Radiological Changes of Glymphatic-meningeal Lymphatic Drainage System After Spontaneous Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a common and extremely critical disease in neurosurgery. The mortality rate within 30 days of the onset of SAH is as high as 50% and about 15% of SAH patients die without reaching the hospital. Nearly half of the survivors have severe neurological dysfunction, causing a huge burden to the families and society of the patients.

Recently, the introduction of the "glymphatic-meningeal lymphatic vessels" drainage system has updated the current concept of intracranial cerebrospinal fluid circulation. After subarachnoid hemorrhage, a large number of blood components flooded into the subarachnoid space and entered the cerebrospinal fluid circulation, which directly affected the function of the lymphatic-meningeal lymphatic drainage system. Many preclinical animal studies have pointed out that the damage of the lymphatic-meningeal lymphatic drainage system is involved in the aggravation of cerebral edema, neuroinflammation, and hydrocephalus after SAH, which ultimately leads to poor prognosis of patients.

However, at present, the changes in the glymphatic-meningeal lymphatic drainage system after SAH have only been confirmed in animal models, and clinical evidence is lacking. With the development of imaging technology, many research teams have confirmed the functional changes of the lymphatic-meningeal lymphatic drainage system in Alzheimer's disease and Parkinson's disease by using different sequences of non-invasive MRI, such as 3D T2-FLAIR, DTI-ALPS, and other sequences.