Striatal dopamine D1‐like receptor binding is unchanged in primary focal dystonia. Issue 14 (21st October 2013)

• Record Type: Journal Article
• Authors: Karimi, Morvarid; Moerlein, Stephen M.; Videen, Tom O.; Su, Yi; Flores, Hubert P.; Perlmutter, Joel S.
• Is Part Of: Movement disorders. Volume 28:Issue 14(2013)
• Page Start: 2002
• Page End: 2006
• Publication Date: 2013-10-21
• Subjects: Movement disorders -- Periodicals; 610
• DOI: 10.1002/mds.25720
• Languages: English
• ISSNs: 0885-3185

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <p> <italic>Background</italic>: Multiple studies have demonstrated decreases in striatal D2‐like (D2, D3) radioligand binding in primary focal dystonias. Although most investigations have focused on D2‐specific receptors (D2R), a recent study suggests that the decreased D2‐like binding may be due to a D3‐specific (D3R) abnormality. However, only limited data exist on the role of D1‐specific receptors (D1R) and the D1R‐mediated pathways within basal ganglia in dystonia. Metabolic positron emission tomography (PET) data in primary generalized dystonia suggest resting state over activity in the D1R‐mediated <italic>direct</italic> pathway, leading to excessive disinhibition of motor cortical areas. This work investigated whether striatal D1‐like receptors are affected in primary focal dystonias. <italic>Methods</italic>: Striatal‐specific (caudate and putamen) binding of the D1‐like radioligand [<sup>11</sup>C]NNC 112 was measured using PET in 19 patients with primary focal dystonia (cranial, cervical, or arm) and 18 controls. <italic>Results</italic>: No statistically significant difference was detected in striatal D1‐like binding between the two groups. The study had 91% power to detect a 20% difference, indicating that false‐negative results were unlikely. <italic>Conclusions</italic>: Because [<sup>11</sup>C]NNC 112 has high affinity for D1‐like receptors, very low affinity for D2‐like receptors, and minimal sensitivity to endogenous dopamine levels, we conclude that D1‐like receptor binding is not impaired in these primary focal dystonias. © 2013 International Parkinson and Movement Disorder Society</p> </abstract>