Yes, a TBI can really impede one's inner life.

I was a professional fiction writer. Before my MVA, my mind was always swimming with ideas, conversations between my characters, etc... For a long time after the accident, my mind was just blank. The internal monologue had stopped. I was in a scarey silence. Left alone, I'd just sit, unaware of the passage of the hours. My sleep was black and dreamless.

As time passed, I began to regain some capacity for thought and imagination. Is it like before? No. I have only have pre-rem dreams and I know I'll never again write creatively. But, at least, I have thoughts.