The pain in optic neuritis: A manifestation of visceralis hyperalgesia [Il dolore nelle neuriti ottiche: una manifestazione di iperalgesia viscerale]

In both retrobulbar and intrabulbar neuropathies a painful symptomatology may occur before or simultaneously to the diminution of visual acuity. The anatomical relationship between extraocular muscles and the optic nerve sheath at the orbital apex could help explain the mechanism involved in the manifestations of pain. We studied 52 patients suffering from optic neuritis. A painful symptomatology of varying types, was present in one patient out of the 5 cases with intrabulbar optic neuritis and in 28 out of the 47 patients with retrobulbar optic neuritis (59.57%). Because of the way in which it is manifested and the type of receptors that are stimulated pain in optic neuritis is considered visceral cluster and migraine headaches are among the best known visceral pains. According to Sicuteri, in these patients, the system of modulation - inhibition of pain is impaired and visceral hyperalgesia occurs. Such a condition may be revealed clinically by means of simple test of ischemia and stasis of the upper limb. We studied 28 cases out of all our patients in order to detect the presence of visceral hyperalgesia. We tested the statistical significance for the association between pain and positivity for Sicuteri test. Results were statistically significant (χ2 test = 5.103, p = 0.024). The significant association between optic neuritis and hyperalgesia suggest that pain in optic neuritis occurs when the nociceptive system is impaired.