There is also a variant of trigeminal neuralgia called atypical trigeminal neuralgia. This variant is also called "trigeminal neuralgia, type 2",based on a recent classification of facial pain. In some cases of atypical trigeminal neuralgia the sufferer experiences a severe, relentless underlying pain similar to a migraine in addition to the stabbing shock-like pains.
Several theories exist to explain the possible causes of this pain syndrome. It was once believed that the nerve was compressed in the opening from the inside to the outside of the skull; but newer leading research indicates that it is an enlarged blood vessel - possibly the superior cerebellar artery - compressing or throbbing against the microvasculature of the trigeminal nerve near its connection with the pons. Such a compression can injure the nerve's protective myelin sheath and cause erratic and hyperactive functioning of the nerve. This can lead to pain attacks at the slightest stimulation of any area served by the nerve as well as hinder the nerve's ability to shut off the pain signals after the stimulation ends.
Anticonvulsants are a common treatment strategy for trigeminal neuralgia. Carbamazepine is the first line drug; second line drugs include baclofen, lamotrigine, oxcarbazepine, phenytoin, gabapentin, and sodium valproate. Uncontrolled trials have suggested that clonazepam and lidocaine may be effective.Low doses of some antidepressants such as amitriptyline are thought to be effective in treating neuropathic pain.