Figure 1. Plasma Methionine according to the clinical severity of N2O consumption. Groups are based on the severity of their clinical symptoms (based on Peripheral Neuropathy Disability (PND) score: level 0: no symptoms; level 1: paresthesia or PND I; level 2: gait disorders or PND II; level 3: thrombosis or combined subacute degeneration of spinal cord or PND III or IV. p-value and rho were obtained by non-parametric Spearman rank test. Data are expressed as median ± IQR.

Figure 2. Plasma Methionine according to plasma Homocysteine. Groups are based on the severity of their clinical symptoms (based on Peripheral Neuropathy Disability (PND) score: level 0: no symptoms; level 1: paresthesia or PND I; level 2: gait disorders or PND II; level 3: thrombosis or combined subacute degeneration of spinal cord or PND III or IV. p-value and rho were obtained by non-parametric Spearman rank test.

Figure 3. Methionine to Homocysteine ratio according to clinical severity. Groups are based on the severity of their clinical symptoms (based on Peripheral Neuropathy Disability (PND) score: level 0: no symptoms; level 1: paresthesia or PND I; level 2: gait disorders or PND II; level 3: thrombosis or combined subacute degeneration of spinal cord or PND III or IV. p-value and rho were obtained by non-parametric Spearman rank test. Data are expressed as median ± IQR.

Table 1. Characteristics of patients according to clinical severity. Groups are based on the severity of their clinical symptoms based on Peripheral Neuropathy Disability (PND) score: level 0: no symptoms, level 1: patients with distal sensory disorders without gait disorders, level 2: patients with walking disorders, but they can walk without help, and level 3: patients with walking disorders who need help or bedridden patients. Data are expressed as mean ± SD.

Table 1. Characteristics of patients according to clinical severity. Groups are based on the severity of their clinical symptoms based on Peripheral Neuropathy Disability (PND) score: level 0: no symptoms, level 1: patients with distal sensory disorders without gait disorders, level 2: patients with walking disorders, but they can walk without help, and level 3: patients with walking disorders who need help or bedridden patients. Data are expressed as mean ± SD.