TY - JOUR
T1 - An accelerometry-based study of lower and upper limb tremor in Parkinson's disease
AU - Scanlon, Blake K.
AU - Levin, Bonnie E.
AU - Nation, Daniel A.
AU - Katzen, Heather L.
AU - Guevara-Salcedo, Alexandra
AU - Singer, Carlos
AU - Papapetropoulos, Spiridon
N1 - Funding Information:
Dr. Scanlon is currently supported by the Office of Academic Affiliations, Advanced Fellowship Program in Mental Illness Research and Treatment, Department of Veteran Affairs, by the Medical Research Service of the Veterans Affairs Palo Alto Health Care System, and by the Department of Veterans Affairs Sierra-Pacific Mental Illness Research, Education, and Clinical Center (MIRECC). Dr. Scanlon has worked as a compensated consultant to MD Consult (Elsevier Inc.) for projects unrelated to the current manuscript. Dr. Levin has no disclosures to report. Dr. Nation is supported by the Veterans Affairs San Diego Healthcare System. Dr. Katzen has grant support (K23-NS045051) from the National Institute for Neurological Disorders and Stroke, National Institute of Health. Dr. Guevara-Salcedo has no disclosures to report. Dr. Singer has received honoraria from Lundbeck, Ipsen, Merz and Allergan for advisory board participation. Dr. Singer has received grant support from Boehringer-Inhelheim, TEVA, SYNOSIA/BIOTIE, Schwartz-Pharma, MERZ, and Allergan. Dr. Papapetropoulos is currently employed by and holds stock at Pfizer Inc.
PY - 2013/6
Y1 - 2013/6
N2 - Over the past two decades, several studies have aimed to quantify the kinetic properties of tremor with primary focus on the upper limbs. However, there is a lack of investigation into the properties of tremor in the lower limbs. The objective of this preliminary study was to investigate the properties of oscillatory movement, at rest and in posture, in both the upper and lower limbs of Parkinson's disease (PD) patients with clinically undetectable to modest rest/postural tremor and healthy controls. PD patients (N = 16) and controls (N = 8) were examined clinically by a movement disorders specialist and oscillatory movements in all four extremities were evaluated using a portable biaxial accelerometer. While tremor intensity and frequency did not differ between groups, the intraindividual variability of rest and postural tremor frequency in the dexterity-dominant lower limb was lower in people living with PD than in healthy adults. Additionally, rest tremor frequency was discrepant between upper and lower limbs in PD. Our work introduces the possibility that minute variations in lower limb movements, which are imperceptible upon expert clinical exam, can be used to differentiate a diseased sample from a healthy one. These preliminary findings suggest that additional work using objective tremor measurement may improve our understanding of lower limb motor dysfunction in PD and lead to the refinement of current, and the development of new, metrics to enhance early diagnosis, differential diagnosis, and symptom quantification.
AB - Over the past two decades, several studies have aimed to quantify the kinetic properties of tremor with primary focus on the upper limbs. However, there is a lack of investigation into the properties of tremor in the lower limbs. The objective of this preliminary study was to investigate the properties of oscillatory movement, at rest and in posture, in both the upper and lower limbs of Parkinson's disease (PD) patients with clinically undetectable to modest rest/postural tremor and healthy controls. PD patients (N = 16) and controls (N = 8) were examined clinically by a movement disorders specialist and oscillatory movements in all four extremities were evaluated using a portable biaxial accelerometer. While tremor intensity and frequency did not differ between groups, the intraindividual variability of rest and postural tremor frequency in the dexterity-dominant lower limb was lower in people living with PD than in healthy adults. Additionally, rest tremor frequency was discrepant between upper and lower limbs in PD. Our work introduces the possibility that minute variations in lower limb movements, which are imperceptible upon expert clinical exam, can be used to differentiate a diseased sample from a healthy one. These preliminary findings suggest that additional work using objective tremor measurement may improve our understanding of lower limb motor dysfunction in PD and lead to the refinement of current, and the development of new, metrics to enhance early diagnosis, differential diagnosis, and symptom quantification.
KW - Extremities
KW - Intraindividual variability
KW - Monitoring
KW - Parkinson's disease
KW - Physiologic
KW - Tremor
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UR - http://www.scopus.com/inward/citedby.url?scp=84891881118&partnerID=8YFLogxK
U2 - 10.1016/j.jocn.2012.06.015
DO - 10.1016/j.jocn.2012.06.015
M3 - Article
C2 - 23639618
AN - SCOPUS:84891881118
VL - 20
SP - 827
EP - 830
JO - Journal of Clinical Neuroscience
JF - Journal of Clinical Neuroscience
SN - 0967-5868
IS - 6
ER -