R MANICKAVASAGAR1, R SINGER2, R SWAMINATHAN1, D PRENTICE3, A IRISH1
1Fiona Stanley Hospital, Perth, WA; 2Canberra Hospital, Canberra, ACT; 3Royal Perth Hospital, Perth, WA
Aim: To characterise the features of acute bilateral basal ganglia dysfunction in dialysis patients and identify possible risk factors and clinical outcomes.
Background: Acute bilateral basal ganglia dysfunction is a rare complication of dialysis, manifesting as a movement disorder with chorea or acute Parkinsonism. In the non-dialysis population, degeneration of the basal ganglia is associated with genetic disorders of iron overload, mutations of Vitamin B5, toxins, hypoxia and metabolic acidosis.
Methods: Retrospective case series describing clinical, biochemical, radiological and post mortem histology features in 15 dialysis patients with acute bilateral basal ganglia syndrome over a 20 year period.
Results: The 15 patients (3 male; 4 ATSI) had an average age of 61±13 years at diagnosis. All were on dialysis (HD= 8/15), had hypertension, diabetes and were receiving parenteral iron and erythropoietin and 14/15 received metformin. 8 patients presented with acute Parkinsonism and 7 with chorea. Several patients had associated hypoglycaemia and metabolic acidosis. The major finding on CT and MRI brain imaging was bilateral hypodensity of the basal ganglia. Autopsy in one patient was consistent with toxic injury to the basal ganglia plus extensive haemosiderosis and iron deposition within the cerebral macrophages. 10 patients died (3 within 90 days) and the median survival was 2.7 years (95% CI 1.4-4.1). There was no difference in survival by mode of presentation (Chorea vs Parkinsonism).
Conclusions: This is the largest reported case series and the first to report brain histology. The bilateral basal ganglia syndrome can present with either chorea or Parkinsonism, manifest specific radiological findings and has serious morbidity and mortality. Female sex, diabetes, metformin and hypertension may predispose.