Establishing the definition and inter-rater reliability of cortical silent period calculation in subjects with focal hand dystonia and healthy controls.
The purpose of this paper is to describe a clearly defined manual method for calculating cortical silent period (CSP) length that can be employed successfully and reliably by raters after minimal training in subjects with focal hand dystonia (FHD) and healthy subjects. A secondary purpose was to explore intra-subject variability of the CSP in subjects with FHD vs. healthy subjects. Two raters previously naïve to CSP identification and one experienced rater independently analyzed 170 CSP measurements collected in 6 subjects with focal hand dystonia (FHD) and 9 healthy subjects. Intraclass correlation coefficient (ICC) was calculated to quantify inter-rater reliability within the two groups of subjects. The relative variability of CSP in each group was calculated by the coefficient of variation (CV). Relative variation between raters within repeated measures of individual subjects was also quantified by CV. Reliability measures were as follows-mean of three raters: all subjects: ICC=0.976; within healthy subjects: ICC=0.965; in subjects with FHD: ICC=0.956. The median within-subject variability for the healthy group was CV=7.33% and in subjects with FHD:CV=11.78%. The median variability of calculating individual subject CSP duration between raters was CV=10.23% in subjects with dystonia and CV=10.46% in healthy subjects. Manual calculation of CSP results in excellent reliability between raters of varied levels of experience. Healthy subjects display less variability in CSP. Despite greater variability, the CSP in impaired subjects can be reliably calculated across raters.
Kimberley
Teresa Jacobson
TJ
University of Minnesota, Department of Physical Medicine and Rehabilitation, Program in Physical Therapy, Minneapolis, MN 55455, USA. tjk@umn.edu
Borich
Michael R
MR
Prochaska
Kristina D
KD
Mundfrom
Shannon L
SL
Perkins
Ariel E
AE
Poepping
Joseph M
JM
D000328:Adult; D000465:Algorithms; D004421:Dystonia / Q000175:diagnosis / Q000503:physiopathology*; D004569:Electroencephalography / Q000379:methods*; D019054:Evoked Potentials, Motor; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D015588:Observer Variation; D011930:Reaction Time; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D050781:Transcranial Magnetic Stimulation / Q000379:methods*
Restor Neurol Neurosci. 2009;27(1):55-65
19164853
Neurology. 1991 Sep;41(9):1449-56
1891097
Muscle Nerve. 1998 Sep;21(9):1209-12
9703450
Neurology. 1994 May;44(5):936-40
8190300
Clin Neurophysiol. 2001 Aug;112(8):1451-60
11459685
Electroencephalogr Clin Neurophysiol Suppl. 1999;52:171-85
10590986
J Neurophysiol. 1987 Nov;58(5):1168-85
3694249
Neurosci Lett. 2000 Apr 28;284(3):147-50
10773420
Electroencephalogr Clin Neurophysiol. 1998 Jan;108(1):1-16
9474057
Acta Neurol Scand. 1996 Feb-Mar;93(2-3):168-74
8741138
Biol Psychiatry. 2001 Mar 1;49(5):460-3
11274658
Brain. 2005 Jan;128(Pt 1):104-15
15483042
J Clin Neurophysiol. 1997 Mar;14(2):136-43
9165408
Electromyogr Clin Neurophysiol. 1998 Apr-May;38(3):189-92
9637946
J Neurosci Methods. 2006 Jan 15;150(1):96-104
16105686
Exp Brain Res. 1994;99(1):84-96
7925799
Clin Neurophysiol. 2004 May;115(5):1076-82
15066533
Neurosci Lett. 1997 Feb 7;222(3):167-70
9148241
Clin Neurophysiol. 2003 May;114(5):938-44
12738441
Neurology. 1999 Feb;52(3):529-37
10025782
Exp Brain Res. 1996 Apr;109(1):127-35
8740215
Neurosci Lett. 2005 Apr 11;378(1):55-8
15763172
Brain. 1997 Apr;120 ( Pt 4):605-19
9153123
Exp Brain Res. 1993;94(3):489-98
8359263
Neuropsychologia. 1971 Mar;9(1):97-113
5146491
Mov Disord. 1994 Mar;9(2):178-82
8196679
Exp Brain Res. 2006 Sep;173(4):603-11
16525803