Chronic and remitting painful diabetic polyneuropathy. Correlations with clinical features and subsequent changes in neurophysiology.

Twenty-nine diabetic patients (19 men, 10 women) aged 19-71 yr with newly developed painful polyneuropathy were studied prospectively for 12-18 mo. Pain remitted completely in 16 patients within 12 mo, but continued in the other 13 patients. At presentation, no differences were found in the type or prevalence of symptoms or neurophysiological measurements (electrophysiology and cardiovascular autonomic function tests) between the patients whose pain remitted and those whose pain continued. Most electrophysiological measurements improved slightly in remitting patients but deteriorated slightly in those whose pain continued to reveal a significant difference (P less than .05) between the groups on final review. Similarly, abnormal autonomic nerve function improved slightly when pain remitted but worsened or persisted in patients whose pain continued, again revealing a significant difference between the groups (P less than .05) on final review. We also observed that pain remission usually occurred if the onset of symptoms shortly followed some sudden metabolic change (e.g., rapid improvement in glycemic control, ketoacidosis, anorexia nervosa) when the duration of diabetes was relatively short or when considerable weight loss preceded the onset of pain. We suggest that remitting and chronic painful diabetic polyneuropathy have distinctive clinical features at presentation and detectable neurophysiological differences during their symptomatic evolution.