Chronic orofacial pain Flashcards
what is a neuralgia?
Nerve pain
Damage to nerve/ brain
intense stabbing pain
where does neuralgic pain appear?
it extends along the course of the affected nerve
what is neuralgia usually caused by?
irritation of or damage to a nerve (but not exclusively)
which nerves that mediate sensation in the head can be involved in neuralgia?
trigeminal (most common form)
glossopharyngeal and vagus
nervus intermedius (geniculate neuralgia) - branch of facial nerve
occipital
incidence of trigeminal neuralgia
4.3:100 000 pop (USA)
gender distribution of trigeminal neuralgia
higher in females
age group usually affected by trigeminal neuralgia
elderly - predominantly in 60s and above
causes of trigeminal neuralgia
idiopathic
classical - vascular compression of the trigeminal nerve (most common known cause)
secondary
- multiple sclerosis
- space-occupying lesion (intra-cranial tumours - benign/malignant)
- others: skull-base bone deformity, CT disease, arteriovenous malformation
classical Trigeminal Neuralgia - why doesn’t a vessel near CN5 necessarily mean it is this?
need vascular trigeminal conflict - compression
often need high resolution MRI with contrast
trigeminal neuralgia - where does the pain appear?
unilateral maxillary or mandibular division pain > ophthalmic division
trigeminal neuralgia type of pain
stabbing pain
trigeminal neuralgia duration
5-10s
single stabs
each attack is a cluster/group of stabs (up to a few mins)
if >few mins likely not trigeminal neuralgia
trigeminal neuralgia triggers
cutaneous
wind/cold
touch
chewing/jaw movements
paroxysmal trigeminal neuralgia
no pain at all between the stabbing attacks
concomitant continuous pain in trigeminal neuralgia
superimposed stabbing attacks
ongoing background pain between paroxysmal attacks, which is commonly described as aching, throbbing, or burning
is trigeminal neuralgia continuous?
no - get remissions and relapses
why can trigeminal neuralgia present as a hybrid?
because it is on continuum with other cranial nerve pain disorders
non-common presentations of TN
acute spasms of ‘sharp shooting pain’
- may be more than one division
- may be bilateral
- may have burning component
- may have vasomotor component
why do trigeminal neuralgia patients often have a ‘mask-like’ face?
inexpressive as fear of making a facial movement that may set off an attack
trigeminal neuralgia - how does the excruciating pain present?
disabling
patient will freeze
what is the crucial aspect when considering trigeminal neuralgia?
no obvious precipitating pathology
trigeminal neuralgia red flags
younger patient (<40yrs)
Bilateral
sensory deficit in facial region
- hearing loss - acoustic neuroma
other cranial nerve lesions
what are two crucial investigations in trigeminal neuralgia?
test cranial nerves (identify sensory deficit)
MRI
what drug group is predominantly used to treat trigeminal neuralgia?
anti epileptic drugs
first line drugs for trigeminal neuralgia
Anti-epileptic:
carbamazepine
oxcarbazepine
lamotrigine
what is the modified release carbamazepine called and why is it good in trigeminal neuralgia?
Tegretol
good to decrease SEs as prevents fluctuations in serum concentration
lamotrigine onset of action
slow
second line drugs for trigeminal neuralgia
gabapentin
pregabalin
phenytoin
baclofen
trigeminal neuralgia - which drug should patients be responsive to?
carbamazepine if tolerated
trigeminal neuralgia - what should drug therapy aim for?
maximise efficacy and minimise SEs
trigeminal neuralgia - when is it often difficult to control pain?
first thing in the morning
trigeminal neuralgia - what can a pain diary be used for?
identify modifications necessary to therapy
can trigeminal neuralgia be responsive to LA?
yes
carbamazepine side effects
blood dyscrasias electrolyte imbalances (hyponatraemia) neurological deficits liver toxicity skin reactions
carbamazepine blood dyscrasias
thrombocytopenia
neutropenia
pancytopenia
carbamazepine electrolyte imbalances
hyponatraemia
Low sodium in blood
what should you be careful combining carbamazepine with?
diuretics or PPIs that can cause hyponatraemia
carbamazepine neurological deficits
paraesthesia
vestibular problems
dizziness
carbamazepine - how severe can skin reactions be?
potentially life-threatening
blood monitoring on carbamazepine
weekly basis for first month then monthly
FBC, urea, LFT, electrolytes
should you prescribe carbamazepine in GDP?
yes, accord SDCEP guidelines
- urgent referral to specialist/ GP for FBC &LFT
- Carb tablets 100mg
- 1 tab twice a day
trigeminal neuralgia -when would surgery not usually be recommended?
if patient managing on medical therapy with moderate drug use and no significant SEs
trigeminal neuralgia - when to consider surgery
when approaching maximum tolerable medical management even if pain controlled
younger patients with significant drug use - will have many years of drug use
trigeminal neuralgia surgical options
microvascular decompression (MVD) destructive central procedures stereotactic radiosurgery destructive peripheral neurectomies
trigeminal neuralgia - what is the preferred surgical treatment where possible?
MVD
trigeminal neuralgia - what does MVD require?
a vessel impinging on the trigeminal nerve root
trigeminal neuralgia MVD 12month mortality and morbidity
1% mortality
10% morbidity
trigeminal neuralgia - destructive central procedures types
- glycerol injection
- radio frequency thermocoagulation
- balloon compression
trigeminal neuralgia - balloon compression mortality at 9months
2%
trigeminal neuralgia - stereotactic radiosurgery
gamma knife - targeted radiation at the trigeminal ganglion to kill trigeminal nerve cells
- good safety profile but only available in Sheffield
- non-invasive
trigeminal neuralgia - destructive peripheral neurectomies
only performed as a last resort after trial LA
6 months pain free without medication - can result in allodynia as well as TN
trigeminal neuralgia - complications after surgery
local effects - peripheral treatments (cryotherapy) sensory loss - corneal reflex - general sensation - hearing loss motor deficits may be reversible or irreversible
causes of painful trigeminal neuropathy
herpes zoster virus (related to active VZV infection, post-herpetic ‘neuralgia’)
trauma (pain develops <6m of traumatic event)
idiopathic
painful trigeminal neuropathy - where is the pain usually localised to?
the distribution(s) of the trigeminal nerve
painful trigeminal neuropathy - how is the pain commonly described?
burning or squeezing
likened to pins and needles
painful trigeminal neuropathy - duration and presentation of pain
primary pain is usually continuous or near-continuous
superimposed brief pain paroxysms may occur, but not the predominant pain type
what symptoms more commonly present in painful trigeminal neuropathy than in Trigeminal Neuralgia?
clinically evident cutaneous allodynia - much larger than the punctate trigger zones present in TN
and/or
sensory deficits
what is allodynia?
pain elicited on innocuous stimuli e.g. touch
how are TN and PTN linked?
thought to be on continuum of the same spectrum
trigeminal autonomic cephalgias - symptoms
unilateral head pain - predominantly V1 v severe/excruciating usually prominent cranial parasympathetic autonomic features (ipsilateral to the headache) - conjunctival injection/lacrimation - nasal congestion/rhinorrhoea - eyelid oedema - ear fullness - mitosis and ptosis (Horner's syndrome) attack frequency and severity differs
cluster headache attack frequency (daily)
1 every other day - 8 per day
paroxysmal hemicrania attack frequency (daily)
1 to 2 - 40
no circadian rhythm
SUNCT attack frequency (daily)
3-200
what does SUNCT stand for?
Short-lasting Unilateral Neuralgiform with Conjunctival injection and Tearing
cluster headache duration of attack
15-180mins (majority 45-90mins)
paroxysmal hemicrania duration of attack
2-30mins
SUNCT duration of attack
5-240 secs
cluster headache pain quality
sharp, throbbing
paroxysmal hemicrania pain quality
sharp, throbbing
SUNCT pain quality
stabbing, burning
cluster headache pain intensity
v severe “suicide headache”
paroxysmal hemicrania pain intensity
v severe
SUNCT pain intensity
v severe
cluster headache circadian periodicity
70%
paroxysmal hemicrania circadian periodicity
45%
SUNCT circadian periodicity
absent
cluster headache - the attack: pain location
mainly orbital and temporal - affects first division of CN5
cluster headache - the attack: unilateral or bilateral?
strictly unilateral
cluster headache - the attack: onset
rapid
max within 9mins in 86%
cluster headache - the attack: resolution
rapid cessation of pain
how do patients appear during a cluster headache attack (compared to migraines)?
restless and agitated
vs migraines - motion sensitivity (want to stay still)
cluster headache attack other symptoms
prominent ipsilateral autonomic symptoms
migrainous symptoms often present
migrainous symptoms
premonitory symptoms - tiredness, yawning
associated symptoms - nausea, vomiting, photophobia, phonophobia
aura in 14%
what % of cluster headache bouts are episodic?
80-90%
what % of cluster headache bouts are chronic?
10-20%
episodic cluster bouts defintion
attacks ‘cluster’ into bouts typically 1-3months with remission lasting at least one month
episodic cluster headaches pain between attacks?
may be continuous background pain between attacks or symptom free between attacks
episodic cluster headaches and alcohol
triggers attacks during a bout but not in remission
cluster headaches circadian periodicity
attacks occur at same time each day
bouts occur at the same time each year
chronic cluster headaches definition
bouts last >1 year without remission
or
remissions last <1 month
location of pain in paroxysmal hemicrania
mainly orbital and temporal
strictly unilateral
paroxysmal hemicrania - onset
rapid
paroxysmal hemicrania - resolution
rapid cessation of pain
paroxysmal hemicrania - what % are restless and agitated during an attack?
50%