A 78-year-old female patient with a 5-year history of bradykinesia and tremor at rest of both upper limbs was referred to our Nuclear Medicine Department because of a rapid functional decline over 3 months with cognitive impairment, generalized myoclonus, and dependence for most basic daily activities. Brain SPECT with 148MBq (4 mCi) of I-123 FP-CIT and 740MBq (20 mCi) of Tc-99m ethylcysteinate dimer (thereafter Tc-99m ECD) was performed.