L-dopa–responsive Parkinson's syndrome in association with phenylketonuria: In vivo dopamine transporter and D2 receptor findings

✍ Scribed by Andrew H. Evans; Durval C. Costa; Sveto Gacinovic; Regina Katzenschlager; John D. O'Sullivan; Simon Heales; Phillip Lee; Andrew J. Lees

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 133 KB
• Volume: 19
• Category: Article
• ISSN: 0885-3185
• DOI: 10.1002/mds.20146

✦ Synopsis

Abstract

Reports of parkinsonism in phenylketonuria are exceedingly rare. We report on a patient who had received a delayed diagnosis of phenylketonuria as an infant and subsequently developed levodopa‐responsive parkinsonism at the age of 33. Single‐photon emission computed tomography (SPECT) using ^123^I‐FP‐CIT ([^123^)I]‐2 beta‐carbomethoxy‐3beta‐(‐4‐iodophenyl)‐N‐(3‐fluoropropyl)‐nortropane) used to measure dopamine transporter levels on two occasions, 7 and 9 years after the onset of neurological symptoms, were normal. Iodine‐123‐iodo‐lisuride SPECT (IBZM) imaging, however, showed reduced caudate over putamen binding. This combination of imaging findings indicates a possible upregulation of postsynaptic D2 receptors in the context of intact presynaptic dopamine nerve terminal density. © 2004 Movement Disorder Society