Can Botox cause sixth cranial nerve palsy 3 months after the injections in forehead?

Forehead Botox will not cause a 6th nerve palsy.  Botox will be effective within a week of the injection. After that time, you shouldn't see any additional effect to surrounding muscles. So, if your issues started 3 months after forehead Botox, they are completely unrelated. Good Luck to you though, hopefully the muscle function will return to normal with time.Andrew Campbell, M.D.Facial Plastic SpecialistQuintessa Aesthetic Centers

Botox results are seen within 2 weeks, it would not have any nerve effect months later.  Best, Dr. Emer.

Hi Bezap, I am not familiar with circumstances in which Botox would cause a sixth cranial nerve palsy three months after injection. Botox takes between three and five days to take effect usually starts wearing off after 4-5 months.

If the 6th nerve palsy didn't occur within the same timeframe as the forehead relaxation happened, then I would really be surprised that the injection has any causal relationship. The fact that the palsy didn't occur until 3 mos after the injection and the forehead function has almost returned completely at this time without any change in the palsy would also indicate another reason for the palsy. Good luck.

Botox or botulinum toxin is a "neurotoxin" that has its paralyzing effect at the neuromuscular junction - this is where the nerve meets the muscle.  It paralyzes muscles by blocking the nerve's ability to release the chemicals (acetylcholine) that tells the muscle fibers to contract.  Botox is not an binary (on or off, all or none) drug.  It is dose dependent and time dependent.  Meaning it weakens muscles and its effect wears off slowly over time (4-6 months).    Total paralysis of your lateral rectus muscle 3 months after botox injection is unlikely for a few reasons.1. The neuromuscular junction of the lateral rectus muscle is way back in your bony orbit, far away from a Botox injector who doesn't know facial anatomy.  Even if they were injecting your crow's feet and got too close to your eyeball - the needle is short and they are far away.  2. Botox doesn't diffuse very far from where it is injected.3. After 3 months, total paralysis of a muscle injected with Botox is unlikelyThe good news is, if your lateral rectus palsy is due to Botox, it should be wearing off soon.  So, if the muscle isn't working by 6 months - don't let any doctors blame it on the Botox.