ABSTRACT
BACKGROUND: Individuals with specific TREM2 gene variants that encode for a Triggering Receptor Expressed on Myeloid cells 2 have a higher prevalence of Alzheimer's disease (AD). By interacting with amyloid and apolipoproteins, the TREM2 receptor regulates the number of myeloid cells, phagocytosis, and the inflammatory response. Higher TREM2 expression has been suggested to protect against AD. However, it is extremely difficult to comprehend TREM2 signaling in the context of AD. Previous results are variable and show distinct effects on diverse pathological changes in AD, differences between soluble and membrane isoform signaling, and inconsistency between animal models and humans. In addition, the relationship between TREM2 and inflammasome activation pathways is not yet entirely understood. OBJECTIVE: This study aimed to determine the relationship between soluble TREM2 (sTREM2) levels in cerebrospinal fluid (CSF) and plasma samples and other indicators of AD pathology. METHODS: Using the Enzyme-Linked Immunosorbent Assay (ELISA), we analyzed 98 samples of AD plasma, 35 samples of plasma from individuals with mild cognitive impairment (MCI), and 11 samples of plasma from healthy controls (HC), as well as 155 samples of AD CSF, 90 samples of MCI CSF, and 50 samples of HC CSF. RESULTS: CSF sTREM2 levels were significantly correlated with neurofibrillary degeneration, cognitive decline, and inflammasome activity in AD patients. In contrast to plasma sTREM2, CSF sTREM2 levels in the AD group were higher than those in the MCI and HC groups. Moreover, concentrations of sTREM2 in CSF were substantially higher in the MCI group than in the HC group, indicating that CSF sTREM2 levels could be used not only to distinguish between HC and AD patients but also as a biomarker to detect earlier changes in the MCI stage. CONCLUSIONS: The results indicate CSF sTREM2 levels reliably predict neurofibrillary degeneration, cognitive decline, and inflammasome activation, and also have a high diagnostic potential for distinguishing diseased from healthy individuals. To add sTREM2 to the list of required AD biomarkers, future studies will need to include a larger number of patients and utilize a standardized methodology.
ABSTRACT
Spinal cord lipomas are rare and benign tumors which may cause progressive neurological deficits due to their local expansion. We present the case of a 59-year-old male patient with severe lumbosacral pain and slowly progressive paresis of the right leg, misdiagnosed with degenerative spine disease. Repeated magnetic resonance (MR) T1-weighted images of the thoracic spine suggested a subacute intramedullary hematoma. Due to progression of the neurological deficit, the patient was referred to a neurosurgeon, who indicated surgical evacuation of the hematoma. The intraoperative finding revealed an intramedullary spinal cord lipoma, which was later confirmed by histological analysis. Since subacute intramedullary hematomas and intramedullary spinal cord lipomas present with similar clinical and radiological features, diffusion-weighted MR imaging should be used to distinguish these entities.
ABSTRACT
Despite growing popularity of endovascular techniques, certain subsets of patients with cerebrovascular compromise may benefit from bypass surgery. We present four cases in which pending ischemic lesion was prevented by (1) A3 resection and reanastomosis following falx meningioma removal, (2) rescue superficial temporal artery-middle cerebral artery (STA-MCA) bypass after pituitary adenoma surgery, (3) STA-MCA bypass for chronic internal carotid artery occlusion, and (4) external carotid artery-MCA bypass using radial artery grafting. Following the procedure, there were no further clinical or radiological deteriorations and long-term patency was confirmed in all four cases.
