How Long Would Numbness Typically Last When Having Pinched Nerve?

The question is about my son. 18 yr old athlete. He was lifting weights doing an overhead press. He felt a pop or crack in his neck and some pain. very soon after that he got a Migrane headache. He has got them before when he didn t have good sleep habits. This Migrane seemed stronger than previous ones but he did not throw up. The next day he woke up with a very sore neck and numbness on the left side of his body. The numbness was in the back of his arm and down his leg. We took him to the hospital and he started a bunch of tests. MRI s, Echo, ect. Things they found were. The possibility of two very small dots on the occiptial lobe of the brain which they said could be there and if so could represent a stroke but also could not really be there. They said he has Chiari Type 1 which could be the cause. They don t believe there has been a disection of arteries in the neck according to MRI s. He did not have a PFO. We left the hospital yesterday with a wide range of possibilities from very scary to no big deal. He continues to have numbness in his left arm and leg. Also he hasn t had a stool movement for a couple of days which is atypical. My questions are 1. If its just a pinched nerve then how long would the numbness typically last. 2. from looking at the information on the web is it possible he had a Sporadic Hemiplegic Migraine (SHM) and if so how long does the numbness usually last in those cases. 3. Does the Chiari have an effect on the nervous system after an injury. The web seems contradictory in this area. 4. Can a stroke or mini stroke be associated with a minor neck injury. 5. How do we know if the chiari is affecting his nervous system. My son is a college football player and its a big part of his life. So this has the family very concerned.