Risk of Stroke

Does the claimed stroke risk from spinal manipulation add up?

A commonly cited figure claims that cervical spinal manipulation carries a stroke risk of 1 in 20,000. But when you multiply that rate by the volume of manipulations performed each year, the resulting number of manipulation-caused dissections exceeds the total number of all cervical artery dissections in the entire US population. Explore the math yourself below.

Summary

At these assumptions, cervical manipulation would cause an estimated 12,480 dissections per year — 126% of the total estimated 9,900 cervical artery dissections in the US from all causes combined.

The claimed risk implies more manipulation-caused dissections than actually exist in the entire population.

Total Manipulations/yr
249.6M
Claimed Dissections
12,480
Total CeAD Cases
9,900
% of Total CeAD
126%

Modify the underlying assumptions to explore different scenarios.

Interpretation: This calculator does not attempt to determine the true risk of stroke from cervical manipulation. It demonstrates that the commonly cited "1 in 20,000" figure is arithmetically implausible: it would require more manipulation-caused dissections each year than the total number of cervical artery dissections observed in the entire US population from all causes combined.

This tool is for educational purposes. It does not constitute medical advice. Adjust the assumptions to explore different scenarios.