This will work for all window panes not just the NERDTree pane. These lines go above in your .vimrc.
set cursorline
set cursorcolumn
These lines go below in your .vimrc.
augroup cursor_off
autocmd!
autocmd WinLeave * set nocursorline nocursorcolumn
autocmd WinEnter * set cursorline cursorcolumn
augroup END