The map is here:
http://www.pathologic-game.com/images/city.jpg
(or
city.zip on the following page:
http://www.pathologic-game.com/files.htm)
It's not really a patch. I just made a map with some marks, most of which are not spoilers and merely information you can easily get yourself speaking to citizens. The textures in game may be altered, so it was not even a problem to make a file suitable for game; one only needs to save .dds, rename it to .tex and put it in data/Textures/.
As far as you know, people on the street do tell you where which part of the town is, and what are the names of these parts. As it is hard to get it all at once, you may look at this map instead.
Assuming you don't know Russian it might be even more confusing, so you may try the one in the English walkthrough (
http://www.pathologic-game.com/path_walkthrough_eng.pdf ). The quality is pretty bad, but the names of the districts are clearly visible.
Upd: found a hi-res version here:
download/file.php?id=138&mode=view. Note that due to parts of the town being coloured, this map may cause overdarkened spots on the maps, because in-game disease map will colour this map over with dark gray and red.