Trigeminal Neuralgia

none2noTrigeminal Neuralgia (TN) is the most common cranio-facial pain syndrome, with an incidence of up to 5 in 100,000. Long-term medical treatment is commonly required, with up to 10% of cases suffering adverse drug-related events. In 1951, Lars Leksell pioneered the application of stereotactic irradiation for the treatment of TN, which may now achieve up to 90% pain control at 1 year and 60% at 2 years. Pain control can remain excellent in 26% of treated patients at 10 years. Radiosurgical treatment targets either the nerve’s emergence (the root entry zone) or the retrogasserian portion of the nerve. Use of the former has a greater likelihood for long-term pain control, but may lead to higher doses to the brainstem. Targeting the latter may reduce the risk of complications, but requires a higher maximum dose to obtain optimal results. Generally speaking, radiosurgical treatment achieves better results in patients receiving high doses of radiations ranging from 70 to 90 Gy. It is also recommended that the length of nerve treated is between 4 and 6 mm. Hypoesthesia and facial numbness are frequently observed after high-dose trigeminal irradiation. Mild hypoesthesia is acceptable and is considered by many an efficacy endpoint of the procedure. Bothersome facial numbness is relatively rare. Sensitive trigeminal disturbances and paresthesia after treatment have been reported to range 6%–54% and 0%–17%, respectively. The prescribed dose and brainstem-delivered dose are correlated with the subsequent rate of sensitive trigeminal disturbances. CyberKnife frameless non-isocentric radiosurgery is an emerging and thoroughly non-invasive treatment for TN that can potentially deliver homogeneous irradiation to an extended length of the trigeminal nerve. This feature makes CyberKnife radiosurgery essentially different from isocenter-based Gamma Knife treatment. By contrast, targeting an extended segment of the trigeminal nerve with Gamma Knife requires placement of a second isocenter and generates hot and cold spots along the nerve. Thus, CyberKnife can administer variable doses to discreet lengths of nerve in order to improve pain control and reduce complication rates. Currently, clinical results reported in the literature are comparable to those offered by the Gamma Knife.mixedSteven D. Chang Anand Veeravagu; Alfredo Conti; Pantaleo RomanelliSteven D. Chang Anand Veeravagu; Alfredo Conti; Pantaleo Romanell