Can contaminated surgical instruments spread Alzheimer's disease?

 Now there's a scary thought!  

A few years ago, some researchers found reasons to believe that amyloid seeds could be carried from one neurosurgery patient to another via surgical instruments.  This implies that contaminated instruments could transmit Alzheimer's disease between patients undergoing neurosurgery.  This in turn led to some alarming headlines.

Now, according to a recent white paper in the British medical journal The Lancet, this risk may exist, but it requires further study to be understood.  The white paper was the product of a working group gathered to investigate the risk.  It was analyzed in this week's Alzfourm.  

The working group concluded that there was little evidence that amyloid seeds could be transmitted during neurosurgery, but the risk shouldn't be dismissed.  Instead, it warranted a long-term epidemiological study.  It also recommended that surgical instruments used for neurosurgery in children be segregated from those used for adults.

If the seeds are actually transmitted, they would come from surgery involving older adults with evolving presence of beta amyloid in their brains.  Once transmitted to a younger person, the seeds would likely take 20 years to develop into a stage of Alzheimer's disease involving cognitive impairment.  Therefore, transmission from one older adult to another would be of much less consequence than transmission from an older adult to a young person. 

One person commenting on the article noted that there are a lot of serious risks that must be considered before any neurosurgery, and the benefits must outweigh those risks.  He suggested that, in comparison, the risk of developing "cerebral amyloid angiopathy" from contaminated instruments is minimal.  Cerebral amyloid angiopathy is a condition involving the familiar beta amyloid, and it is often, but not always, associated with Alzheimer's disease.  The commenter also suggested that further epidemiological study is warranted.