Severe Trauma May Damage The Brain as Well as the Psyche

NOTE: This is only a portion of the article.  Read the entire post at http://www.nytimes.com/1995/08/01/science/severe-trauma-may-damage-the-brain-as-well-as-the-psyche.html?pagewanted=all

Cortisol is a major means the body uses, with adrenaline, to arouse itself so quickly; its action, for example, triggers an increase in blood pressure and mobilizes energy from fat tissue and the liver.

“The dark side of this picture is the neurological effects,” said Dr. Sapolsky. “It’s necessary for survival, but it can be disastrous if you secrete cortisol for months or years on end. We’ve known it could lead to stress-exacerbated diseases like hypertension or adult onset diabetes. But now we’re finding the hippocampus is also damaged by these secretions.”

Studies in animals show that when glucocorticoids are secreted at high levels for several hours or days, there is a detectable effect on memory, though no neuronal death. But with sustained release from repeated stress, “it eventually kills neurons in the hippocampus,” said Dr. Sapolsky. “This has been shown solidly in rats, with the cell biology well understood.”

A parallel effect has long been known among patients with Cushing’s disease, a hormonal condition in which tumors in the adrenal or pituitary glands or corticosteroid drugs used for a prolonged time cause the adrenal glands to secrete high levels of a hormone called ACTHm and of cortisol. Such patients are prone to a range of diseases “in any organ with stress sensitivity,” including diabetes, hypertension and suppression of the immune system, said Dr. Sapolsky.

Cushing’s patients also have pronounced memory problems, especially for facts like where a car was parked. “The hippocampus is essential for transferring such facts from short-term to long-term memory,” said Dr. Sapolsky.

In 1993, researchers at the University of Michigan reported that magnetic resonance imaging had shown an atrophy and shrinkage of the hippocampus in patients with Cushing’s disease; the higher their levels of cortisol, the more shrinkage.

In an apparent paradox, low levels of cortisol in post-trauma victims were found in a separate research report, also in the July issue of The American Journal of Psychiatry. Dr. Rachel Yehuda, a psychologist at Mount Sinai Medical School in New York City, found the lower levels of cortisol in Holocaust survivors who had been in concentration camps 50 years ago and who still had post-traumatic symptoms.

“There are mixed findings on cortisol levels in trauma victims, with some researchers finding very high levels and others finding very low levels,” said Dr. Sapolsky. “Biologically speaking, there may be different kinds of post-traumatic stress.”

In a series of studies, Dr. Yehuda has found that those post-trauma patients who have low cortisol levels also seem to have “a hypersensitivity in cell receptors for cortisol,” she said. To protect itself, the body seems to reset its cortisol levels at a lower point.

The low cortisol levels “seem paradoxical, but both too much and too little can be bad,” said Dr. Yehuda. “There are different kinds of cells in various regions of the hippocampus that react to cortisol. Some atrophy or die if there is too little cortisol, some if there is too much.”

Dr. Yehuda added, “In a brain scan, there’s no way to know exactly which cells have died.”

To be sure that the shrinkage found in the hippocampus of trauma victims is indeed because of the events they suffered through, researchers are now turning to prospective studies, where before-and-after brain images can be made of people who have not yet undergone trauma, but are at high risk, or who have undergone it so recently that cell death has not had time to occur.

Dr. Charney, for example, is planning to take M.R.I. scans of the brains of emergency workers like police officers and firefighters and hopes to do the same with young inner-city children, who are at very high risk of being traumatized over the course of childhood and adolescence. Dr. Pitman, with Dr. Yehuda, plans a similar study of trauma victims in Israel as they are being treated in emergency rooms.

Dr. Yehuda held out some hope for people who have suffered through traumatic events. “It’s not necessarily the case that if you’ve been traumatized your hippocampus is smaller,” she said. She cited research with rats by Dr. Bruce McEwen, a neuroscientist at Rockefeller University, showing that atrophied dendritic extensions to other cells in the hippocampus grew back when the rats were given drugs that blocked stress hormones.

Dr. Sapolsky cited similar results in patients with Cushing’s disease whose cortisol levels returned to normal after tumors were removed. “If the loss of hippocampal volume in trauma victims is due to the atrophy of dendrites rather than to cell death, then it is potentially reversible, or may be so one day,” he said.

NOTE: This is only a portion of the article.  Read the entire post at http://www.nytimes.com/1995/08/01/science/severe-trauma-may-damage-the-brain-as-well-as-the-psyche.html?pagewanted=all

MR Brain Spectroscopy Detects Damage In The Hippocampus Of Patients Exposed To Excess Cortisol

New research shows that patients who are “biochemically cured” of Cushing’s syndrome have levels of brain metabolites which are associated with neural damage. This will have implications for treatment of Cushing’s patients, but might also suggest that patients using high levels of glucocorticoid drugs may suffer similar long-term problems. The work was presented yesterday at the European Congress of Endocrinology in Copenhagen.

Cushing’s syndrome is an endocrine disease causing an overproduction of the stress hormone cortisol. Surgery and medical treatment can normalise cortisol levels, however recently it has been shown that “biochemically cured” patients continue to have memory problems. Now for the first time a group of researchers from the Sant Pau Hospital in Barcelona has scanned the brains of patients who had suffered from Cushing’s syndrome and found that they exhibit changed levels of brain metabolites, which are associated with memory and cognitive impairments. This finding may also have clinical implications for otherwise healthy patients who take high levels of glucocorticoid drugs for inflammatory, rheumatoid diseases, allergies and probably everyday chronic stress.

Cortisol (a glucocorticoid hormone), is naturally produced by the adrenal glands in response to stress. Long term exposure to high levels of cortisol is known to be associated with a range of cognitive impairments – this is true for Cushing’s syndrome patients, and probably would be also for those who take glucocorticoid drugs.

Eugenia Resmini and colleagues, working at the Centre for Biomedical Research on Rare Diseases (CIBERER), Sant Pau hospital in Barcelona, used proton magnetic resonance spectroscopy to measure a series of metabolites in the hippocampus of the brains of 18 patients who had been treated for Cushing’s syndrome, and compared these results to 18 healthy control subjects. They found that levels of the metabolite NAA (NAcetyl-aspartate) were significantly lower in the Cushing’s patients, indicating neural dysfunction, whereas Glx (Glutamate +Glutamine) levels were higher, suggesting that glial cells were proliferating as a repair mechanism.

According to Dr Resmini MD, PhD, Endocrinologist at the Centre for Biomedical Research on Rare Diseases (CIBERER), Hospital de Sant Pau, Barcelona, Spain:

“Patients with Cushing’s syndrome are exposed to abnormally high levels of glucocorticoids, which is associated with a wide range of cognitive impairments, as well as loss of brain volume. We studied the hippocampus, which is a critical area for learning and memory and, as it is rich in glucocorticoid receptors, is especially vulnerable to glucocorticoid overexposure. Cushing’s syndrome patients with severe memory impairment are known to have a smaller hippocampus. We have now found abnormal levels of metabolites in the hippocampi of Cushing’s patients with normal hippocampal volumes, indicating that these are early markers of glucocorticoid neurotoxicity, which would precede hippocampal volume reduction.

“Identifying these metabolites as a marker would be a way of allowing earlier diagnosis and treatment of cognitive impairments. This may also allow us to monitor patients taking glucocorticoid drugs, which have potentially damaging side effects. On the other hand, the fact that these markers are still present in Cushing’s patients after being “biochemically cured”, may show that once cognition has been damaged in Cushing’s syndrome, it may not be fully reversible. For this reason an earlier diagnosis of the disease and a rapid normalization of hypercortisolism would avoid the progression of hippocampal damage and of memory problems”.

From Medical News Today

Abnormal Metabolites Found in Cured Cushing’s Patients

Patients with Cushing’s syndrome have abnormal brain metabolites suggestive of neuronal dysfunction even after they appeared to have been cured, according to a study presented at the annual European Congress of Endocrinology, held from April 27 to May 1 in Copenhagen.

(HealthDay News) — Patients with Cushing’s syndrome have abnormal brain metabolites suggestive of neuronal dysfunction even after they appeared to have been cured, according to a study presented at the annual European Congress of Endocrinology, held from April 27 to May 1 in Copenhagen.

Using proton magnetic resonance spectroscopy, Eugenia Resmini, M.D., Ph.D., from Hospital Sant Pau in Barcelona, Spain, and colleagues measured metabolites in the hippocampi of 18 adults with Cushing’s syndrome who had been biochemically cured and 18 age- and education-matched healthy adults.

The researchers found that the two groups had similar left and right total hippocampal volumes. Patients with Cushing’s syndrome had significantly lower NAcetyl-aspartate in the left and right hippocampus as well as significantly lower NAcetyl-aspartate plus N-Acetyl-aspartyl-glutamate in the right hippocampus. In addition, patients with Cushing’s syndrome had significantly higher glutamate plus glutamine in both hippocampi. The alterations are suggestive of neuronal dysfunction, according to the authors.

“Persistently abnormal metabolites are evidenced in the hippocampi of Cushing’s syndrome patients despite endocrine cure,” Resmini and colleagues conclude. “These functional alterations could be early markers of glucocorticoids neurotoxicity and would precede hippocampal volume reduction.”

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