'Subarachnoid cyst' after evacuation of chronic subdural hematoma: Case report of an unusual postoperative morbidity

Current Understanding of Central Nervous System Drainage Systems: Implications in the Context of Neurodegenerative Diseases

Until recently, it was thought that there were no lymphatic vessels in the central nervous system (CNS). Therefore, all metabolic processes were assumed to take place only in the circulation of the cerebrospinal fluid (CSF) and through the blood-brain barrier's (BBB), which regulate ion transport and ensure the functioning of the CNS. However, recent findings yield a new perspective: There is an exchange of CSF with interstitial fluid (ISF), which is drained to the paravenous space and reaches lymphatic nodes at the end. This circulation is known as the glymphatic system. The glymphatic system is an extensive network of meningeal lymphatic vessels (MLV) in the basal area of the skull that provides another path for waste products from CNS to reach the bloodstream. MLV develop postnatally, initially appearing around the foramina in the basal part of the skull and the spinal cord, thereafter sprouting along the skull's blood vessels and spinal nerves in various areas of the meninges. VEGF-C protein (vascular endothelial growth factor), expressed mainly by vascular smooth cells, plays an important role in the development of the MLV. The regenerative potential and plasticity of MLV and the novel discoveries related to CNS drainage offer potential for the treatment of neurodegenerative diseases such as dementia, hydrocephalus, stroke, multiple sclerosis, and Alzheimer disease (AD). Herein, we present an overview of the structure and function of the glymphatic system and MLV, and their potential involvement in the pathology and progression of neurodegenerative diseases.

The number of burr holes and use of a drain do not interfere with surgical results of chronic subdural hematomas

Burr hole evacuation has been the most frequently-used procedure for the treatment of chronic subdural hematomas (CSDH).

OBJECTIVE

To evaluate whether the use of a drain and/or the number of burr holes for treatment of CSDH modifies the rates of recurrence and complications.

METHODS

A retrospective review of 142 patients operated on because of CSDH, between 2006 and 2015, analyzing recurrence and complications of the use of one or two burr holes with or without the use of a drain.

RESULTS

Thirty-seven patients had bilateral CSDH (26%) and 105 (73.9%) patients had unilateral CSDH. Twenty-two (59.4%) patients were given a drain and 15 (40.6%) were not. A total number of recurrences occurred in 22 (15.5%) patients and the total number of complications was in six (4.2%) patients. Mean follow-up time was 7.67 months.

CONCLUSIONS

The number of burr holes and the use of the drain did not alter the rates of recurrence and complications in the treatment of CSDH.