“Silent Stroke” and Non-High-Risk Surgery

Heart surgery and surgeries involving tumors of the head or neck are considered high risk for stroke because the vascular system is being directly accessed or manipulated and any clots caused by the manipulation of blood vessels will quickly go to the brain. However, no surgery is completely without risk.

While the chances of a stroke for non-cardiac surgeries is less than 1%, there is real concern that perioperative covert strokes, also called “silent strokes,” may occur in as many as one-third of older patients.

In 2019, Science Daily published a study that followed over 1100 non-cardiac surgery patients aged 65 and older who had no history of stroke. These patients had an MRI of their brains after the surgery in order to look for acute brain infarction. The study found that 7% of these patients 65 and older had overt – or obvious – strokes and 42% demonstrated cognitive decline one year after surgery. This is a startling finding since strokes supposedly occur in less than 1% of non-cardiac and non-neurological surgeries.

More disturbing, however, was the discovery that 29% of the patients who did not have an overt stroke after surgery showed cognitive decline one year post-surgery. This is what is called a covert or silent stroke. The patients who had silent strokes were also found to be at a higher risk of TIA, often called a mini-stroke, in subsequent years.

Another study looked at non-cardiac and non-neurological surgeries, such as hip replacement, hernia repair, knee repair, biopsy, etc. They found that the highest-risk surgeries were hip replacement, removal of part of the intestine, and removal of part of the lung. Other risk factors for stroke after surgery included older age, kidney disease, COPD, tobacco use, and high blood pressure. In this study of nearly 175,000 people, the overall risk was indeed less than 1%, but the chance of dying from a perioperative stroke within 30 days was found to be 8 times higher than a non-operative stroke.

These findings are valuable for medical personnel, as they help them assess the best way to protect their patients, and also for patients and their families, as they consider how to lessen the risks and watch for signs of postoperative cognitive decline.

These studies also highlight the critical importance of very close observation for signs of perioperative stroke and quick action to limit long-term damage. The finding that perioperative strokes have an 8-fold increase in death over strokes that occur outside the hospital may be connected to the fact that an in-hospital stroke can take up to 4 hours to be detected. With a stroke, delayed detection is often deadly.

Neuralert Technologies is committed to ending the devastation caused by in-hospital strokes with its innovative stroke detection monitor, combining a unique, non-invasive wristband technology with a state-of-the-art patented algorithm developed by the University of Pennsylvania to detect asymmetry in arm movement, one of the initial indications of stroke onset.

Because Neuralert’s algorithm is able to rule out other reasons for asymmetry (for instance, an IV in the arm, eating, or talking on the phone) the frequency of false alerts is extremely low. Your hospital staff will know that when they get an alert from the Neuralert technology, that the patient needs immediate attention. Quick treatment decreases the severity of the effects of stroke, saves lives, shortens hospital stays, and reduces costly litigation. Partner with Neuralert to optimize your hospital’s stroke response protocols.