Monday, December 20, 2010

A note on Dialysis Dementia

Dialysis dementia occurs in patients on chronic hemodialysis. It has been said due to toxicity from aluminum in the dialysis bath. The incidence of the disease has decreased with the use of aluminum-free water.

Symptoms are dysarthria, apraxia, slurred speech, stuttering and hesitation. Later myoclonus, asterixis, seizures, personality changes and frank psychosis are reported with frequent suicide. Disease has variable course. Within few months, the disease may even progress to apneic spells. In some patients, however, the disease is transient. Drug-resistant seizures are said to be part of it but it is mostly due to removal of pyridoxine during hemodialysis.

Treatment is to stop aluminum-containing phosphate binders. Aluminum chelation with deferoxamine lead to dramatic improvement. Control of secondary hypoparathyroidism, iron deficiency anemia, and hyperphosphatemia reduces aluminum absorption by the gastrointestinal tract. The concentration of aluminum in the dialysate should be monitored too. Pyridoxine supplementation must be given. Benzodiazepines are effective in controlling the myoclonus. Phenytoin is used for tonic-clonic seizures because relatively little is removed by hemodialysis.