@inbook{f81497158694452084734b7060a009d7,
title = "Observations on the cortical silent period in Parkinson's disease",
abstract = "Transcranial magnetic stimulation is a tool in the neurosciences to study motor functions and nervous disorders, amongst others. Single pulses of TMS applied over the primary motor cortex lead to a so-called cortical silent period in the recording from the corresponding muscle, i.e. a period of ≥ 100 ms with no muscle activity. We here show that in Parkinson's disease (PD), this cortical silent period in some cases is interrupted by short bursts of EMG activity. We describe in detail these interruptions in two patients with PD. These interruptions may number up to 3 per cortical silent period and show a consistent frequency across trials and hemispheres within a given patient; the two patients described here do differ, however, in the time-delay of the interruptions and hence the induced frequency. For one patient, the frequency of the interruptions proved to be around 13 Hz, the other patient showed a frequency of around 17 Hz. The results corroborate earlier findings of cortical oscillations elicited by pulses of TMS and may be related to abnormal oscillatory activity found in the cortical-subcortical motor system in PD.",
keywords = "beta frequency, EMG, motor cortex, oscillations, TMS",
author = "{Van Der Werf}, {Y. D.} and Berendse, {H. W.} and {Van Someren}, {E. J.W.} and D. Stoffers and Stam, {C. J.} and Wolters, {E. Ch}",
year = "2007",
month = dec,
day = "1",
doi = "10.1007/978-3-211-73574-9-19",
language = "English",
isbn = "9783211735732",
series = "Journal of Neural Transmission, Supplementa",
number = "72",
pages = "155--158",
editor = "Manfred Gerlach and Jurgen Deckert and Kay Double and Eleni Koutsilieri",
booktitle = "Neuropsychiatric Disorders An Integrative Approach",
edition = "72",
}