Evoked potential abnormalities in postoperative patients with biliary atresia.

The somatosensory evoked potentials from the lower extremities were measured postoperatively in 15 patients with biliary atresia to investigate whether they were free of neurologic dysfunction. Because long-standing cholestasis causes progressive neuropathy due to malabsorption of vitamin E, the serum vitamin E, D, and A levels were also examined to evaluate the fat-soluble vitamin status. The cerebral evoked potentials to posterior tibial nerve stimulation were recorded in all 15 patients as well as in 45 controls, but spinal evoked potentials examined at the level of the cauda equina could not be recorded in five patients more than 8 years of age with long-standing icterus. The remaining 10 patients exhibited spinal evoked potentials as observed in the controls, but the mean neural conduction velocity at the cauda equina was significantly lower than that of the 45 controls (42.0 +/- 5.1 m/s vs 52.3 +/- 6.8 m/s, P = .0002). The serum vitamin E, D, and A levels were within the normal range in 13, 9, and 1 of 15 patients, respectively. These results suggest that the patients with long-term follow-up are still at risk of developing neural disturbances even with normal serum vitamin E status.