Advances and technical standards in neurosurgery最新文献

Medical observations can often be of important help for basic research and conversely. Here we review advances in basic and applied neuroscience that provide both theoretical and practical tools for neurosurgery. To this end, in the first two sections, we address the increased precision of functional brain mapping in clinical contexts and the processes of how the brain dynamically adapts to structural changes following surgery to optimize recovery. In the third section, we focus on the more recently studied field of social/affective neuroscience and how it results to neurosurgery advances, pointing out theoretical advances but also future challenges of primary interest for the sake of neurosurgical practices and better patients' outcome.

Selective dorsal rhizotomy represents one of the major neurosurgical tools in treating pediatric spasticity. Intraoperative rootlet selection is the key step of the procedure in order to achieve good outcomes. Intraoperative monitoring (IOM) and anatomical selection of the rootlets are the gold standard in the aforementioned selection leading the surgeon during the procedure. The tendency toward minimally invasive procedures further increases IOM importance, warranting the use of electrophysiology in choosing the more suitable rootlets for cutting. Discharge pattern and percentage of resection represent the most important topics in surgical guidance, relying onto the very same pathophysiological mechanism causing spasticity to choose targets.

In this chapter, the current status of dorsal rhizotomy is reviewed, highlighting its significant evolution over the past four decades. The first major advancement was sparked by Fasano's introduction of intraoperative neurophysiological procedures and Peacock's modification of the surgical site to the cauda equina. Subsequent advancements in surgical and neurophysiological techniques have expanded the indications for rhizotomy beyond spastic cerebral palsy, a condition affecting 0.2% of live births worldwide. Dorsal rhizotomy can significantly benefit children with spasticity by improving their mobility, daily activities, and social participation.

There are many approaches to performing selective dorsal rhizotomy (SDR). The two most commonly performed approaches are the cauda equina approach, popularized by Warwick Peacock in 1980, and the conus medullaris approach, as used initially by Foerster and later Gros, and having its modern incarnation in the work of Tae Sun Park. Peacock changed from the traditional conus approach as he felt this approach led to unpredictable outcomes and bladder and bowel complications in some patients at the time. With the modern addition of intraoperative neurophysiology and further advances in the selection of patients for SDR, this technique of performing selective dorsal rhizotomy at the level of the cauda equina lives on with long-term data in support of its use. The author elaborates on the cauda equina approach to SDR in this chapter.

Spasticity arises from the exaggeration of the monosynaptic reflex, attributed to the loss of inhibitory influences from descending supraspinal structures, though not exclusively. Defined by its resistance to muscle stretching, spasticity yields two significant outcomes. Firstly, muscles tend to remain in a shortened position, restricting movement. Secondly, hypertonia, coupled with a lack of mobilization, leads to soft tissue changes, including a loss of viscoelasticity. This non-velocity-dependent biomechanical aspect limits movements, even at slow velocities, rendering them unresponsive to antispastic agents. Proactively addressing hypertonia/spasticity is crucial to prevent the fixation of disorders and the potential irreducibility of this vicious circle. Understanding the role of the reticular formation, its afferent projections, and efferent pathways is essential for comprehending circadian tone variations and the variability in clinical presentations among patients. The mechanism of hypertonia in children with cerebral palsy is twofold: a neural component due to spasticity (velocity dependent) and a biomechanical component linked to soft tissue changes. Although clinically challenging to differentiate, this distinction is crucial, as only the former responds to antispastic treatments, while the latter requires physiotherapy. Additionally, spasticity is often accompanied by dystonia, a sustained hypertonic state induced by voluntary motion attempts. Distinguishing spasticity from dystonia is essential, as dorsal rhizotomy minimally affects the dystonic component. Spasticity, by opposing muscle stretching and lengthening, leads to muscles remaining in a shortened position, resulting in soft tissue changes and contracture, ultimately restricting movements. Hypertonia and lack of mobilization create a vicious circle, culminating in severe locomotor disability due to irreducible musculotendinous retraction and joint ankylosis/bone deformities. These evolving consequences must be carefully considered during a child's assessment for decision-making. The hypotonic effects of lumbosacral dorsal rhizotomy, acting not only at a segmental level on the lower limbs but also supra-segmentally through the reticular formation, are also discussed.

We still base spasticity management on rehabilitation and lesional surgical procedures. These techniques have been well-studied, and long-term follow-up data is available. However, we can still not treat the cause of the spasticity with any of these modalities, and advances in neuromodulation and genetic therapies are promising this in the future. In this chapter, the author describes the new developments in spasticity surgery. The focus is on advances in lesioning techniques, neuromodulation strategies-cerebral, spinal, and peripheral techniques-and genetic and stem cell research. There is still no conclusive evidence showing better outcomes and improved long-term data than our current medication and lesion-based approach, but as the technology improves, this may change. We hope to reach a point where we aim to care for patients with spasticity at the individual cause of each person's spasticity and cure them.

Colloid cysts of the third ventricle are benign and rare lesions of the central nervous system. Although gross total resection is the standard treatment of these lesions, there are multiple surgical routes proposed and discussed in the literature. Similarly, the origin of these colloid cysts remains a topic of debate. Long-term outcomes of anterior transcallosal approach have been analyzed and compared with the recent meta-analyses published in the literature. Additionally, the origin of these cysts is explored using immunohistochemical analysis.Eighty operations on 76 patients by a single surgeon over 37 years have been studied and the long-term outcomes have been presented. Additionally, ependyma, choroid plexus, and colloid cyst specimen have been compared using immunohistological staining with cytokeratin, S100, and PAX-7.The long-term outcomes with comparison with the literature show that microsurgical gross total resection using anterior transcallosal approach is the ideal treatment over other modalities. Preoperative hydrocephalus is a strong indicator for the location of the colloid cyst within the anterior third ventricle and for the selection of transforaminal versus interforniceal approach. In pathological study, the clear staining with PAX-7 points to this pathology being a remnant of the paraphysis.

Introduction: Glioblastoma (GB) remains the most prevalent and aggressive primary tumor of the central nervous system, with median overall survival between 14 and 20 months. Maximal extent of resection is associated with extended overall survival. Lobectomy may lend itself in the management of patients with glioblastomas in certain anatomical areas for accomplishing maximal or even supramaximal resection.

Patient selection: Patients with good preoperative KPS, with a tumor confined to one lobe, and no infiltration of the subependymal zone are good candidates for lobectomy.Preoperative considerations: A thorough medical history, a detailed neurological examination, along with diagnostic work-up is essential in decision-making and proper surgical planning. Neurocognitive evaluation is also of paramount importance.Frontal lobectomy: High-speed drill is used for performing a frontotemporal craniotomy in non-dominant cases, while a more extensive fronto-parieto-temporal osseous flap is required in dominant cases for detailed cortical and subcortical mapping via an awake procedure. A corticectomy is then performed along with subpial resection of the white matter of the involved lobe.Temporal lobectomy: The same craniotomy strategy is used in temporal lobectomies. A corticectomy is performed through the inferior temporal gyrus, removal of the underlying white matter, and entrance to the ipsilateral temporal horn. After the neocortical resection, the mesial temporal structures have to be removed under the microscope. The importance of subpial resection technique cannot be overemphasized.

Complications: Complications such as neurocognitive deficits, paresis, dysphasia, infections, hydrocephalus, and hemorrhage are mainly reported in lobectomies performed for epilepsy. In GB lobectomy studies, no statistically significant differences were observed regarding complications.

Results: In the pertinent literature, lobectomy demonstrates a mean overall survival of 25 months, compared to 13.72 months for gross total resection (GTR), and a progression-free survival of 16.13 months, compared to 8.77 months for GTR.

Intracystic IFNα proved to be a safe and effective option in the multimodal management of cystic craniopharyngioma (CRF).In our institutional experience, controversial cases have arisen concern and unanswered questions, that are becoming more common with the availability of new target therapies for other brain tumors.Reliable criteria to define the response to treatment should be defined. Additionally, the best timing of surgical resection after target therapy is not clear. Surgery is postponed in case of favorable response, but tumor relapse may present a different architecture eventually increasing surgical morbidity. Finally, in case of good response to the target therapy a close follow-up is required, since rebound may occur in exceptional cases.These data should represent the benchmark for future studies using either systemic administration of IFN or other intracystic drugs.

Craniovertebral junction (CVJ) tumor removal is challenging due to their close relationships with critical neurovascular structures and the brainstem. First attempts at removal of these lesions through the midline posterior suboccipital route were associated with significant postoperative morbidity and mortality. Hence, various neurosurgical approaches have been proposed for dealing with such lesions more safely. Anterolateral, extreme, and far lateral approaches have been developed with the aim to move more anterolaterally the angle of dissection, thus minimizing the retraction needed to reach CVJ tumors. However, there is still no clear evidence about the optimal approach for dealing with such lesions. If the brainstem retraction is minimized by more lateral routes, these approaches are time-consuming and are linked with a high risk of approach-related complications that is proportionate to the extent of bony drilling and to the neural and vascular manipulations.Here we present our technique for the microsurgical removal of CVJ tumors through a simple posterolateral approach. In addition, we briefly summarize the pros and cons of the different surgical approaches for CVJ lesions.