But a fake facial palsy may happen in case the needle touches the ramifications of the facial nerve.
It is in reality an NEUROPRAXIA which means that the injured nerve which will recupere in max 3 weeks .
In such case,you can follow the complete restitutio ad integrum with EMG ( electromyogramm) and the total recuperation takes maximum 3 weeks to 1 month.
In case of copies, irreversible facial paralysis may occur because of the neurolysis or chemical extensive neurotmesis of the facial nerve or its terminations.Check here
Vasodilatators and corticoids can be useful.