[The optic and trigemino-facial reflexes in the diagnosis of multiple sclerosis]

The optic facial reflex (ofr) has been studied in a group of subjects affected by multiple sclerosis (ms) and compared with the trigemino-facial reflex (tfr) as well as clinical data. From the literature it appears that the afferent pathway of the ofr, after the optic chiasma crosses the midbrain tegmentum and from there goes directly to the pons. The ofr was impaired in 14 subjects out of 20 (70%), the tfr only in 7 (35%). This difference is attributed to the fact that the visual pathways are frequently affected by demyelinating processes. The ofr in contrast with the tfr, because of anatomophysiological differences, does not supply the exact localization of the damage. In our series of patients affected by ms the data from ofr reflected exactly the signs of optic nerve lesions. When these were not found, ofr abnormality was attributed to lesions located behind the chiasma or in the midbrain. A close correspondence between data supplied from the ofr and the diagnosis of ms according to Mc Alpine is emphasized: this makes the ofr a very useful diagnostic test of ms. The combined use of ofr and tfr, in addition to fulfilling the criteria of detecting multiple sites of demyelination, can be useful to investigate the brain stem.