Researchers at UT Southwestern Medical Center in Dallas have found that a new assessment device can effectively track Parkinson’s disease progression and symptoms severity, even when used in conjunction with medication intended to control and mitigate symptoms such as trembling.
The device, called “APDM Mobility Lab,” uses a portable set of sensors to track gait, balance and other patient movement performance, providing clinicians with data measurements that make assessment of depth and severity of Parkinson’s symptoms in affected individuals more efficient and objectively accurate.
The UTSW research team’s findings appear in the Journal of the Neurological Sciences in a paper entitled “Automated gait and balance parameters diagnose and correlate with severity in Parkinson disease“ (http://dx.doi.org/10.1016/j.jns.2014.07.026), coauthored by Dr. Richard Dewey, Jr. (corresponding author), Svjetlana Miocinovic, D. Campbell Dewey, Dr. Pravin Khemani – Assistant Professor of Neurology and Neurotherapeutics, Dr. Shilpa Chitnis – an Associate Professor of Neurology and Neurotherapeutics, and third-year medical student Richard B. Dewey III, all of the University of Texas Southwestern Medical Center Department of Neurology; Ira Bernstein Dr. Ira Bernstein Clinical Professor of Clinical Sciences UTSW Department of Clinical Sciences; and Dr. Ross Querry — an Associate Professor of Physical Therapy and Orthopaedic Surgery at the UTSW Department of Physical Therapy.
The coauthors report their evaluation of individual Parkinson’s disease cases using the APDM Mobility Lab to assess the suitability of instrumented gait and balance measures for diagnosis and estimation of disease severity in PD, while employing a statistical method to reduce variables of interest. They found a set of 20 variables that differentiate PD from controls, and another set of 20 variables correlating with symptom severity.
Each study subject was asked to perform iTUG (instrumented Timed-Up-and-Go) and iSway (instrumented Sway) using the APDM Mobility Lab. MDS-UPDRS parts II and III postural instability and gait disorder (PIGD) scores, the mobility subscale of the PDQ-39, and Hoehn & Yahr stage were measured in the PD cohort, and the two sets of gait and balance variables were defined by high correlation with diagnosis or disease severity, evaluated using multiple linear and logistic regressions, ROC analyses, and t-tests.
The UTSW scientists found that in this prospective cohort study both iTUG and iSway variables differentiated 135 PD subjects from 66 age-matched controls evaluated. The area under the ROC curve was 0.82 and 0.75 respectively and correlated with all PD severity measures (R2 ranging from 0.18 to 0.61). They observed that objective exam-based scores correlated more strongly with iTUG than iSway, and that the chosen set of iTUG variables was abnormal even in very mild disease cases, while age and gender influenced gait and balance parameters and were consequently controlled in all analyses.
“Objective assessment tools for Parkinsons disease are needed to accelerate progress in developing effective therapies,” says Dr. Richard Dewey, Jr.,, a Professor of Neurology and Neurotherapeutics, and Clinical Director of the Clinical Center for Movement Disorders at UT Southwestern, and senior author of the study, in a UTSW release. “We might be able to actually measure the patients progress or regression thoroughly and objectively.”
A progressive neurological disorder whose symptoms include hand, arm, leg, jaw, and face tremors, joint rigidity or stiffness; as well as impaired balance, coordination and motor skills dexterity. PD patients can also lose facial movements and even the ability to speak. According to the Parkinson’s Disease Foundation, PD affects more than 10 million people globally, including more than one million in the U.S. living with the disease, and with 60,000 new U.S. cases diagnosed annually — most often in persons aged 50 and older and more frequently men than women.
Currently, there is no cure for Parkinson’s disease, although some medications can moderate symptoms, and PD can be difficult to diagnose accurately. There are no blood or laboratory tests proven to help diagnose sporadic Parkinson’s disease, either, with diagnosis typically arrived at through reviews of the patient’s medical history combined with neurological examination and observation.
The APDM Mobility Lab is manufactured by Portland, Oregon, based APDM (the acronym stands for “Ambulatory Parkinson’s Disease Monitoring”) — a company whose focus is principally on development of fully-featured technologies for monitoring human movement with wearable sensors, and on designing complete solutions for assessment and monitoring of people with movement disorders to help optimize therapy, accelerate clinical trials, and improve patients’ quality of life. The APDM Mobility Lab device uses wearable sensors that provide sophisticated signal processing capable of tracking even subtle changes in gait, stride, balance, rotation, and efficiency as well as range of movement in upper and lower limbs and torsos. Similar systems are typically used in conjunction with athletic training as well as by universities in research and evaluation programs.
APDM’s wearable movement monitors are about the size of a watch, and use the latest solid state MEMS technology to precisely record movement with their complete kinematic sensors suite that include triaxial accelerometers, gyroscopes, and magnetometers. APDM claims its sensors are the longest-lasting in the industry, and nominally able to hold a charge over 16 hours while continuously logging at 128Hz.,In the medical field, these IMUs are used to monitor human movement for clinical research, biomechanical research, physical therapy research, movement disorders research, and athletic tuning.
Dr. Thomas McConnell, a Clinical Professor of Pathology at UT Southwestern who is himself an early-stage Parkinson’s disease patient, was one of the clinical trial’s participant subjects, and is cited noting; “I understand the necessity of good research to advance medical care and treatment. This is a diagnostic trial, not therapeutic. But now we have hope for an earlier and more certain diagnosis of Parkinson’s disease, and identifying the most effective treatment.”
The UT Southwestern Clinical Center for Movement Disorders is a tertiary referral center that provides patients with the most advanced treatments available for Parkinson’s disease and other movement disorders, and accommodates more than 4,000 patient visits annually. The center’s physicians bring extensive experience with patients suffering from Parkinson’s disease, Huntington’s disease, other tremor disorders, tic disorders, and dystonia. The multidisciplinary center offers extensive Parkinson’s disease treatment and examination facilities, including an advanced neurophysiology lab with state-of-the-art autonomic testing, which can be useful in diagnosing certain forms of Parkinsonism and works closely with complimentary services such as psychiatry, and speech, physical, and occupational therapy to provide comprehensive care for patients.
UT Southwestern Medical Center
Journal of the Neurological Sciences
Parkinsons Disease Foundation
UT Southwestern Medical Center