Bipolar Disorder Forum - bi-polar rage symptoms

Hi, I'm new here and haven't read much. I'm sorry, but I'd be thrilled for any help someone can offer.

Here's the situation. I live with my boyfriend, his sister and their mom. His mom is bi-polar, from what I've been told. She's been institutionalized in the past, but she only gets bad very rarely. Every 4 - 6 years or so. Again, this is all second-hand information from him and his sister.

Two days ago, she went from being completely fine to.. not well. At all. She hasn't slept for 2+ days. She goes from crying to peaches and cream to intense rage in the span of minutes. She doesn't remember little things from one minute to the next. She has no concept of cold (we're in MI and it feels somewhere around 10 degrees right now), earlier she was walking outside without a jacket and keeps opening doors and windows. She jumps from thought to thought and can't keep up with them. As of right now, she's been in a rage since about 3pm. To the point where she's making things up to be mad at (she started yelling at the top of her lungs that someone had locked her out of her bedroom, but the door was just closed. She was positively assured the entire house smelled of gas and that my boyfriend had left the stove on. He hadn't and it didn't, but it led to a 10 minute scream-fest with her spewing insults at him. Now it has 'calmed down' to her just manically running about the house while stomping/throwing things around). But in the middle of her yelling, she'll just randomly start laughing. There's more, but you get the idea.

What I find to be the most scary about this all is she won't/can't acknowledge that anything different is happening. If you try and tell her it is, or that something is wrong, she talks right over you or pretends you didn't say anything. She insists everything is fine and we're the ones being crazy. I'm told that in the past, while in the thick of this, if any kind of authority is called she behaves perfectly normal and tells them she has no idea why her children would do this. Thus, our hands are completely tied when it comes to getting her help and getting her well again.

Sorry if this is jumbled, I'm just so stressed out right now. I've never dealt with, or seen, anything like this. It's frightening, especially because right now her rage is focused on me. Anything you can offer would be an immense help. Thank you.