RESUMO
The process of memory entails the activation of numerous neural networks and biochemical pathways throughout the brain. The phenomenon of memory decline in relation to aging has been the subject of extensive research for several decades. The correlation between the process of aging and memory is intricate and has various aspects to consider. Throughout the aging process, there are various alterations that take place within the brain and, as expected, affect other functions that have already been linked to memory and its function such as involving microcirculation and sleep. Recent studies provide an understanding of how these mechanisms may be interconnected through the relatively new concept of the glymphatic system. The glymphatic system is strongly correlated to sleep processes. Sleep helps the glymphatic system remove brain waste solutes. Astrocytes expand and contract to form channels for cerebrospinal fluid (CSF) to wash through the brain and eliminate waste. However, the details have not been totally elusive, but the discovery of what we call the glymphatic system enables us to connect many pieces of physiology to understand how such factors are interconnected and the interplay between them. Thus, the purpose of this review is to discuss how the glymphatic system, sleep, memory, and aging are interconnected through a network of complex mechanisms and dynamic interactions.
RESUMO
INTRODUCTION: High-resolution vessel wall imaging (HR-VWI) is emerging as a tool of notable utility in the diagnosis of intracranial vessel pathology. Its role in monitoring vessel wall disease response to treatment, however, is less well-established. CASE REPORT: We report the case of a 45-year-old man with left middle and anterior cerebral artery infarcts and an National Institute of Health Stroke Scale (NIHSS) score of 2. Time-of-flight magnetic resonance angiography and digital subtraction angiography showed multifocal intracranial vessel pathology without extracranial vessel involvement. Comprehensive investigation with echocardiography and 24 hours Holter electrocardiography was unrevealing and the coagulation and routine autoimmune panel results were within normal limits. Cerebrospinal fluid showed mildly elevated protein and a diagnosis of probable primary central nervous system (PCNS) angiitis was made. The diagnosis was corroborated by intracranial HR-VWI, which showed homogenous, concentric enhancement of the left supraclinoid internal carotid artery (ICA) wall. The patient received high-dose IV methylprednisolone and cyclophosphamide. Repeat brain magnetic resonance imaging with HR-VWI at 3 and 9 months showed reduction and final resolution of vessel wall enhancement without recurrent infarcts. He has since remained clinically stable with an NIHSS score of 0 on low-dose oral glucocorticoids. CONCLUSIONS: Our report illustrates the utility of HR-VWI in diagnosing a case of PCNS angiitis through the demonstration of a vasculitic pattern of mural enhancement. Furthermore, it has provided evidence of disease response to treatment, assisting us in modifying treatment accordingly. Tracking disease activity and response to treatment in cases of central nervous system vasculitis can be another important use of HR-VWI in clinical practice besides assisting in establishing the diagnosis.
