February 13, 2014
‘Nearly-comatose’ Pakistani student may be sent home
(ABC News) – A nearly-comatose Pakistani student, who was studying in Wisconsin, may be sent back to Pakistan after his student visa runs out at the end of February even though he can no longer talk or care for himself. Muhammad Shahzaib Bajwa, 20, was studying at the University of Wisconsin-Superior when he was in a car accident in November. The car carrying Shahzaib Bajwa hit a deer and the 20-year-old suffered multiple fractures in his face after the animal went through the windshield. At the hospital he choked on his own blood and temporarily went into cardiac arrest.
The genetics of drug tolerance
(Medical Xpress)—Put yourself in the shoes of a psychiatrist. You just diagnosed a person with schizophrenia, and you can prescribe any number of antipsychotic drugs, all of which can cause serious side effects. You know that older drugs, such as haloperidol, work well, but a third of all schizophrenia patients who take it suffer from Parkinsonian-like symptoms, such as tremors, involuntary spasms, and uncontrollable facial movements. You also know that those side effects are permanent in about half the people who experience them. In other words, you could be prescribed a drug that causes permanent brain damage.
“Robocop”: When will cyborgs walk among humans
(CBS News) – Although the fields of robotics and artificial intelligence have made significant gains within the past 15 years, do not expect to see RoboCops walking among humans in the near future, said Charles Higgins, an associate professor of neuroscience and electrical engineering at the University of Arizona in Tucson.
February 12, 2014
Brain dead and pregnant: Why one baby was born and one wasn’t
(ABC News) – With two stories gaining national attention this winter about brain-dead, pregnant women and their unborn children, it’s difficult to think of one without the other. In Canada, Robyn Benson was kept on life support for more than a month to save her unborn baby. More than 3,000 miles away, in Texas, Marlise Munoz’s husband fought to take her off life support. But how similar – and how different – were they really? Compare them side by side here.
Medication: The smart-pill oversell
(Nature) – For most people with ADHD, these medications — typically formulations of methylphenidate or amphetamine — quickly calm them down and increase their ability to concentrate. Although these behavioural changes make the drugs useful, a growing body of evidence suggests that the benefits mainly stop there. Studies indicate that the improvements seen with medication do not translate into better academic achievement or even social adjustment in the long term: people who were medicated as children show no improvements in antisocial behaviour, substance abuse or arrest rates later in life, for example. And one recent study suggested that the medications could even harm some children.
February 11, 2014
18 people have been exposed to incurable disease
(CNN) – Doctors and hospital officials from Novant Health Forsyth Medical Center in Winston-Salem, North Carolina, are notifying 18 neurosurgery patients that they might have been exposed to Creutzfeldt-Jakob disease, a serious and incurable neurological disorder. “Today we are reaching out to 18 neurosurgery patients who were exposed to Creutzfeldt-Jakob disease over the last three weeks at Forsyth Medical Center,” said Jeff Lindsay, president of the center, according to CNN affiliate WGHP.
Is intelligence written in the genes?
(The Telegraph) – A gene which may make people more intelligent has been discovered by scientists. Researchers have found that teenagers who had a highly functioning NPTN gene performed better in intelligence tests. It is thought the NPTN gene indirectly affects how the brain cells communicate and may control the formation of the cerebral cortex, the outermost layer of the human brain, also known as ‘grey matter.’
February 10, 2014
Are men ‘hardwired’ for violence? Brain structure, stress, and genetic influence rates of aggression
(Medical Daily) – “Behavior originates in the brain, and violence is no exception.” So begins an article by Dr. Debra Niehoff, adjunct professor in the Department of Social and Behavioral Science at Bucks County Community College, which reviews the current literature and then explains both the biologic and environmental factors that may lead to aggressive behavior on the part of both men and women. Niehoff ultimately suggests that violence is not “hardwired” into men — or certain individuals for that matter — but due to differences in brain structure and function, stress response, and genetics, they may be more vulnerable than women to factors that increase aggressive behavior.
Human embryonic stem cells induced to spontaneously form cortical tissue
(Medical Xpress) – During development, the nervous system forms as a flat sheet called the neuroepithelium on the outer layer of the embryo. This sheet eventually folds in on itself to form a neural tube that gives rise to the brain and spinal cord—a process that involves the proliferation and migration of immature nerve cells to form the brain at one end and the spinal cord at the other. Yoshiki Sasai, Taisuke Kadoshima and colleagues from the RIKEN Center for Developmental Biology have now shown that human embryonic stem (ES) cells can spontaneously organize into the cerebral cortical tissue that forms at the front, or ‘brain’ end, of the developing neural tube.
February 7, 2014
Typically, in these posts my goal is to discuss the science behind a certain technique to help us understand the ethical issues surrounding the technique. With the recent case of Jahi MacMath, the thirteen-year-old girl who was declared brain dead after complications from tonsil surgery, rather than evaluating a new technology, it might be helpful to discuss the definition of brain death.
What is brain death?
Brain death is not to be mistaken for persistent vegetative state (PVS). When someone is diagnosed as being in a PVS, this means that the person does not have higher brain function, but maintains lower brain function. There is brain stem activity, which regulates involuntary actions such as breathing, circulation, and digestion. Someone in a PVS will undergo sleep-wake cycles and can respond to stimuli.
Coma is related to PVS in that it is due to a lack of higher brain function, and the person maintains brain stem activity. However, someone in a coma is not awake and does not respond to stimuli. Coma can often be temporary (Orr, 184).
Loss of higher brain function is different from whole-brain death or losing both higher and lower brain function. In this case (brain death) there is no brain function, even in the brain stem. All involuntary actions must be maintained by machines and medication. Whole brain death is only declared after a series of tests, which include physical tests, EEGs and imaging. In the U.S., different may states have different requirements, but typically, brain death must be determined by two different doctors at two different times. In Jahi McMath’s case, five physicians, two from the attending hospital and three chosen by the parents, declared her whole-brain dead.
The “traditional” definition of death is based on cardiopulmonary (heart-lung) function. If the heart stops pumping and there is no respiration, then the person is considered dead. According to a statement from Jahi’s family in the Los Angeles Times, they will accept her death if her heart stops beating while she is on the respirator, but do not accept brain death as a valid criterion for death.
Whole-brain death was accepted as a definition of death in the 1970s, and is considered an accepted definition of death in all fifty states in the United States. This change was being considered in the 1950s when transplantation and prosthetics were becoming more commonplace. There was a move to change from a biological definition of death to a mental definition of death (Engelhardt, 242, 243). A person could lose all of his or her limbs, receive prosthetics and still be the same person. A person could receive a kidney, liver, heart, or lung transplant, all vital organs, and maintain his or her identity. The reasoning was that biological components must not be the only identifier of life and death.
However, the motivations behind changing the definition of death also came along because of organ transplantation and respirator technology. Once blood flow stops, there is a very narrow window of time in which organs can be removed from a person and transplanted to another patient. By allowing for brain death as a valid definition of death, blood and oxygen could be continued even if the patient is declared dead, until the organs can be transplanted. With the use of medical technology, the person’s body may appear to be normal, and they may seem to be “alive.” The historical reasons for the change in the definition of death (to facilitate organ retrieval) contribute to the discomfort many have with defining death based on brain function rather than heart and lung function.
Why is brain death controversial?
Often the controversy surrounding brain death involves patients who have lost higher brain function, but maintain brain stem activity. These are the stories that tend to make the news, including the rare cases where someone shows some recovery. One of the more famous cases was that of Terri Schiavo. She had lost higher brain function due to a heart attack, and was left in a persistent vegetative state. In PVS cases, the patient has certain, albeit minimized, interaction with the external world, and maintains certain bodily functions, making it very difficult to justify declaring this person legally dead.
Higher-brain death is more controversial because it places an arbitrary limit on the amount of brain activity that is necessary for one to be considered alive. Furthermore, prognosis is difficult because several factors contribute to whether the brain injury is truly permanent and how extensive it really is. A younger person is more likely to recover from traumatic brain injury than an older person. Someone who loses brain function due to lack of oxygen, as in Terri Schiavo’s case, is less likely to regain brain function compared to someone who sustained a traumatic brain injury. Additionally, the longer someone is in a PVS, the lower their chance of any recovery (Orr, 184-192).
Determining whole-brain death is less arbitrary than higher-brain death because the criteria includes that there is no discernable brain function. This is determined by a series of tests, including physical examination, responses to stimuli, voluntary respiration after being weaned from a respirator, and EEG and imaging data.
Whole-brain death is not without some controversy. First, occasionally EEG readings will show that some cells maintain activity but not the whole brain stem itself. This makes interpreting the EEG data a little more difficult. Additionally, whole-brain death involves making a distinction between biological death and mental death, even though a human being is both mind and body. Although the biological tissue is being kept alive by artificial means, to what extent must one be kept artificially alive to be considered technically dead? For example, a person with a pacemaker is being kept artificially alive by a machine, but we typically consider these people alive.
Pediatric cases pose unique issues for bioethicists. The parents serve as the child’s surrogates, and in the case of Jahi McMath, the parents do not wish for their child to be taken off life support. A key bioethics question here is whether the parents have to accept whole brain death as the criterion for death. Furthermore, they cite religious reasons for not doing so. When it comes to matters of life and death, often certain allowances are made for various faith traditions.
Critics of Jahi’s parents argue that the doctors are not required to treat a futile case. In Jahi’s case, several other treatments must be in place in order for her body to continue on a ventilator. Because her brain stem is inactive, her body cannot do involuntary functions without the aid of other technology and medication. Some would maintain that measures, such as inserting a feeding tube would be inappropriate in this case, particularly because her body’s ability to digest food is severely limited. Others would consider a feeding tube basic care and therefore required, but would not consider it mandatory to resuscitate her heart, should she go into cardiac arrest.
Jahi’s case could also be a case of the difference between withholding life-saving treatment versus withdrawing treatment that is not benefiting a patient. While temporally the patient undergoes cardiopulmonary death (or cessation) after being removed from a respirator, the ethical question is what is the actual cause of death, assuming the family’s definition of cardiopulmonary death? Is it the removal of the respirator or is it the result of post-surgery complications? Additionally, is the point to hasten death, or is death inevitable, assuming cardiopulmonary definition of death. Even if this is the case, is the family required to remove their child from the respirator?
As of the writing of this article, Jahi McMath was transported to an undisclosed facility that will continue to keep her on life support as per the request of her parents. Reports on January 9 indicate that her body had deteriorated badly, but another report in CNN says that after receiving treatment at the new facility, she has stabilized. As of February 7, she is still on life support at the undisclosed location.
Engelhardt, H. Tristam, Jr. The Foundation of Bioethics, 2nd edition. New York: Oxford University Press, 1996.
Munson, Ronald. Intervention and Reflection: Basic Issues in Biomedical Ethics, 8th edition. Belmont, California: Thomas Higher Education, 2008.
Orr, Robert D. Medical Ethics and the Faith Factor: A Handbook for Clergy and Health-Care Professionals. Grand Rapids: Eerdmans, 2009.
Brain-dead, a Canadian woman remains a silent partner awaiting birth
(New York Times) – Nearly six weeks after a pregnant Canadian woman was declared brain-dead, she remains on life support in Victoria, British Columbia, because of her family’s hope that her fetus will mature enough to be delivered. The decision by Robyn Benson’s family to try to deliver her child has drawn growing attention in Canada, largely because of a series of moving blog posts by her husband, Dylan Benson.
Study on stroke in women focuses on risks from pregnancy
(The Wall Street Journal) – Controlling high blood pressure and other risk factors related to pregnancy and use of birth control can significantly reduce a woman’s chance of suffering a stroke later in life, according to guidelines published Thursday. The recommendations, issued by the American Heart Association and the American Stroke Association, are the first from those groups to specifically address preventing strokes in women. While men and women share many risk factors for the disease, the guidelines underscore how events during a woman’s reproductive years mean such factors also can differ between the sexes.
Diuretic drug prevents autism in mice and rats
(Nature) – Children with autism typically begin showing obvious symptoms, such as trouble making eye contact and slow language development, a year or more after birth. A study in mice and rats now hints that prenatal drug treatment could head off these problems. The findings, reported today in Science, do not suggest that autism spectrum disorders can be prevented in children. But researchers not involved in the study say that they add support to a controversial clinical trial suggesting that some children with autism benefited from taking a common diuretic medication called bumetanide.
February 6, 2014
The pivotal role of the stem cell environment in brain development
(Medical Xpress) – Higher mammals, such as humans, have markedly larger brains than other mammals. Scientists from the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden recently discovered a new mechanism governing brain stem cell proliferation. It serves to boost the production of neurons during development, thus causing the enlargement of the cerebral cortex – the part of the brain that enables us humans to speak, think and dream.
February 5, 2014
An artificial arm gives one man the chance to feel again
(NPR) – With a standard prosthetic, Sorensen can’t feel anything he’s holding or touching. So when he heard about an experimental prosthetic that would let him feel again, he jumped at the chance to try it. “First of all I was thinking, this, this can’t be true,” he says. But it was, and Sorensen traveled to Rome to become the first person to try it.
The genetics of developmental disabilities
(San Francisco Gate) – On April 14, 2003 the National Human Genome Research Institute (NHGRI), the Department of Energy (DOE) and their partners in the International Human Genome Sequencing Consortium announced the successful completion of the Human Genome Project. What has this project help us understand the genetics of developmental disabilities? I asked Genetics Counselor Kim Barr of Kaiser Permanente to answer this and other questions about the genetics of autism and other developmental disabilities.
Helping young adults with neurodevelopmental disabilities
(Medical Xpress) – In a study published today by the medical journal Paediatrics & Child Health, IRCM researchers address shortcomings in transitional care in the Canadian healthcare system. The team led by Eric Racine and Emily Bell, Montréal neuroethics experts, identified important challenges in the transition from paediatric to adult health care, especially among youth with neurodevelopmental disabilities (such as autism spectrum disorders, fetal alcohol spectrum disorders and cerebral palsy).
February 4, 2014
A brain surgery decades ago is getting a new look and raising questions about memory
(Washington Post) – A new examination of the brain of Patient H.M. — the man who became an iconic case in neuroscience when he developed a peculiar form of amnesia after parts of his brain were removed during surgery in 1953 — shows that his surgeon removed less of his brain than thought.
‘Google-like’ database of brain scans may help doctors treat disorders
(Mashable) – A team of Johns Hopkins engineers and radiologists are building a “Google-like” searchable digital library of children’s brain scans in an effort to improve the way doctors treat and diagnose patients with brain disorders. Supported by a three-year grant of $600,000 from the National Institutes of Health, the brain-scan database will help doctors in two ways. They will be able to search the database for images that match a patient’s scan to diagnose any irregularities seen. By comparing brain scans, doctors can also possibly identify a change in a brain structure that shows the early onset of a disease. Identifying diseases earlier means a quicker start for treatment.
February 3, 2014
Seeking the genetic underpinnings of lupus
(Medical Xpress) – Lupus is one of the most enigmatic of diseases. It can take years to diagnose, marked as it is by a laundry list of seemingly unrelated symptoms: fever, fatigue, rashes, hair loss, sensitivity to light, seizures and even psychosis. Nearly 2 million Americans have some form of lupus, an autoimmune disorder, that is, one in which the immune system wages war on the body’s own cells and tissues. More than 90 percent of those who suffer from it are women—and there is no cure.
January 29, 2014
Permanent changes in brain genes may not be so permanent after all
In normal development, all cells turn off genes they don’t need, often by attaching a chemical methyl group to the DNA, a process called methylation. Historically, scientists believed methyl groups could only stick to a particular DNA sequence: a cytosine followed by a guanine, called CpG. But in recent years, they have been found on other sequences, and so-called non-CpG methylation has been found in stem cells, and in neurons in the brain. (Health News Digest)