Endoscopic Endonasal Transclival Approach to the Ventral Brainstem: Anatomic Study of the Safe Entry Zones Combining Fiber Dissection Technique with 7 Tesla Magnetic Resonance Guided Neuronavigation.

Background: Treatment of intrinsic lesions of the ventral brainstem is a surgical challenge that requires complex skull base antero- and posterolateral approaches. More recently, endoscopic endonasal transclival approach (EETA) has been reported in the treatment of selected ventral brainstem lesions.

Objective: In this study we explored the endoscopic ventral brainstem anatomy with the aim to describe the degree of exposure of the ventral safe entry zones.

Survival outcomes following repeat surgery for recurrent glioblastoma: a single-center retrospective analysis.

The aim of the present study is to evaluate the impact of extent of resection at initial and repeat craniotomy on overall survival of patients with recurrent glioblastoma. The authors retrospectively reviewed the records of all adults patients who underwent repeat resection of recurrent glioblastoma following radiation and chemotherapy at an academic tertiary-care institution between 2011 and 2015. We evaluated the survival outcomes with regard to extent of resection considering both the initial and repeat resections.

Hydrocephalus following bilateral dumbbell-shaped c2 spinal neurofibromas resection and postoperative cervical pseudomeningocele in a patient with neurofibromatosis type 1: a case report.

Study Design Case report. Objective To present a rare case of hydrocephalus following bilateral dumbbell-shaped C2 spinal neurofibromas resection and postoperative cervical pseudomeningocele in a patient with neurofibromatosis type 1 (NF1). Methods The patient's clinical course is retrospectively reviewed.

Key role of uridine kinase and uridine phosphorylase in the homeostatic regulation of purine and pyrimidine salvage in brain.

Uridine, the major circulating pyrimidine nucleoside, participating in the regulation of a number of physiological processes, is readily uptaken into mammalian cells. The balance between anabolism and catabolism of intracellular uridine is maintained by uridine kinase, catalyzing the first step of UTP and CTP salvage synthesis, and uridine phosphorylase, catalyzing the first step of uridine degradation to beta-alanine in liver. In the present study we report that the two enzymes have an additional role in the homeostatic regulation of purine and pyrimidine metabolism in brain, which relies on the salvage synthesis of nucleotides from preformed nucleosides and nucleobases, rather than on the de novo synthesis from simple precursors.

A simulation model for analysing brain structure deformations.

Recent developments of medical software applications--from the simulation to the planning of surgical operations--have revealed the need for modelling human tissues and organs, not only from a geometric point of view but also from a physical one, i.e. soft tissues, rigid body, viscoelasticity, etc.

Analysis of RR variability in drug-resistant epilepsy patients chronically treated with vagus nerve stimulation.

Vagus nerve stimulation (VNS) has been suggested as an adjunctive treatment for drug-resistant epilepsy when surgery is inadvisable. The overall safety profile of VNS seems to be favorable as only minor adverse effects have been described. The purpose of this study was to determine if cardiac vagal tone is eventually modified by short- and long-term VNS.

Daytime vigilance and quality of life in epileptic patients treated with vagus nerve stimulation.

Objectives: The goal of this study was to determine if vagus nerve stimulation (VNS) has any effect on daytime vigilance and perceived sense of well-being.

Methods: Multiple Sleep Latency Tests (MSLTs) were performed and visual reaction times (VRTs) obtained in eight epileptic patients before and during treatment with VNS. Prior to VNS initiation patients' baseline MSLT and VRT scores were recorded.

Volumetric analysis of CT orbital images.

The determination of the volume of eye muscles is a problem of considerable interest in Graves' ophtalmopathy both with respect to the diagnostic quantisation of the disease and to the measured assessment of the effectiveness of pharmacological treatment. The aim of this research is to design and test an advanced method for processing computerised tomography (CT) orbital images in order to obtain a three-dimensional reconstruction of infra-orbital muscle structures and to analyse them from a morphometric viewpoint. CT images of subjects suffering from Graves' disease were acquired before and after pharmacological treatment with immunosuppressors.

Deformation analysis of brain regions.

The analysis of 2D and 3D deformations applied to structures having non regular geometry is presented. Deformations are studied in order to understand complex dynamic problems coded into image sequences. In particular, methods have been developed suitable to control the reconstruction and the spatial deformation of cerebral structures, in their different aspects of morphometry, isometry and densitometry.

[The risk of pulmonary embolism in neurosurgery].

Pulmonary embolism (PE) is a frequent necroscopic finding in neurosurgical patients and this contrasts with the difficult diagnosis of it when the patient is still alive. Such a lack of diagnosis has promoted numerous studies into deep-vein thrombosis (DVT) which is, in most cases, the cause of pulmonary embolism. However, a prophylaxis of DVT cannot be indiscriminately carried out in neurosurgical patients because it is not without potential risks.

[Enteral nutrition in the critical neurosurgical patient. Effectiveness and tolerance of a prepared liquid diet].

The response of prealbumin was studied in 15 neurosurgical patients following 7 days of enteral nutrition by Nutrisond. Baseline values were compared to day 4 and 7 to assess the degree of change. The prealbumin of day 7 versus baseline value showed a significant increase in the mean serum concentration (16.

Parkinsonian syndrome in the course of aqueductal stenosis hydrocephalus.

Report of a case of hydrocephalus secondary to stenosis of the aqueduct with associated parkinsonian syndrome. The suggested etiopathogenesis: damage to the striatal system favored by underlying weakness of the basal ganglia.

Spatial summation across the vertical meridian in hemianopics: a test of blindsight.

Twenty hemianopic patients with retrochiasmatic lesions have been tested for spatial summation of pairs of flashes simultaneously presented either to the same hemifield or to opposite hemifields across the vertical meridian. In such a task normal subjects show summation, i.e.

Repair of skull defects by autogenous bone grafts.

To repair the infant skull as completely and efficiently as possible, the authors describe and recommend greater use of an autogenous graft taking the outer table of the skull from adjacent or symmetrical sites to the defect.

[Primary empty sella syndrome. Clinical and radiological study, and evaluation of pituitary function].

Empty sella syndrome is an anatomoclinical condition in which the herniation of the chiasmatic cavities inside the sella turcica causes deformation of the bone and compression of the hypophysis and its peduncle, often in association with neurological and endocrine symptoms. Over the past four years 22 patients with primary empty sella syndrome were studied at Pisa University's Department of Neurosurgery with particular emphasis on clinical and radiological pictures and hypophyseal function. Pneumocisternography and computerised tomography of the cranium and cavities were used to verify the diagnosis.

Pulmonary embolism in neurosurgical patients: diagnosis and treatment.

Pulmonary embolism was suspected in 45 neurosurgical patients who were treated between January, 1980, and December, 1981. Hypoxemia with respiratory alkalosis and sudden tachycardia gave rise to this suspicion more often than any other sign or symptom. Perfusion lung scanning confirmed the presence of pulmonary embolism in 23 of these cases.

Neurotoxic effects of 2,5-hexanedione in rats: early morphological and functional changes in nerve fibres and neuromuscular junctions.

The study was directed at detecting changes occurring in the early stages of the neurotoxic process induced by an intensive treatment with 2,5-hexanedione. Rats were injected intraperitoneally each day with 450 mg/kg of body weight for the first 14 days and then with 300 mg/kg for an additional 20 days. After 34 days of treatment typical axonal lesions were observed in the sciatic branches, together with electrophysiological signs of denervation in several fibres of the leg muscles.

Effects of chronic nerve conduction block on formation of neuromuscular junctions and junctional AChE in the rat.

The development of ectopic n.m.j.

Partial denervation in inactive muscle effects innervated and denervated fibres equally.

Possible causal factors of denervation-induced changes in muscle include inactivity, products of nerve degeneration and lack of a nerve-borne trophic agent. We now show that if the innervated fibres in a partially denervated rat muscle are rendered inactive, they undergo a reaction as intense as that of the denervated fibres. This provides further support for the view that the effects of denervation on the extrajunctional muscle membrane result from a combination of muscle inactivity and of nerve breakdown products acting diffusely throughout the muscle.

[Degeneration of the afferent fibers simulating the effects of motor denervation on skeletal muscle].

Degeneration of afferent nerve fibres was induced in rats in order to observe its effects on the properties of the extra-junctional membrane of soleus muscle fibres. In one approach, removal of dorsal root ganglia L4 and L5 was accomplished in preparations with intact or impulse-blocked (with tetrodotoxin containing cuffs around the sciatic nerve) efferent innervation. Spike resistance to tetrodotoxin developed in the inactive deafferented preparations earlier and to a greater extent than in control, that is only impulse-blocked, preparations.

[Effects of partial denervation on the distribution of acetylcholine receptors and other membrane properties in innervated and paralyzed fibers of rat skeletal muscle].

The origin of the membrane changes induced in skeletal muscle by denervation has been investigated by examining partially denervated rat hindlimb muscles rendered inactive for 2-3 days by a chronic conduction block in the sciatic nerve. Extra-junctional sensitivity to acetylcholine and spike resistance to tetrodotoxin developed to the same extent in the denervated and the adjacent innervated but inactive fibres. On the other hand, impulse-blocked fibres of control muscles not containing denervated fibres showed, at this early time, little membrane changes.