Controversies in Trigeminal Neuralgia: A Review.

Trigeminal neuralgia (TN) is an area full of controversies. The anatomical distribution of various sensory fibers in the sensory root of the trigeminal nerve at the root entry zone (REZ), the classification of TN, clinical features to differentiate from other facial pain syndromes, pathogenesis of TN, the plethora of treatment modalities for the medically intractable TN with their relative merits and demerits, are an interesting area of study. Understanding these aspects will help us to find concrete answers to these various issues. Dandy's concept of accessory fascicles near the trigeminal REZ, which carry the touch and proprioceptive fibers, paved the way for partial sensory rhizotomy by posterior fossa approach. Similarly, Jannetta's concept of microvascular compression at the REZ paved the way for the popular microvascular decompression surgery. The search for less risky, less invasive procedures has paved the way for the various percutaneous procedures and radiosurgery for intractable TN. But all the procedures have their share of complications and recurrence rates. Still, despite several theories and concepts, the exact pathogenesis of TN remains unclear. More research is needed to find the exact pathogenesis of TN and also a minimally invasive procedure without any recurrence of pain for medically intractable TN.