Symptoms of Trigeminal Neuralgia
Trigeminal neuralgia presents with sudden, unilateral, severe, brief stabbing paroxysmal pain in one or more branches of the trigeminal nerve, characterized by electric shock-like attacks lasting seconds to minutes with mandatory pain-free refractory periods between attacks. 1, 2
Classic Pain Characteristics
The pain has several defining features that distinguish it from other facial pain syndromes:
- Pain quality: Electric shock-like, lancinating, stabbing sensations—not continuous burning or aching 1, 2, 3
- Duration: Individual attacks last seconds to minutes, not hours 4, 2
- Pattern: Paroxysmal episodes with mandatory refractory periods (pain-free intervals) between attacks—patients cannot trigger attacks repeatedly without these intervals 4, 2
- Location: Most commonly affects the V2 (maxillary) and V3 (mandibular) branches, less commonly V1 (ophthalmic) 2
- Laterality: Strictly unilateral 1, 2, 3
Trigger Zones and Precipitating Factors
A hallmark feature is the presence of trigger zones and innocuous stimuli that provoke attacks:
- Trigger zones: Small areas where minimal stimulation precipitates painful flare-ups 3, 5
- Common triggers: Talking, chewing, brushing teeth, shaving, light touch, cold air, or even a breeze across the face 3, 6, 7
- Trigger mechanism: These seemingly benign stimuli can provoke the characteristic electric shock-like pain 6
Physical Examination Findings
In classical trigeminal neuralgia, the neurological examination is typically completely normal between painful episodes. 2, 6
Key examination points include:
- Sensory testing: No sensory deficits in the trigeminal distribution in classical TN—the presence of sensory loss suggests secondary causes requiring urgent imaging 4, 2
- Motor function: No motor weakness in muscles of mastication—weakness is rare and suggests a secondary cause 2
- No visible inflammation: Trigeminal neuralgia does not cause visible swelling or inflammation, as it is primarily a pain syndrome without autonomic features in its classical form 4
- Trigger point identification: Gentle palpation of perioral and nasal regions may identify specific trigger zones 2
Type 2 (Atypical) Presentation
Some patients present with a variant form:
- Continuous background pain: Type 2 trigeminal neuralgia presents with prolonged continuous pain between the characteristic sharp shooting attacks 4
- Central mechanism: This variant may originate from more central mechanisms rather than peripheral neurovascular compression 4
- Imaging indication: The presence of continuous pain should prompt MRI evaluation to rule out secondary causes including multiple sclerosis, tumors, or other structural lesions 4
Associated Features During Attacks
- Facial spasms: May occur during intense flare-ups (tic douloureux) 3
- No autonomic symptoms: Classical trigeminal neuralgia does not include tearing, eye redness, rhinorrhea, or nasal congestion—these features suggest trigeminal autonomic cephalgias (SUNCT/SUNA) instead 1, 4, 2
Red Flags Requiring Alternative Diagnosis
Certain features should prompt consideration of other conditions:
- Continuous pain without refractory periods: Suggests post-herpetic neuralgia, atypical odontalgia, or persistent idiopathic facial pain 1, 4
- Autonomic features (tearing, conjunctival injection, rhinorrhea): Indicates SUNCT/SUNA, not true trigeminal neuralgia 4, 2
- Bilateral pain: Trigeminal neuralgia is strictly unilateral 1, 2
- Sensory deficits: Require urgent imaging to exclude secondary causes 4, 2
- Age over 50 with temporal pain: Consider giant cell arteritis to prevent blindness 1, 2