Vasectomy Causing a Rare Dementia?

Primary progressive aphasia (PPA) is a rare form of dementia in which difficulty in language functioning - finding the right words, understanding others, reading, and writing – occur as isolated symptoms in people under 65. It starts gradually as difficulty in finding the right words when speaking or writing, and progresses.

Based on a clinical observation in a patient (he described the onset of the condition shortly after his vasectomy), workers at Northeastern University reported results of a study that showed that the rate of vasectomy in 47 PPA patients (40%) was significantly higher than that in 57 age-matched controls (16%).

The investigators conclude that vasectomy may be a risk factor for PPA in men. They speculate that vasectomy can produce an immune reaction to sperm, with antibodies that may also attack certain brain cells. All this remains to be explored further. Although PPA is rare, vasectomy is a common and effective form of birth control, so we need to know, fairly quickly.

However, before panicking, remember that it was 40% of PPA patients who had had vasectomies, not the other way around. It’s likely that less than 1% of patients diagnosed with dementia before age 65 may actually have PPA. Considering there are probably 50 million men who have had vasectomies, the actual risk is very, very small.