CN V Pathology
Trauma which results in skull fracture, tumors and facial surgery may all result in disturbance of peripheral branches of the sensory component of CN V. This presents as a decrease in sensation to the area served by the peripheral nerve.
Trigeminal neuralgia (tic doloureux) results in pain in the lips, gums, cheek or chin without sensory loss. It is generally idiopathic but may be caused by demyelinative plaque, zoster, or tumor.
Trigeminal neuropathy (lesions of the motor branch of CN V) is caused by tumors of middle cranial fossa, schwannomas of CN V or lesions in cavernous sinus. This leads to asymmetry of jaw on opening or weakness with mastication.