- Most common cause of 7th Cranial Nerve Palsy
- Make Dx by R/O other possibilities
How to R/O Other Causes of CN7 Palsy
1. No Sx like fever, severe HA, confusion, other Neuro deficits- Worry about CNS infection; maybe Primary HIV (see below)
- Palpate canal entrance for masses
- Percuss mastoid for tender Mastoiditis
- Otoscopy for Otitis
- Vesicles in canal or on ext. ear = Zoster (~ “Bell’s)
- Weak forehead & eyebrow muscles = Bell’s
- Normal strength of forehead & eyebrow = Stroke
- No other Cranial Nerve deficits in Bell’s (if also vertigo, it’s due to Zoster)
- Occurs 1-4 weeks after infection
- Usually H/A & fever (often 2-3 wks before facial palsy)
- Often bilateral CN7 Palsy
- Risk Factors: Sexual & Needle-Sharing
- Dx: HIV RNA by PCR (viral load)
- Only if high index suspicion
- exposed in endemic area (mid-May to late-July)
- Symptom onset mid-June to Dec.
- Rx Prednisone for simple Bell’s while waiting (see below)
- Bilateral Palsy (Tx Bell’s also)
- Erythema Migrans rash
- Other Sx (arthralgias, radiculopathy, paresthesias, headache)
- Children (Bell’s is rare in Peds)
- See Blog text; also Nutshell Summary
- Bilat. Palsy (if not Primary HIV or Lyme)
- Recurrent Bell’s Palsy
- Only helps during first few days, not >1 wk.
- Severe Palsy: Add Acyclovir 800 mg 5x/d, OR Valacyclovir 1000 mg T.I.D.
- Patch eyelid closed at night, day too if severe palsy (prevent corneal drying)
- No improvement at all by 3 mos.
- Persistent disability at 1 yr.