The New Bad Actor in Neurological Diseases

Written by Olivia Woodford-Berry, '19
Edited by Hannah Ngo, '21

From computer scientists studying artificial intelligence to neurologists investigating neurodivergence, researchers across specialties struggle to understand the inner working of neural networks and the human brain. Indeed, despite expansive advances made in the medical field over the last fifty years, there is still little understanding of neurological diseases. However, a recent study by Gargi Banerjee and David Werring of University College, London, suggests Prion diseases may be more prevalent than previously anticipated. [1] ​

Figure 1: Brain Atrophy

A prion is an infectious protein particle similar to a virus but lacking DNA.  According to the CDC, Prion diseases, or transmissible spongiform encephalopathies (named for the “spongy” holes it causes in the brain, Figure 1), are “a family of rare progressive neurodegenerative disorders that affect both humans and animals.” [2] In this study, researchers examined amyloid‐β (Aβ), a protein hallmark of Alzheimer’s Disease and cerebral amyloid angiopathy (CAA), that can be transmitted, as a prion, through procedures such as childhood neurosurgery or graft insertion. Amyloid‐β transmission has been identified in patients with specific neurological diseases, but there has been little research surrounding the impact of such Amyloid‐β transmissions on patients throughout their lives.  In this experiment, researchers found a correlation between patients with symptomatic amyloid‐β cerebral amyloid angiopathy and exposure to this transmission at young ages, suggesting that this condition is in fact due to the transmission of prions. [1]

This study suggests that neural graft procedures may introduce prions and be a potential cause of some neurological diseases, which means that there are thousands of patients potentially at risk for neurodegenerative conditions.  In Japan, about 20,000 patents received a neurological graft annually from 1983 to 1987. In the United States, approximately 4,000 patients received dural (connective tissue around the brain) transplants per year during a similar timeframe. While this study cannot prove absolute causation, it increases our understanding of the number of potential mechanisms of transmission for early onset (“iatrogenic”) CAA. Thus, this connection may help patients who have received these procedures more easily reach a diagnosis should they present with ambiguous neurological symptoms. In this way, this study represents a small but crucial step towards understanding neurodegenerative diseases.

Sources: 

[1] Banerjee G, Adams ME, Jaunmuktane Z, Lammie GA, Turner B, Wani M, Sawhney IM, Houlden H, Mead S, Brandner S, Werring DJ. Early‐onset Cerebral Amyloid Angiopathy Following Childhood Exposure to Cadaveric Dura. Annals of neurology. 2019 Feb 1.

[2] https://www.cdc.gov/prions/index.html

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