Men who have had a vasectomy may face an increased risk of developing a rare type of dementia, Northwestern University researchers discovered.
Sandra Weintraub, principal investigator and professor of psychiatry and behavioral sciences and of neurology at Northwestern’s Feinberg School of Medicine, began investigating a possible link between the surgery and primary progressive aphasia – PPA when one of her male patients connected the onset of his language problem at age 43 to the period after his vasectomy.
At a twice-yearly Chicago support group for PPA patients Weintraub sees from around the country, the male patient rushed into the room and asked the men sitting there, “OK, guys, how many of you have PPA?” Nine hands went up.
“How many of you had a vasectomy?” he demanded next. Eight hands shot up.
Weintraub and her team of researchers surveyed 47 men with PPA who were being treated at Northwestern’s Cognitive Neurology and Alzheimer’s Disease Center and 57 men with no cognitive impairment who were community volunteers. They ranged from 55 to 80 years old.
Of the non-impaired men, 16 percent had undergone a vasectomy. In contrast, 40 percent of the men with PPA had had the surgery.
“That’s a huge difference,” said Weintraub, director of neuropsychology in the Cognitive Neurology and Alzheimer’s Disease Center. “It doesn’t mean having a vasectomy will give you this disease, but it may be a risk factor to increase your chance of getting it.”
In addition, the men who had undergone a vasectomy developed PPA at a younger age (58 years) than men with PPA who hadn’t had one (62 years.)
Preliminary evidence from the study also seemed to connect another form of dementia to a vasectomy. In a smaller group of 30 men with a dementia called frontotemporal dementia (FTD,) 37 percent had undergone a vasectomy. The earliest symptoms of FTD are personality changes, lack of judgment and bizarre behavior. As in PPA, FTD usually starts at an earlier age, in the 40s and 50s.
The most common form of dementia caused by brain deterioration in individuals over age 65 is Alzheimer’s disease. Weintraub did not find an increased rate of vasectomy in patients with Alzheimer’s.
Many patients with FTD and PPA share a common brain disease that is completely different from Alzheimer’s. Whether a patient will get the behavioral or language problems depends on where the disease causes the most destruction in the brain. In FTD, most of the da mage is in the frontal lobes; in PPA, it’s in the language centers of the left hemisphere of the brain.
Weintraub theorizes a vasectomy may raise the risk of PPA (and possibly FTD) because the surgery breeches the protective barrier between the blood and the testes, called the blood-testis barrier.