Clinical and electroencephalographic changes in progressive uremic encephalopathy.

A study of nine patients, aged 23 to 67 years, showed a remarkable sequence of EEG findings in progressive uremic encephalopathy. The initial characteristics suggested a disorder of subcortical gray matter, followed by involvement of cortical gray matter and finally white matter. The same EEG findings tended to persist in the early stages of the disease and were present throughout the night and during dialysis. During dialysis, the EEG background and clinical picture between paroxysms sometimes showed deterioration. Seizures indicated a grave prognosis. Five of six patients with seizures died. In some patients, progressive uremic encephalopathy may develop without hemodialysis. Routine EEGs in dialysis units or in patients prior to admission can help uncover progressive uremic encephalopathy before the clinical emergence of this disorder.