I am not sure how to analyse a half verse from the Mahaaniddesa [PTS
I.42, verse 5]:

cittabhangaa mato loko pan~n~atti paramatthiyaa

cittabhangaa: ablative "when the mind dissolves/stopes"
mato loko: Nominative "world is dead"
pan~n~atti: Nominative "making known"
paramatthiyaa: paramam (Accusative) atthiyaa
(meaning/realization/attainment) "highest meaning/realization"

I'm not sure what kind of form is atthiyaa. What is this ending
(iyaa), is atthiyaa a derivative of attha? If so, what will be the
difference in meaning?

The only logical translation I could find is:
"Because the highest meaning/realization is known, the world is dead
when the mind dissolves".

I will appreciate any help in explaining me this half verse.
Mettacittena,
keren.