Chronic inflammatory demyelinating polyneuropathy in an adolescent with type 1 diabetes mellitus

Abstract

tromyography, 4 channels), evidenced decreased conduction velocities with normal amplitude in the median, ulnar, left fibular and posterior tibial nerves, except in the deep right fibular nerve, where although the amplitude was 75% of the lower limit of the normal range (LLNR), the conduction study was 80% lower than LLNR. The distal motor latencies of the median, left ulnar, superficial fibular and sural nerves were prolonged (above 120% of the normal range). The F waves presented prolonged latencies in the ulnar and posterior tibial nerves. The examination with monopolar needle showed decrease in the recruitment of action potentials of the motor unit. The patient was initially treated with human immunoglobulin (400 mg/Kg/day, IV, 5 days), improving the sensory symptoms for about a month, with subsequent relapse, in smaller intensity. There was not improvement of the lower limb weakness. A second EMG, performed 2 months after therapy with immunoglobulin, evidenced increment in the amplitude of the sensory and motor action potential, and decrease of the distal motor latencies, with persistence of the conduction velocities though. The examination showed F waves with prolonged latency in the left ulnar and posterior tibial nerves, with normal latency in the left ulnar nerve. The examination with monopolar needle showed normal recruitment.