Journal of Neural Transmission

, Volume 115, Issue 9, pp 1313–1319 | Cite as

l-dopa modulates motor cortex excitability in Alzheimer’s disease patients

  • Alessandro Martorana
  • Alessandro Stefani
  • Maria Giuseppina Palmieri
  • Zaira Esposito
  • Giorgio Bernardi
  • Giuseppe Sancesario
  • Mariangela Pierantozzi
Alzheimer's Disease and Related Disorders - Original Article


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.


Transcranial magnetic stimulation Intracortical inhibition Alzheimer’s disease levodopa acetylcholine 


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Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Alessandro Martorana
    • 1
    • 2
  • Alessandro Stefani
    • 1
    • 2
  • Maria Giuseppina Palmieri
    • 1
    • 2
  • Zaira Esposito
    • 1
  • Giorgio Bernardi
    • 1
    • 2
  • Giuseppe Sancesario
    • 1
  • Mariangela Pierantozzi
    • 1
    • 2
  1. 1.Dipartimento di Neuroscienze, Clinica NeurologicaUniversità di RomaRomeItaly
  2. 2.Santa Lucia Foundation IRCCS Hospital at the European Centre for Brain ResearchRomeItaly

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