Methods of cognitive status research in patients with glioblastoma

Introduction: Glioblastoma is a high-grade, aggressive central nervous system tumor with predominantly astrocytic differentiation, characterized by fast invasive growth into the surrounding brain parenchyma and aggressive clinical course. The short life expectancy of patients diagnosed with glioblastoma necessitates the need to maximize their quality of remaining life. One of the most common reasons for quality of life impairment in these patients is the cognitive deficit accompanying the disease. There is a lack of a unified and standardized method for the assessment of cognitive functions in these patients, which meets all the necessary criteria to be convenient and usable in the wide clinical practice.Aim: The aim of the present study is to compare the Montreal cognitive assessment (MoCA) brief screening test with an extended neuropsychological examination to determine its applicability in patients diagnosed with glioblastoma. Material and methods: The study includes 27 patients undergoing neurosurgical intervention for histologically proven IDH-wildtype glioblastoma in the Department of Neurosurgery, “St. Marina” University Hospital – a tertiary healthcare center, for the period January 2019 to December 2022. Preoperatively, patients were examined with the short MoCA screening test and an extended neuropsychological examination including the following subtests: Issac set test, Trail making test A and B, Luria test, Raven‘s color matrices, Stroop test and Bender test.Results: Of all the patients studied, those with a MoCA score below 26 points present at least one negative test of the extended neuropsychological examination. MoCA patients with scores of 26 or more do not demonstrate cognitive impairment in the extended neuropsychological impairment.Conclusion: The obtained results support the claim that the MoCA short screening test is applicable for preoperative diagnosis of cognitive disorders in patients with glioblastoma. Due to the study‘s small sample size, further research is needed to definitively prove this claim

Historical origin and meaning of the term „glial tumor“

In everyday neurosurgical practice, the term „glial tumor“ is associated with astrocytomas, glioblastomas, and oligodendrogliomas, although historically this has not always been the case. The term „glial tumor“ was first given by Virchow in the 19th century as a term initially combining all primary brain tumors under this name. It derives from the name of the group of „supporting“ nerve cells - glia or neuroglia (from the Greek glia - glue), a group which for many years was wrongly ascribed only a cohesive or supporting function.In 1926, in their classification of glial tumors - A Classification of the Tumors of the Glioma Group on a Histogenetic Basis with a Correlated Study of Prognosis, one of the founding fathers of neuropathology Percival Bailey and the founding father of modern neurosurgery – Harvey Cushing ascribed several different tumors in this group: in addition to neuroepithelioma, spongioblastoma multiforme, astrocytoma and ependymoma, they also add medulloblastoma, astroblastoma, oligodendroglioma and unipolar spongioblastoma. Since then, the classification of glial tumors has undergone many changes to its current form. In the latest classification of brain tumors published in 2021, glial tumors are united in a common group together with glioneuronal and neuronal tumors. Their extensive group includes tumors with different prognosis, age presentation, molecular profile and therapeutic response. From a neurosurgical point of view, the term „glial tumor“ does not carry a prognostic value, but only determines the belonging of the tumor to the astrocyte, oligodendrocyte cell line or their precursor cells. In relation to that an interesting question arises- why the remaining tumors originating from glial cells other than astrocytic, such as ependymomas, lost their belonging to the group of glial tumors, or such as intracranial schwannomas, are not included in it at all

Age as a factor for cognitive decline in patients with glial tumors

Introduction: Cognitive impairment appears in almost all patients with glial tumors during the course of this neuro-oncological disease. There are various reasons for this in regards to the glial tumor: grade of malignancy, rate of growth, molecular nature, mass effect, and presence of perifocal edema. But these factors do not always correlate with the degree of patient’s cognitive impairment. The present study’s aim is to account for age as a factor in the occurrence of cognitive decline in patients with glial tumors.Materials and methods: The study includes thirty two patients diagnosed with a glial tumor, treated operatively in the Neurosurgery Clinic of University hospital „St. Marina“ in Varna between 2019 and 2022 year. Twenty nine of those patients are diagnosed with glioblastoma, two are diagnosed with diffuse astrocytoma and one with astrocytoma grade 3 according to WHO. The mean age of the patients is 58.4 ± 11.4 years. The youngest patient is 25 years old and the oldest is 78 years old. Preoperatively, all patients are subjected to a series of cognitive tests.Results: From the studied sample, patients diagnosed with glioblastoma showed lower cognitive scores compared to the patients diagnosed with other glial tumors. Patients diagnosed with glioblastoma are significantly older than the patients diagnosed with other glial tumors.Conclusion: The older age of patients affected by glioblastoma may be an additional reason beside tumor factors for lower cognitive test outcome compared to patients affected by lower-grade gliomas