[Client][Patch 5.23] Lags on mac client

I'm experiencing terrible ping spikes ingame since the new 5.23 patch. Usually in the loading screen the ping is in a normal range (30-50) and after the game starts i got spikes to about 400-500 every few seconds that slowly normalize and then jump up again. The game is unplayable like this. movement and spells need 1-2 seconds to be executed and you can not land any skill shot or last hit minions like this.

Anyone experiencing the same issues ?

I'm using the mac client on my macbook pro late 2013 running OS X Mavericks. I did not change anything on my system configuration. Other network services work normally. I have a stable low ping to teamspeak server and other games. The problem is just arising in lol and only since the new patch.