Trigeminal Neuralgia Flashcards
What are the 3 categories of pain?
nociceptive
neuropathic
nociplastic
What is nociceptive pain?
normal physiological response (e.g. trauma, inflammation, non healing injury)
pain that arises from actual or threatened damage to non-neural tissue and is due to the activation of nociceptors
what is neuropathic pain?
lesion or disease of the somatosensory nervous system
what is nociplastic pain?
results In increased sensitivity from the altered function of pain related pathways in the periphery and CNS
- triggered by non-nociceptive stimuli
what type of pain is trigeminal neuralgia ?
neuropathic
What is trigeminal neuralgia?
a disorder characterised by recurrent unilateral brief electric shock pains, abrupt in onset and termination
- limited to the distribution of one or more divisions of the trigeminal nerve
- triggered by innocuous (non-harmful) stimuli
- may develop without apparent cause or be a result of another diagnosed disorder
trigeminal neuralgia - consequences
suicide
- 78% of patients had considerable negative thoughts
depression and anxiety
8% have had irreversible and unnecessary dental treatment
47% have been prescribed 3 medications which have been ineffective
name the classifications of trigeminal neuralgia
classical
secondary
idiopathic
features of classical trigeminal neuralgia
develops without apparent cause other than neurovascular compression
purely paroxysmal / sudden
with concomitant/associated continuous pain
what is secondary trigeminal neuralgia?
Trigeminal neuralgia caused by an underlying disease
diseases which may cause trigeminal neuralgia
multiple sclerosis
space occupying lesion
other
- skull base deformity
- connective tissue disease
genetic causes of neuropathy
idiopathic trigeminal neuralgia features
unilateral or bilateral pain in the distribution of one or more trigeminal nerve branches
- indicative of neural damage but of unknown aetiology
- purely paroxysmal
- with concomitant continuous pain
Classical TN pathophysiology
neurovascular conflict of the superior cerebellar artery
compression leads to demyelination
resulting in ectopic firing
- can be observed in asymptomatic patients
idiopathic TN pathophysiology
no conflict but unregulated sodium ion inflow resulting in depolarisation
secondary TN pathophysiology
pathological process resulting in a reduction in myelin coverage at the pons
Trigeminal neuralgia - how might a patient describe the pain?
stabbing
electric shock
severe
memorable first episode
scary
10/10
Trigeminal neuralgia onset
spontaneous, sometimes triggers
trigeminal neuralgia site
unilateral
- usually 1 branch 60%
- 35% 2 branches
- 4% ophthalmic
Trigeminal neuralgia character
sharp/electric shock like pain
- severe
Trigeminal neuralgia - radiates or localised?
tends to spread along branch of Trigeminal nerve
- may have a focused starting point
trigeminal neuralgia - associated features
distress
suicidal ideation
depression
background pain?
- exclude autonomic features
trinomial neuralgia - time and frequency
random, short lived
- up to 2 minutes
- multiple times a day
may have constant less severe background pain
trigeminal neuralgia potentially relieving factors
not moving face
avoiding triggers?
medication
trigeminal neuralgia - how it affects sleep
may or may not wake up from sleep
how can tN affect life quality and mental health?
when attacks become very frequent, patients may become unable to perform daily activities and may avoid eating and communicating for fear of triggering new crisis
common TN triggers
eating
washing face
brushing teeth
eating
speaking
smiling
cold wind
stress
temperature change
bilateral TN symptoms
may suggest other disease
- perhaps MS
Trigeminal neuralgia - red flag features to ask about
sensory motor defects
deafness
loss of balance
optic neuritis
history of cranio-facial malignancy
bilateral TN
systemic symptoms
< 30 years of age
trigeminal neuralgia - examination
E/O
- no abnormalities
- exclude TMD
intra oral
- no abnormalities
- exclude acute dental infection
- exclude cracked cusps
trigeminal neuralgia - how to manage in GDP
obtain accurate diagnosis
- exclude TMD/dental pathology
consider prescibing carbamazepine
- liase with GP for blood monitoring
- call OM for advice if unsure on whether it is safe to prescribe
Consider LA if patient is in extreme pain
Urgent referral to OM or OMFS for definitive advice
Prescribing Carbamazepine - considerations
check BNF for interactions
care in elderly
- increases risk of falls
care in those operating heavy machinery or driving or childcare
arrange blood monitoring with GP
- FBC/U+E/LFT
Carbamazepine dose and frequency
100mg tablets 2x a day for 10 days
- space out doses as much as possible throughout the day
Carbamazepine risks
hyponatraemia
- low sodium in the blood
- increased with other medications such as bendroflumethiazide
falls
unsteadiness
confusion
rash/skin reaction
- more common in Han Chinese and Thai populations
side effects usually dose dependent
- low risks at 100mg 2x daily
TN management in secondary care
MRI scan for all patients
- space occupying lesion
- MS
- neurovasuclar conflict
- CT considered if MRI contra-indicated
Medication optimisation - lowest dose that controls symptoms
- carbamazepine
- oxcarbazepine
- LA in acute episodes
- consider gabapentin, prcegablin, baclofen or lamotrigine in refractory cases
TN management neurosurgery considerations
may be best long term pain control outcome in suitable cases
are medications ineffective?
- significant side effects?
is there neurovascular conflict?
is the patient medically well?
does the patient accept the surgical risks?
neurosurgical approaches for TN
mircrovasuclar decompression
neuro-ablative procedures e.g. balloon compression
stereotactic radiosurgery
microvascular decompression requirements
there needs to be neurovascular conflict
6 hour operation under GA
Microvascular decompression risks
lower chance of numbness
several surgical risks
Neuro-ablative procedures - outline
shorter procedure
- 30 minutes
percutaneous
needle carefully placed in Meckles cave
higher chance of numbness
fewer risks
short in patient stay
why is an MRI taken for trigeminal neuralgia patients?
to exclude underlying disease
What are trigeminal autonomic cephalalgias?
group of headache disorders
may present similarly to TN but will have autonomic features
what are the 4 types of trigeminal autonomic cephalalgias?
cluster headache
paroxysmal hemicrania
SUNCT/SUNA
hemicrania continua
Cluster headache signs and symptoms
attacks of severe, strictly unilateral pain which is orbital, supraorbital or temporal or in any combination of these sites
lasting 15-180minutes and occurring from once every other day to 8 times a day
cluster headache associated symptoms…
ipsilateral conjunctival injection/bloodshot eyes
lacrimation
nasal congestion
rhinorrhoea/runny nose
forehead and facial sweating
miosis
ptosis and/or eyelid oedema
and/or restlessness or agitation
paroxysmal hemicrania signs and symptoms
attacks of severe, strictly unilateral pain which is orbital, supraorbital, temporal or in any combination of these sites
lasting 2-30 minutes and occurring several times a day
paroxysmal hemicrania associated symptoms
ipsilateral conjunctival injection/bloodshot eyes
lacrimation
nasal congestion
rhinorrhoea
forehead and facial sweating
miosis
ptosis and/or eyelid oedema
drug of choice to treat paroxysmal hemicrania
indomethacin
what is SUNCT/SUNA?
Short acting , Unilateral. Neuralgiform headache attacks with Conjunctival injection and tearing
Short acting. unilateral, neuralgiform headache attacks with cranial autonomic symptoms
SUNCT/SUNA signs and symptoms
attacks of moderate, or severe strictly unilateral head pain
lasts seconds to minutes , occurring at least once a day
SUNCT/SUNA associated symptoms
prominent lacrimation
redness of ipsilateral eye
Hemicrania continua signs and symptoms
persistant, strictly unilatéral headache
- headache is sensitive to indomethacin
may have a migrainous component
Hemicrania continua associated symptoms
associated with
ipsilateral conjunctival injection
lacrimation
nasal congestion
forehead and facial swelling
miosis
ptosis and/or eyelid oedema
and/or restlessness or agitation.
Trigeminal autonomic cephalalgias are usually managed by which branch of medicine?
neurology
Cluster headache acute management
oxygen
triptans
lidocaine
cluster headache prophylaxis
corticosteroids - short term
lithium
indomethacin
verapamil
SUNCT/SUNA medication options
IV lidoncaine, gabapentin, lamotrigine topiramate
hemicrania continua medication
indomethacin
Trigeminal autonomic cephalalgias - GDP management
exclude dental component
if unsure if TN or TAC OM referral
TAC best managed by neurology
