Urinary 3-methoxy-4-hydroxyphenylglycol sulfate excretion in seventy-three schoolchildren with minimal brain dysfunction syndrome.

Although many authors have studied the urinary excretion of 3-methoxy-4-hydroxyphenylglycol (MHPG) of minimal brain dysfunction (MBD) children to explore a possible mechanism for this disorder, the mechanism remains unclear. The present study extends the determinations of urinary MHPG X SO4 in MBD schoolchildren to a larger sample to determine whether or not the function of central norepinephrine (NE) of MBD children is normal. 24-hr urinary excretion of MHPG X SO4 was determined in 73 schoolchildren with MBD and 57 normal controls. MGPG X SO4 level was significantly lower in the MBD children than in the control group. 38 of these children received an open trial of methylphenidate and the urine specimen was examined blindly. The children with marked improvement showed significant decrease in urinary MHPD X SO4 while the nonresponders showed no change, but rather a slight increase. This was also demonstrated in a second drug trial in which eight MBD children received Chinese herbal medicine. The authors compare the clinical data with the biochemical findings and point out that the MBD children developed hypoactivity of central NE, especially those with positive genetic factors in their family history.