Cerebrospinal fluid draining lymphatics in health and disease: advances and controversies

The meninges, consisting of the dura, arachnoid and pia mater that surround the brain and spinal cord, have been recognized from the earliest anatomical studies. First identified in 1787, lymphatic vessels in the dura are now receiving greater attention as their contribution to cerebrospinal fluid (CSF) clearance in diverse neurological conditions is being investigated. New methods have increased the understanding of dural lymphatics, but much is still being learned about their heterogeneity, intracranial and extracranial connections, and factors that govern their functions and maintenance. Current research is striving to understand the regulation of CSF drainage and influence of brain antigen and immune cell transit through dural lymphatics on aging impairments and the severity of neurodegenerative and neuroimmune diseases, traumatic brain injury, stroke and other neurological disorders. Achieving these goals should lead to safe and effective methods for manipulating CSF clearance through dural lymphatics for therapeutic benefit. McDonald et al. review studies of lymphatic vessels in the dural layer of the meninges and discuss the role of lymphatics in the function and maintenance of the central nervous system, aging, neuroimmunity and the progression of neurological disorders such as Alzheimer’s disease and Parkinson’s disease.