[Idiopathic polyneuritis. Course, prognosis and electrodiagnostic findings].

In acute idiopathic polyneuritis, the slowing of nerve conduction velocity does not allow prognostical statements. However, a marked reduction of muscle potential amplitude after stimulation and recording points implies a large number of damaged axons. This effect occurs earlier and is more reliable than pathological spontaneous activity in the EMG. Following complete or almost complete loss of indirect muscle excitability, improvement of function can be expected only after sprouting of nerve fibers--therefore after some months at best; permanent defects must bei anticipated especially in distal muscle groups. We experienced this most commonly--but not exclusively--in cases with highly acute courses which led to tetraparalytic syndroms. Clinical courses with slowly progressive disease during months and recurrent courses of idiopathic polyneuritis can also lead to permanent paresis.