Bells Palsy & Trigeminal Neuralgia Flashcards
Bells Palsy
what is the most common etiology?
unilateral facial nerve palsy
Bells Palsy
epidemiology (age, gender, seasonality)
- usually adults, peak ages 20-40 y/o
- men and women equally affected
- rarely occurs in the summer
Bells Palsy
risk factors?
5
- DM
- immunocompromised
- pre-eclampsia
- recent URI
- recent pfizer vax
Bells Palsy
differentiate upper and lower motor neuron lesions
- UMN: lesions affecting the corticobulbar tract
- LMN: lesions affecting individual branches
Bells Palsy
pathophys
may affect any/all four fiber types carried by facial nerve
* somatomotor axons to facial muscle (presents as facial weakness)
* axons supplying stapedial muscle (hyperacusis)
* gustatory fiber insult (hypo or dys geusia)
* sensory fiber insult (otalgia and post-auricular pain, lacrimal/salivary gland dysfunction)
Bells Palsy
describe the HSV hypothesis
- cause causing primary infection on the lips (cold sores), the virus travels up sensory nerve axons and then reactivates and causes damage to myelin
Bells Palsy
may be secondary to?
- autoimmune reactions that cause facial nerves to demyelinate
Bells Palsy
within how long do sx evolve?
72 hours
Bells Palsy
presentation of illness
5 components
- unilateral facial palsy of acute onset
- ipsilateral post-auricular pain, mild to mod otalgia, hyperacusis, or phonophobia
- hypo or dysgeusia
- subjective tongue or facial hypoesthesia
Bells Palsy
PE Exam components which will be unremarkable
- focused neuro exam
- complete head/neck exam (CN exam, otoscopy, tuning fork exams)
Bells Palsy
what is Bell Phenomenon
L eye rolls upward and inward
Bells Palsy
which side of the face is usually affected?
R side of the face
Bells Palsy
sparing of the brow on PE indicates?
upper motor neuron lesion
Bells Palsy
essentials of dx
3 essentials +/- 2 others
- sudden onset of lower motor neuron facial palsy
- hyperacusis or impaired taste
- no other neurologic abnormalities
- post-auricular pain or trigeminal neuralgia
Bells Palsy
diagnosis to exclude
- facial palsy of known etiology or a palsy that is progressive, waxing, waning, or affects facial zones in an uneven fashion
IS NOT BELLS PALSY
Bells Palsy
what would uneven distribution of weakness indicate?
neoplasm
Bells Palsy
what if it was vesicular palsy?
zoster
Bells Palsy
diagnostics
3 components
- “if it looks like a horse, it’s probably a horse”
- imaging PRN to r/o stroke or neoplasm
- Lyme testing if indicated
Bells Palsy
differentials
8
- Herpes Zoster
- Lyme Disease
- Benign Facial Nerve Tumor
- Malignant Facial Nerve Tumor
- Delayed onset palsy from facial trauma
- chronic otitis media or cholesteotoma
- otitis externa
- CVA
Bells Palsy
Tx (firstline)
- corticosteroids w/in 72 hrs of sx osnet
- burst and toper
- Anti virals (if HSV; valacyclovir or acyclovir)
Bells Palsy
tx: eye protection
- artificial tears during the day
- tape shut at night w/ lubricant
Bells Palsy
where to refer for severe cases?
- neuro-opthalmologist
- neurologist
Bells Palsy
recovery for incomplete vs complete paralysis
- incomplete paralysis: 94% recovery
- complete paralysis: 61% recovery
Bells Palsy
poor prognosis w/
4 things
- advanced age
- DM
- taste disturbance
- pregnancy
Bells Palsy
follow up
within 1-2 wks to monitor response to therapy and follow condition of affected eye
Trigeminal Neuralgia
AKA
tic douloureux
Trigeminal Neuralgia
epi (gender, age, risk factor)
- more common in females than males
- usually begins after age 40 (most common onset 60-70 yrs)
- HTN is risk factor
Trigeminal Neuralgia
etiology
unclear and likely multi factorial
Trigeminal Neuralgia
essentials of diagnosis
3
- brief episodes of stabbing facial pain
- pain is in the territory of the 2nd and 3rd division of the trigeminal nerve
- pain is exacerbated by touch
Trigeminal Neuralgia
which CN is attaked and causing stabbing facial pain?
- CN V
Trigeminal Neuralgia
International Headache Society Classifications
A: paroxysmal attacks of pain lasting from a fraction of a second to 2 min, affects 1+ divisions of trigeminal nerve
B: pain is at least: intense/sharp/superficial/stabbing OR precipitated from trigger areas/factors
C: attacks stereotyped in the individual pt
D: no clinically evident neurologic deficit
E: not attributed to another disorder
Trigeminal Neuralgia
where does pain shoot from in 60% of pts?
from corner of mouth to angle of jaw
Trigeminal Neuralgia
where does pain commonly run?
along line dividing either mandibular and maxillary nerves or maxillary and ophthalmic portions or nerve
Trigeminal Neuralgia
where does pain jolt from in 30% of cases?
- upper lip or canine teeth to eye/eyebrow
- spares the orbit itself
Trigeminal Neuralgia
fewer than 5% of cases involve what?
ophthalmic branch
Trigeminal Neuralgia
triggers
4
- chewing, talking, smiling
- drinking hold/cold fluids
- touching, shaving, brushing teeth, blowing nose
- encountering cold air from open car window
Trigeminal Neuralgia
what are 2 things that pts may try to do to avoid triggering?
- rubbing the face/trigger area
- hold face still while talking
Trigeminal Neuralgia
3 components of the trigeminal nerve
- V1: opthalmic nerve
- V2: maxillary nerve
- V3: mandibular nerve
Trigeminal Neuralgia
describe associated pain
6
- severe, paroxysmal, lancinating
- starts as sensation of electrical shocks in the affected area
- crescendos in < 20s to excruciating discomfort
- begins to fade within seconds and leaves a burning ache
- pain fully abates between attacks even if they are severe/frequent
- may cause grimace, wince, or aversive head movement
Trigeminal Neuralgia
tx
- AEDs (carbamazepine or oxcarbazepine)
- Gabapentin
- Lamotrigine
Trigeminal Neuralgia
describe AEDs for tx
- inhibit neuronal sodium channel activity, reducing excitability of neurons
Trigeminal Neuralgia
describe gabapentin for tx
- modulation of excitatory transmitters involved in pain
Trigeminal Neuralgia
describe lamotrigine for tx
- inhibits release of glutamate (excitatory amino acid) and inhibits neuronal sodium channel activity which stabilizes neuronal membranes, reducing excitability
Trigeminal Neuralgia
surgical tx
- microvascular decompression
- Gamma knife tx
- Radiofrequency
Trigeminal Neuralgia
what does gamma knife tx do?
damages trigeminal nerve to stop transmission of pain signals
Trigeminal Neuralgia
what does radiofrequency do?
damages trigeminal nerve to stop transmission of pain signals
Trigeminal Neuralgia
complications of surgery
2
- permanent anesthesia over face
- disabling, spontaneous post-op pain (worse than original pain, untreatable)
Trigeminal Neuralgia
prognosis
- chronic
- tx usually fail
