"Cadaveric spasm" refers to a kind of instant rigor mortis. After we die, the muscles of the body stiffen, from using up its oxygen supply and because wastes - carbon dioxide and urea - are no longer brought away from the muscle cells. It also has to do with the depletion of muscle enzymes. So, cadaveric spasm is a muscle phenomenon in which some muscles of the body become stiff instantly, rather than in the usual two to eight hours normal rigor takes to develop. The reason for such rapid rigor mortis, usually, is the extreme exertion of the muscles during the act of dying, especially as can happen during a struggle.

So, for instance, when somebody is in a struggle with another person before dying, the hand muscles may go into instant rigor mortis -- like in a mystery novel, when a button is tightly grasped in the hand of the deceased and is found later when the hand is opened. There are cases of people who have collapsed and died of a heart attack while long-distance running, and rigor mortis set in much faster in those cases, because of the depletion of oxygen and buildup of waste that occurs during such stressful exercise.

Although cadaveric spasm is not common, I have seen it. Because of the time factor, in order to see the condition, one has to view the body at the scene where it was found. One can find stiffness and rigor mortis in a body within minutes after death has occurred. As a medical examiner, I have seen cadaveric spasm in bodies that are taken out of bodies of water. In the process of drowning and in the exertion in trying to swim to shore, the hands of the victim, especially, become depleted of oxygen - and may have seaweed or other objects caught in the last grasp before death.

Is it possible to determine a person's gender from body fluids - blood, urine, saliva?

Yes, it's definitely possible to determine gender from body fluids, whether it's blood, urine or saliva, because these substances have cells that contain DNA. And if one can do a DNA analysis, one can determine whether there's a Y chromosome, which is present in males, but not in females. So, the determination of gender is entirely dependent on identifying a Y chromosome at the gender spot. So DNA makes it very easy. Before DNA testing, we could determine gender because there were certain antibodies and fluorescent stains that could be used to determine the Y chromosome. Fluorescent stains were developed in the '70s and '80s, and worked by staining a spot and then the Y chromosome would fluoresce. However, DNA is much easier and a much more definitive way to determine gender from a body fluid.

When someone freezes to death, what exactly is the mechanism of death?

When somebody freezes to death - which is called hypothermia - death usually occurs from cardiac arrhythmia, because the cold slows down the heart, preventing it from functioning. When our body temperature falls below ninety degrees Fahrenheit, the heart begins to have difficulty functioning; below eighty-three degrees Fahrenheit, almost everybody would have a cardiac arrest or death-inducing arrhythmias.

Interestingly, however, a number of years back when an Air Florida flight crashed in the Potomac River in Washington, D.C., one of the flight attendants was rescued after about a half hour in the water. Her body temperature was eighty-three degrees Fahrenheit - and she survived; if her temperature had fallen another degree or two, she would not have survived. That case shows how quickly the body's temperature can fall when it is in ice or in water near freezing temperature, which is about thirty-two degrees. When there is ice in the water, the body loses temperature very quickly, much more quickly than in the open air. Also, if a person is nude and out in very cold weather, the loss of body heat is still much slower than in when a person is in water.

I've heard that it's nearly impossible to determine that someone has died of a potassium overdose, because potassium levels naturally rise after death. Is this true?

Potassium overdose is very difficult to determine at autopsy. The best way to determine potassium overdose is by collecting blood during a cardiac arrest code. If a person is in the hospital and has suffered an overdose of potassium, a code is called when the heart stops beating properly. And at that time the potassium level hasn't started to rise as the result of death. When death occurs, after an hour or two the potassium level starts to rise automatically, but immediately at the time of death, it's still valid to measure the potassium in the body. The cells of the body are very rich in potassium -- except for blood cells; once we die, the other cells start to break apart and flood the bloodstream with potassium. As a result, potassium rises post mortem and will obscure a poisoning. However, there's one area of the body that's protected against this potassium fluctuation: the vitreous humor, which is the fluid in the back of the eyes. What we can do at autopsy is draw the vitreous humor and look for potassium. In eye fluid, post mortem potassium rises much more slowly than in the bloodstream. Sometimes that has been helpful in determining that a person has died from a potassium overdose, as in the case of Dr. Jeffrey Swango, who murdered a young woman at Ohio State University Hospital. By doing an analysis of the deceased's blood at the time of the cardiac arrest and finding a big jump in her potassium level, investigators determined that she'd been poisoned by potassium.

Would you explain the difference between the Rokitanksy and Virchow methods of performing autopsies? Which do you use?

Karl Rokitansky and Rudolph Virchow, two giants of pathology of the 19th century, developed many autopsy techniques. Until the 1850's to 1860's, autopsies were generally limited to prisoners who had been executed. But in the latter part of the 1800's there was an appreciation that autopsies were very important; that by performing them, physicians could learn about diseases and their causes - which is one reason they're still so important today. Practicing in Germany, Virchow and Rokitansky were the two leaders in this field. Rokitansky developed a method of removing the body organs all at once. That is, the heart, liver, kidneys, urinary bladder, prostate gland, etc., were removed in one block and then dissected on the autopsy table, apart. That's called the Rokitanksy method. It's a good way to teach medical residents how to do an autopsy, because the professor can examine all the different organs in the same relationships they had inside the body. This may also be important in examining gunshot wounds, stab wounds - to determine the trajectories.

Virchow developed a method of autopsy in which each organ is removed separately - the heart separate and the lungs separate, for example. This method requires a little bit more knowledge about the body, as well as more expertise. It's the method that I use, and it's the method that most experienced forensic pathologists use. After learning, initially, about the relationships of the organs to one another through use of the Rokitansky method, it is more effective and easier - especially in medical examiner cases - to take out and examine the organs one at a time.

Is it possible to become infected with Creutzfeldt-Jakob disease (or other spongiform encephalopathies) from performing an autopsy?

Jakob-Creutzfeldt Disease is caused by a virus similar to the one that causes "mad cow disease"; it's also similar to a disease found in New Guinea called kuru. If a decedent has Jacob-Creutzfeld - or Creutzfeldt-Jacob (I've heard it referred to mostly as Jakob-Creutzfeldt Disease) the person doing the autopsy can be infected if there's a break in the skin and there's transmission of the virus from blood to blood. One doesn't become infected if there's no break in the skin.

We had a situation in the 1970s - when we started to do cornea transplants from autopsies - that there were a couple of transplants of corneas from people who had died of Jakob-Creutzfeldt Disease. The persons who received the transplants then developed Jakob-Creutzfeldt, because of the viruses being transmitted through the corneas. (Since then much more care has been taken about preventing infectious disease transmission through organ transplants.)

But, for the person performing the autopsy, the most common problem is accidentally cutting's one's finger through the gloves. That could allow transmission of not only the Jakob-Creutzfeldt virus, but also tuberculosis, hepatitis and HIV. And, if we cut ourselves doing an autopsy, we can get a localized infection of the nature which is easily treated with antibiotics. But the big worry in doing an autopsy are still tuberculosis, hepatitis and AIDS.

Is it possible for a death from multiple stab wounds to be a suicide? If so, have you ever seen a case where this had happened?

It is not only possible, it's common. When a person commits suicide with a knife, multiple incised wounds - cuts - are very common, and multiple stab wounds are common. Most people who cut themselves during attempted suicides survive. In New York City, when I was Chief Medical Examiner, we did a study in the '70s, and there were about 1500 suicides a year in the city. The most common were drug overdoses using barbiturates - sleeping pills. The second most common were jumps from buildings and third most common were suicides by hanging. Way down the list, about number ten, were suicides from stab and cut wounds, because most of the time when somebody cuts or stabs himself, the individual will live long enough to get to, or be taken to, a hospital. When deaths occur by suicidal stab wounds there are often multiple stab wounds in the chest area, that injure the heart. Yes, I've seen quite a number of those.

When someone receives a blood transfusion, how long do the transfused cells live in the recipient's body? Could the transfused blood affect a DNA profile?

A normal red blood cell lives about 120 days. When blood is transfused, there will be blood cells of different ages, and they will live pretty much the same the same length of time in the recipient's body as in the donor's. The average person has about five quarts of blood, so if a person is given ten units - pints - of blood in a transfusion, that can effect the recipient's DNA profile. If, for example, a dying person has multiple gunshot wounds, he may be given a massive blood transfusion in the attempt to to keep him alive. But when the body comes to autopsy we have to be very careful; if we take just normal blood from the person, we may be getting the profile of the donor rather than the decedent. Remember, though, that the DNA profile from blood is not gotten from the red blood cells. Red blood cells have no nuclei - it's the one cell in the whole body that doesn't have nuclear DNA. So, when we perform DNA testing, we use the white blood cells because, while they make up less than one-tenth of one percent of the blood volume (blood is 99.9 percent red blood cells), they have nuclei, and therefore, DNA. But, the white cells may stay alive longer than the red cells, and those are the ones that can give a false positive.

Leave questions for Dr. Baden at the Autopsy Bulletin Boards.