It's possible the infection is not in the brain itself, rather, outside of the brain, in the inside of the skull, or possibly outside of the scalp. Also could be in the sinus tissue.
I have a similar problem. The neurological effects I have are moderate to minor (no seizures) which leads me to believe they are due to the worms just causing inter-cranial pressure by continuing to grow and multiply in the head, but without directly attacking/damaging the brain.
I've tried the following on seperate occasions with limited success (because they just keep coming back):
Albendazole combined with Ivermectin and Doxycycline
Albendazole combined with Praziquantel
Garlic + Vitamin C