Progress in neurological surgery最新文献

Since its introduction, diffusion tensor imaging (DTI) has become an important tool in neuroscience given its unprecedented ability to image brain white matter in vivo. The interest in understanding the mechanisms of action of Deep Brain Stimulation in different targets and indications, together with the constant drive towards the improvement in long-term clinical outcomes, has found a logical complement in the application of tractography in this field. Diffusion tensor imaging has been traditionally associated with an increased susceptibility to MRI artifacts, and expensive computational resources. Recent advances have however improved these restrictions, allowing for countless applications in Neurosurgery, as demonstrated by the large number of original research papers published in the last decade. In this chapter, we review the current status of the implementation of DTI during DBS of the basal ganglia, discussing the findings, potential challenges and the expected improvements in surgical outcomes deriving by the routine use of tractography in functional neurosurgery.

Histopathological typing and grading are the cornerstones of the World Health Organization classification of the central nervous system tumors. It provides clinicians with information on the natural course of the disease and thus guides therapeutic choices. Nonetheless, patients with histologically identical tumors may have different outcomes and response to therapy. In recent years, extensive research has been done on three molecular markers in adult gliomas, namely MGMT promoter methylation, 1p/19q co-deletion, and IDH1/IDH2 mutations. These markers may have either a prognostic or a predictive value, differentiation of which is often difficult as both can coexist. At present, MGMT promoter methylation is considered as a predictive marker for response of glioblastoma to chemotherapy with temozolomide, particularly in elderly patients, 1p/19q co-deletion is a molecular signature of oligodendroglial tumors and predictive marker for response of anaplastic gliomas to PCV chemotherapy, and IDH1/IDH2 mutations have a strong favorable prognostic value across all glioma histopathological grades.

Clinicians dealing with patients affected by malignant brain tumors are frequently involved in providing palliative and supportive care, particularly at the end of life. It requires a multidisciplinary approach by a well-trained specialized neuro-oncology team. Early initiation of palliative care integrated with standard anticancer therapy may be effective for symptom management and results in improvement of the quality of life. However, studies specifically addressing these issues are very limited, thus do not allow the creation of any reliable evidence-based guidelines. Therefore, there is a definite need for improvement in the quality of palliative and supportive care in neuro-oncology and for specific education for its providers.

Systemic chemotherapy of malignant brain tumors has failed to achieve sufficient drug concentrations at the neoplasm site and frequently results in severe toxicities. Therefore, the local application of several anticancer agents, oncolytic viruses and vectors for gene therapy, immune-modifying preparations, and angiogenesis inhibitors has been investigated widely. Various modes of their administration were introduced, including intratumoral injections, implantation of reservoirs or pumps, convection-enhanced delivery, and use of nanocarriers, thermoreversible gels, microchips, and drug-loaded polymers. Many of these therapeutic approaches have shown promising results in management of high-grade gliomas.

Gliomas located in eloquent cortex impose a unique surgical obstacle. The oncological benefit of aggressive resection must be balanced with preservation of functional tissue and optimization of surgical outcome. Technical advances in preoperative functional imaging, refinement of intraoperative mapping, and conceptual understanding of cerebral plasticity have significantly improved the outcome of this patient population.

This report summarizes the state-of-the-art and controversies around patient selection for deep brain stimulation (DBS) for various conditions. Parkinson's disease (PD): several class I studies have shown superiority of DBS over best medical treatment for advanced PD with fluctuations and further inclusion criteria. One class I study suggests that PD patients with early motor complications might gain more quality of life if operated within 3 years after the onset of fluctuations. The subthalamic nucleus (STN) is still the standard target. STN DBS has an impact on impulse control disorders though the exact mechanism is unclear. Tremor: essential tremor (ET) patients found to be eligible for DBS surgery should first be treated with primidone, propranolol, and with a combined therapy preoperatively. Second-line drugs (i.e., topiramate and gabapentin) may be useful. No class I studies exist for DBS treatment of ET. The optimal target of DBS in ET might be the posterior subthalamic area. Dystonia: there is class I evidence for primary generalized and segmental dystonia and for some botulinum-resistant focal dystonias. The impact of age, symptom duration, and DYT-mutation status in primary dystonia on the outcome of DBS surgery clearly demands more studies. DBS has a role in SCGE-mutation positive myoclonus dystonia and tardive dystonia. Finally, neurostimulation in secondary dystonia might be considered in selected patients based on an individual patient's approach.

Pharmacological treatment is the cornerstone in the management of movement disorders. Although most available treatment options have no impact on the underlying process of each movement disorder, symptomatic therapies can significantly improve patient's quality of life and level of disability. Here, we review the current knowledge on clinical symptomatic management of Parkinson's disease (both early and advanced stages), essential tremor, dystonia, and chorea. Ideally, treatment should be carried out by specialists with reasonable experience in movement disorders, as it needs to be tailored for each patient depending on several appraisals, including but not limited to patients' needs, compliance issues, potential side effects, caregiver support, and presence of comorbidities. When medications fail to improve patient's disability, stereotactic surgery is a well-established option for most of these disorders.

The effectiveness of chemotherapy or chemoradiotherapy for diffuse astrocytoma (DA) has been largely unknown until recently. However, a randomized controlled study (RTOG 9802) showed that adding of procarbazine, CCNU, and vincristine (PCV) chemotherapy to fractionated radiotherapy (FRT) in patients with "high-risk" WHO grade II gliomas, including DA, has significant positive impact on both progression-free survival and overall survival. Effectiveness of temozolomide (TMZ) in cases of low-grade gliomas was also reported, and a randomized phase III trial comparing FRT alone or in combination with TMZ in cases of unresectable DA (JCOG 1303) is currently ongoing.

There has been substantial research interest in delivering therapeutic neurotrophic factors directly to the brain for the treatment of Parkinson's Disease (PD) and other movement disorders. Direct infusion of glial cell-line derived neurotrophic factor has been investigated in both pre-clinical models and clinical trials. In this chapter we discuss past and present research investigating the potential of direct drug delivery to the brain for the treatment of PD and other movement disorders.

Gene therapy is a clinical tool that may eventually provide therapeutic benefit to patients suffering from movement disorders through a few potential mechanisms: direct correction of the pathogenic mechanism, neuroprotection, neurorestoration or symptom control. The therapeutic mechanism is therefore dependent on knowledge of disease pathogenesis and the required temporal and spatial specificities of gene expression. An additional critical challenge is achieving the most complete transduction of the target structure while avoiding leakage into neighboring regions or perivascular spaces. Although critical clinical work is ongoing to optimize the direct intracerebral delivery of transgenes to the brain, the field has recently entered a new technological era, where interventional-MRI-guided convection-enhanced delivery is the gold standard for verifying accurate vector delivery in real-time.