Dr. Rahul Chakor Neurologist
Special Interest in Neuroimmunology, Epilepsy

Persistent idiopathic facial pain (PIFP)

This condition was earlier termed as atypical facial pain. The IHS defines it as "a persistent facial pain that is present daily and persists for all or most of the day and does not have the characteristics of cranial neuralgias".

Symptoms

The pain is localized to one side of the face, is deep in location and poorly localized to a nerve distribution. Commonly patients point to the cheek, maxilla, nasolabial fold, jaw or neck. The pain is quite severe in intensity and waxes and wanes. It is unilateral but may become bilateral over years. It may be initiated by minor injury, surgery, dental procedure. It persists long after the initial event. The examination is normal.

The diagnosis of PIFP is by exclusion of all local and other neurological causes of pain. Facial pain can be referred from a lung cancer with vagal involvement. Local tumors and metastases have to be carefully excluded by appropriate investigations.

Etiology

The etiology and pathophysiology of PIFP is not well understood. There may be central as well as a peripheral component. A peripheral nerve injury may result in long term neuroplastic changes leading to sensitization of trigeminal pain system.

This condition was earlier attributed to as a psychogenic disorder but definite neurobiological changes corresponding to the patient’s pain have been recently demonstrated.

Differential diagnosis

This is similar to TN.

Medical Treatment

This could be difficult and unsatisfactory. Tricyclic antidepressants have modest efficacy as have selective serotonin reuptake inhibitors and serotonin-noradrenalin reuptake inhibitors.

Transcutaneous nerve stimulation has been tried with variable success.