Decreased dopamine D receptor binding in essential blepharospasm.
OBJECTIVE
The purpose of this study was to investigate whether dopamine D(2) receptor binding was altered in the striatum of essential blepharospasm patients.


METHODS
Striatal dopamine D(2) receptor binding was measured with positron emission tomography and [(11)C]raclopride. We studied eight drug-naive patients with bilateral blepharospasm and eight age-matched normal controls.


RESULTS
The uptake indices in the blepharospasm group were significantly reduced by 11.7% in the caudate (P < 0.005), 11.6% in the anterior putamen (P < 0.0001), and 10.3% in the posterior putamen (P < 0.005) relative to the control group.


CONCLUSIONS
This study indicates decreased dopamine D(2) receptor binding in the entire striatal region of blepharospasm patients. The findings suggest that decreased dopamine D(2) receptor binding might be one of the predisposing factors that leads to the dysfunction of the motor circuit, resulting in the loss of broad inhibition of unwanted movements during an intended movement in blepharospasm patients.
Horie
C
C
Department of Ophthalmology and Visual Science, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Suzuki
Y
Y
Kiyosawa
M
M
Mochizuki
M
M
Wakakura
M
M
Oda
K
K
Ishiwata
K
K
Ishii
K
K
D001764:Blepharospasm / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology*; D001905:Botulinum Toxins / Q000627:therapeutic use; D002250:Carbon Radioisotopes; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D018492:Dopamine Antagonists / Q000378:metabolism / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D020891:Raclopride / Q000378:metabolism* / Q000627:therapeutic use; D011859:Radiography; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D012016:Reference Values
D002250:Carbon Radioisotopes; D018492:Dopamine Antagonists; D017448:Receptors, Dopamine D2; D020891:Raclopride; D001905:Botulinum Toxins