Weakness of the Facial Nerve, the 7th of the 12 “Cranial Nerves” that begin in the brain & control movements and sensation of the head and neck. Bell’s Palsy usually just occurs on one side. The 7th Nerve controls movement (strength) of the face, so if muscles become weak (the word “palsy” means “weakness”), a patient:
- can’t raise their eyebrow well (or at all)
- can’t close their eye completely
- can’t grimace / smile / frown well
- has a droopy face.
Facial Palsy is usually due to inflammation of a tiny opening in the bone right in front of the ear, where the nerve exits from the brain to reach the face. The most common cause one is Herpes Simplex Type-1, which causes cold sores / fever blisters on the lips (not Type-2, the common STD). Next most common is Herpes Zoster (Shingles) from reactivation of the Varicella (chickenpox) virus. Lyme Disease should be suspected in high-risk areas during high-risk seasons. Other rare causes include Acute (Primary) HIV, ear tumors or infections, fluid collection for any reason (e.g. pregnancy); it’s also more common in Diabetes.
Most importantly, Facial Palsy (aka Bell’s) is not a stroke (death of part of the brain). Actually, rare cases are, and there’s a way to tell. When stroke is the cause, the eyebrow isn’t affected, only the lower face. We have a patient raise their eyebrows, & we count the wrinkles on each side. Fewer wrinkles on the affected side means eyebrow weakness, so no stroke.
Without treatment, 85% of patients begin to recover within 3 weeks, and achieve full or almost-complete recovery within 6 – 12 months. Those with more severe weakness at the beginning may have some permanent effects. The most important part of treatment is high-dose steroid medication (e.g. prednisone) for 10 days; anti-Herpes medicine (at high doses, as given for Zoster) may also help, but isn’t as important. Treatment should be begun as soon as possible.