(EDIT, May 31, 2014: It has come to my attention that this post is referenced in a book on bioethics. If you have come from that book, remember that (although I’ve done my best to be accurate) this is a blog, not a peer-reviewed scientific article. Be sure and read all the comments at the end of the post. BBN)
The mitochondria are the power plants of the cells. They take the sugar and turn it into the power that runs all the processes of the body. Leigh’s disease is a defect in the genes of these mitochondria or of the body’s ability to make a protein or an enzyme that is used in the mitochondria, like pyruvate dehydrogenase.
The prognosis for individuals with Leigh’s disease is poor. Individuals who lack mitochondrial complex IV activity and those with pyruvate dehydrogenase deficiency tend to have the worst prognosis and die within a few years. Those with partial deficiencies have a better prognosis, and may live to be 6 or 7 years of age. Some have survived to their mid-teenage years.
The defect can be nearly complete or it can be very mild depending on which of the many genes that can be involved are involved. The cells may be able to make energy but only very slowly – or very, very slowly. Or some cells may be able to make some power, but others can’t. Some functions of the body need constant energy, others do not.
Pro-Life Blogs and other blogs carry posts about the very sad case of little Emilio Gonzales, who has been diagnosed with “Leigh’s Disease.” Unfortunately, they are full of implications that doctors (and even the Bishop of the diocese of Austin) are planning to “murder” the baby boy.
We do not have good tests to determine where the genes went wrong and they can go wrong in several places causing different symptoms and even different symptoms in the same child at different times. So this is a “syndrome” or a diagnosis given when we see a pattern of symptoms. AIDS is a syndrome that has only one cause — infection with a virus instead of many different gene defects — but it still develops differently in different people and can mimic different diseases in the early stages.
Sometimes Leigh’s disease does respond to thiamine – but only if the defect is in certain genes. Not in the vast majority of cases.
Another name for the syndrome is “Subacute Necrotising Encephalitis,” because in the late stages, areas of the brain die and break down. This little boy’s nerve cells all over his body, including large areas in his brain, have died. This can be seen on his MRI.
It’s also supported by the findings on his EEG – that shows that he is having seizures one third to one half of the time. The seizures cause more cells to die.
However, the pain nerves still live: the report says he still reacts to painful stimuli as though he is in pain. He isn’t able to process the pain.
Other organ systems fail as the lactic acid builds in his blood and tissues – cooking the proteins that make up the muscles, enzymes, and most structures of the body. If you’ve ever been sore the day after exercise, you know what lactic acid build up in one spot feels like and how long it takes to go away.
And, of course, growing and healing takes energy. The fastest growing cells for most of us line the intestines and make up the liver where food is processed – they die first, but can grow back sometimes – so the symptoms seem to come and go. When they are dead, it hurts the patient to give him tube feedings that must be absorbed by the gut or to give IV feedings that contain anything that must be processed by the liver.
Even the kidneys use energy. And the sphincters of the bowel and bladder do, too. If there is an imbalance between nerves, the sphincters spasm shut – so Emilio needs a catheter in his bladder.
The lungs stiffen with prolonged ventilator use. The stiff lungs and muscles mean that the pressure from the ventilator needs to be so high in order to give him enough oxygen that he is having leaks appear in his lungs as some of the airways break. The baby’s lungs are repeatedly collapsing and having to be re-inflated. This means that over and over, he has a “pneumothorax.”The air goes into the sac around his lungs, squeezing the lung tissue itself down. The pressure outside the lungs is even higher than the pressure the ventilator is making inside the lungs — each push from the ventilator pushes more air through the leak.
The docs then have to place a chest tube or chest tubes – possibly in a baby, they would use the temporary insertion of large bore needles – to release the air around the lungs, and allow the lung itself to inflate.
Some of the air moves between the tissues of his body, coming to the surface in little pockets – causing “subcutaneous emphysema.” Patients tell me that the pneumothorax and the subcutaneous emphysema hurt. The chest tube does not take away the air in the tissues – that takes days or weeks to be reabsorbed.
What would I do? I would suggest that the mother and the docs adopt a strategy of “this much and no more.” Give Emilio droppers of fluids by mouth, to keep his mouth moist. Hold him as much as possible. Continue the ventilator, but stop placing the chest tubes and stop changing the ventilator settings. Do not add new medicines and do not resuscitate when the heart stops.
The Ethics Committee Report has been published at the North Country Gazette.
Medical Update Since Last Ethics Committee Meeting on 2/19/07:
Dr. Alexandra Wilson, the patient’s current attending physician, states that Emilio is unable to move his arms and legs and only has abnormal posturing movements with stimulation. He rarely opens his eyes, does not gag, cannot cough and cannot breathe without use of the ventilator; his pupils are not normally responsive to light. In addition, he can not empty his bladder and has to have a catheter. He does appear to experience pain, as he grimaces in response to deep stimulation, and is now receiving pain medications. He also bites his tongue, which causes bleeding, making it necessary to place a device in his mouth to prevent further injury to his tongue. In addition, he has experienced repeated full and partial collapses of his lungs, and his physicians and the treatment team are having great difficulty keeping his lungs inflated, even with the assistance of the mechanical ventilator. Finally, he is now having seizures, some of which produce visible physical symptoms, and scans (MRIs) of his head show progressive loss of brain tissue.
Dr. Brendle Glomb, pediatric pulmonologist, then discussed Emilio’s pulmonary status, which as noted above has continued to deteriorate. He explained the current functioning and support provided by the ventilator, and then described why Emilio would no longer benefit from a tracheostomy. He also noted that the repeated collapse and reinflation of Emilio’s lungs is damaging to the lungs, and increases the risk that they will tear or even burst during attempts at re-inflation.
Dr. Jeffrey Kane, pediatric neurologist, then discussed Emilio’s current neurological status, which has continued to deteriorate since the last consultation. Overall Emilio shows no purposeful response or movement, which is evidence that the deeper functioning of the brain is absent. In addition, Emilio’s EEG suggests that Emilio is experiencing many more seizures than those at the bedside can see. Based on his review of Emilio’s most recent EEG, Dr. Kane believes Emilio’s brain may be experiencing seizures between 1/3 and ½ of the time. Dr. Kane believes that the seizure activity will continue to increase, and that continued seizures will accelerate the death of Emilio’s remaining brain tissue. In response to a question, Dr. Kane noted that the current brain damage is not reversible, even if the seizure activity for some reason should slow or stop. Instead, he believes that Emilio will continue to experience the relentless and progressive loss of his brain tissue and brain function, and that no therapy or other intervention has been identified which could stop or reverse this process.
Dr. David Anglin, a pediatric intensivist involved in Emilio’s care, then discussed Emilio’s care-setting. He noted that during the Ethics Consultation on February 19, 2007, there was some hope that Emilio might be able to be transferred to a lower-acuity care setting or discharged home, and particularly if he were to undergo a tracheostomy and receive a feeding tube. However, given Emilio’s continued deterioration, he is too ill to survive anywhere but an intensive care setting, and he certainly is not a candidate to be discharged to home.
Edit 03/19/07 at 21:30 – cleaning up grammar.