• Neurologic complications affect 30 to 60% of allograft organ transplant recipients.
   
• Many of these complications are related to immunosuppresant medication neurotoxicity.
   
• Calcineurin inhibitors such as tacrolimus (FK-506 or Fujimycin) and cyclosporin are classically associated with the following neurologic disorders:
  • Cranial Nerve Palsy:  Tacrolimus toxicity can cause reversible  internuclear ophthalmoplegia.
  • Movement Disorders:  Tacrolimus and cyclosporin often cause tremor, which can be further compounded by the development of asterixis should the patient also have significant renal or hepatic insufficiency.
  • Visual Abnormalities:  Cortical blindness, visual disturbances, hallucinations, retinal toxicity, and optic neuropathies have all been attributed to calcineurin inhibitor toxicity.  Opsoclonus (rapid, involuntary, uncontrolled, multivectorial eye movements) has specifically been associated with cyclosporin neurotoxicity. 
     

• Neurotoxicity related to immunosuppresant drug therapy is most likely to occur early after transplantation and during a rejection episodes, times at which medication doses are typically at their highest.  Dose adjustment often results in resolution of symptoms.
   
• Be sure to check drug levels of immunosuppresant medications, particularly when a transplant patient presents with a neurologic disorders.

 

References

 Zivkovic S. Neuroimaging and neurologic complications after organ transplantation. J Neuroimaging. Apr 2007;17(2):110-23.