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[ 123 I]‐FP‐CIT‐SPECT demonstrates dopaminergic deficit in orthostatic tremor
Author(s) -
Katzenschlager Regina,
Costa Durval,
Gerschlager Willibald,
O'Sullivan John,
Zijlmans Jan,
Gacinovic Svetoslav,
Pirker Walter,
Wills Adrian,
Bhatia Kailash,
Lees Andrew J.,
Brown Peter
Publication year - 2003
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.10475
Subject(s) - dopaminergic , dopamine transporter , putamen , parkinsonism , dopamine , parkinson's disease , caudate nucleus , medicine , orthostatic vital signs , levodopa , psychology , endocrinology , nuclear medicine , disease , blood pressure
There is increasing evidence of a potential role of the dopaminergic system in orthostatic tremor (OT): Association with parkinsonism and treatment effects of L‐dopa and dopamine agonists have been reported. Eleven patients with isolated OT had single‐photon emission computed tomography (SPECT) using 123 I‐FP‐CIT ([ 123 I]‐2β‐carbomethoxy‐3β‐(‐4‐iodophenyl)‐N‐(3‐fluoropropyl)‐nortropane) as dopamine transporter tracer. Results were compared with 12 age‐matched normal controls and 12 patients with Parkinson's disease (PD). A marked reduction in striatal tracer binding was found in OT compared to normal controls ( p < 0.001). Tracer uptake was significantly higher and more symmetrical than in PD, and caudate and putamen were equally affected. L‐dopa challenges, performed in seven patients, showed a small but non‐significant improvement on EMG and a small but significant improvement in clinical parameters on blinded video rating. Two‐month open‐label L‐dopa treatment (600 mg/day) led to a small improvement in two of five patients but no significant overall change. Olfactory function on University of Pennsylvania Smell Identification Test was normal. Our finding of a marked tracer uptake reduction on dopamine transporter SPECT supports a role of the dopaminergic system in OT. Lack of evidence of a clinically relevant therapeutic response to L‐dopa suggests that other mechanisms must also be involved in the pathogenesis. Ann Neurol 2003