Isolated cranial nerve palsies in multiple sclerosis

During a 10 year period 24 patients with definite multiplesclerosis with isolated cranial nerve palsies were studied (third andfourth nerve: one patient each, sixth nerve: 12 patients, seventhnerve: three patients, eighth nerve: seven patients), in whom cranialnerve palsies were the presenting sign in 14 and the only clinical signof an exacerbation in 10 patients. MRI was carried out in 20 patientsand substantiated corresponding brainstem lesions in seven patients(third nerve: one patient, sixth nerve: four patients, eighth nerve:two patients). Additional abnormal findings of electro-oculography, ormasseter reflex, or blink reflex, or combinations of these were foundin 20 patients and interpreted in favour of a brainstem lesion at thelevel of the respective cranial nerve. In 11 of 14 patients withisolated cranial nerve palsies as the presenting sign of multiplesclerosis, dissemination in space was documented by MRI, and in theremaining three by evoked potentials. In patients with multiplesclerosis with isolated cranial nerve palsies, MRI is the mostsensitive method of documenting dissemination in space andelectrophysiological testing the most sensitive at disclosing brainstem lesions.