struvite and Paraplegia

Renal stone disease is a common problem in patients with spinal cord injury. The factors responsible are thought to include hypercalciuria and chronic urinary infection. There have, however, been no comparative studies of urinary composition in patients with neuropathic bladder with and without renal stone disease. Blood, 24-h urine samples and circadian variation of urinary composition were studied in male paraplegic patients with renal stone disease accompanied by urinary infection and in similar patients without stone disease with and without urinary infection. Two categories of stone patients were recognised, according to whether or not urinary oversaturation with magnesium ammonium phosphate occurred. The urine of all stone patients was oversaturated with calcium phosphate for part of each day. Urinary calcium was elevated in 16% and plasma urate in 30% of the paraplegics studied.

Topics: Adolescent; Adult; Aged; Calcium; Circadian Rhythm; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Paraplegia; Phosphates; Struvite; Urinary Tract Infections

Chronic urinary infection is thought to be a major factor in the causation of urinary calculi in paraplegic patients. Acetohydroxamic acid is reported to be effective in some patients for the management of this type of stone disease, but there have been no studies of urinary saturation levels during therapy with this drug. In this study 10 patients received oral acetohydroxamic acid for seven days. Marked lowering of urinary pH and ammonium levels were observed, but decreases in urinary saturation were small. The administration of acetohydroxamic acid resulted in increased urinary excretion of magnesium and phosphate, effects that have not previously been reported.

Topics: Adult; Calcium Phosphates; Humans; Hydrogen-Ion Concentration; Hydroxamic Acids; Magnesium; Magnesium Compounds; Male; Middle Aged; Paraplegia; Phosphates; Struvite; Urinary Calculi; Urinary Tract Infections

The composition of the stone was determined in 24 paraplegic patients from whom 26 stones were surgically removed. Twenty-five of the 26 stones consisted of 90 per cent magnesium ammonium phosphate and 10 per cent carbonate apatite. The remaining single stone was composed of 90 per cent calcium oxalate and 10 per cent magnesium ammonium phosphate. Renal function improved significantly with the removal of the stones.

Topics: Adult; Aged; Humans; Magnesium; Magnesium Compounds; Male; Middle Aged; Paraplegia; Phosphates; Spinal Cord Injuries; Struvite; Urinary Calculi; Urinary Tract Infections