The etiology of low-grade gliomas: pathological and clinical considerations about radiation-induced low-grade gliomas.

The only environmental factor undoubtedly linked to an increased risk of brain tumors (including gliomas) is therapeutic X-rays. We aim to conduct a detailed study of radiation-induced low-grade gliomas, in order to better understand the pathogenesis of such gliomas. Furthermore, we want do prove whether or not there are significant differences, according to clinical features and biological behavior, between this type of tumor and general low-grade gliomas. We analyzed the existent literature of low-grade radiation-induced glioma case reports and other epidemiological reports based on the experience of the senior author. We were able to collect 20 cases of such gliomas. Demographic data and previous X-ray details, along with latency intervals of all patients are provided. The amount of radiation able to cause mutations is not necessarily very high, as tumors occur even after low doses of radiation (as 3-5 GY). The incidence of this kind of tumors may be underestimated and may rise in the future. Care must be taken when observing patients who were irradiated more than 10 years before, especially in the recent years in which access to radiosurgical and radiation therapies has increased in the general population for treating many cerebral pathologies. Radiation-induced low-grade gliomas appear to be different from general gliomas only in terms of age in which they occur. In terms of clinical and biological behavior, there seem to be no differences, even though exceptional cases are reported.

Lumbar spinal degenerative "microinstability": hype or hope? Proposal of a new classification to detect it and to assess surgical treatment.

PURPOSE: The stage of unstable dysfunction, also defined as "active discopathy" by Nguyen in 2015 and configuring the first phase of the degenerative cascade described by Kirkaldy-Willis, has specific pathoanatomical and clinical characteristics (low back pain) in the interested vertebral segment, without the presence of spondylolisthesis in flexion-extension radiography. This clinical condition has been defined as "microinstability" (MI). The term has currently not been recognized by the scientific community and is subject of debate for its diagnostic challenge. MI indicates a clinical condition in which the patient has a degeneration of the lumbar spine, causing low back pain, and radiological examinations do not show a spondylolisthesis. METHODS: We elaborated a clinical score test based on preoperative radiological examinations (static and dynamic X-Rays, CT and MRI) to detect and assess MI. Then, we enrolled 74 patients, all the levels from L1 to S1 were analysed, for a total amount of 370 retrospectively analysed levels. We excluded patients with degenerative scoliosis, as it is related to an advanced stage of degeneration. The test has been developed with the aim of furnishing quantitative data on the basis of the aforementioned radiological examinations and of elaborating a diagnosis and a treatment for the degenerative pathology in dysfunctional phase, responsible for low back pain. RESULTS: We performed a statistical analysis on the results obtained from the test in terms of significativity and predictive value with a 1-year follow-up, calculating the p value and the χ (2) value. CONCLUSIONS: In patients with low back pain and negative dynamic X-Rays, an accurate analysis of the radiological exams (CT, MRI, X-Rays) allows to formulate a diagnosis of suspect MI with a good predictive value. This situation opens many clinical and medicolegal scenarios. The preliminary results seem to validate the test with a good predictive value, especially towards ASD, but they need further studies. On the basis of the results obtained, the test seems to allow a good classification of the dysfunctional phase of the degenerative cascade, identifying and classifying MI as a pathologic entity, defining its pathoanatomical and clinical relevance and elaborating a treatment algorithm.