[Electrophysiological studies on the prognosis in idiopathic facial paralysis]

The literature on electrophysiological techniques used so far for the prognostication of idiopathic facial palsies contains reports on 31 patients with idiopathic facial palsy, in whom - after electric stimulation of the nervus facialis at the point where it exits from the foramen stylomastoideum - the amplitude of the compound muscle action potential of the M. orbicularis oris was measured. The extent of the SPA's decline was related to the progress of the disease. In those cases where the SPA declined by at least 75-100 per cent, the palsy regressed either in an unsatisfactory manner or not at all. However, where the decline amounted to at most 67 per cent a restitutio ad integrum took place or residual symptoms which do not disturb the patients were found. The prognosis can be made between the 5th and 10th day after the palsy has developed. If in cases of idiopathic palsy the diagnosis is made at an early date, this method is more reliable than any other technique.