[Polyneuropathies in old age].

70 patients were examined in a prospective study to clarify causes of polyneuropathies becoming manifest beyond the age of 60. 29 patients (41.4%) had mixed symmetrical sensorimotor polyneuropathy and 21 (30%) symmetrical sensory polyneuropathy. Peripheral neurological deficits were asymmetrically distributed in 20 patients (28.6%). Polyneuropathy was monocausal in 31 patients (44.3%), whereas a variety of pathogenetic factors was found in 29 patients (41.4%). Aetiology remained undetermined in 10 patients (14.3%). The causes of polyneuropathies differ markedly in elderly patients from those found in studies not restricted to specific age groups. Insufficient gastrointestinal absorption, in particular, appears to be a prominent pathogenetic factor, more often than even diabetes mellitus (n = 39, corresponding to 55.7%). However, diabetes was the underlying pathogenetic factor in 90% of patients with asymmetrically distributed polyneuropathies. In spite of this, multifactorial pathogenesis in the elderly would require a search for causes other than diabetes even in asymmetrically distributed polyneuropathies.