Unravelling the role of unmyelinated nerve fibres in trigeminal neuralgia with concomitant continuous pain

•Disease duration does not differ between patients with purely paroxysmal pain and with concomitant continuous pain.•Concomitant continuous pain in trigeminal neuralgia is associated with C fibre-related laser evoked potentials attenuation.•Unmyelinated fibre loss may trigger abnormal activity in denervated trigeminal second-order neurons.