Focal neurologic signs are things that happen to your body that show there might be something wrong with your brain.
Your brain is like the boss of your whole body, it tells your arms and legs what to do and helps you think and feel things. But sometimes, there might be a problem with a certain part of the brain, and that can show up in different ways.
For example, if someone has trouble moving their arm or leg on one side of their body but not the other, that could be a focal neurologic sign. Or if they have trouble talking or seeing out of one eye, that could also be a focal neurologic sign.
Doctors can use these signs to figure out what's going on in your brain and help you get better.