To explore the protective effect of magnesium sulfate on the nerve injury in severe hand, foot and mouth disease (HFMD) caused by enterovirus A71 (EV-A71) and to investigate its clinical and prognostic effects.

A total of 240 cases of severe HFMD with EV-A71 infection and nerve injury were enrolled. According to the random number table method, the patients were randomly divided into conventional treatment group (control group) and magnesium sulfate treatment group (treatment group), with 120 cases in each group. The control group was given the routine treatment, and the treatment group was given the magnesium sulfate adjuvant treatment on the basis of routine treatment. The neurological symptoms and signs, clinical efficacy and prognosis were observed before and after treatment in the two groups. The blood and cerebrospinal fluid neuron-specific enolase (NSE), S100-β protein and neuropeptide Y(NPY) were analyzed before and after treatment. The amplitude integrated electroencephalogram (aEEG) was used to monitor the abnormal recovery of EEG. The t-test was applied to analyze quantitative data, and the chi-square test was used for qualitative data comparison.

Among children with severe HFMD, there were 83 cured cases, 29 improved cases and 8 ineffective cases in control group, with the total effective rate of 93.3%; while in the treatment group, 101 cases were cured, 18 cases were improved and 1 case was ineffective, the total effective rate was 99.2%. The therapeutic effects (Z=2.918, P=0.004) and the total effective rate (χ²=4.156, P=0.041) were statistically significantly different between the two groups. Three days after treatment, the average levels of serum NSE, S100-β protein and NPY in magnesium sulfate treatment group were significantly lower than those in control group (t=-7.239, -10.020 and -11.053, respectively, all P<0.01). Five days after treatment, the average levels of cerebrospinal fluid NSE, S100-β protein and NPY in magnesium sulfate treatment group were significantly lower than those in control group (t=-6.546, -13.308 and -10.258, respectively , all P< 0.01). After treatment, the neurological function score in treatment group was significantly lower than that in control group and that before treatment, and the differences were statistically significant (t=-9.473 and 12.162, respectively, both P<0.01). The recovery time of the main symptoms and signs in treatment group was (2.33±0.76) d, which was significantly shorter than that of control group ([3.21±0.82] d), the difference was statistically significant (t=-12.52, P<0.05). The average length of hospital stay in treatment group was (5.79±1.42) d, which was shorter than that in control group ([6.71±1.46] d), and the difference was statistically significant (t=-4.932, P<0.05). Of the 240 children with severe HFMD, 194 (80.8%) patients had abnormal aEEG. Before treatment, the aEEG abnormal rates in control group and the magnesium sulfate treatment group were 79.2% (95 cases) and 82.5% (99 cases), respectively, there was no significant difference (χ²=0.430, P>0.05); while after treatment for 3 days, 76 cases in treatment group returned to normal, and the recovery rate of aEEG was 76.8%, which was higher than that in control group (52.6%). The difference was statistically significant (χ²=12.406, P<0.05).

Magnesium sulfate adjuvant therapy can reduce the abnormal levels of NSE, S100-β and NPY in blood and cerebrospinal fluid, relieve clinical symptoms, shorten the course of disease and average length of hospital stay, improve the neurological function score, and promote the recovery of abnormal aEEG. Thus, it has neuroprotective effect on severe HFMD with nervous system lesion.

Hand, foot and mouth disease; Magnesium Sulfate; Neuroprotection