Serial nerve conduction studies in vitamin B12 deficiency-associated polyneuropathy.
This report is on a 22-year-old male vegetarian with acute polyneuropathy secondary to vitamin B(12) deficiency. He presented with weakness and numbness of the distal limbs and absent deep tendon reflex in all four extremities. Nerve conduction study (NCS) showed an axonal type sensori-motor polyneuropathy. Serum biochemical studies revealed vitamin B(12) level of 119 pg/mL (reference range 185-710 pg/mL), with elevated creatine kinase (CK) (719 U/L) and homocysteine (Hcy) (24.04 μmol/L) levels. Anti-parietal cell antibody test was positive. The patient received both oral and intramuscular injection of vitamin B(12). The amplitude of the median and ulnar motor NCS increased 2.5 months later, while muscle power of the ankle plantar flexion and dorsiflexion recovered after 3.5 and 5.5 months, respectively. Follow-up NCS after 14.5 months showed response in sural NCS, but not the peroneal NCS. Follow-up also showed decreased serum Hcy and CK to 9.6 μmol/L and 198 U/L, respectively, and increasing amplitude of response. Recovery sequence involved muscle power of the proximal muscles, hands, plantar flexion, and dorsiflexion of the feet, and followed by sensory conduction.
Huang
Chi-Ren
CR
Department of Neurology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, No. 123, Tai-Pei Rd, Niao-Song Township, Kaohsiung, 833, Taiwan.
Chang
Wen-Neng
WN
Tsai
Nai-Wen
NW
Lu
Cheng-Hsien
CH
D018450:Disease Progression; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009431:Neural Conduction / Q000502:physiology*; D009460:Neurologic Examination; D010525:Peripheral Nerves / Q000473:pathology / Q000503:physiopathology; D011115:Polyneuropathies / Q000209:etiology*; D014806:Vitamin B 12 Deficiency / Q000150:complications*; D055815:Young Adult