Trigeminal neuralgia Flashcards
What is it
Chronic, debilitating condition resulting in intense and extreme episodes of pain in the face.
Results from a neuropathic disorder of the Vth cranial nerve (trigeminal nerve)
Describe the character of the extreme episodes
Sporadic and sudden and often like ‘electric shocks’, lasting from a few seconds to several minutes
What mixed modalities are detected by the trigeminal nerve
Sensation
Nociception
Thermoception
Motor supply to the muscles of mastication
Most commonly, the maxillary and/or mandibular branch are involved
Epidemiology
Peak incidence lies between the ages of 50 and 60 years
Prevalence increases with age
Annual incidence in UK of 27 per 100,000
More common in females
Genetic predisposition (but lack of penetrance and transmission method unclear)
Aetiology
Usually compression of the trigeminal nerve by a loop of artery or vein
5-10% of cases due to tumours, MS, abnormalities of the skull base or arteriovenous malformations
Presentation
Sudden, unilateral, brief, stabbing, recurrent pain in the distribution of one or more branches of the Vth cranial nerve.
Pain occurs in paroxysms which last from a few seconds to two minutes.
The frequency of the paroxysms ranges from a few to hundreds of attacks a day.
Periods of remission can last for months to years, but tend to shorten over time.
May be preceding symptoms.
SHARP, SEVERE shock-like pains.
3-5% of patients will have bilateral pains
Examples of preceding symptoms
Tingling or numbness
Diagnostic criteria: site
Pain is unilateral in the distribution of the trigeminal nerve, bilateral in only 3% of patients, and rarely is the pain active on both sides at the same time.
Diagnostic criteria: periodicity
Episodic and sudden onset of pain, lasting a few seconds to minutes and stopping suddenly, with many attacks a day. There is a refractory period between each attack. Pain might then go into remission for weeks or months; pain-free intervals gradually shorten between episodes.
Diagnostic criteria: character
Electric shock-like, sharp, shooting.
Diagnostic criteria: severity
Very severe attacks, but attacks can get milder when patients are given drug treatment.
Diagnostic criteria: factors affecting pain
Can be provoked by light touch to the face, eating, cold winds, or vibrations.
Diagnostic criteria: associated factors
Associated factors: rarely associated with history of other chronic pain or migraine. Some forms have more continued aching background pain after main attack. Rarely associated with autonomic features
Triggers of pain
Vibration. Skin contact - eg, shaving, washing. Brushing teeth. Oral intake. Exposure to wind.
Red flags
Sensory changes, deafness or other ear problems.
Difficulty achieving pain control, poor response to carbamazepine.
History of any skin lesions or oral lesions that could lead to perineural spread.
Ophthalmic division only or bilateral as suggestive of benign or malignant lesions or multiple sclerosis.
Age of onset under 40 years.
Optic neuritis.
Family history of multiple sclerosis.
Investigations
MRI scan
What is MRI scan used to identify
Sinusitis.
Extracranial masses along the course of the trigeminal nerve.
Pathological enhancement of the trigeminal nerve that could indicate perineural spread of malignancy.
Cavernous sinus masses.
Demyelination plaques that might indicate multiple sclerosis.
Intrinsic brain lesions in the thalamus or trigeminal brain stem pathways such as lacunar infarctions.
Cerebellopontine angle mass lesions such as tumour, epidermoid, dermoid, or arachnoid cyst, aneurysm, or arteriovenous malformation.
Conservative management
Support and education
Referral if severe pain, pain significantly limits ADL
Atypical fatures (e.g. burning pain between paroxysms) are present
Medical management
CARBAMAZEPINE (1st line - anticonvulsant)
Once patients have been in remission for one month, the drug should be gradually withdrawn
Surgical management
Rhizotomy
Stereotactic radiosurgery (if severe pain or SEs from medication)
Microvascular decompression
Complications
Pain could be so intense that it can lead to a poor quality of life due to mental and physical incapacity
How long are each of the following headaches: Migraine Tension Cluster Trigeminal neuralgia
Migraine - 4-72 hours
Tension - min to days
Cluster - 15-180 min
Trigeminal neuralgia - seconds
Describe pain severity in each of following headaches: Migraine Tension Cluster Trigeminal neuralgia
Migraine - mild/moderate
Tension - mild/moderate
Cluster - severe/v severe
Trigeminal neuralgia - severe/very severe
Describe type of pain sensation in each of the following headaches: Migraine Tension Cluster Trigeminal neuralgia
Migraine - throbbing
Tension - pressing.tight
Cluster - boring/hot poker
Trigeminal neuralgia - electric/lightening/stabbing
Describe pain distribution in head for each of following headaches: Migraine Tension Cluster Trigeminal neuralgia
Migraine - Uni/bilateral
Tension - uni/Bilateral
Cluster - unilateral
Trigeminal neuralgia - unilateral
Which of the following headaches associate with photo or phonophobia: Migraine Tension Cluster Trigeminal neuralgia
Migraine - Photo and Phono
Tension - photo or phono
Cluster - both possible
Trigeminal neuralgia - neither
Which of the following headaches associates with nausea and vomiting Migraine Tension Cluster Trigeminal neuralgia
Migraine - nausea +/- vomiting
Tension - no
Cluster - maybe nausea (+/- vomiting)
Trigeminal neuralgia - no
In what patients should giant cell arteritis be suspected
In all >50 year olds with a headache that has lasted a few weeks
