Acute neurological presentation due to copper deficiency in a hemodialysis patient following gastric bypass surgery.

Acquired copper deficiency has been recently recognized as a cause of myelopathy, and has been reported to occur many years after gastric bypass surgery performed to aid weight reduction in morbidly obese patients. We report a case of a young woman treated by hemodialysis who presented with acute neurological symptoms 5 months after gastric bypass surgery for severe obesity. She had symptoms and signs of cerebellar, spinal cord and peripheral nerve disease, which improved following parenteral copper supplementation. Now that gastric bypass surgery is being offered to morbidly obese hemodialysis patients, this case highlights the importance of monitoring copper levels in hemodialysis patients following gastric bypass surgery.

Renal tubular acidosis.

Renal tubular acidosis (RTA) is a form of metabolic acidosis due to abnormal alkali (bicarbonate) loss by the kidneys or their failure to excrete net acid. While the latter does occur in chronic renal failure, the term RTA is usually applied only when the glomerular filtration rate is normal or near normal. As well as a cause of metabolic acidosis, RTA often presents as renal stone disease with nephrocalcinosis, rickets/osteomalacia, and growth retardation in children. In this brief review, we have summarized the classification, clinical features and the underlying cell and molecular pathophysiology of RTA. However, despite significant advances in our understanding of the mechanisms of RTA, its treatment is still empirical and based largely on alkali replacement therapy; but its wider significance in renal stone and bone disease is becoming increasingly recognized.