Trigeminal neuralgia. Current concepts regarding etiology and pathogenesis

Area of Science:

• Neurology
• Neuroscience
• Pain Research

Background:

• The etiology of trigeminal neuralgia (TN) remains debated, with clinical data suggesting peripheral causes and experimental data favoring central mechanisms.
• Effective TN treatments modulate neurotransmission in the trigeminal nucleus, impacting both excitatory and inhibitory pathways.

Purpose of the Study:

• To reconcile conflicting clinical and experimental data regarding the cause of trigeminal neuralgia.
• To propose a unifying hypothesis for the pathogenesis of trigeminal neuralgia.

Main Methods:

• Review and synthesis of existing clinical and experimental data on trigeminal neuralgia.
• Hypothesis formulation based on reconciling divergent findings.

Main Results:

• Clinical observations support a peripheral origin for trigeminal neuralgia.
• Experimental data indicate central mechanisms, specifically in the trigeminal nucleus, are involved.
• Effective drugs enhance inhibition and reduce excitation in the trigeminal nucleus.

Conclusions:

• Trigeminal neuralgia is proposed to have a peripheral cause with central pathogenesis.
• Chronic trigeminal nerve irritation leads to impaired segmental inhibition and ectopic action potentials.
• This combination results in abnormal neuronal discharges perceived as TN pain attacks.