I can tell you some things too look for though. Look for a kid with below average coordination. Check the ears and eyes as well. Check for working vision in both eyes at the same time. I passed two armed forces entrance exams and I'm single eye functional. Look at their shoes. How are they wearing? Are they broke over the sides? That can point to walking off balance.
Try verbal commands and retention while doing dual tasking. Have a radio playing or some other distraction and see if they become agiated while trying to task or communicate. The kid you have too tell too take out the trash three times and the third time acts like they just understood you likely did just understand you. Look for Dyslexic signs as well as skipping words, sentences, even paragraphs while reading out loud.
For the above any kid with chronic ear infections, allergies, sinus troubles, etc I would watch closely for this to become a possibility. Or for that matter this applies to adults as well.
If a doctor doesn't catch it and a Shrink starts writing meds like Ritalin or SSRI's etc very bad things can happen. I'm not a doctor. I'm a patient who as an adult diagnosed with General Anxiety Disorder had to gather enough information about my disorders so Shrinks didn't kill me. LOL. It all pointed back to the clues I listed above :>}