[Objective] To examine and compare the effects of 2 and 10 audio stimulation frequencies with a stimulation interval of 500 ms for rhythmic exercise (foot stepping). [Methods] The subjects were 10 healthy volunteers (6 men and 4 women; mean age, 27.2±5.9 years). The absolute error and coefficient of variation related to the foot stepping interval with respect to before and after stimulation presentation, and before and after 2 and 10 audio stimulation frequencies were determined. [Results] The absolute error was significantly smaller after 2 and 10 audio stimulation frequencies (p<0.05). The coefficients of variation were not significantly different after 2 and 10 audio stimulation frequencies (p<0.05). The absolute error and coefficients of variation were not significantly different between before and after 2 and 10 audio stimulation frequencies. [Conclusion] Application of auditory stimulus may improve the accuracy of foot stepping at an interval of 500 ms.
Baba’s diabetic neuropathy classification was recommended for the evaluation of diabetic polyneuropathy (DPN) in 2013. Because it was mainly studied in type 2 diabetes mellitus (DM), we examined whether it would be compatible with type 1 DM. Thirty-eight patients with type 1 DM were enrolled (mean age 59.6 years old) and were compared with forty-two patients with type 2 DM (mean age 63.8 years old), Nerve conduction studies included the tibial and sural nerves. In results, all the patients with type 2 DM were applicable to Baba’s criteria. However, seven patients with type 1 DM (19%) were not. They showed abnormally small amplitude of sensory nerve action potentials of the sural nerve, while its conduction velocity and minimum F wave latency of the tibial nerve were normal. Compound muscle action potential of the tibial nerve was normal as well. These results suggest that in about 20% of patients with type1 DM the different mechanism or time course contribute to the pathophysiology between type 1 and type 2 DM, leading to sensory-dominant axonal polyneuropathy without affecting the factor of velocity.
We encountered a 75-year-old man suspected of having acute motor and sensory axonal neuropathy that developed several days after a bee sting. He complained of muscle weakness that had progressed after he’d been stung in 50 different places by bees. After anaphylactic shock and rhabdomyolysis developed, he was managed in the intensive-care unit (ICU), but no sedation was used. He returned to the general ward from the ICU on the sixth hospital day, and rehabilitation was started. Nevertheless, his muscle weakness progressed; he could no longer reach his mouth with his upper limbs and needed walking assistance. We performed nerve conduction studies on the 19th hospital day. In addition to a reduced amplitude of compound muscle action potential (CMAPs) and sensory nerve action potential (SNAPs), decreased conduction velocity and prolongation of F-wave latency were found. A cerebrospinal fluid examination revealed slight protein elevation. While antiGM1-IgG and antiGQ1b-IgG antibodies were negative, we considered the possibility of autoimmune neuropathy, and intravenous immunoglobulin therapy was administered on hospital days 29–33. His activities of daily living gradually improved, along with recovery of his muscle strength. He was able to walk alone on the 58th hospital day and returned home able to go up and down stairs. We repeated our nerve conduction studies, and reduced CMAP and SNAP amplitudes were noted, with a marked left-right difference. The diagnosis of axonal type of Guillain-Barré syndrome (acute motor and sensory axonal neuropathy: AMSAN) was ultimately made. The latent period from bee sting to the onset of neuropathy has been reported to be 3 to 10 days in such cases.