Lewis-Sumner syndrome: analysis of atypical onset with primary asymmetric lesions of lower limb nerves

Lewis-Sumner syndrome is the most common atypical form of chronic inflammatory demyelinating polyneuropathy (CIDP). In most patients, the disease is slowly progressive, which slows down the correct diagnosis. Timely diagnosis in some cases is also complicated by an abnormal primary lesion of the lower limb nerves in patients with Lewis-Sumner syndrome, for whom the typical clinical picture is upper flaccid distal paraparesis. The objective of the study is to determine the frequency of Lewis-Sumner syndrome (LSS), with the lower limb nerve onset; to characterize clinical and paraclinical characteristics of patients with the syndrome. Materials and Methods. The authors analyzed clinical data, results of stimulation electroneuromyography and ultrasound examination of peripheral nerves of 36 LSS patients. Results. The authors observed a high percentage (44 %) of LSS patients with lower limb nerve onset. However, changes in the neurophysiological and sonographic examination of the lower limb nerves, specific for CIDP, were not revealed. Changes typical of dysimmune neuropathy were verified only in the study of clinically intact long upper limb nerves. Conclusion. In asymmetric neuropathy of the lower limbs of idiopathic genesis, one should remember about LSS and, even despite the presence of symptoms only in the lower limbs, examine the peripheral nerves of the upper limbs.