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.
