Magnetic response imaging has demonstrated increased signal intensities wit
hin the basal ganglia in patients with hepatic encephalopathy; the densitie
s are considered to represent manganese deposition. We measured whole blood
manganese concentrations in nine children with congenital portosystemic ve
nous shunts detected by screening tests for galactosaemia. Beyond 1 year of
age, these patients showed significantly higher manganese concentrations t
han controls (2.40 +/- 0.43 versus 1.48 +/- 0.38 mug/dl; P = 0.0001). Four
of the nine patients were studied by magnetic response imaging. T1-weighted
images showed increased signal intensities in the basal ganglia of those f
our patients, suggesting manganese accumulation.
Conclusion Children with congenital portosystemic venous shunts showed mang
anese elevations in blood and magnetic response imaging changes in the basa
l ganglia. These children should avoid excessive manganese intake.