Research About Memory Loss And Anesthesia
Have you ever heard someone talk about a loved one not being quite the same after general anesthesia? General anesthesia has been periodically connected to worsened cognitive functioning, but is this connection real or just a coincidence? Does research support this association?
The short answer? It depends which research study you read.
A handful of studies have found some connection, including the following:
- One study concluded that there was an increased risk of dementia after participants received general anesthesia.
- A second study found that people who had received anesthesia during surgery had a significantly greater risk of developing dementia specifically in the time frame of three to seven years after surgery.
- A third research study noted that a specific medication and type of surgerysevoflurane during spinal surgerywas associated with a decline in cognition in people who had been diagnosed with mild cognitive impairment. Mild cognitive impairment is a condition that increases the risk of Alzheimer’s disease, although some people with MCI remain stable and others even return to normal cognitive functioning.
However, other research contradicts those findings:
Surgery Performed Under Propofol Anesthesia Induces Cognitive Impairment And Amyloid Pathology In Apoe4 Knock
- 1Department of Anesthesiology and Pain Medicine, Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, Chuncheon, South Korea
- 2Institute of New Frontier Research, College of Medicine, Hallym University, Chuncheon, South Korea
- 3Department of Neurology, Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, Chuncheon, South Korea
Background: Postoperative cognitive dysfunction following anesthesia and surgery is a common and severe complication, especially in elderly patients. A pre-existing cognitive impairment may impart susceptibility to further cognitive dysfunction the mechanism remains unclear. We hypothesized that the specific impacts of anesthesia and surgery on individuals with preclinical Alzheimers disease may render them more susceptible to an increase in the risk of cognitive impairment. The aim of this study was to compare the cognitive impairment between normal adult mice and those with preclinical AD after propofol anesthesia and surgery.
Propofol anesthesia followed by surgery induced persistent changes in cognition, and pathological hippocampal changes in pre-symptomatic, but vulnerable AD mice. It would be appropriate to explore whether preclinical AD patients are more vulnerable to POCD development.
What If Side Effects Bother Me
If you have any concerns about side effects after undergoing a dental anesthesia procedure, reach out to your dental professional right away. Its vital to take an active role in your dental care, especially when it comes to surgery, and we encourage you to do so.
Dentists treat millions of patients with anesthesia safely every year. Your dental professional will guide you in what anesthesia is best for your procedure. Its essential to understand your dental treatments risks and benefits and always let your dental team know if side effects come up. The key is that you and your dental professional work together so that you can stay comfortable, healthy, and smiley.
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Is There Any Evidence Of Anaesthesia Causing Memory Loss
Lets look a little more into the phenomenon known as post operative cognitive dysfunction , as its a condition that has been researched closely.
Most of these POCD studies have focused on the elderly, because thats where this phenomenon is most commonly seen.
A 2001 paper in The New England Journal of Medicine kept track of patients who received coronary artery bypass surgery using a specific method where a heart-lung machine circulates and oxygenates the blood. The researchers found that many patients complained that they had a mental haziness after the surgery. According to the paper authors, more than half of the patients left the hospital with signs of cognitive decline and 42% were still impaired 5 years later.
Though critics were unsure whether the data was accurate, later studies revealed that the patients still developed cognitive difficulties at about the same rate whether they had pump or off pump surgery.
Other studies have reached different conclusions. For example, in February 2016, an anesthesiologist named Juraj Sprung of the Mayo Clinic and a team looked at the prevalence of mild cognitive impairment . MCI is essentially a mental downturn that often is a precursor to Alzheimers disease. The team compared how often MCI appeared in people who had undergone an operation or procedure that required general anaesthetic since the age of 40 against how often it appeared in people who had not. They did not find a link.
Why Arent We Sure Yet
Dementia doesnt occur in amatter of days. It happens over the years.The symptoms show up slowly and often spontaneously. The reason there are somany contradictory or confusing studies regarding this matter is that it may require years of observation. It is notcompletely possible to conduct a study for such a long period, especially when the subjects are above the age of 60.
Most studies conducted on thistopic involved animals such as mice. The studies included highly invasive testprocedures that may be too risky on human subjects. It is why most studies thatinvolve people are usually based on observation rather than tests andexperimentation.
Two of the most widely acknowledge research on this topic revealed completely contradictory conclusions. One followed more than 130,000 elderly who went through surgery within the past 7 years. It concluded that anesthesia could cause long-term changes in older brains that arent too resistive to its effects. This research found general anesthetics to be a contributing factor in dementia.
On the other hand, there was a study that involved more than 8000 pair of twins. The results were completely opposite, and no connection between anesthetics and dementia was found. The researcher concluded that the decline in cognitive abilities of the patients had less to do with the surgery and anesthesia, and more to do with the condition that called for surgery in the first place.
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Causes Of Memory Loss Post Surgery
While local anesthesia is administered to those who undergo minor procedures, in case a complicated surgery is to be performed, the patient is administered general anesthesia. The administration of general anesthesia brings about a state of unconsciousness, which helps the surgeons perform various complicated procedures.
When one is administered general anesthesia, the nerve impulses are blocked and the brain is unable to communicate to other parts of the body. This leads to a loss of sensation and loss of consciousness. The anesthetics numb the body and thus, the procedures, which would otherwise cause a lot of pain, can be comfortably performed. Until the anesthesia wears off, the patient would not experience pain and discomfort. However, administration of an anesthetic does pose certain health risks.
General anesthetics are administered intravenously or inhaled as a gas through a mask. Under normal circumstances, the liver and kidneys break the anesthetic down, and the anesthetic is then flushed out from the body. In rare cases, the effect of anesthesia may not wear off completely. If residual concentrations of anesthetics are still left in the body, these may impact the nervous system. Until the traces of anesthetics are flushed out completely, one may experience a difficulty in remembering things.
Who Is At Risk Of Pocd
Besides age, other factors that increase patients risk of POCD include:
- Preexisting cognitive issues, such asmild cognitive impairment ordementia. MCI is a transitional phase between normal mental function and Alzheimer’s disease or other forms of dementia.
- Medical conditions such asdiabetes or cerebrovascular disease, which reduces blood flow and oxygen to the brain and increases the risk ofstroke
- Lower education levels or lower IQ scores
- A low preoperative vitamin D level
POCD risk also varies by type, complexity, and length of surgery. Dr. Anderson explains:
- Cardiac surgery seems to be one of the highest risk surgeries. As high as 40 percent can have postoperative cognitive decline. The age of patients most commonly having cardiac surgery contributes to this elevated risk level.
- As the complexity and the length of surgery goes up, so does the risk of postoperative cognitive decline. A knee scope has relatively minimal risk compared to a six-hour abdominal surgery, for example.
- Trauma and surgeries associated with trauma, such as hip fractures and car accidents, tremendously increase your risk.
People over age 60 are two times more likely to encounter POCD than younger surgery patients.
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The Known Effects Of Anesthesia On Brain Cell
The frailty factor is unignorably real, but it doesnt completely rule out anesthesia as the reason behind memory loss or its connection to degenerative diseases such as Alzheimers.
General anesthesia used during most surgical procedures can increase the level of toxic clumps on amyloid and tau proteins. These toxins inside the brain cell are indicative of Alzheimers disease. They can cause severe damage to the brain cells over time.
Anesthesia can also prevent braincells from sending signals to the repair cell. This is one of the most importantsteps of cell repair and regenerationafter surgery. Due to the inability tosend signals, the repair is delayed to the point where inflammation gets worse.Prolonged damage can have long term and short-term impact on the patientscognitive ability.
Another study revealed that connection between anesthesia and dementia is more profound among patients with an increased genetic risk. It may not necessarily trigger dementia on its own, but it can bring the underlying symptoms to the surface. Since it lowers the body temperature and levels of oxygen in the blood, it can speed up cell degeneration in such patients.
Researchers Discover Why Anesthetics Cause Prolonged Memory Loss
Researchers at the University of Toronto’s Faculty of Medicine have shown why anesthetics can cause long-term memory loss, a discovery that can have serious implications for post-operative patients.
Until now, scientists haven’t understood why about a third of patients who undergo anesthesia and surgery experience some kind of cognitive impairmentsuch as memory lossat hospital discharge. One-tenth of patients still suffer cognitive impairments three months later.
Anesthetics activate memory-loss receptors in the brain, ensuring that patients don’t remember traumatic events during surgery. Professor Beverley Orser and her team found that the activity of memory loss receptors remains high long after the drugs have left the patient’s system, sometimes for days on end.
Animal studies showed this chain reaction has long-term effects on the performance of memory-related tasks.
“Patientsand even many doctorsthink anesthetics don’t have long-term consequences. Our research shows that our fundamental assumption about how these drugs work is wrong,” says Orser, a Professor in the Departments of Anesthesia and Physiology, and anesthesiologist at Sunnybrook Health Sciences Centre.
“There’s a lot going on after surgery, which can alter our ability to think clearly. Loss of sleep, new environments and medications can all impact a patient’s mental function. Anesthetics likely compound these issues,” says Orser.
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Im Having Memory Problems After Anesthetic And Surgery Is That Common
This article was published more than 3 years ago. Some information in it may no longer be current.
The question: I recently had knee-replacement surgery, and I just dont feel like myself. Im a retired school principal and I used to have an excellent memory. Now I struggle to remember the simplest things even my husbands name. I am slowly getting better, but it has been very frustrating and frightening. My doctor said I could be suffering a side effect from the anesthetic or the operation. Is this a common problem after surgery?
The answer: Doctors have long assumed that patients return to normal once an anesthetic wears off. But in recent years, a growing body of research suggests that some people experience lingering cognitive impairment after being wheeled out of the operating room.
We now know that between 10 and 20 per cent of patients will have problems at the time they are discharged from hospital, says Dr. Beverley Orser, an anesthesiologist at Sunnybrook Health Sciences Centre in Toronto.
And one in 10 of those affected will still have problems three to six months later. What happens at the one-year mark is still debated, she says, adding that some may never fully recover.
The cognitive impairment seems to affect memory, word-finding and attention as well as certain executive functions of the brain, such as decision-making and problem-solving.
So what are patients and health-care providers supposed to do while researchers probe for solutions?
Memory Loss Cause # 10 Dementia
A noticeable explanation to getting worse memory concerns, particularly the ability to remember recent occasions, names, as well as telephone number, is Alzheimers disease as well as associated mental deteriorations. While not all older adults experience memory-related conditions, the threat of establishing dementia increases with age. New improvements in technology have made it possible to spot Alzheimers condition in your medical professionals workplace with a simple eye test, and there are numerous cognitive tests that can additionally be executed to help find out the precise nature of your memory issues, so make certain to reach out to your doctor if you presume your memory issues are ending up being an issue for you..
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Anaesthesia And Long Term Memory Effects
It isnt uncommon for people to observe elderly surgical patients experiencing confusion after their operation. These symptoms usually fade with time.
However, in recent years, more research has been pointing to something a little more serioussomething called postoperative cognitive dysfunction . POCD involves problems with memory, attention, and concentration that can last months or sometimes even a lifetime.
Why is this concerning? Well, a 2008 study showed that people who still had POCD 3 months after surgery were more likely to die in thefirst year after
Causes Of Memory Loss
Here are some of the more common things that can cause memory loss:
Medications. A number of prescription and over-the-counter medications can interfere with or cause loss of memory. Possible culprits include: antidepressants, antihistamines, anti-anxiety medications, muscle relaxants, tranquilizers, sleeping pills, and pain medications given after surgery.
Smoking harms memory by reducing the amount of oxygen that gets to the brain. Studies have shown that people who smoke find it more difficult to put faces with names than do nonsmokers. Illegal drugs can change chemicals in the brain that can make it hard to recall memories.
Sleep deprivation. Both quantity and quality of sleep are important to memory. Getting too little sleep or waking frequently in the night can lead to fatigue, which interferes with the ability to consolidate and retrieve information.
Depression and stress. Being depressed can make it difficult to pay attention and focus, which can affect memory. Stress and anxiety can also get in the way of concentration. When you are tense and your mind is overstimulated or distracted, your ability to remember can suffer. Stress caused by an emotional trauma can also lead to memory loss.
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Management Of Pocd Or Other Mental Changes After Surgery
People reporting changed mental function after undergoing an operation should be taken seriously. The discussion above reveals this to be a real and serious problem, and one which potentially has an enormous impact upon the personal functioning of the individuals concerned, as well as a significant impact upon their surroundings and the societies in which they live. Management should be serious and efficient. Why efficient? That sounds cold and unpleasant. Actually, efficiency is of utmost importance. Delay and incorrect management reduces the chance of successful management, as well as increasing the distress of the individuals concerned and their families. Rapid placement of people into correct treatment regimes improves the chances of successful management, and means the incurable are placed in appropriate support programs.
Here are some personal thoughts regarding general management of POCD and postoperative altered mental function according to when they occur, and how long they last.
What We Know And Dont Know About Memory Loss After Surgery
By Judith GrahamApril 12, 2018
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Temporarily Eliminating Microglia Prevents Cognitive Decline In Mice
In experiments led by UCSF postdoctoral fellows Xiaomei Feng, PhD, and , PhD, the researchers examined how surgery impacted cognition in mice whose microglia were experimentally depleted.
Normally, mice trained in a conditioned behavior task prior to surgery perform worse at remembering the task three days after the operation. Remarkably, when researchers gave 10 mice a drug treatment to deplete microglia levels to roughly 5 percent of normal for seven days before undergoing the surgery, the animals were completely protected against this form of cognitive decline.
This work demonstrates the central importance of microglia as transducers of surgical trauma in the periphery, said Maze, who is also William K. Hamilton Distinguished Professor of Anesthesia in the Department of Anesthesia and Perioperative Care at UCSF. They dictate the downstream inflammatory and neurological consequences in the brain.
The experimental drug used in the study, PLX5622, is made by Plexxikon Inc., a Berkeley, Calif.-based biotech company, and targets a molecule called colony-stimulating factor 1 receptor , which microglia require in order to survive and replenish or expand their numbers.
Our plan is to conduct more preclinical research to explore the potential of this approach, in the hopes that it eventually proves to be clinically applicable not only in surgery, but also in other diseases that lead to cognitive decline, Koliwad said.