Effect of Deep Brain Stimulation on Parkinsonian Tremor

The recordings of this database are of rest tremor velocity in the index finger of 16 subjects with Parkinson's disease (PD) who receive chronic high frequency electrical deep brain stimulation (DBS) either uni- or bi-laterally within one of three targets:

This surgical procedure involves implanting an electrode into subcortical structures (Vim, GPi or STN) for long-term stimulation at frequencies greater than 100 Hz. The mechanism by which high frequency DBS suppresses tremor and reduces other symptoms in PD is unknown.

Parkinson’s disease is characterized by the progressive loss of dopamine neurons in the substantia nigra of the midbrain, and is associated with motor symptoms including tremor (usually rest tremor, though sometimes postural tremor), bradykinesia and rigidity. In Parkinson’s disease, tremor becomes more regular or harmonic, its frequency is shifted to a lower range (typically 4–6 Hz), its amplitude increases, the shape of its oscillations changes, and it fluctuates over time. These changes are subtle and intermittent at first, becoming more permanent and obvious as the disease progresses.

Parkinsonian rest tremor velocity recording (subject g2) under four conditions

Figure 1. Two seconds of Parkinsonian rest tremor velocity (metres/second) recordings from subject g2 (stimulator implanted in the GPi) under four conditions: (a) no stimulation and no medication, (b) deep brain stimulation and no medication, (c) no stimulation and 150% medication, (d) deep brain stimulation and 150% medication. Note the zoomed vertical scale in (b), (c) and (d).

Chronic high frequency deep brain stimulation of the Vim can decrease tremor amplitude in a spectacular way. Deep brain stimulation of the GPi and STN have been shown to relieve not only tremor but also other symptoms of PD such as rigidity and dyskinesia. See Figure 1 for an example of the effect of deep brain stimulation of the GPi on tremor.

Velocity laser recording of rest tremor

Figure 2. Velocity laser recording of rest tremor.

The raw data were obtained using a low intensity velocity-transducing laser that was directed at a piece of reflective paper on the subject’s index finger tip (Figure 2), with the output voltage proportional to the velocity of the finger.

DBS/Medication Conditions:

Tremor was recorded for approximately 60 seconds under various conditions:

  1. two conditions of DBS (on-off) and two conditions of medication (L-dopa on-off)
    [total: 55 recordings of approx 60 seconds each]
  2. every 15 minutes when DBS was stopped for 60 minutes (medication off)
    [total: 46 recordings of approx 60 seconds each]

Please note that not all subjects were tested under all conditions.

For the "medication off" condition, the subject did not take any medication for at least 12 hours. For the "medication on" condition, the subject took 150% of his or her morning dose of dispersible Modopar and testing began after the neurologist determined the medication had taken effect (approximately 40 minutes).

Subjects:

The 16 subjects can be divided into two groups:

  1. Subjects 1–8 with high amplitude tremor (HAT) who are receiving DBS to relieve tremor (Group 1), and
  2. Subjects 9–16 with low amplitude tremor (LAT) who are receiving DBS to relieve other symptoms such as rigidity or dyskinesias (Group 2).

The file subject_description.txt contains information on the 16 subjects:

InformationDescription
SUBJECT2 character subject identification:
Stimulation target (v=Vim, s=STN, g=GPi), and
Subject number (1-16)
AGEAge at the time of testing (years)
GENDERMale (n=11) or female (n=5)
STIM TARGETVim = ventro-intermediate nucleus of the thalamus
GPi = internal Globus Pallidus
STN=subthalamic nucleus
BI/UNI-LATERALBilateral stimulation (n=12) or unilateral stimulation (n=4)
EFF FREQFrequency (Hz) of effective stimulation (> 100 Hz)
INEFF FREQFrequency (Hz) of so-called ineffective stimulation (< 100 Hz)
INTENSITYStimulation intensity (V)
PULSE WIDTHStimulation pulse width (µsec)
MODECont = continuous stimulation,
Cycl=cyclic stimulation (e.g. 1 minute on, 1 second off)
STIM CONTACTSListed in order of proximal distal direction on quadripolar stimulating electrode:
- negative polarity
+ positive polarity
. not stimulated
YEAR DIAGNOSEDYear diagnosed with Parkinson's disease
YEAR DBS RIGHTYear of right brain DBS surgery
YEAR DBS LEFTYear of left brain DBS surgery
TOT DAILY MEDTotal medication of morning, noon and evening doses (mg)
150% SINGLE DOSEDose taken before testing "medication on" condition (mg)

Filename Structure:

The file name structure of the records is:

Filename Examples:

Tremor Recordings:

The rest tremor recordings can be classified as one of 8 categories, for subjects with high amplitude tremor (HAT) and for subjects with low amplitude tremor (LAT):

  1. ren: Deep brain stimulation on, Medication on
    HAT subjects: n=5 recordings
    LAT subjects: n=8 recordings
  2. ref: Deep brain stimulation on, Medication off
    HAT subjects: n=5 recordings
    LAT subjects: n=8 recordings
  3. ron: Deep brain stimulation off, Medication on
    HAT subjects: n=7 recordings
    LAT subjects: n=8 recordings
  4. rof: Deep brain stimulation off, Medication off
    HAT subjects: n=6 recordings
    LAT subjects: n=8 recordings
  5. r15of: Deep brain stimulation off for 15 minutes, Medication off
    HAT subjects: n=3 recordings
    LAT subjects: n=8 recordings
  6. r30of: Deep brain stimulation off for 30 minutes, Medication off
    HAT subjects: n=4 recordings
    LAT subjects: n=8 recordings
  7. r45of: Deep brain stimulation off for 45 minutes, Medication off
    HAT subjects: n=3 recordings
    LAT subjects: n=8 recordings
  8. r60of: Deep brain stimulation off for 60 minutes, Medication off
    HAT subjects: n=4 recordings
    LAT subjects: n=8 recordings
Total:HAT subjects: n=37 recordings
LAT subjects: n=64 recordings

The file file_description.txt contains a summary of recordings per subject in each category.

Reference:

Beuter, A., Titcombe, M.S., Richer, F., Gross, C., Guehl, D., 2001. Effect of deep brain stimulation on amplitude and frequency characteristics of rest tremor in Parkinson's disease. Thalamus & Related Systems, Volume 1 (3): 203–211 (published by Elsevier Science).

Icon  Name                    Last modified      Size  Description
[PARENTDIR] Parent Directory - [   ] RECORDS 2001-08-27 17:17 1.1K list of record names [TXT] subject_description.txt 2001-10-01 10:29 3.2K [DIR] refh/ 2001-10-18 11:41 - [DIR] rofh/ 2001-10-18 12:57 - [DIR] r15ofh/ 2001-10-18 13:03 - [DIR] r30ofh/ 2001-10-18 14:44 - [DIR] r45ofh/ 2001-10-18 14:46 - [DIR] r60ofh/ 2001-10-18 14:57 - [TXT] file_description.txt 2001-10-18 18:44 11K [DIR] renh/ 2001-10-19 10:34 - [IMG] vlaser.gif 2001-10-19 11:31 4.6K [IMG] g2.gif 2001-10-19 12:52 6.5K [DIR] renl/ 2001-10-19 14:19 - [DIR] refl/ 2001-10-19 14:26 - [DIR] ronl/ 2001-10-19 14:32 - [DIR] rofl/ 2001-10-19 14:35 - [DIR] r15ofl/ 2001-10-19 14:37 - [DIR] r30ofl/ 2001-10-19 14:41 - [DIR] r45ofl/ 2001-10-19 14:55 - [DIR] r60ofl/ 2001-11-09 14:52 - [DIR] ronh/ 2001-11-09 14:53 - [   ] MD5SUMS 2005-07-13 02:26 328 [   ] SHA1SUMS 2005-07-13 02:26 434 [   ] SHA256SUMS 2007-09-18 12:40 701

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Updated Friday, 28 October 2016 at 16:58 EDT

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