Leptomeningeal Disease

My father was recently diagnosed with Stage IV Lung Cancer. We were (mildly) hopeful as he has the EGFR gene. But on a repeat brain MRI they found Leptomeningeal disease/cancer. Everything I read about this feels like a death sentence. He has no “typical symptoms” (no cough, SOB, bone pain, etc) but the effects to his brain seem significant.

We went from perfectly normal to my father slipping away in just over a month.

I’m just looking for some personal stories about Leptomeningeal disease (truly, the good AND the bad). I am trying to be as realistic and honest with myself as possible during this whole journey.