looking for old sci-fi "brain monster" movie...

Tweet

HI, i hope someone can help... the movie i'm looking for had an "invisible" killer, until, if i remember correctly.. they was some radiation and then the "invisible killers" began to show up as a brain with what i can remember as a spinal cord that they would wrap around the victims neck and the brain would end up behind the vicitims head and two fang like protubences would dig into the back of the neck and suck out their brain and/or spine??? if anyone can help me discover the name and/or know if it's obtainable on vhs or dvd, i'd really appreciate it, it's an old favorite of mine from when i was a kid back in the late 60's - early 70's (not sure of the last time i remember seeing it) and would like to have it my collection. THANKS!!