Trigeminal Nerve Injury (Lui) Flashcards
What are initial questions to ask if patient present complaining of neuropathy?
- When was the procedure
- When did symptoms start
- Are symptoms the same, improving, getting worse
- Are you in pain?
What is the layman’s term for distorted sensation?
Numbness
What are 3 primary things that could cause a patient to seek treatment in a nerve injury?
- Distorted sensation
- Impaired function
- Pain (dysethesia)
Which nerves has a LOWER rate of spontaneous regeneration: those in soft tissue or those in bony canal?
Soft Tissue
Which nerve has better chance of spontaneous recovery: lingual or IAN and why?
IAN, inside a bony canal
What provides the best opportunity for sensory recover if an observed or known injury occurs?
Prompt microsurgery
Full recovery in 1 month indicates what?
Neurapraxia (bruised nerve)
Is recovery anticipated if neurosensory dysfunction lasts for >1 month and what does that indicate?
It indicates a higher grade injury with uncertain spontaneous recovery
If have a patient has nerve injury symptoms for more than 1 month, what diagnosis should you consider?
Microsurgical consult
Most injuries resolve in ____ months, but only if improvement begins before ___ months?
3-9 months 3 months
What is prognosis for patient that is anesthetic at 3 months?
Poor
Will surgery improve function and objective testing or will it reduce pt’s pain and their subjective feeling of numbness?
Improve function and objective results only
Numbness is subjective or objective feeling?
Subjective
What is the only objective way to know the extent and what the nerve problem is?
Quantitative Sensory Testing (QST)
Myelination increases what?
Conduction velocity
Do nerves have blood vessels?
Yes
What are 3 types of neural fascicular patterns?
- Monofascicular
- Oligofascicular
- Polyfascicular
Which fascicular pattern is severly damaged easier?
Monofascicular
What is the big picture with the QST with respect to conduction velocities?
Different fibers have different velocities
The pseudo unipolar neurons of CN V region in which ganglion and head where?
Trigeminal ganglia and go to the trigeminal nucleus
What tract does the trigeminal nerve impulse travel to get to the primary somatosensory cortex?
Trigeminothalamic
What are 7 common causes of nerve injury?
- Local anesthesia
- Implant placement
- Endodontic therapy
- Mucoperiosteal flap
- Chemical
- Infection (Vincent’s syndrome)
- Third molar surgery
What are 7 chemicals that can cause neurotrauma?
- Tetracycline power
- Surgical
- Canoy’s solution
- Eugenol
- Intracanal endodontic medicaments
- Calcium hydroxide
- Local anesthetics
What should you do if you know that an implant has approximated the IAN?
Remove and replace immediately
What degree is a nerve injury that reaches to the endoneurium?
1st degree
What degree is the nerve injury that goes through the endoneurium?
2nd degree
What degree is a nerve injury going to the perineurium?
3rd degree
What degree is a nerve injury through the perineruium?
4th degree
What degree is a nerve injury through the epineurium?
5th degree
What can form at the end of a nerve injury and prevent healing or transmission?
Neuroma (Wallerian degeneration)
What is the difference between Sunderland and Seddon nerve injury classifications?
Sunderland is 5 degrees, Sneddon is 3
Seddon Neurapraxia is what degree in Sunderland?
1st degree
Seddon Axontomesis is what degree in Sunderland?
2nd degree
Seddon Neurotomesis is what degree in Sunderland?
5th degree