Lambson's parents wrote on a blog detailing the boys' recovery that Thursday was a "great" day for their son.
"He is a little agitated and strong," they wrote. "It's the Alex we all know and love."
The early test results for both Alex and Dane include positive results, said Danita Cohen, spokeswoman for University Medical Center in Las Vegas, where the boys are being treated.
The two were waiting for a ride after school in their usual spot under a pine tree Tuesday when they were struck. They were within yards of Snow Canyon High School, surrounded by dozens of other students.
The boys have been kept under heavy sedation, and doctors were keeping them artificially cooled to prevent swelling of their brains. MRI results Thursday morning indicated the boys' brain activity was strong enough for them to be removed from respirators.
Dane's kidneys are still working overtime to flush out enzymes produced by tissue damaged in the lightning strike. He has had fluid in his lungs since the strike, but that seems to be clearing, Broderick said.
Damage to muscle tissue, including the heart, is common, said Dr. Meena Vorha, head of pediatrics at the hospital, on Wednesday.
Most lightning-caused deaths and long-term injuries are caused by a lack of oxygen to the brain and other organs because most strikes occur in wilderness areas where medical care is slow to come. But those aren't big concerns for Alex and Dane because school administrators immediately began CPR and medical crews arrived shortly afterward, doctors said.
Both boys have suffered severe burns: Dane on the bottom of his feet and Alex on about 15 percent of his body, mostly on his torso. He will likely need skin grafts.
The strike also broke some of Alex's bones, which will take time to heal, Vorha said.
Accounts in the boys' names have been set up at Zions Bank branches to help pay for medical expenses not covered by insurance.
Doctors are closely monitoring the boys' progress.
Making sure the heart is pumping in the proper rhythm is important, said H. Scott Bjerke, director of trauma at Research Medical Center in Kansas City, Mo. He said it is possible for the heart to stop again after the initial cardiac arrest.
Dane has been on heart medication to make sure that doesn't happen, said his stepfather, Tim Broderick.
Also, victims of lightning strikes can have their eardrums ruptured, while cataracts may form in their eyes, Bjerke added.
Cataracts have been reported as late as two years after the strike, but most often it occurs within the first week of the event.
The long-term effects of lightning strikes are inconsistent and are still being researched.
O Both families said they want to thank everyone for their continued support and prayers.
They say their phones have been ringing nonstop, and they ask people to visit www.alexanddane.blogspot.com for updates or to leave well-wishes. The boys will be shown the blog when they awake.
"Thank you sincerely for your concern and friendship," the families wrote. "Alex and Dane will always remember the support of friends and family."