Variability of hand tremor in rest and in posture — A pilot study

Abstract

Previous, studies have demonstrated variability in the frequency and amplitude in tremor between subjects and between trials in both healthy individuals and those with disease states. However, to date, few studies have examined the composition of tremor. Efficacy of treatment for tremor using techniques such as Botulinum neurotoxin type A (BoNT A) injection may benefit from a better understanding of tremor variability, but more importantly, tremor composition. In the present study, we evaluated tremor variability and composition in 8 participants with either essential tremor or Parkinson disease tremor using kinematic recording methods. Our preliminary findings suggest that while individual patients may have more intra-trial and intra-task variability, overall, task effect was significant only for amplitude of tremor. Composition of tremor varied among patients and the data suggest that tremor composition is complex involving multiple muscle groups. These results may support the value of kinematic assessment methods and the improved understanding of tremor composition in the management of tremor.

Using a Smart Phone as a Standalone Platform for Detection and Monitoring of Pathological Tremors

“…This demonstrates that the smart phone can provide a reliable measure of tremor of different amplitudes. This is important as it is well known that while not all PD patients exhibit tremor, those that have tremor can exhibit highly variable tremor amplitude and that this amplitude can fluctuate over short periods of time (Duval et al, 1997; Duval and Beuter, 1998; Rahimi et al, 2011). Tremor severity can also fluctuate within a given day and over multiple days which makes long-term monitoring of patients a necessity.…”

Towards remote monitoring of Parkinson’s disease tremor using wearable motion capture systems

“…Tools that actually measure this amplitude would therefore be justified as being more consistent. Consequently, similar to other such studies [18,31,32,34,35], this study is also lacking the comparison of the proposed high-resolution system with a widely accepted kinematic tool.…”

“…Although PD tremor is classically a rest tremor, our prior work has shown that postural tremor is significant in PD [7,18,31]. The duration of this task was designed to include the re-emergent tremor.…”

“…These types of sensors are often attached in close proximity to body joints in order to measure rate of change, and consequently, tremor amplitude [3]. Joint angles can be directly measured using goniometers, which can be placed across a body joint to provide measures of rapid movements [3,9,18]. Numerous commercially available devices (APDM [19], REMPARK [20], Kinesia [21], PERFORM [5], Motus [22], Lift Labs [5], Physilog [23]) are able to track tremor in a single joint or body part.…”

A real-time system to aid clinical classification and quantification of tremor in Parkinson's disease

“…Starting from the accelerometer [10] data is possible to quantify the amplitude of oscillations and particularly the intensity of tremor at the various frequencies in the spectrum through the Power Spectral Density (PSD). This also allows an estimate of how much the tremor is disabling for the patient by limiting his normal activities into daily routine.…”