Clinical and [^99mTc]TRODAT-1/[¹²³I]IBZM SPECT imaging findings in dopa-responsive dystonia

We report the clinical and dopamine transporter/D2 receptor single-photon emission computed tomographic (SPECT) imaging findings in a 39-year-old woman with a 24-year history of dopa-responsive dystonia (DRD). The SPECT imaging of the dopamine transporter with [^99mTc]TRODAT-1 is helpful in differentiating DRD from early-onset idiopathic parkinsonism. In the later clinical course, the [¹²³I]IBZM SPECT is also helpful in differentiating these two conditions. The patient showed a dramatic and sustained response to levodopa, and needed a smaller dose of levodopa for symptom control in the later course.