open access

Vol 45, No 2 (2011)
ARTYKUŁ ORYGINALNY
Submitted: 2010-03-22
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Essential tremor – assessment of tremor accelerometric parameters' symmetry and the relationship between hand dominance and severity of tremor

Agnieszka Machowska-Majchrzak, Krystyna Pierzchała, Stanisław Pietraszek, Beata Łabuz-Roszak
DOI: 10.1016/S0028-3843(14)60022-0
·
Neurol Neurochir Pol 2011;45(2):121-127.

open access

Vol 45, No 2 (2011)
ARTYKUŁ ORYGINALNY
Submitted: 2010-03-22

Abstract

Background and purpose

Essential tremor (ET) is likely the most common movement disorder. The aim of the study was to carry out spectral analysis of the essential tremor recorded by an accelerometer and assess the symmetry of tremor parameters between the two hands.

Material and methods

We examined 39 patients with ET diagnosed clinically using the criteria of the Movement Disorder Society. The control group consisted of 52 healthy persons. A biaxial accelerometer mounted at the dorsal side of the hand was used. Spectral analysis was performed. Tremor intensity, frequency of spectral peaks, centre frequency, standard deviation of the centre frequency, and harmonic index were measured. The side-to-side symmetry of these parameters was analysed. The relationship of hand dominance and severity of tremor was also analysed.

Results

There was significant side-to-side asymmetry of intensity in ET. The intensity in the more affected hand was over two times higher than that in the less affected one. The tremor was more severe in the nondominant hand in 62% of patients. In spite of significant difference in tremor intensity between the two sides, tremor frequency was similar in both hands. The standard deviation of centre frequency was significantly lower and the harmonic index was significantly higher in the more trembling hand.

Conclusions

Accelerometric registration revealed that asymmetry of intensity and symmetry of frequency are characteristic features of ET. The remaining two coefficients reflecting the rhythmicity and regularity of tremor also differed considerably between the hands.

Abstract

Background and purpose

Essential tremor (ET) is likely the most common movement disorder. The aim of the study was to carry out spectral analysis of the essential tremor recorded by an accelerometer and assess the symmetry of tremor parameters between the two hands.

Material and methods

We examined 39 patients with ET diagnosed clinically using the criteria of the Movement Disorder Society. The control group consisted of 52 healthy persons. A biaxial accelerometer mounted at the dorsal side of the hand was used. Spectral analysis was performed. Tremor intensity, frequency of spectral peaks, centre frequency, standard deviation of the centre frequency, and harmonic index were measured. The side-to-side symmetry of these parameters was analysed. The relationship of hand dominance and severity of tremor was also analysed.

Results

There was significant side-to-side asymmetry of intensity in ET. The intensity in the more affected hand was over two times higher than that in the less affected one. The tremor was more severe in the nondominant hand in 62% of patients. In spite of significant difference in tremor intensity between the two sides, tremor frequency was similar in both hands. The standard deviation of centre frequency was significantly lower and the harmonic index was significantly higher in the more trembling hand.

Conclusions

Accelerometric registration revealed that asymmetry of intensity and symmetry of frequency are characteristic features of ET. The remaining two coefficients reflecting the rhythmicity and regularity of tremor also differed considerably between the hands.

Get Citation

Keywords

essential tremor, quantitative analysis, tremor parameters, power spectrum

About this article
Title

Essential tremor – assessment of tremor accelerometric parameters' symmetry and the relationship between hand dominance and severity of tremor

Journal

Neurologia i Neurochirurgia Polska

Issue

Vol 45, No 2 (2011)

Pages

121-127

DOI

10.1016/S0028-3843(14)60022-0

Bibliographic record

Neurol Neurochir Pol 2011;45(2):121-127.

Keywords

essential tremor
quantitative analysis
tremor parameters
power spectrum

Authors

Agnieszka Machowska-Majchrzak
Krystyna Pierzchała
Stanisław Pietraszek
Beata Łabuz-Roszak

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