Recurrent painful ophthalmoplegic neuropathy (RPON) is a very rare disease characterized by recurrent attacks (at least two) of unilateral headache associated with ipsilateral ophthalmoplegia due to paresis of one or more cranial motor nerves, not due to any orbital, parasellar, or posterior fossa lesions. The differential diagnoses for this condition are broad. In addition to disability during an acute attack, this disease could also cause a permanent neurologic deficit. The understanding of RPON pathogenesis has changed over time, leading to a change in the classification of this disorder between editions of the International Classification of Headache Disorders, in which the condition was moved from the chapter on migraine to the chapter on cranial neuralgias and central causes of facial pain. There is no consensus on the pathogenesis of RPON. It is possible that multiple pathogenic mechanisms underlie various clinical forms of the disease. A depiction of pathologic analyses of patients with radiologically confirmed changes in the affected nerves during and outside of attacks would significantly contribute to knowledge of its pathogenesis. Brain imaging should be performed in each patient during an acute RPON attack and at a regular schedule between attacks. Further case reports and case series are required before further conclusions can be made regarding RPON pathogenesis and proposals for treatment options.
