Tom Morton’s review published on Letterboxd:
One of the things I love most about watching Vincent Price films is that, because I'm picking them out just because they're Vincent Price films, I tend to go in with no real knowledge of what to expect. Often that just leads to standard-issue horror fun but other times it results in something like this, which offers one of the most genuinely unhinged horror premises I've ever encountered. I knew that this was one of the main William Castle films homaged in Matinee but I did NOT know that it would be about a weird fucking invisible bug that lives in the human spine and is responsible for the feeling of terror that can only be released with a hearty scream.
Obviously once you've determined that a bug can only be defeated by a scream, this leads to drugging and terrorising a deaf-mute woman to find out what happens when a person cannot scream, and things get even weirder from then on. There's also a delighfully cruel subplot about Vincent Price's unfaithful wife which leads to a whole bucketload of hilariously bitchy dialogue between the two of them which might be even more fun than the weirdo spine-bug stuff.
Castle's main gimmick for this film (vibrating chairs!) may not be available for home viewers but there's a secondary gimmick to this one that very much does work at home and adds an extra layer of surprise to this spectacularly strange gem, and some fourth-wall breaking sequences that are also quite fun in a campy sort of way. But yeah, it's the deeply bizarre premise that really makes this one stand out. I loved it.