I Have An 8 Week Old Daughter That Was Born

I have an 8 week old daughter that was born 5 weeks premature. She was in the nicu for 4 days and then progressed enough to come home. She is doing great and growing good and she doesn't really cry. There have been 3 nights though where she woke up in a full out scream her arms and legs were stretched out and we could not bend them, when we would try to hold her close she pushes herself away and keeps her arms and legs straight out, she won't focus on anything and keeps staring during the "episode" and nothing we could do would calm her down. The "episodes" last between 5-10 minutes and as soon as it's over she falls back asleep. The three nights that this has happened have all been within the last month or so.