This can be very confusing..........Atypical TN has a constant and severe aching, boring or burning pain that is superimposed upon otherwise typical TN symptoms. Atypical TN is characterized by a unilateral, prominent constant and severe aching, boring or burning pain superimposed upon otherwise typical TN symptoms. This should be differentiated from cases of typical TN that develop a minor aching or burning pain within the affected distribution of the trigeminal nerve.

Vascular compression, as described above in typical TN, is thought to be the cause of many cases of atypical TN. Some believe atypical TN is due to vascular compression upon a specific part of the trigeminal nerve (the portio minor), while others theorize that atypical TN represents a more severe form or progression of typical TN.

Atypical TN pain can be at least partially relieved with medications used for typical TN, such as carbamazepine (Tegretol®). MVD surgery is curative for many patients with atypical TN, but not as reliably as for those with typical TN. It is also important to note that rhizotomy procedures may be effective in treating atypical TN, but are more likely to be complicated by annoying or even painful numbness (i.e. deafferentation pain).