their association with outcome. We included 44 articles reporting 57 patients with mean age of 57.6?±?13.9 years and a male/female ratio of 23/34. A RCH was more frequently reported as a complication of decompressive procedures for spinal canal stenosis, particularly when associated with instrumented fusion, followed by spinal tumor debulking and disc herniation removal. In the majority of cases, RCH occurrence was characterized by progressive impairment of consciousness, whereas some patients complained non-specific symptoms. Coagulation disorders, hypertension, and placement of postoperative subfascial drainages were the most frequently reported risk factors. The occurrence of intraoperative dural lesions was described in about 93 % of patients. Zebra sign was the most common bleeding pattern (about 43 % of cases) followed by parenchymal hematoma (37.5 %) and mixed hemorrhage (about 20 %). Impairment of consciousness at clinical onset and intake of anticoagulants/antiplatelets appeared associated with poor outcome at univariate analysis. However, more than 75 % of patients showed a good outcome and a RCH often appeared as a benign and self-limiting condition, which usually did not require surgical treatment, but only prolonged clinical surveillance, unless of the occurrence of complications.     

Machine learning model prediction of 6-month functional outcome in elderly patients with intracerebral hemorrhage

Spontaneous intracerebral hemorrhage (ICH) has an increasing incidence and a worse outcome in elderly patients. The ability to predict the functional outcome in these patients can be helpful in supporting treatment decisions and establishing prognostic expectations. We evaluated the performance of a machine learning (ML) model to predict the 6-month functional status in elderly patients with ICH leveraging the predictive value of the clinical characteristics at hospital admission. Data were extracted by a retrospective multicentric database of patients?≥?70 years of age consecutively admitted for the management of spontaneous ICH between January 1, 2014 and December 31, 2019. Relevant demographic, clinical, and radiological variables were selected by a feature selection algorithm (Boruta) and used to build a ML model. Outcome was determined according to the Glasgow Outcome Scale (GOS) at 6 months from ICH: dead (GOS 1), poor outcome (GOS 2–3: vegetative status/severe disability), and good outcome (GOS 4–5: moderate disability/good recovery). Ten features were selected by Boruta with the following relative importance order in the ML model: Glasgow Coma Scale, Charlson Comorbidity Index, ICH score, ICH volume, pupillary status, brainstem location, age, anticoagulant/antiplatelet agents, intraventricular hemorrhage, and cerebellar location. Random forest prediction model, evaluated on the hold-out test set, achieved an AUC of 0.96 (0.94–0.98), 0.89 (0.86–0.93), and 0.93 (0.90–0.95) for dead, poor, and good outcome classes, respectively, demonstrating high discriminative ability. A random forest classifier was successfully trained and internally validated to stratify elderly patients with spontaneous ICH into prognostic subclasses. The predictive value is enhanced by the ability of ML model to identify synergy among variables.

     

Structure of N-linked oligosaccharides attached to chlorovirus PBCV-1 major capsid protein reveals unusual class of complex N-glycans

The major capsid protein Vp54 from the prototype chlorovirus Paramecium bursaria chlorella virus 1 (PBCV-1) contains four Asn-linked glycans. The structure of the four N-linked oligosaccharides and the type of substitution at each glycosylation site was determined by chemical, spectroscopic, and spectrometric analyses. Vp54 glycosylation is unusual in many ways, including: (i) unlike most viruses, PBCV-1 encodes most, if not all, of the machinery to glycosylate its major capsid protein; (ii) the glycans are attached to the protein by a β-glucose linkage; (iii) the Asn-linked glycans are not located in a typical N-X-(T/S) consensus site; and (iv) the process probably occurs in the cytoplasm. The four glycoforms share a common core structure, and the differences are related to the nonstoichiometric presence of two monosaccharides. The most abundant glycoform consists of nine neutral monosaccharide residues, organized in a highly branched fashion. Among the most distinctive features of the glycoforms are (i) a dimethylated rhamnose as the capping residue of the main chain, (ii) a hyperbranched fucose unit, and (iii) two rhamnose residues with opposite absolute configurations. These glycoforms differ from what has been reported so far in the three domains of life. Considering that chloroviruses and other members of the family Phycodnaviridae may have a long evolutionary history, we suggest that the chlorovirus glycosylation pathway is ancient, possibly existing before the development of the endoplasmic reticulum and Golgi pathway, and involves still unexplored mechanisms.     

AQP1 in red blood cells of uremic patients during hemodialytic treatment

Hemodialysis influences the transport of water through the erythrocytic membrane, and induces morphologic and functional modifications. Recently water channels, called aquaporins (AQP), have been identified on the membrane of red blood cells. The aim of the present study was, therefore, to evaluate any relationships between volumetric changes in erythrocytes (MCV), plasma osmolarity and membrane expression of AQP1 in 22 uremic patients during a hemodialysis session, and compare value with those in a control group of 22 healthy volunteers. Membranal AQP1 expression was evaluated using three methods: indirect immunofluorescence under confocal microscopy, immunoenzymatic method after membrane extraction, and immunoblotting. In uremic subjects, at baseline membrane AQP1 expression was significantly lower, whereas plasma osmolality was higher than in controls. At 1 and 2 h of replacement therapy, a progressive increase was observed in erythrocytic AQP1, values similar to those in controls being attained after 3.5 h. During the session osmolality values reduced progressively, becoming significantly lower than basal values. The mean erythrocytic corpuscular volume in patients with ESRD was significantly lower than in cntrols at baseline. This value increased during hemodialysis, attaining statistical significance with respect to the basal value at 3.5 h of dialysis. Close correlations were found between plasma osmolality and AQP1 values (r = -0.930; p < 0.05), and also between MCV and plasma osmolality trend (r = -0.909; p < 0.05). There was a linear correlation (r = 0.63, p < 0.05) between plasma AVP concentrations and plasma osmolality. The variations found in plasma osmolarity during hemodialysis, may induce AQP1 expression on the membrane of intact red blood cells.     

Clinical and biochemical features in a Congolese infant with congenital disorder of glycosylation (CDG)-IIx.

We describe an infant girl with psychomotor retardation, growth retardation, mild facial dysmorphy, evidence of liver involvement and a type 2 pattern of serum sialotransferrins. Serum transferrin glycan analysis with MALDI-TOF showed an extremely altered N-glycan pattern with a large number of truncated asialoglycans pointing to a severely defective N-glycan processing. The basic defect in this patient with CDG-IIx has not yet been identified.     

In vivo evidence that erythropoietin has a neuroprotective effect during subarachnoid hemorrhage

To ascertain in vivo whether recombinant human erythropoietin has a neuroprotective effect on the cortex during subarachnoid hemorrhage, 56 rabbits were divided into the following groups: Group 1 control sham operated plus placebo (n=14; saline solution - NaCl 0.9%); Group 2 control sham operated plus recombinant human erythropoietin (n=14); Group 3 subarachnoid hemorrhage plus placebo (n=14); Group 4 subarachnoid hemorrhage plus recombinant human erythropoietin (n=14; intraperitoneal administration of recombinant human erythropoietin immediately after inducing subarachnoid hemorrhage). In none of the Groups 1 and 2 animals was subarachnoid hemorrhage induced. In Group 3 rabbits, an increase in locomotor activity (open field apparatus) was observed 24, 48 and 72 h after surgery, and the mortality rate was 42.9% within 72 h after surgery, and, no increase in locomotor activity was observed in Group 4 rabbits, which survived for at least 72 h. Our findings suggest that recombinant human erythropoietin may be of benefit in the treatment of subarachnoid hemorrhage.     

Borderline mental development in a congenital disorder of glycosylation (CDG) type Ia patient with multisystemic involvement (intermediate phenotype)

Summary CDG Ia (phosphomannomutase deficiency) has a wide clinical spectrum with the most severe affected patients having multisystemic disease in addition to severe nervous system involvement. We report a patient with CDG Ia and an intermediate phenotype due to mild neurological impairment and borderline cognitive abilities despite the occurrence of typical extraneurological symptoms. These included liver involvement, coagulopathy and failure to thrive with enteropathy. Genotype analyses showed that he was compound heterozygous for T237R/C241S mutations. This observation underlines that the CDG Ia clinical spectrum may include intraindividual variability that might reflect different degrees of glycosylation abnormalities among distinct body compartments. CDG Ia should be considered in cases of unexplained liver involvement and/or enteropathy in patients with mild developmental delay and subtle neurological signs. Electronic Supplementary Material Supplementary material is available for this article at Communicating editor: Verena Peters     

Effects of haemodialysis on circulating endothelial progenitor cell count

During haemodialysis (HD) the endothelium is the first organ to sense and to be impaired by mechanical and immunological stimuli. We hypothesized that a single HD session induces mobilization of endothelial progenitor cells (EPCs) and that cardiovascular risk factors may influence this process. We quantified EPCs at different maturational stages (CD34+, CD133+/VEGFR2+) in blood samples from 30 patients, during HD and on the interdialytic day, and in 10 healthy volunteers. Samples were drawn at the start of HD, 1, 2 and 3 h after, at the end of HD and at 24 h on the interdialytic day. Patients were divided into two groups based on a recent risk scoring system (SCORE project): low-risk (LR) and high-risk groups (HR). HD patients showed a significantly reduced basal number of EPCs with respect to healthy volunteers. In contrast, we observed increasing EPCs during HD whereas they diminished on the interdialytic day. The EPC number was directly correlated with HD time progression. The EPC number during HD was increased in the HR group with respect to the LR group. We had a direct correlation between risk score and number of EPCs. Cardiovascular risk factors influenced the mobilization of stem cells from the bone marrow. This feature could be the direct consequence of an augmented request of stem cells to respond to the most important endothelial impairment but could also show a defective capacity of EPCs to home in and repair the sites of vascular injury.