Dustin Heldman - Academia.edu (original) (raw)
Papers by Dustin Heldman
Neuromodulation: Technology at the Neural Interface
Neurology, 2018
Objective: To evaluate the impact of Carbidopa/Levodopa Enteral Suspension (CLES) on motor sympto... more Objective: To evaluate the impact of Carbidopa/Levodopa Enteral Suspension (CLES) on motor symptoms using wearable sensors and correlate the objective measures with results of patient-reported outcomes. Background: An emerging class of wearable sensors and big data analytics enable an objective evaluation of real-world evidence on treatment efficacy. Design/Methods: PROviDE is a US-based, prospective, longitudinal observational study to evaluate long-term comparative effectiveness of CLES in eligible patients. As part of a sub-study, motor symptoms are also being evaluated using a validated wearable sensor system which includes two sensors. The system continuously measures tremor, dyskinesia, mobility and arm swing. Endpoints from wearable sensors are collected at periodic intervals during a 4 month period (~1 month before treatment and ~3 months after treatment period). Results: The PROviDE wearable sensor sub-study has currently enrolled 13/50 planned patients. From the enrolled p...
Parkinsonism & Related Disorders, 2011
Background-Essential tremor (ET), characterized primarily by postural and kinetic tremor, is typi... more Background-Essential tremor (ET), characterized primarily by postural and kinetic tremor, is typically measured in the clinic with subjective tremor rating scales. These ratings are often used to adjust medications and assess efficacy in clinical trials. However, tremor ratings require the presence of a clinician and do not necessarily capture tremor fluctuations throughout the day during activities of daily living (ADL). Objective-To evaluate the ability of motion sensors to discriminate tremor from voluntary posture and motion, classify tremor as postural or kinetic, and rate tremor severity during standardized tasks and non-standardized activities of daily living. Methods-Ten subjects with ET wore motion sensors on the index finger and performed standardized motor tasks from the Washington Heights-Inwood Genetic Study of Essential Tremor (WHIGET) tremor rating scale (wTRS) and non-standardized ADL tasks. Four movement disorder specialists independently rated video segments of the standardized tasks but not the ADL tasks.
Handbook of clinical neurology, 2020
The gold standard in brain-computer interface (BCI) modalities is multi single-unit recordings in... more The gold standard in brain-computer interface (BCI) modalities is multi single-unit recordings in the primary motor cortex. It yields the fastest and most elegant control (i.e., most degrees of freedom and bitrate). Unfortunately, single-unit electrodes are prone to encapsulation, which limit their single-unit recording life. However, encapsulation does not significantly affect intracortical local field potentials (LFPs). LFPs and single-unit activity were recorded from the motor cortices of three monkeys (Macaca fascicularis) while they performed a standard 3D center-out reaching task and a 3D circle-drawing task. The high frequency (HF) (60-200 Hz) spectral amplitudes of a subset of the LFPs were found to be directionally tuned much like single units. In fact, stable isolation of single units on the same electrode increased the likelihood that the HF-LFP would be significantly cosine tuned to hand direction. The presence of significantly tuned single units further increased the li...
Parkinsonism & Related Disorders
Journal of Parkinson's Disease
IEEE Transactions on Biomedical Engineering
Movement Disorders Clinical Practice
Journal of Parkinson's Disease
Clinical rating of bradykinesia in Parkinson disease (PD) is challenging as it must combine sever... more Clinical rating of bradykinesia in Parkinson disease (PD) is challenging as it must combine several movement features into a single score. Additionally, in-clinic assessment cannot capture fluctuations throughout the day. To evaluate the reliability and responsiveness of a motion sensor-based tablet app for objective bradykinesia assessment in clinic and at home as compared to clinical ratings. Thirty-two PD patients treated with subthalamic deep brain stimulation (DBS) were outfitted with a motion sensor on the index finger of the more affected hand to perform two repetitions of finger-tapping, hand opening-closing, and arm pronation-supination tasks with DBS on and 10, 20, and 30 minutes after turning DBS off. Tasks were videotaped for blinded clinician rating using the Modified Bradykinesia Rating Scale (MBRS). Participants were then sent home with an app-based system to perform two repetitions of the same tasks six times per day spaced two hours apart, three days per week, for two weeks. Intraclass correlation (ICC) and minimal detectable change (MDC) were calculated. As the effects of DBS wore off, motion sensors detected worsening of amplitude sooner than did clinician-rated MBRS for all three tasks. ICCs were significantly higher and MDCs were significantly lower for motion sensors in the clinic and at home than for clinician ratings (p < 0.01). The tablet-based app demonstrated higher reliability and responsiveness in capturing bradykinesia-related tasks in the clinic and at home than did clinician ratings. This tool may enhance the assessment of novel therapies.
Digital Biomarkers
Background: Parkinson's disease (PD) motor symptoms can fluctuate and may not be accurately refle... more Background: Parkinson's disease (PD) motor symptoms can fluctuate and may not be accurately reflected during a clinical evaluation. In addition, access to movement disorder specialists is limited for many people with PD. The objective of this study was to assess the impact of motion sensor-based telehealth diagnostics on PD clinical care and management. Methods: Eighteen adults with PD were randomized to control or experimental groups. All participants were instructed to use a motion sensor-based monitoring system at home 1 day per week for 7 months. The system included a finger-worn motion sensor and tablet-based software interface that guided patients through tasks to quantify tremor, bradykinesia, and dyskinesia. Data were processed into motor symptom severity reports, which were reviewed by a movement disorder neurologist for the experimental group participants. After 3 months and 6 months, the control group participants visited the clinic for a routine appointment, while the experimental group participants had a videoconference or phone call instead. Results: Homebased assessments were completed with a median compliance of 95.7%. For a subset of participants, the neurologist successfully used information in the reports, such as quantified responses to treatment or progression over time, to make therapy adjustments. Changes in clinical characteristics from study start to end were not significantly different between the groups. Discussion: Individuals with PD were able and willing to use remote monitoring tech
Brain Research, 2016
A different innervation pattern of proximal and distal muscles from the contra- and ipsilateral m... more A different innervation pattern of proximal and distal muscles from the contra- and ipsilateral motor circuits raises the question as to whether bilateral, contra- and ipsilateral subthalamic stimulation may have different effects on the distal and proximal movements of the upper limb. To answer this question, we performed kinematic analyzes in patients with Parkinson's disease. Twenty-eight Parkinsonian patients treated by bilateral subthalamic stimulation were examined with an age-matched control group of 28 healthy subjects. They performed 14s of finger tapping, hand grasping and pronation-supination. The patient group performed these sessions in four conditions (BOTH ON, BOTH OFF, CONTRA ON, IPSI ON) after withdrawal of dopaminergic medication for 12h and a fifth condition after taking medication (BOTH ON-MED ON). A motion sensor with a three-dimensional gyroscope was worn on the index finger. Speed, amplitude, rhythm and decrement of movements were calculated and compared across these conditions. Speed and amplitude of the more distal movements were improved similarly by contra- and bilateral stimulation. Bilateral stimulation was more effective than contralateral stimulation for the more proximal movements. Contra- and bilateral stimulation ameliorated the rhythm similarly in each movement task. Decrement of distal and proximal movements was not affected by the stimulation conditions. This is the first study to show that the outcome of bi- and unilateral subthalamic stimulation on proximal and distal upper limb movements should be evaluated separately postulating the different somatotopic organization of subloops in the cortico-basal ganglia motor circuits.
Ieee Transactions on Neural Systems and Rehabilitation Engineering, 2006
Neuromodulation: Technology at the Neural Interface
Neurology, 2018
Objective: To evaluate the impact of Carbidopa/Levodopa Enteral Suspension (CLES) on motor sympto... more Objective: To evaluate the impact of Carbidopa/Levodopa Enteral Suspension (CLES) on motor symptoms using wearable sensors and correlate the objective measures with results of patient-reported outcomes. Background: An emerging class of wearable sensors and big data analytics enable an objective evaluation of real-world evidence on treatment efficacy. Design/Methods: PROviDE is a US-based, prospective, longitudinal observational study to evaluate long-term comparative effectiveness of CLES in eligible patients. As part of a sub-study, motor symptoms are also being evaluated using a validated wearable sensor system which includes two sensors. The system continuously measures tremor, dyskinesia, mobility and arm swing. Endpoints from wearable sensors are collected at periodic intervals during a 4 month period (~1 month before treatment and ~3 months after treatment period). Results: The PROviDE wearable sensor sub-study has currently enrolled 13/50 planned patients. From the enrolled p...
Parkinsonism & Related Disorders, 2011
Background-Essential tremor (ET), characterized primarily by postural and kinetic tremor, is typi... more Background-Essential tremor (ET), characterized primarily by postural and kinetic tremor, is typically measured in the clinic with subjective tremor rating scales. These ratings are often used to adjust medications and assess efficacy in clinical trials. However, tremor ratings require the presence of a clinician and do not necessarily capture tremor fluctuations throughout the day during activities of daily living (ADL). Objective-To evaluate the ability of motion sensors to discriminate tremor from voluntary posture and motion, classify tremor as postural or kinetic, and rate tremor severity during standardized tasks and non-standardized activities of daily living. Methods-Ten subjects with ET wore motion sensors on the index finger and performed standardized motor tasks from the Washington Heights-Inwood Genetic Study of Essential Tremor (WHIGET) tremor rating scale (wTRS) and non-standardized ADL tasks. Four movement disorder specialists independently rated video segments of the standardized tasks but not the ADL tasks.
Handbook of clinical neurology, 2020
The gold standard in brain-computer interface (BCI) modalities is multi single-unit recordings in... more The gold standard in brain-computer interface (BCI) modalities is multi single-unit recordings in the primary motor cortex. It yields the fastest and most elegant control (i.e., most degrees of freedom and bitrate). Unfortunately, single-unit electrodes are prone to encapsulation, which limit their single-unit recording life. However, encapsulation does not significantly affect intracortical local field potentials (LFPs). LFPs and single-unit activity were recorded from the motor cortices of three monkeys (Macaca fascicularis) while they performed a standard 3D center-out reaching task and a 3D circle-drawing task. The high frequency (HF) (60-200 Hz) spectral amplitudes of a subset of the LFPs were found to be directionally tuned much like single units. In fact, stable isolation of single units on the same electrode increased the likelihood that the HF-LFP would be significantly cosine tuned to hand direction. The presence of significantly tuned single units further increased the li...
Parkinsonism & Related Disorders
Journal of Parkinson's Disease
IEEE Transactions on Biomedical Engineering
Movement Disorders Clinical Practice
Journal of Parkinson's Disease
Clinical rating of bradykinesia in Parkinson disease (PD) is challenging as it must combine sever... more Clinical rating of bradykinesia in Parkinson disease (PD) is challenging as it must combine several movement features into a single score. Additionally, in-clinic assessment cannot capture fluctuations throughout the day. To evaluate the reliability and responsiveness of a motion sensor-based tablet app for objective bradykinesia assessment in clinic and at home as compared to clinical ratings. Thirty-two PD patients treated with subthalamic deep brain stimulation (DBS) were outfitted with a motion sensor on the index finger of the more affected hand to perform two repetitions of finger-tapping, hand opening-closing, and arm pronation-supination tasks with DBS on and 10, 20, and 30 minutes after turning DBS off. Tasks were videotaped for blinded clinician rating using the Modified Bradykinesia Rating Scale (MBRS). Participants were then sent home with an app-based system to perform two repetitions of the same tasks six times per day spaced two hours apart, three days per week, for two weeks. Intraclass correlation (ICC) and minimal detectable change (MDC) were calculated. As the effects of DBS wore off, motion sensors detected worsening of amplitude sooner than did clinician-rated MBRS for all three tasks. ICCs were significantly higher and MDCs were significantly lower for motion sensors in the clinic and at home than for clinician ratings (p < 0.01). The tablet-based app demonstrated higher reliability and responsiveness in capturing bradykinesia-related tasks in the clinic and at home than did clinician ratings. This tool may enhance the assessment of novel therapies.
Digital Biomarkers
Background: Parkinson's disease (PD) motor symptoms can fluctuate and may not be accurately refle... more Background: Parkinson's disease (PD) motor symptoms can fluctuate and may not be accurately reflected during a clinical evaluation. In addition, access to movement disorder specialists is limited for many people with PD. The objective of this study was to assess the impact of motion sensor-based telehealth diagnostics on PD clinical care and management. Methods: Eighteen adults with PD were randomized to control or experimental groups. All participants were instructed to use a motion sensor-based monitoring system at home 1 day per week for 7 months. The system included a finger-worn motion sensor and tablet-based software interface that guided patients through tasks to quantify tremor, bradykinesia, and dyskinesia. Data were processed into motor symptom severity reports, which were reviewed by a movement disorder neurologist for the experimental group participants. After 3 months and 6 months, the control group participants visited the clinic for a routine appointment, while the experimental group participants had a videoconference or phone call instead. Results: Homebased assessments were completed with a median compliance of 95.7%. For a subset of participants, the neurologist successfully used information in the reports, such as quantified responses to treatment or progression over time, to make therapy adjustments. Changes in clinical characteristics from study start to end were not significantly different between the groups. Discussion: Individuals with PD were able and willing to use remote monitoring tech
Brain Research, 2016
A different innervation pattern of proximal and distal muscles from the contra- and ipsilateral m... more A different innervation pattern of proximal and distal muscles from the contra- and ipsilateral motor circuits raises the question as to whether bilateral, contra- and ipsilateral subthalamic stimulation may have different effects on the distal and proximal movements of the upper limb. To answer this question, we performed kinematic analyzes in patients with Parkinson's disease. Twenty-eight Parkinsonian patients treated by bilateral subthalamic stimulation were examined with an age-matched control group of 28 healthy subjects. They performed 14s of finger tapping, hand grasping and pronation-supination. The patient group performed these sessions in four conditions (BOTH ON, BOTH OFF, CONTRA ON, IPSI ON) after withdrawal of dopaminergic medication for 12h and a fifth condition after taking medication (BOTH ON-MED ON). A motion sensor with a three-dimensional gyroscope was worn on the index finger. Speed, amplitude, rhythm and decrement of movements were calculated and compared across these conditions. Speed and amplitude of the more distal movements were improved similarly by contra- and bilateral stimulation. Bilateral stimulation was more effective than contralateral stimulation for the more proximal movements. Contra- and bilateral stimulation ameliorated the rhythm similarly in each movement task. Decrement of distal and proximal movements was not affected by the stimulation conditions. This is the first study to show that the outcome of bi- and unilateral subthalamic stimulation on proximal and distal upper limb movements should be evaluated separately postulating the different somatotopic organization of subloops in the cortico-basal ganglia motor circuits.
Ieee Transactions on Neural Systems and Rehabilitation Engineering, 2006