Two cases of medically and surgically intractable SUNCT: a reason for caution and an argument for a central mechanism.

We report two cases of SUNCT that demonstrate the medically and surgically refractory nature of this disorder and support the hypothesis that the causative 'lesion' lies within the central nervous system. After both patients had failed medical therapies, the first underwent a glycerol rhizotomy, gammaknife radiosurgery and microvascular decompression of the trigeminal nerve. The second patient underwent gammaknife radiosurgery of the trigeminal root exit zone and two microvascular decompression surgeries. Neither patient benefited from these procedures. Currently, the first patient suffers from anaesthesia dolorosa and the second patient from unilateral deafness, chronic vertigo and dysequilibrium as a result of surgical trauma. These cases of SUNCT highlight the uncertainty regarding the role of surgery given the potential for significant morbidity. These cases also suggest that SUNCT originates and may be maintained from within the CNS and this central locus explains why SUNCT is not typically amenable to interventions aimed at the peripheral portion of the trigeminal nerve.