Effects of treatment with OKT3 on brain perfusion in a heart transplant patient with SPET with 99mTc-HMPAO

A heart transplant patient treated with OKT3 developed a severe headache which worsened and was accompanied by a sudden decrease in the patient's consciousness level and aphasia when the treatment course was completed. CT was performed and was normal. SPET imaging with 99mTc-HMPAO of cerebral blood flow done 16 hours later revealed multiple and clear focal defects in the blood flow. Analysis of cerebral spinal fluid revealed aseptic pleocytosis. Five days after the completion of treatment, the symptoms remitted and a new control SPET 3 weeks later was completely normal. A diagnosis of neurotoxicity secondary to OKT3 administration was established.