Functional capacity after peripheral nerve lesion: significance of pain syndromes

Abstract

The loss of functional capacity by peripheral nerve lesion is easy to be estimated: A certain neurologic dysfunction results in a characteristic reduction of the former individual capacity. In contrast, the effect of accompanying pain to every-day life and working ability is not known exactly. In this study, we compared the results of judgement in nerve lesions under the circumstances of additional pain syndromes. From January 1994 until December 1998 we saw 57 patients with peripheral nerve lesions, part of them with an additional pain syndrome. Beside conventional neurological examination a detailed pain analysis has been done. Lesions of the median or ulnar nerves showed regularly disturbances in neurological functions (10/14 for the median nerve, 13/16 for the ulnar nerve). Astonishing is the fact, that serious pain after nerve lesion only occurs in cases of partial nerve lesion. We saw neuralgias in 6 patients with ulnar neuropathy, in three cases of median nerve lesions we could see severe neuralgia (causalgia we found in 3 cases of ulnar neuropathy, in 6 cases after Median Nerve lesion). Patients with a lesion of the central plexus brachialis showed in 10 of 11 cases an additional pain syndrome. Other nerves have been affected more rarely. For the judgement of the loss of earning capacity we saw an additional pain related diminuition of at least 10% compared to those patients without pain problems. The common grading scales for peripheral nerve lesions are not suitable in cases accompanied by an additional pain syndrome. Beside a functional deficit the effect of severe pain in these patients has to be estimated. On an average, patients with additional pain-problems get a 10% extended loss of earning capacity, even more in particular cases.