Vasectomy linked to dementia

"My friend recently mentioned that her husband had scheduled a vasectomy for next month. This didn't surprise me... their kids are grown, they don't want more and what's not to like about being free of the hassles of birth control?

It's a common operation. Globally, it's estimated that more than 50 million men have had a vasectomy and it has always seemed there are few, if any, disadvantages to the sterilization procedure. However, a new study has found a surprising and potentially disturbing association between vasectomy and a particular form of dementia.

In and of itself, this kind of dementia is unusual. Called primary progressive aphasia (PPA), this is caused by a neurodegenerative disease of the brain that affects healthy brain cells initially in the left-sided area that houses language ability, called the perisylvian region. PPA follows a predictable course, typically taking about two years to produce enough symptoms for a definitive diagnosis, Sandra Weintraub, PhD, professor of psychiatry and behavioral sciences at Northwestern University told me. What's first noticed is that people can't remember words -- initially this may seem like a common symptom, perhaps brought on by stress, but with PPA it continues to progress to the point where they're unable to recall words to express their thoughts. "Ultimately it affects reading and comprehension, and then, like all neurodegenerative diseases, it spreads and affects other areas of the brain, causing other cognitive and behavioral symptoms," Dr. Weintraub explained.

Dr. Weintraub, lead researcher on this study published in the journal Cognitive and Behavioral Neurology, said the discovery of a possible link between vasectomy and PPA was serendipitous. While still lucid, a patient of hers insisted that his symptoms began right after his recent vasectomy. Dr. Weintraub initially discounted the possibility the two were linked, she says... that is until the day "he walked into a support group for PPA patients and asked how many of the men in the room had had the operation. Eight out of nine hands shot up. So I decided to investigate."

COMPELLING FINDINGS

What she found was disturbing. In order to compare prevalence of vasectomy, overall, with vasectomy patients who have developed PPA, Dr. Weintraub and her researchers surveyed two groups of men -- 47 men with PPA and 57 men without. They learned that only 16% of the non-impaired group had undergone vasectomies compared with 40% of patients in the PPA group.

GUILT BY ASSOCIATION -- BUT NOT CAUSATION

PPA is associated with -- not caused by -- vasectomy, stresses Dr. Weintraub, noting that women get PPA too -- and that the vast majority of men who have vasectomies do not develop the problem. The reason for the association is not yet known, though Dr. Weintraub did offer one speculative hypothesis: "Vasectomy breaks the blood-testes barrier that protects the testes from possible unfamiliar and harmful compounds in the blood. Some sperm gets released into the bloodstream -- since intact sperm are not normally found in circulation, the immune system may regard them as pathogens and react by creating defensive antibodies. Perhaps those antibodies to sperm cross into and harm this particular part of the brain."

Additional research is planned to further explore the link between vasectomy and PPA. The association could lie in a factor that may predispose some men to be more vulnerable to the effects of vasectomy than others, or another entirely unknown factor may be at play. Although the findings may have significance for PPA, at present they don't provide sufficient evidence to be used in reaching a decision about whether or not to undergo vasectomy. Risk, of course, is associated with many medical procedures, and the size of the risk in this case, although unknown, is presumably small since the prevalence of PPA is very low. In the meantime, however, Dr. Weintraub urges men considering the sterilization procedure to think through the decision carefully. Though the numbers are small, she feels the findings are significant."

Source:

Sandra Weintraub, PhD, a professor of psychiatry and behavioral sciences at Northwestern University in Chicago.