Value of 99mTc-TRODAT-1 SPECT to predict clinical response to methylphenidate treatment in adults with attention deficit hyperactivity disorder.
BACKGROUND
In a previous study, binding of Tc-TRODAT-1 to the dopamine transporter (DAT) was found to be higher in patients with attention deficit hyperactivity disorder (ADHD) as compared to healthy controls.


OBJECTIVE
To determine whether the degree of Tc-TRODAT-1 binding to the striatal DAT may have a predictive role on the response to methylphenidate (MPH) in patients with ADHD.


METHODS
Twenty-two adult patients suffering from ADHD underwent a brain SPECT scan with Tc-TRODAT-1. After the scan patients received MPH, individually medicated up to 60 mg.day. Severity of illness was estimated using the Clinical Global Impression (CGI-S) Scale before treatment. Ten weeks after the beginning of MPH treatment the improvement in global symptoms was rated by the Clinical Global Improvement Scale (CGI-I).


RESULTS
Before treatment 17/22 patients with ADHD presented with higher striatal DAT binding as compared to age-matched healthy controls (+23.8%; P<0.01). After treatment with MPH a significant improvement of ADHD symptoms was demonstrated by the CGI-I in 16 of these 17 patients (CGI-S before: 4.8; CGI-I after MPH: 1.9; P<0.01). Five patients showed reduced DAT binding prior to therapy (-14.4%; P=0.04); these patients did not respond to MPH therapy (CGI-S before: 4.5; CGI-I after MPH: 4.2; P=0.40).


CONCLUSIONS
Our findings suggest that ADHD patients with primarily elevated binding of Tc-TRODAT-1 to the striatal DAT responded better to therapy with MPH as compared to those with normal or low DAT binding. Consequently, our results - even if obtained on a small collective indicate that measurement of DAT may be an important prognostic predictor for therapy response to MPH.
la Fougère
Christian
C
Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Germany. christian.lafougere@med.uni-muenchen.de
Krause
Johanna
J
Krause
Klaus-Henning
KH
Josef Gildehaus
Franz
F
Hacker
Marcus
M
Koch
Walter
W
Hahn
Klaus
K
Tatsch
Klaus
K
Dresel
Stefan
S
D000328:Adult; D000367:Age Factors; D001289:Attention Deficit Disorder with Hyperactivity / Q000000981:diagnostic imaging* / Q000473:pathology*; D001921:Brain / Q000378:metabolism; D050483:Dopamine Plasma Membrane Transport Proteins; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000494:pharmacology; D008875:Middle Aged; D015609:Organotechnetium Compounds; D011485:Protein Binding; D011859:Radiography; D019275:Radiopharmaceuticals; D012720:Severity of Illness Index; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014326:Tropanes
D050483:Dopamine Plasma Membrane Transport Proteins; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D014326:Tropanes; C104196:technetium Tc 99m TRODAT-1; D008774:Methylphenidate