Analyzing the Effects of Parameters for Tremor Modulation via Phase-Locked Electrical Stimulation on a Peripheral Nerve

(1) Background: Non-invasive neuromodulation is a promising alternative to medication or deep-brain stimulation treatment for Parkinson’s Disease or essential tremor. In previous work, we developed and tested a wearable system that modulates tremor via the non-invasive, electrical stimulation of peripheral nerves. In this article, we examine the proper range and the effects of various stimulation parameters for phase-locked stimulation. (2) Methods: We recruited nine participants with essential tremor. The subjects performed a bean-transfer task that mimics an eating activity to elicit kinetic tremor while using the wearable stimulation system. We examined the effects of stimulation with a fixed duty cycle, at different stimulation amplitudes and frequencies. The epochs of stimulation were locked to one of four phase positions of ongoing tremor, as measured with an accelerometer. We analyzed stimulation-evoked changes of the frequency and amplitude of tremor. (3) Results: We found that the higher tremor amplitude group experienced a higher rate of tremor power reduction (up to 65%) with a higher amplitude of stimulation when the stimulation was applied at the ±peak of tremor phase. (4) Conclusions: The stimulation parameter can be adjusted to optimize tremor reduction, and this study lays the foundation for future large-scale parameter optimization experiments for personalized peripheral nerve stimulation.

Daily Activity Recognition and Tremor Quantification from Accelerometer Data for Patients with Essential Tremor Using Stacked Denoising Autoencoders

Human activity recognition (HAR) has received more and more attention, which is able to play an important role in many fields, such as healthcare and intelligent home. Thus, we have discussed an application of activity recognition in the healthcare field in this paper. Essential tremor (ET) is a common neurological disorder that can make people with this disease rise involuntary tremor. Nowadays, the disease is easy to be misdiagnosed as other diseases. We have combined the essential tremor and activity recognition to recognize ET patients’ activities and evaluate the degree of ET for providing an auxiliary analysis toward disease diagnosis by utilizing stacked denoising autoencoder (SDAE) model. Meanwhile, it is difficult for model to learn enough useful features due to the small behavior dataset from ET patients. Thus, resampling techniques are proposed to alleviate small sample size and imbalanced samples problems. In our experiment, 20 patients with ET and 5 healthy people have been chosen to collect their acceleration data for activity recognition. The experimental results show the significant result on ET patients activity recognition and the SDAE model has achieved an overall accuracy of 93.33%. What’s more, this model is also used to evaluate the degree of ET and has achieved the accuracy of 95.74%. According to a set of experiments, the model we used is able to acquire significant performance on ET patients activity recognition and degree of tremor assessment.

ATTENTION DEFICIT HYPERACTIVITY DISORDER SYMPTOMS IN ADULTS WITH ESSENTIAL TREMOR

Background: Essential tremor is the most common movement disorder. İn this disease, which is characterized by tremor that increases with action and passes at rest, different accompanying symptoms can also be seen. Objective: The purpose of this study was to investigate attention deficit hyperactivity symptoms in adults with ET. Methods: Fifty six essential tremor patients and 56 controls were included in the study. Patients were recruited from outpatient clinic at Kirikkale University Medicine Faculty. An informed consent form was signed by each patient after detailed information. Institutional ethics committee approval was obtained. Patients’ characteristics such as education level, gender, age and disease duration were recorded. Symptoms of ADHD in patients and controls were determined by using the Adult Report Deficit / Hyperactivity Disorder Self Report Scale. Short Form-36 and Hospital Anxiety and Depression Scale were also performed. Essential tremor severity was determined by using the Whiget essential tremor scale. Results: Essential tremor patients had significantly higher rate of Adult Attention Disorder Self-Report Scale Deficit/Hyperactivity scores compared to controls. Scores of Adult Attention Deficit/Hyperactivity Disorder Self-Report Scale were associated with depression and anxiety scores and physical and mental component scores of Short Form-36 in bivariate analyses. There was a positive correlation between tremor severity and ASRS scores( ASRS A scores= 17,3±5,5, p=0,032, ASRS B scores= 27,7±6,7,p=0,043, ASRS T scores= 45±12,2, p=0,017) however there was no significant statistical relationship between the duration of disease and ASRS scores. Conclusion: This study showed that ADHD symptoms can be observed in adult essential tremor patients and this may be associated with increased psychosocial morbidity and lowered quality of life in ET patients.