The known and unknown of post-pump chorea: a case report on robust steroid responsiveness implicating occult neuroinflammation

Abstract

Post-pump chorea (PPC) is characterized by the development of choreiform movements following cardiopulmonary bypass (CPB) surgery. PPC occurs almost exclusively in children, and its pathophysiology remains unclear. Here we present an adult case of PPC after bovine aortic valve replacement (AVR) which exhibited dramatic and reproducible response to steroid, suggesting the presence of occult neuroinflammation. This observation suggests a novel underlying mechanism in certain subgroups of PPC, which is likely a heterogeneous condition to start with. Further research into the pathomechanisms of PPC could offer insights into managing this otherwise symptomatic control-only condition.

Keywords: bioprosthetic aortic valve; cardiopulmonary bypass (CPB); chorea (non-Huntington’s); hypoxia inducible factor; neuroinflammation; post-pump chorea.

Figure 1

Evolution of clinical presentation, inflammatory biomarkers and imaging findings. (A) The MRIs were unremarkable on three occasions, including when the symptoms were most severe (POD 25) and during the recurrence (POD 38). (B) An acute ischemic stroke at the head of the right caudate (white arrowhead) was seen incidentally on POD 60 when the chorea was resolving. (C) The timing of immunomodulation (yellow) and clinical symptoms (red and green) was plotted against the days after valve replacement. The initial presentation began with cognitive changes (green, POD 7) and chorea (red, POD 14), then with symptom resolution on POD 30 during the pulse steroid (POD 27–31). Oral steroid was stopped on POD 39 with symptoms recurrence around POD 46 and then at maximum around POD 54–55. The second course of pulse steroid lasted from POD 56–60 with significant clinical improvement by POD 58. The inflammatory markers ESR (magenta) and CRP (cyan) were trended (dotted lines denote upper limit of normal range). AVR, aortic valve replacement; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; POD, postoperative day.