Questions and Concerns regarding my young brother's stroke

My 24 year-old brother suffered a massive stroke (possibly several) Sunday morning as a result of an accidental overdose. We have a tight-knit family and him and I were very close, so this has been devastating. He was intubated for three days, but is now breathing on his own. Due to the the breakdown of his muscles his kidneys are doing very poorly and soon they are deciding whether or not he will need dialysis. I am praying that he won't! Apparently he had more than one stroke; mostly the left hemisphere of his brain was affected and some frontal lobe. He has paraysis on his right side but we have seen *a tiny bit* of movement in his right arm and leg. He seems to recognize us and can respond somewhat to commands ("open your mouth," "sit up" etc.) but has not spoken. When he attempts to speak he says "ummmm" several times, like he is searching for the words. I did here him say "uh-huh" when a nurse asked if he knew he was in the hospital. He does chuckle and makes appropriate facial expressions occasionally as well. My questions:

What are the differences, if any, from a young person's recovery from a stroke vs. an older person's? Is there any literature or information anywhere relevant to his age? I understand that each person's recovery is unique, but it seems most information and studies I find are all on older patients.

My brother has been VERY restless. He is constantly shifting his position, using his good arm to adjust the position of his bad arm and leg, moving his blankets and pillows, fumbling with the buttons on his hospital bed.... He seems constantly uncomfortable. It is very unnerving because he can't communicate what he wants or needs. He calms down when we hold his hand and stroke his hair though. I'm wondering if this is normal? Has anyone experienced this shortly after a stroke? Why?

The BIG question is in regards to his speech. When will he get it back, if ever? I don't expect you to know the answer, but is there a timeframe of when stroke survivors begin to find words? What I have read is discouraging... It seems that the more time that passes without the survivor speaking, the less likely it is that they will ever speak. How long was it before you or your loved ones spoke? What is the longest that you know of?

What helps the most? What can me or family do in order to speed his recovery and help him in any way?

I guess that is all for now. I just ordered six books on strokes and stroke recovery off of Amazon, so I am attempting to educate myself and my family. This is difficult and I am very afraid that I may lose my brother as the hilarious, talented, intelligent, awesome person he was. But if I can even get a glimmer of him back I will be happy.

Thanks in advance for any input, best wishes to all of you.