Bethesda, MD—Everyone knows that its important to keep a cool head, but a new study published online in The FASEB Journal shows that for Alzheimer’s patients, a cool head may make the disease worse. In the research report, scientists show that a protein associated with Alzheimer’s (called “tau”) builds up in brain cells at an increased rate when temperatures fall, such as when a patient is anesthetized or experiences hypothermia. This finding should be of immediate concern to surgeons, dentists, and any other health care professionals who anesthetize patients with Alzheimer’s or patients at an elevated risk for the disease.
“We hope that this research will initiate an interest in taking precautions to limit the impact of anesthesia on the disease,” said Emmanuel Planel of Columbia University Medical Center and one of the scientists involved in the work.
To make this discovery, the scientists used two groups of mice that make the abnormal tau protein that accumulates in Alzheimer’s patients. One group was anesthetized, and one group was not. A week after anesthesia, the two groups were compared for the amount of tau protein clumps in their brain cells. The anesthetized group had more of these clumps than the group that was not anesthetized. Furthermore, in mice showing advanced signs of the disease, the build up of tau proteins occurred faster than in those in the early stages.
“Every patient wants a surgeon with a cool head,” said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal, “but surgeons might not want the same for their patients. People are anesthetized for all kinds of reasons, even dental work, but this study really should make patients and doctors reconsider whether it’s really necessary.”
In related work, scientists from The New York State Office of Mental Retardation and Developmental Disabilities' (OMRDD) New York State Institute for Basic Research in Developmental Disabilities (IBR) report in the March 2009 issue of the Journal of Alzheimer's Disease that anesthesia induces phosphorylation of tau. Tau is a key neuronal protein involved in neurodegeneration in Alzheimer's disease (AD) and several other neurodegenerative disorders. Anesthesia has previously been found to be associated with cognitive impairment and the risk for AD. This study helps elucidate the molecular mechanisms underlying these associations.
The researchers found that in test animals, anesthesia for short periods (30 seconds to 5 minutes) induced tau phosphorylation at some selective phosphorylation sites to a small but significant extent. Anesthesia for a longer time (1 hour) induced much more dramatic phosphorylation at the same sites, possibly as a result of anesthesia-induced hypothermia. The observation that anesthesia did not induce global hyperphosphorylation of brain proteins, but instead specific hyperphosphorylation of tau protein at the AD-related abnormal hyperphosphorylation sites suggests that tau hyperphosphorylation might be the mechanism that links anesthesia and the risk of cognitive impairment and/or AD.
AD is the most common cause of dementia in adults and affects approximately 27 million individuals worldwide and over four million in the United States alone. Most AD cases are sporadic and are believed to be caused by multiple factors. Understanding the mechanism by which anesthesia may increase the risk for cognitive impairment will help in the design of strategies for preventing and treating dementia and AD. "This is a very important finding related to Alzheimer's disease," said OMRDD Commissioner Diana Jones Ritter. "I am pleased that these findings will lead to helping people live richer lives through the research findings."
Briegull, I wondered why I had not received the Dementia Weekly you were quoting. Then I went back to my e-mail (I had just checked it 20 minutes ago) and there it was. You sure read it and got it on the website quickly. Thanks,
Far from the study above, - but have you noticed that AD patients are more cold natured that others. My DH is always cold. Today, he is wearing long sleeve knit shirt and a sweater plus a lap throw.. the CH is set on 70 degrees and the gas fireplace logs are burning. A minute ago, he actually had a "shivver". He is usually more cold natured than I am...but today he is especially so.
Absolutely! (startles)...and if we are driving along, and I cross a speed hump or go over a pot hole, and the car is jarred, he reacts like "Uhhh!", and, of course I would have slowed down completely!!! I used to call him a "drama queen" because of his over-reaction to the least little thing. My car is a small luxury car and handles bumps extremely well, but he still acts like we had been rear-ended by a mack truck! I have learned to bite my lip and say NOTHING!, but it drives me totally nuts!
Yes ! - my husband definitely is a whole lot colder than others - always wears a t-shirt plus a sweatshirt and sometimes a vest - this is inside - when we go out he has a very warm thermal jacket zipped up to his neck which seldom gets unzipped, even when we're in a store.
He has, until this year, worn long underwear (both tops and bottoms) at least 9 months of the year .... something changed this year and he seems to have forgotten that he wore it religiously - and I didn't remind him :) ...... I'm VERY thankful for that what with him being not only urine incontinent but also occasionally bowel incontinent ....... long underwear over Depends would have been a nighmare to say the least !
He also startles very easily. Even when Rosie barks unexpectedly he jumps.
I sort of thought perhaps the startling was because of the fact the mind is in its own little world now and just not quite as sharp as it used to be.
Last winter my DH slpot all winter with his bedroom window cracke open an inch, except the nights it went below zero. His bed is right by the window. He only removed his sweat pants and covered up with a hevy fleece blanket and a big comforter. This year he stays dressed and the window is shut. The thermosatat is set to keep the house at 70 -- I can't take it cooler, makes me sleepy. He used to sleep in just his T-shirt and with less covers. Definitely a change since Dementia joined us.
Yes, my DW has also become more cold natured in the past year or so, and yes, she exhibits a startle reflex if I do something unexpected like touch her face with a napkin or if I start to move her chair away from the table or various other things like that.
You have remember areas of the brain are not functioning correctly. This can be causing the pituitary and thyroid to not work correctly. Plus, look at the side effects of the drugs they are on - I know it was listed with statins. I was reading postings from people on side effects of aricept and some mentioned hypothermia. Everything is controlled in the brain therefore anything can be effected.
Well doncha know??????????????.... Maybe it's going to be a better summer..it's so hot in Texas. OR, I wonder if he'll be more suseptible to the heat as well. I hate to read the fine print on drug labels. It will scare you to death!!!!
I understand why they have to list all the side effects though. Sure as anything, they will be sued by someone if they don't.
My husband is also cold all the time now, but also no matter what he is doing his hands particularly are like frozen ice cream all the way to his elbows.
Do you think he has Peripheral Neuropathy..My aunt had that in her hands and feet..and was always freezing. We made "muffs" for her hands and she wore thermal socks. I felt so sorry for her. She was so uncomfortable.
Neuropathy is a medical term describing disorders of the nerves of the peripheral nervous system (specifically excluding encephalopathy and myelopathy, which refer to the central nervous system.)[1] It is usually considered equivalent to peripheral neuropathy.
According to some sources, a disorder of the cranial nerves can be considered a neuropathy.[2]
Peripheral neuropathy is defined as deranged function and structure of peripheral motor, sensory, and autonomic neurons, involving either the entire neuron or selected levels.[3]