The decision came after a scorching hearing in which lawmakers barraged EcoHealth Alliance’s president with claims of misrepresenting work with Chinese virologists.The Biden administration, under acute pressure from House lawmakers, moved on Wednesday to ban funding for a prominent virus-hunting nonprofit group whose work with Chinese scientists had put it at the heart of theories that Covid leaked from a lab.The decision, announced in a letter from the Department of Health and Human Services, came on the heels of a scorching congressional hearing this month at which lawmakers barraged the group’s president with suggestions that he had misrepresented work with virologists in Wuhan, China, where the pandemic began. Republicans went further, demanding that Peter Daszak, the president of the nonprofit, EcoHealth Alliance, be criminally investigated.For EcoHealth, which relied on federal funding to study the threat of wild animal viruses, the loss of funding is another twist in a saga that has long dominated discussions of how the pandemic began.In April 2020, under orders from the Trump administration, the National Institutes of Health terminated a grant to EcoHealth amid President Donald J. Trump’s feud with China over the origin of the coronavirus. Three years later, an internal federal watchdog agency determined that the N.I.H. had failed to give a proper cause for ending the grant, which supplied an average of roughly $625,000 per year. The N.I.H. restarted a pared-back version of the award.Now, with Republicans stepping up their campaign against EcoHealth, and Democrats joining in the anger, the Biden administration has cut off funding for EcoHealth again.Health officials said they were suspending three active N.I.H. grants to EcoHealth that totaled $2.6 million for last year. And they proposed barring the group from receiving future federal research funding. Such bans, they said, usually last no more than three years, but could be longer or shorter.We are having trouble retrieving the article content.Please enable JavaScript in your browser settings.Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.Thank you for your patience while we verify access.Already a subscriber? Log in.Want all of The Times? Subscribe.

The studies, pulled because of copied data, illustrate the sluggishness of scientific publishers to address serious errors, experts said.Scientists in a prominent cancer lab at Columbia University have now had four studies retracted and a stern note added to a fifth accusing it of “severe abuse of the scientific publishing system,” the latest fallout from research misconduct allegations recently leveled against several leading cancer scientists.A scientific sleuth in Britain last year uncovered discrepancies in data published by the Columbia lab, including the reuse of photos and other images across different papers. The New York Times reported last month that a medical journal in 2022 had quietly taken down a stomach cancer study by the researchers after an internal inquiry by the journal found ethics violations.Despite that study’s removal, the researchers — Dr. Sam Yoon, chief of a cancer surgery division at Columbia University’s medical center, and Changhwan Yoon, a more junior biologist there — continued publishing studies with suspicious data. Since 2008, the two scientists have collaborated with other researchers on 26 articles that the sleuth, Sholto David, publicly flagged for misrepresenting experiments’ results.One of those articles was retracted last month after The Times asked publishers about the allegations. In recent weeks, medical journals have retracted three additional studies, which described new strategies for treating cancers of the stomach, head and neck. Other labs had cited the articles in roughly 90 papers.A major scientific publisher also appended a blunt note to the article that it had originally taken down without explanation in 2022. “This reuse (and in part, misrepresentation) of data without appropriate attribution represents a severe abuse of the scientific publishing system,” it said.Still, those measures addressed only a small fraction of the lab’s suspect papers. Experts said the episode illustrated not only the extent of unreliable research by top labs, but also the tendency of scientific publishers to respond slowly, if at all, to significant problems once they are detected. As a result, other labs keep relying on questionable work as they pour federal research money into studies, allowing errors to accumulate in the scientific record.We are having trouble retrieving the article content.Please enable JavaScript in your browser settings.Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.Thank you for your patience while we verify access.Already a subscriber? Log in.Want all of The Times? Subscribe.

Media accounts of a German man’s extreme vaccination history spurred researchers to analyze his immune responses.Two years ago, German doctors stumbled across news reports of a man being investigated for receiving scores of coronavirus vaccines with no medical explanation.Then followed a flurry of speculation about what he had been up to. As it turned out, prosecutors were looking into whether he had been receiving so many extra doses as part of a scheme to collect stamped immunization cards that he could later sell to people who wanted to skirt vaccine mandates.But to the doctors, the man was a medical anomaly, someone who had defied official recommendations and turned himself into a guinea pig for measuring the outer limits of an immune response. Last year, they asked prosecutors investigating his vaccine splurge to pass along a request: Would he like to join a research project?Once prosecutors closed their fraud investigation without criminal charges, the man agreed.By the time the doctors first saw him, the 62-year-old man had received 215 doses of coronavirus vaccine, they said. Flouting their pleas to stop, he received another two shots in the next months, expanding his immunological stockpile to a combined 217 doses of eight different Covid vaccine types over two and a half years.After months of studying him, the doctors, led by Dr. Kilian Schober, an immunologist at the University of Erlangen-Nuremberg in the German state of Bavaria, reported their findings this week in The Lancet Infectious Diseases, a medical journal.The man had seemingly never been infected with the coronavirus. He reported no vaccine side effects. And, most interestingly to the researchers, his repertoire of antibodies and immune cells was considerably larger than that of a typical vaccinated person, even if the precision of those immune responses remained effectively unchanged.We are having trouble retrieving the article content.Please enable JavaScript in your browser settings.Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.Thank you for your patience while we verify access.Already a subscriber? Log in.Want all of The Times? Subscribe.

The stomach cancer study was shot through with suspicious data. Identical constellations of cells were said to depict separate experiments on wholly different biological lineages. Photos of tumor-stricken mice, used to show that a drug reduced cancer growth, had been featured in two previous papers describing other treatments.Problems with the study were severe enough that its publisher, after finding that the paper violated ethics guidelines, formally withdrew it within a few months of its publication in 2021. The study was then wiped from the internet, leaving behind a barren web page that said nothing about the reasons for its removal.As it turned out, the flawed study was part of a pattern. Since 2008, two of its authors — Dr. Sam S. Yoon, chief of a cancer surgery division at Columbia University’s medical center, and a more junior cancer biologist — have collaborated with a rotating cast of researchers on a combined 26 articles that a British scientific sleuth has publicly flagged for containing suspect data. A medical journal retracted one of them this month after inquiries from The New York Times.A Columbia University cancer surgeon, Dr. Sam S. Yoon, and a junior researcher have published a combined 26 articles that a data sleuth said contained irregularities.Marcus Santos/ZUMA Wire, AlamyMemorial Sloan Kettering Cancer Center, where Dr. Yoon worked when much of the research was done, is now investigating the studies. Columbia’s medical center declined to comment on specific allegations, saying only that it reviews “any concerns about scientific integrity brought to our attention.”Dr. Yoon, who has said his research could lead to better cancer treatments, did not answer repeated questions. Attempts to speak to the other researcher, Changhwan Yoon, an associate research scientist at Columbia, were also unsuccessful.

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A British biologist and blogger discovered faulty data in many studies conducted by top executives of the Dana-Farber Cancer Institute.A prominent cancer center affiliated with Harvard said it will ask medical journals to retract six research papers and correct dozens of others after a British scientist and blogger found that work by some of its top executives was rife with duplicated or manipulated data.The center, the Dana-Farber Cancer Institute in Boston, one of the nation’s foremost cancer treatment and research facilities, moved quickly in recent days to address allegations of faulty data in 58 studies, many of them influential, compiled by a British molecular biologist, Sholto David.In many cases, Dr. David found, images in the papers had been stretched, obscured or spliced together in a way that suggested deliberate attempts to mislead readers. The studies he flagged included some published by Dana-Farber’s chief executive, Dr. Laurie Glimcher, and its chief operating officer, Dr. William Hahn.The retractions come as researchers in the United States face growing pressure to account for instances of scientific misconduct, sloppy work or outright fraud. Image sleuths have recently found evidence of fabricated data in scores of influential papers on Alzheimer’s disease. Last year, Marc Tessier-Lavigne resigned as president of Stanford University after some of his published papers were found to contain manipulated results.Allegations of misconduct have ballooned in part because experts have access to new artificial intelligence tools that can flag suspicious images depicting experimental results.In the wake of recent high-profile misconduct claims, experts have drawn attention to a “publish or perish” culture in academia, which pressures researchers to generate striking results and place papers in major journals, whatever the merits of a study. Some researchers have also said that certain labs, explicitly or not, encourage junior researchers to take shortcuts.We are having trouble retrieving the article content.Please enable JavaScript in your browser settings.Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.Thank you for your patience while we verify access.Already a subscriber? 

Newly released documents indicate that a U.S. genetic database had received the sequence of the coronavirus two weeks before it was made public by others.In late December 2019, eight pages of genetic code were sent to computers at the National Institutes of Health in Bethesda, Md.Unbeknown to American officials at the time, the genetic map that had landed on their doorstep contained critical clues about the virus that would soon touch off a pandemic.The genetic code, submitted by Chinese scientists to a vast public repository of sequencing data run by the U.S. government, described a mysterious new virus that had infected a 65-year-old man weeks earlier in Wuhan. At the time the code was sent, Chinese officials had not yet warned of the unexplained pneumonia sickening patients in the central city of Wuhan.But the U.S. repository, which was designed to help scientists share run-of-the-mill research data, never added the submission it received on Dec. 28, 2019, to its database. Instead, it asked the Chinese scientists three days later to resubmit the code with certain additional technical details. That request went unanswered.It took almost another two weeks for a separate pair of virologists, one Australian and the other Chinese, to work together to post the genetic code of the new coronavirus online, setting off a frantic global effort to save lives by building tests and vaccines.The initial attempt by Chinese scientists to publicize the crucial code was revealed for the first time in documents released on Wednesday by House Republicans investigating Covid’s origins. The documents reinforced questions circulating since early 2020 about when China learned of the virus that was causing its unexplained outbreak — and also drew attention to gaps in the American system of monitoring for dangerous new pathogens.We are having trouble retrieving the article content.Please enable JavaScript in your browser settings.Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.Thank you for your patience while we verify access.Already a subscriber? 

A new study describes a method for faster and more precise diagnoses, which can help surgeons decide how aggressively to operate.Once their scalpels reach the edge of a brain tumor, surgeons are faced with an agonizing decision: cut away some healthy brain tissue to ensure the entire tumor is removed, or give the healthy tissue a wide berth and risk leaving some of the menacing cells behind.Now scientists in the Netherlands report using artificial intelligence to arm surgeons with knowledge about the tumor that may help them make that choice.The method, described in a study published on Wednesday in the journal Nature, involves a computer scanning segments of a tumor’s DNA and alighting on certain chemical modifications that can yield a detailed diagnosis of the type and even subtype of the brain tumor.That diagnosis, generated during the early stages of an hourslong surgery, can help surgeons decide how aggressively to operate, the researchers said. In the future, the method may also help steer doctors toward treatments tailored for a specific subtype of tumor.“It’s imperative that the tumor subtype is known at the time of surgery,” said Jeroen de Ridder, an associate professor in the Center for Molecular Medicine at UMC Utrecht, a Dutch hospital, who helped lead the study. “What we have now uniquely enabled is to allow this very fine-grained, robust, detailed diagnosis to be performed already during the surgery.”Their deep learning system, called Sturgeon, was first tested on frozen tumor samples from previous brain cancer operations. It accurately diagnosed 45 of 50 cases within 40 minutes of starting genetic sequencing. In the other five cases, it refrained from offering a diagnosis because the information was unclear.The system was then tested during 25 live brain surgeries, most of them on children, alongside the standard method of examining tumor samples under a microscope. The new approach delivered 18 correct diagnoses and failed to reach the needed confidence threshold in the other seven cases. It turned around its diagnoses in less than 90 minutes, the study reported — short enough for it to inform decisions during an operation.Currently, in addition to examining brain tumor samples under a microscope, doctors can send them for more thorough genetic sequencing.But not every hospital has access to that technology. And even for those that do, it can take several weeks to receive results, said Dr. Alan Cohen, the director of the Johns Hopkins Division of Pediatric Neurosurgery and a cancer specialist.“We have to start treatment without knowing what we’re treating,” Dr. Cohen said.The new method uses a faster genetic sequencing technique and applies it only to a small slice of the cellular genome, allowing it to return results before a surgeon has started operating on the edges of a tumor.Dr. de Ridder said that the model was powerful enough to deliver a diagnosis with sparse genetic data, akin to someone recognizing an image based on only one percent of its pixels, and from an unknown portion of the image.“It can figure out itself what it’s looking at and make a robust classification,” said Dr. de Ridder, who is also a principal investigator at Oncode Institute, a cancer research center in the Netherlands.But some tumors are still difficult to diagnose. The samples taken during surgery are about the size of a kernel of corn, and if they include some healthy brain tissue, the deep learning system may struggle to pick out enough tumor-specific markers.In the study, doctors dealt with that by asking the pathologists examining samples under a microscope to flag the ones with the most tumor for sequencing, said Marc Pagès-Gallego, a bioinformatician at UMC Utrecht and a co-author of the study.There can also be differences within a single patient’s tumor cells, meaning that the small segment being sequenced may not be representative of the entire tumor. Some less common tumors may not correspond to those that have previously been classified. And some tumor types are easier to classify than others.Other medical centers have already started applying the new method to surgical samples, the study’s authors said, suggesting that it can work in other people’s hands.But Dr. Sebastian Brandner, a professor of neuropathology at University College London, said that sequencing and classifying tumor cells often still required significant expertise in bioinformatics as well as workers who are able to run, troubleshoot and repair the technology.“Implementation itself is less straightforward than often suggested,” he said.Brain tumors are also the most well-suited to being classified by the chemical modifications that the new method analyzes; not all cancers can be diagnosed that way.The new method is part of a broad movement toward bringing molecular precision to diagnosing tumors, potentially allowing scientists to develop targeted treatments that are less damaging to the nervous system. But translating a deeper knowledge of tumors to new therapies has proved difficult.“We’ve made some gains,” Dr. Cohen said, “but not as many in the treatment as in the understanding of the molecular profile of the tumors.”

Two episodes, where the Republican senator froze and did not respond to some questions, may be symptoms of a serious illness, according to neurologists not involved in his medical care.A four-line letter, signed by the attending physician of Congress and released by Senator Mitch McConnell on Thursday, suggested that his recent spells of speechlessness were linked to “occasional lightheadedness” perhaps brought on by his recovery from a concussion last winter or “dehydration.”But seven neurologists, relying on what they described as unusually revealing video of Mr. McConnell freezing up in public twice recently, said in interviews Thursday and Friday that the episodes captured in real time likely pointed to more serious medical problems afflicting the longtime Republican leader.Some of the neurologists, while cautioning that they could not diagnose the minority leader from afar, said that the letter and other comments from Mr. McConnell’s office appeared to fall short of explaining why he abruptly stopped speaking during news conferences in late July and again on Wednesday.“If I gave that tape to a medical student and that was his explanation, I’d fail him,” said Dr. Orrin Devinsky, a professor of neurology at the NYU Grossman School of Medicine, referring to the account given by the attending physician of Congress on Thursday. “Medically, these episodes need to be taken seriously.”The neurologists said that the episodes justified close medical attention and could prompt treatment to keep them from recurring. While several possibilities were suggested, including mini-strokes, doctors said that the spells appeared most consistent with focal seizures, which are electrical surges in one region of the brain.The senator’s aides have not revealed what type of follow-up care Mr. McConnell may be receiving, and his office said on Friday it had nothing to add beyond the letter by the Congressional physician, Dr. Brian P. Monahan.More details about the medical history of Mr. McConnell, 81, including whether he has been having such episodes off camera, would also help rule out other possible explanations for the spells, neurologists said.Whether caused by seizures or mini-strokes or something else, spells like Mr. McConnell’s would not preclude most patients from working or socializing normally, doctors said.“Seizures have a stigma in our society, and that’s unfortunate because these are very brief electrical interruptions in behavior,” said Dr. Jeffrey Saver, a professor of neurology at U.C.L.A. “Between those rare episodes, which are usually well controlled with medicines, people function perfectly normally.”Still, experts said that seizures carried some elevated risk of cognitive or behavioral problems and could affect older patients differently.Rarely does the public get as complete a glimpse of a serious medical event in a public figure as it did twice in recent weeks with Mr. McConnell. For neurologists, videos like those showing Mr. McConnell from the moment he appeared to lose the ability to speak are far more than mere curiosities.They can help form the basis of a diagnosis, as homemade videos of everyday patients occasionally do in standard neurology practices.“They’re very helpful, because you’re not subject to the vagaries of someone’s description and you can capture the beginning of it, which is important especially for seizures,” said Dr. Anthony Kim, a professor of neurology at the University of California, San Francisco.Details as small as the direction in which people’s eyes are pointed during such an episode offer potential clues about the cause, Dr. Kim said.After watching Mr. McConnell’s symptoms play out — his abrupt stop in speech, his eyes fixed in the distance, his seeming recovery after about 30 seconds — Dr. Kim said that “the possibility at the top of my list would be a seizure.”That Mr. McConnell’s second spell so closely mirrored the first pointed even more strongly to a seizure, neurologists said.Mini-strokes, which result from a clot that reduces blood flow to the brain, can also cause brief periods of impaired speech. But they rarely produce the same constellation of symptoms each time they recur, given that clots are unlikely to travel at random to the same part of the brain twice.Focal seizures, on the other hand, are often triggered by an irregularity in one specific part of the brain, creating what doctors refer to as stereotypic symptoms. They are known to stop patients dead in their tracks, seeming to cut them off from their surroundings.Patients can often respond reflexively to questions during such an episode — as Mr. McConnell did on Wednesday, saying “yeah” when asked if he had heard a reporter’s question — even if they appear unable to voice their thoughts or engage with their environment.Mr. McConnell suffered a concussion in March, a risk factor for seizures. The seizures can be caused by a bleed in the brain or a scar from a traumatic head injury. Previous strokes or other kinds of damage to brain tissue can also lead to seizures in older people, who as a group experience the onset of seizures almost as often as children do.Some seizures are provoked by triggers like abnormal blood sugar levels. But if someone has had two seizures that cannot be explained in that way, neurologists said that would typically be enough for a diagnosis of epilepsy, a common neurological disorder affecting more than three million Americans that can arise at any age. They would generally prescribe anti-seizure medication.“Two seizures you definitely would want to treat,” said Dr. Sami Khella, the chief of neurology at Penn Presbyterian Medical Center. “You don’t want them to happen — they’re not good for you.”Many patients function completely normally and show normal brain wave activity between seizures, allowing them to remain active and working even as they are forced to forgo activities like driving.But they do cause patients to miss periods of time during episodes. A seizure at an inopportune moment, like when crossing the street, can be dangerous. And focal seizures involving one region of the brain can generalize, causing episodes characterized by jerking movements or epileptic spasms.Beyond that, one or two seizures can beget more, a cycle that neurologists try to interrupt with treatment. “The more the brain seizes, the more it learns to seize,” Dr. Khella said.Other complications can follow. A phenomenon known as sudden, unexpected death in epilepsy kills an estimated one in 1,000 people with epilepsy each year.“If you do get epilepsy as an elderly individual, there are concerns about things like memory, about cognitive function, because your resilience at 80 is going to be far less than when you’re 20 or 30,” said Dr. Devinsky, who directs NYU Langone’s Comprehensive Epilepsy Center.Neurologists said they could not rule out other possible explanations for Mr. McConnell’s episodes.Dr. Gavin Britz, a neurosurgeon at Houston Methodist, said he would want to exclude Parkinson’s disease, which can also cause freezing episodes.But neurologists agreed that suggestions that Mr. McConnell was merely lightheaded, while possible, were difficult to square with the video. Dehydration could exacerbate other conditions, they said, but such patients would be unlikely to stay upright or recover so quickly without fluids, as Mr. McConnell appeared to do.“We don’t have 100 percent information, so we’re kind of in the dark,” Dr. Devinsky said. “But we do have this very powerful clinical information, which is quite honestly how I have to diagnose seizures and epilepsy all the time, often without the video.”

The drug Wegovy eased issues for people with a type of heart problem, adding to the treatment’s benefits beyond weight loss.One of the leading new obesity drugs, Wegovy, eased symptoms and raised the quality of life of patients with obesity and a common type of heart failure, a study funded by the drug’s maker found, adding to the evidence that the medications can produce health benefits beyond weight loss.The study, published on Friday in The New England Journal of Medicine, evaluated the drug in people with a condition known as preserved ejection fraction in which the heart pumps normally but has lost the flexibility needed to fill with blood. The condition accounts for roughly half of all heart failure cases.Patients given Wegovy in the trial showed greater improvements in physical fitness and in symptoms like fatigue and shortness of breath than those administered a placebo. The study, which included 529 participants and lasted for a year, was not designed to assess cardiac emergencies, but it found that 12 patients on the placebo and only one on Wegovy were hospitalized or required an urgent medical visit for heart failure.The drug showed more pronounced relief of heart failure symptoms than other treatments, the study said.“This is a huge patient population that is extremely symptomatic, for which we’ve had very few if any treatment options, and in which obesity is highly prevalent,” said Dr. Mikhail Kosiborod, a cardiologist at Saint Luke’s Mid America Heart Institute in Kansas City and the study’s lead investigator, who also consults for Novo Nordisk, the maker of Wegovy. “It’s going to be a true paradigm shift.”Cardiologists used to see obesity as a condition that simply coexisted with heart failure. But the new study strengthened the evidence of obesity being a main driver of the disease.“It’s a proof of concept that in many patients with this type of heart failure, where obesity is in fact causal, it needs to be treated as a root cause of heart failure and needs to be targeted as a therapeutic strategy,” Dr. Kosiborod said.Another study evaluating the drug in heart failure patients with obesity and diabetes is expected to wrap up this year. If that study, too, produces promising results, Novo Nordisk has said it could seek to have the drug formally recommended for the treatment of heart failure.Scientists who did not work on the trial said it would be important to study the drug over longer periods in more patients, allowing researchers to determine whether it actually reduced the likelihood of hospitalizations or deaths. But given the severity of physical limitations and symptoms in patients with this type of heart failure, the improvements on those measures alone were notable, they said.On a 100-point measure of quality of life and physical abilities, patients given Wegovy experienced a greater improvement of their symptoms by roughly eight more points than patients on the placebo, according to the study. People on Wegovy also showed greater gains on a six-minute walk test.“It’s a short trial, and so we can’t say much about long-term sustained benefits, but I think the magnitude of the benefit is impressive relative to what other interventions have shown in the same population,” said Dr. Daniel Drucker, a senior scientist at the Lunenfeld Tanenbaum Research Institute at Mt. Sinai Hospital in Toronto who has studied the new drugs. He has received fees from Novo Nordisk but was not involved in the latest trial.Wegovy and another version of the same drug for diabetes patients, Ozempic, have quickly become popular for the significant weight loss results they have shown — so much so that Novo Nordisk has struggled to meet growing demand.But the latest study built on other recent evidence that the drug does more than cut weight.The company, for example, announced this month that Wegovy also slashed the risk of heart complications by 20 percent among a different pool of patients in a large trial, a result that was seen as crucial for persuading more insurers to cover the new weight loss drugs. Researchers are waiting for the company to release the underlying data to the study to examine the topline results.“Obesity is associated with 200 other obesity-related diseases,” said Dr. Ania Jastreboff, an endocrinologist and obesity medicine specialist at Yale University who consults for makers of obesity drugs. “If we treat this one disease, we can potentially impact the health of so many patients in many different ways, and this is yet another important example.”Experts believe that weight loss on its own probably accounted for some of the improvements in patients’ heart health. But determining exactly how big a role weight loss played and what other factors may have contributed will require more research.The heart failure study released on Friday, for example, found indications that Wegovy may have reduced inflammation. Patients on the drug also had lower levels of an important marker of heart congestion, another sign that the drug is doing something that may have an effect on heart failure.“We still need to understand that better,” Dr. Kosiborod said.

Senator Dianne Feinstein developed this rare and potentially debilitating complication after a shingles infection.Dianne Feinstein, a Democratic senator from California, has returned to the Capitol after spending more than two months recovering from shingles. The disease, often characterized by a painful rash, is triggered by the same virus that causes chickenpox, which stays in people’s bodies for life and, years later, can become reactivated.For Ms. Feinstein, 89, the virus also brought on a previously unreported case of encephalitis, a rare but potentially debilitating complication in which the brain swells. The condition is often caused by an infection or an immune response.What are the symptoms of encephalitis?Post-shingles encephalitis can cause headache, fever, sensitivity to light, vomiting, confusion, a stiff neck or even seizures.It can also leave some patients with more lasting problems. Those include memory or language trouble, sleep disorders, mood disorders, walking difficulty and other cognitive problems. Older patients tend to have the most trouble recovering.There are milder and more serious cases. A French study from last year looking at several dozen critically ill patients with the condition found that about one-fifth of them were significantly disabled a year after being hospitalized and one-third had died.A separate study in Denmark from 2020 found that roughly half of post-shingles encephalitis patients admitted to hospitals were at least moderately disabled three months after being discharged.How common is the condition?Dr. Adrien Mirouse, a physician and immunologist based at Sorbonne University in Paris, who led the French study last year, estimated that fewer than 1 percent of shingles patients go on to develop encephalitis.But precise rates, he said, were difficult to pin down: Milder cases often go unreported, making it hard to know the real number of patients with shingles or post-shingles encephalitis.Brain swelling has historically been thought to affect mostly those shingles patients with immune deficiencies. But recent studies have found that many patients are simply older and struggling with a routine weakening of their immune systems. For that reason, the condition may be increasingly common as populations age, experts said.What is the outlook for patients?It is not entirely clear why some shingles patients who develop encephalitis fare better or worse with the condition. Older age appears to put people at greater risk for more serious problems.But published case studies have described even younger patients who show signs of retrieving their cognitive functions, only to deteriorate again.“You may have some symptoms that last after the encephalitis,” Dr. Mirouse said of patients. “It’s not sure you will be able to recover completely. That’s true at 89, it’s also true at 30 or 20.”Ms. Feinstein may have been at higher risk for developing encephalitis because her shingles had spread to her face and neck, which is known to put patients at risk of brain inflammation.How else can shingles affect people’s cognition?Inflammation alone can damage cells in the brain.But shingles can also contribute to cognitive decline in other ways, including by damaging blood vessels of the brain, said Dr. Sharon E. Curhan, a physician and epidemiologist at Brigham and Women’s Hospital and Harvard Medical School, who is studying the link between shingles and changes in cognition.Shingles patients also face a significantly higher long-term risk of having a stroke, a condition that itself can lead to cognitive decline, according to a study led by Dr. Curhan published last year.Ms. Feinstein had received a shingles vaccine, which in most people provides strong protection against the virus and the complications that can follow. Federal health officials recommend the vaccine for people 50 and older and younger adults with weakened immune systems.