Research Highlight: Lymphatic System Therapy as a Prospective Treatment for Neurological Diseases

by Kurtis Chien

Cerebrospinal fluid is the fluid that surrounds the brain.1 It is produced throughout the day in the cerebral ventricles and eventually drains out of the cranial cavity.1 Past researchers hypothesized that cerebrospinal fluid could drain through either veins or lymphatic vessels, but they were not adequately equipped to determine the exact pathway of drainage.1 Recent research by Ma et al. 2017 was able to determine the predominant pathway by which cerebrospinal fluid leaves the brain by using radiolabeled tracers.2 Researchers infused the lateral ventricles of mouse brains with tracer molecules of various sizes.2 When the brains were imaged, it was found that the tracer molecules were transported to the lymph nodes.2 The researchers also determined that the flow of cerebrospinal fluid exiting the cranial cavity decreased as the mice aged.2

The brain has few immune cells, so one of the purposes of cerebrospinal fluid is to wash out toxins.1 These toxins can include misfolded proteins, which could otherwise accumulate to cause neurodegenerative diseases such as Alzheimer’s disease.1 So, with the current mechanism of cerebrospinal fluid drainage in mind, a proposed method of treatment for these neurodegenerative diseases may be to increase the flow of the lymphatic system.1 The theory follows that a greater lymphatic flow would mean more cerebrospinal fluid exiting the cranial cavity, which would flush more toxic proteins from the brain.1

The concept would require further research, and a starting point could be to determine if mice with Alzheimer’s disease do express a slower rate of lymphatic flow, which would signify insufficient cerebrospinal fluid drainage.2 Such data could further clarify the role of the lymphatic system and support therapeutic techniques that interact with the lymphatic flow.2

 

References:

  1. ETH Zurich. (2017, November 10). Dementia treatment research: Exit through the lymphatic system. ScienceDaily. Retrieved November 11, 2017 from www.sciencedaily.com/releases/2017/11/171110084307.htm
  2. Ma, Q., Ineichen, B. V., Detmar, M., & Proulx, S. T. (2017, November 10). Outflow of cerebrospinal fluid is predominantly through lymphatic vessels and is reduced in aged mice. Retrieved November 10, 2017, from https://www.nature.com/articles/s41467-017-01484-6