Does Nightmare difficulty affect item spawns?

[davestovies]

Playing through this game again and I'm about a third of the way through my Item Hoarder run on normal. Loaded up my save and had it switch to Nightmare which didn't seem to be too much of a problem however now I can't find a battery pickup that the guide's showing. 

 

There's supposed to be a battery I can pick up in the music hall area of the school but it doesn't appear in my game. I'm following a video guide and he can clear be seen picking it up. I have the same amount of batteries (16) as the guy in the video before he picks it up so I don't know what the problem is. I'm guessing that Nightmare mode might make changes to item locations however I can't find anywhere that says so, so I was hoping to find a solution on here. 

 

I can add pictures of my game and the video guide for reference if needed.

[Harrowed23]

I noticed that too. On multiple locations the batteries are missing in comparision with the guide from IBadDriverI. I played through the whole game with it and ended up with exactly 79 items when picking up the last butterfly. And as I was in the last section of the game I could'nt go back. But I'm not sure if there were any items left in the areas before that the guide maybe didn't show.