TY - JOUR
T1 - L-dopa modulates motor cortex excitability in Alzheimer's disease patients
AU - Martorana, Alessandro
AU - Stefani, Alessandro
AU - Palmieri, Maria Giuseppina
AU - Esposito, Zaira
AU - Bernardi, Giorgio
AU - Sancesario, Giuseppe
AU - Pierantozzi, Mariangela
PY - 2008/9
Y1 - 2008/9
N2 - In Alzheimer's disease (AD), transcranial magnetic stimulation (TMS) studies have shown abnormalities of motor cortical excitability, such as a decreased intra-cortical inhibition (ICI) and changes in resting motor threshold (rMT). We studied the effects of l-dopa on rMT and ICI in a cohort of moderate AD patients after paired-pulse TMS. Results were compared with a control group of healthy subjects. As expected, AD patients showed a significant reduction in ICI and a lower rMT. l-dopa administration (soluble form, melevodopa 200 mg) promptly reversed the ICI impairment up to normalization. This effect was specific, since it was not mimicked in control subjects. These results indicate a possible role of dopamine in modulating AD cortical excitability, thus suggesting an interaction between dopaminergic ascending pathways and endogenous intracortical transmitters. In addition, considering that l-dopa showed a pharmacological profile similar to the one of cholinomimetics, l-dopa might represent a reliable tool to study new therapeutic perspective and strategies for AD.
AB - In Alzheimer's disease (AD), transcranial magnetic stimulation (TMS) studies have shown abnormalities of motor cortical excitability, such as a decreased intra-cortical inhibition (ICI) and changes in resting motor threshold (rMT). We studied the effects of l-dopa on rMT and ICI in a cohort of moderate AD patients after paired-pulse TMS. Results were compared with a control group of healthy subjects. As expected, AD patients showed a significant reduction in ICI and a lower rMT. l-dopa administration (soluble form, melevodopa 200 mg) promptly reversed the ICI impairment up to normalization. This effect was specific, since it was not mimicked in control subjects. These results indicate a possible role of dopamine in modulating AD cortical excitability, thus suggesting an interaction between dopaminergic ascending pathways and endogenous intracortical transmitters. In addition, considering that l-dopa showed a pharmacological profile similar to the one of cholinomimetics, l-dopa might represent a reliable tool to study new therapeutic perspective and strategies for AD.
KW - Acetylcholine
KW - Alzheimer's disease
KW - Intracortical inhibition
KW - Levodopa
KW - Transcranial magnetic stimulation
UR - http://www.scopus.com/inward/record.url?scp=50649095166&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=50649095166&partnerID=8YFLogxK
U2 - 10.1007/s00702-008-0082-z
DO - 10.1007/s00702-008-0082-z
M3 - Article
C2 - 18594753
AN - SCOPUS:50649095166
SN - 0375-9245
VL - 115
SP - 1313
EP - 1319
JO - Journal of Neuro-Visceral Relations
JF - Journal of Neuro-Visceral Relations
IS - 9
ER -