Diagnosis

Aluminum encephalopathy syndrome is a progressive encephalopathy of infants and children with chronic renal insufficiency who have taken aluminum-containing products such as phosphate binders for several years.3,16-18 Adults occasionally are also affected. Patients have elevated brain aluminum concentration.17,19 Aluminum absorption is increased in renal insufficiency by secondary hypoparathyroidism, and aluminum excretion is reduced.3 The aluminum is stored in bones and other tissues.17

Aluminum encephalopathy occasionally is seen in patients with normal renal function receiving large amounts of aluminum, such as aluminum bladder irrigation.20,21 There is speculation that aluminum intoxication may play a role in Alzheimer’s disease, based upon morphologic and immunologic similarities of the two conditions.22

The clinical features of aluminum encephalopathy are:3

  • motor disturbances (dysmetria, tremor, hypotonia, myoclonus)
  • seizures (usually tonic-clonic, may be simple or complex partial)23
  • speech disturbances
  • vegetative state (ultimately)

The EEG has a characteristic pattern of a slow background with superimposed bursts of high-amplitude slow waves, sharp waves, and complexes of spikes and slow waves.6,23

Imaging studies show cortical atrophy.

The diagnosis of aluminum encephalopathy syndrome is suggested by the presence of typical symptoms in a child with chronic renal disease who has been taking aluminum-containing products.3 The diagnosis is confirmed by elevated plasma and bone aluminum concentrations and by typical EEG and imaging findings.3

Aluminum encephalopathy syndrome must be differentiated from uremic encephalopathy and electrolyte imbalances such as acute hypercalcemia and severe phosphate depletion.3

Management

Products containing aluminum must be stopped. Aluminum chelation with deferoxamine is indicated in advanced cases.3,21

Infant diets should consist of low-phosphate formulas with calcium carbonate added.3 Calcium citrate and aluminum-containing antacids should be avoided.3

Benzodiazepines such as clonazepam and diazepam are effective in controlling myoclonus.

Phenytoin usually is used to control the tonic-clonic or partial seizures. Relatively little phenytoin is removed by hemodialysis, and intravenous loading doses can be given to maintain a desired plasma concentration after the procedure. (See Correction for drug loss during hemodialysis)

Adapted from: Browne TR. Renal disorders. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;49-62. With permission from Elsevier (www.elsevier.com).

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Reviewed By: 
Steven C. Schachter, MD
on: 
Sunday, February 1, 2004