Nils Danner and Laura Säisänen contributed equally to this article.
Article first published online: 9 JUN 2011
Copyright © 2011 Movement Disorder Society
Volume 26, Issue 11, pages 2095–2100, September 2011
How to Cite
Danner, N., Säisänen, L., Määttä, S., Julkunen, P., Hukkanen, T., Könönen, M., Hyppönen, J., Kälviäinen, R. and Mervaala, E. (2011), Motor cortical plasticity is impaired in Unverricht–Lundborg disease. Mov. Disord., 26: 2095–2100. doi: 10.1002/mds.23813
Relevant conflicts of interest/financial disclosures: Nils Danner received financial support from the Finnish Medical Foundation Duodecim and the Finnish Epilepsy Research Support Foundation. Reetta Kälviäinen received financial support from the Academy of Finland/the NEURO Research Programme, the Vaajasalo Foundation, and UCB Pharma.
Full financial disclosures and author roles may be found in the online version of this article.
- Issue published online: 19 SEP 2011
- Article first published online: 9 JUN 2011
- Manuscript Accepted: 8 MAY 2011
- Manuscript Revised: 1 APR 2011
- Manuscript Received: 26 JAN 2011
- transcranial magnetic stimulation;
- paired associative stimulation;
- progressive myoclonus epilepsy;
- Unverricht–Lundborg disease
Patients with Unverricht–Lundborg disease, also referred to as progressive myoclonus epilepsy type 1, exhibit widespread motor symptoms and signs in addition to epileptic seizures, which suggest abnormal excitability of the primary motor pathways. To explore the plasticity of the sensory–motor cortex, we employed a modern neurophysiological method, the paired associative stimulation protocol, which resembles the concept of long-term potentiation of experimental studies. Seven patients with genetically verified Unverricht–Lundborg disease and 13 healthy control subjects were enrolled in the study to characterize cortical sensory–motor plasticity. In the study protocol, peripheral electric median nerve stimulation preceded navigated transcranial magnetic stimulation targeted to the representation area of thenar musculature on the contralateral primary motor cortex. The protocol consisted of 132 transcranial magnetic stimulation trials at 0.2 Hz, preceded by peripheral sensory stimulation at 25 ms. Motor-evoked potential amplitudes were analyzed at baseline and after the paired associative stimulation protocol at an intensity of 130% of the individual motor threshold. The patients with Unverricht–Lundborg disease exhibited an average decrease of 15% in motor-evoked potential amplitudes 30 minutes after paired associative stimulation, whereas in the control subjects, a significant increase (101%) was observed (P < .05), as expected. The results indicate a lack of normal cortical plasticity in Unverricht–Lundborg disease, which stresses the role of abnormal motor cortical functions or sensorimotor integration as possible pathophysiological contributors to the motor symptoms. The impaired cortical plasticity may be associated with the previously reported structural and physiological abnormalities of the primary motor cortex. © 2011 Movement Disorder Society