Idiopathic CN3 palsy

Dr. Ducey presented a perplexing case of a patient with long-standing ESRD on dialysis who presented with subacute progressive diplopia and blurry vision and L temporal headaches, found to have left pupil-sparing CN3 palsy and optic disc edema. Despite an extensive workup, a unifying diagnosis was not uncovered. Throughout the case, the patient required multiple imaging studies with contrast, which presented a not-uncommon problem of stratifying the risk of nephrogenic systemic fibrosis (NSF) in a patient who receives gadolinium-based contrast. Dr. Ducey's PICO revolved around the epidemiology, risk factors, and treatments for NSF. Some takeaways:

  • NSF occurs in patients with renal failure and the incidence appears directly related to GFR
  • Presents days to months after contrast exposure
  • Usually presents as swelling and tightening of the skin. Occasionally, there can be MSK or other organ involvement
  • Pathogenesis is not well-understood
  • Incidence has been downtrending since 2010 likely secondary to reduced exposure to gadolinium-based contrast in patients with renal failure
  • Treatments are limited. It is hypothesized that increasing the GFR may halt or reverse disease progression, though has not been validated
  • OHSU's gadolinium contrast, Gadoterate, has a half-life of 1.3hrs in normal individuals but a half-life of 34 hours in ESRD