Аннотация:Background and aimsLewis-Sumner syndrome (LSS) is an atypical form of chronic inflammatory demyelinating polyneuropathy (CIDP) with clinical phenotype of asymmetric motor and sensory disturbances with initial involvement and more prominent presentation in the arms. However, some of these patients may have lower-limb onset, making the diagnosis more challenging. The aim of our study was to estimate the prevalence of lower-limb onset patients with LSS and define their clinical features.MethodsWe collected data from 32 medical charts of patients with LSS. All the patients satisfied at least “probable” criteria EFNS/PNS, 2010.ResultsWe evaluated that 15/32 (46%) of the patients presented with lower-limb onset. 4/32 (12%) had only lower-limbs involvement at the time of diagnosis. All of them had an asymmetrical deficit. The mean time of the diagnosis in patients with symptoms only in the lower limbs was 10[3;12] vs 3[1;11] years (p < 0.05). Nerve conduction study (NCS) of the lower limbs was lacking demyelinating features and interpreted as primary axonal in all patients. Only additional investigation of the upper extremities led to the diagnosis. Complementary investigation with nerve ultrasound revealed changes only in the upper extremities.ConclusionsWe demonstrated the high prevalence of LSS with lower-limb onset. Noteworthy, that some of the patients may have isolated clinical distribution in the lower limbs. This should raise the suspicion of LSS and highlight the importance of complex NCS of the upper and lower extremities in all patients with asymmetric neuropathy. We also found that nerve ultrasound of the lower extremities in LSS has limited significance.