TY  - JOUR
A1  - Aster, Hans-Christoph
A1  - Romanos, Marcel
A1  - Walitza, Susanne
A1  - Gerlach, Manfred
A1  - Mühlberger, Andreas
A1  - Rizzo, Albert
A1  - Andreatta, Marta
A1  - Hasenauer, Natalie
A1  - Hartrampf, Philipp E.
A1  - Nerlich, Kai
A1  - Reiners, Christoph
A1  - Lorenz, Reinhard
A1  - Buck, Andreas K.
A1  - Deserno, Lorenz
T1  - Responsivity of the striatal dopamine system to methylphenidate — A within-subject I-123-β-CIT-SPECT study in male children and adolescents with attention-deficit/hyperactivity disorder
JF  - Frontiers in Psychiatry
N2  - Background:
Methylphenidate (MPH) is the first-line pharmacological treatment of attention-deficit/hyperactivity disorder (ADHD). MPH binds to the dopamine (DA) transporter (DAT), which has high density in the striatum. Assessments of the striatal dopamine transporter by single positron emission computed tomography (SPECT) in childhood and adolescent patients are rare but can provide insight on how the effects of MPH affect DAT availability. The aim of our within-subject study was to investigate the effect of MPH on DAT availability and how responsivity to MPH in DAT availability is linked to clinical symptoms and cognitive functioning.


Methods
Thirteen adolescent male patients (9–16 years) with a diagnosis of ADHD according to the DSM-IV and long-term stimulant medication (for at least 6 months) with MPH were assessed twice within 7 days using SPECT after application of I-123-β-CIT to examine DAT binding potential (DAT BP). SPECT measures took place in an on- and off-MPH status balanced for order across participants. A virtual reality continuous performance test was performed at each time point. Further clinical symptoms were assessed for baseline off-MPH.


Results
On-MPH status was associated with a highly significant change (−29.9%) of striatal DAT BP as compared to off-MPH (t = −4.12, p = 0.002). A more pronounced change in striatal DAT BP was associated with higher off-MPH attentional and externalizing symptom ratings (Pearson r = 0.68, p = 0.01). Striatal DAT BP off-MPH, but not on-MPH, was associated with higher symptom ratings (Pearson r = 0.56, p = 0.04).


Conclusion
Our findings corroborate previous reports from mainly adult samples that MPH changes striatal DAT BP availability and suggest higher off-MPH DAT BP, likely reflecting low baseline DA levels, as a marker of symptom severity.
KW  - methylphenidate
KW  - attention deficit/hyperactivity disorder (ADHD)
KW  - striatum
KW  - single photon emission computed tomography (SPECT)
KW  - responsivity
KW  - caudate nucleus
KW  - dopamine transporter (DAT)
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-270862
SN  - 1664-0640
VL  - 13
ER  - 
TY  - JOUR
A1  - Isaias, Ioannis Ugo
A1  - Spiegel, Jörg
A1  - Brumberg, Joachim
A1  - Cosgrove, Kelly P.
A1  - Marotta, Giorgio
A1  - Oishi, Naoya
A1  - Higuchi, Takahiro
A1  - Küsters, Sebastian
A1  - Schiller, Markus
A1  - Dillmann, Ulrich
A1  - van Dyck, Christopher H.
A1  - Buck, Andreas
A1  - Herrmann, Ken
A1  - Schloegl, Susanne
A1  - Volkmann, Jens
A1  - Lassmann, Michael
A1  - Fassbender, Klaus
A1  - Lorenz, Reinhard
A1  - Samnick, Samuel
T1  - Nicotinic acetylcholine receptor density in cognitively intact subjects at an early stage of Parkinson's disease
JF  - Frontiers in Aging Neuroscience
N2  - We investigated in vivo brain nicotinic acetylcholine receptor (nAChR) distribution in cognitively intact subjects with Parkinson's disease (PD) at an early stage of the disease. Fourteen patients and 13 healthy subjects were imaged with single photon emission computed tomography and the radiotracer 5-[(123)I]iodo-3-[2(S)-2-azetidinylmethoxy]pyridine ([(123)I]5IA). Patients were selected according to several criteria, including short duration of motor signs (<7 years) and normal scores at an extensive neuropsychological evaluation. In PD patients, nAChR density was significantly higher in the putamen, the insular cortex and the supplementary motor area and lower in the caudate nucleus, the orbitofrontal cortex, and the middle temporal gyrus. Disease duration positively correlated with nAChR density in the putamen ipsilateral (ρ = 0.56, p < 0.05) but not contralateral (ρ = 0.49, p = 0.07) to the clinically most affected hemibody. We observed, for the first time in vivo, higher nAChR density in brain regions of the motor and limbic basal ganglia circuits of subjects with PD. Our findings support the notion of an up-regulated cholinergic activity at the striatal and possibly cortical level in cognitively intact PD patients at an early stage of disease.
KW  - nicotinic receptors
KW  - Parkinson disease
KW  - 5IA-SPECT
KW  - dopamine acetylcholine
KW  - cognitive decline
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119351
VL  - 6
ER  -