If you regularly experience headaches, dizziness, balance problems and blurred vision, our Neanderthal cousins could be to blame.
These are common symptoms of Chiari malformations, structural defects in which the lower part of the brain extends into the spinal cord. People with this condition have skulls shaped like those of our ancient relatives, leading to a hypothesis (known as the Archaic Homo Introgression Hypothesis) that it may be a genetic legacy from interbreeding between modern humans and Neanderthals.
To investigate this, Kimberly Plomp of the University of the Philippines Diliman and colleagues zeroed in on Chiari 1, the mildest form of the condition, which affects around 1 in 100 people.