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While tremor is often the most visible symptom of Parkinson’s disease, bradykinesia can be the most impairing to the patient. The term "bradykinesia" literally means "slowed movements"; however, in the literature, the "bradykinesia" is often used synonymously with the terms "akinesia" and "hypokinesia." Technically, "bradykinesia" only refers to slowness of movement; however, lack of spontaneous movement (akinesia) and smaller than desired movements (hypokinesia) are often grouped together as "bradykinesia." This misuse in terminology can result in widespread variability in clinical ratings.

The standard clinical method for evaluating bradykinesia is qualitative assessment by a clinician and score assignment (0 – 4) based on the Unified Parkinson’s Disease Rating Scale (UPDRS). This score is assigned while the subject completes repetitive tasks of finger-tapping, hand opening-closing, and pronation-supination. Evaluators are instructed to account for a wide array of factors such as speed, amplitude, fatiguing, hesitations, arrests in movement, and how these variables change during the task. This is challenging to even the most experienced movement disorder specialist. A given patient could be scored a 2 on the UPDRS finger-tapping task due to slow and large amplitude movements or fast and small amplitude movements. It is difficult to gauge weights that specific clinicians place on different bradykinesia manifestations.

The inconsistency among raters may have implications beyond symptom severity assessments. Recent data have shown that speed and amplitude respond differentially to dopaminergic medication ^[1]. Furthermore, it is unknown if the underlying neural mechanisms that cause the various bradykinesia manifestations are the same. A quantitative understanding of different bradykinesia features could ultimately lead to the development of more targeted treatments for specific patients with Parkinson’s disease.

One of the most difficult aspects of monitoring Parkinson’s disease (PD) motor symptoms, is that the severity of tremor and bradykinesia (slowed movements) greatly fluctuates throughout the day.

When medication is at its peak effectiveness, the patient is said to be “On.” Similarly, when medication has completely worn off, the subject is said to be “Off.” Symptoms are often worst first thing in morning, but improve after the first dose of medication. However, as the medication wears off, symptoms return mid-day. These cycles of waxing and waning motor symptoms continue throughout the day. Controlling these “On” and “Off” cycles can be difficult, as patients with PD are typically evaluated in the neurologists’ office, which only allows the physician to capture a snapshot of motor symptoms. Furthermore, patients typically are instructed to refrain from taking medication the night prior to the office visit. A state of anxiety in this condition may amplify PD symptoms during motor evaluation. Monitoring motor symptoms at home would provide clinicians with improved tracking of these complex motor fluctuations and in-turn optimize medication dose to improve patient quality of life.

Kinesia is a compact wireless system developed by CleveMed to quantify movement disorder symptoms. In clinical trials, Kinesia objectively quantified tremor and bradykinesia in PD patients in the clinic. Objective symptom ratings output by the Kinesia system were highly correlated to clinician ratings. CleveMed has recently begun a clinical study in which the Kinesia system is being used throughout the day, at home, by patients with PD. Preliminary results demonstrate that Kinesia can capture the “On” and “Off” motor symptom fluctuations in a subject’s home. Monitoring PD symptoms on a more continuous basis at a patient’s home should improve clinical outcomes and decrease costs especially for disparate patient populations in areas not in close proximity to movement disorder specialists.

Parkinson’s disease (PD) is a neurodegenerative disorder that is caused by the death of dopamine producing neurons in the brain. Primary motor symptoms of PD include tremor, rigidity, bradykinesia (slowed movements or hesitations) and gait and balance issues. Since there is currently no cure for PD, the symptoms are treated typically with pharmaceutical interventions.

One of the more common medications prescribed for PD is L-Dopa, which is used to increase levels of dopamine in the brain. While effective, a common issue with the use of L-Dopa is that there is a fine line between the correct amount of medication and too much. Too much medication results in dyskinesias, or wild, uncontrollable movements. Also, the effectiveness of L-Dopa decreases over time.

When L-Dopa is no longer effective as a treatment for PD symptoms, patients can consider a surgical procedure called deep brain stimulation, or DBS. When patients opt to have DBS surgery, tiny electrodes are implanted in the brain through a hole in the skull which emit pulses of stimulation that aide in symptom alleviation. The location of the electrode can vary depending on the patient but the two most common are subthalamic nucleus (STN) and the globus pallidus interna (GPi). A patient can also have electrodes implanted on one side of the brain or both, depending on whether their symptoms are unilateral or bilateral. The electrode or electrodes connect to a pulse generator which is typically implanted below the skin near the collarbone. The implanted pulse generator, or IPG, controls the electrode stimulation output. Parameters such as amplitude (the power of the stimulation), frequency (how often the stimulations pulses occur) and duration (how long each pulse lasts) must be set.

During DBS surgery the patient is awake and fully aware. This is because a nurse must perform motor assessments with the patient to determine if the electrode has been placed in an optimum location and depth. This assessment includes motor tasks that the patient is asked to complete to determine the severity levels of their symptoms. This can sometimes be time consuming as the patient must complete the assessment each time the electrode is moved.

Once surgery is completed, patients will return to the clinic to have the IPG settings adjusted. Again, a nurse will administer a motor assessment and alter the amplitude, frequency and duration of the pulses until an optimum combination is found with best alleviates the patient’s symptoms. This adjustment is repeated a number of times as symptoms worsen due to the progression of the disease.

While the exact reason DBS works is still not known, the number of PD patient lives the surgery has improved is dramatic. Patients with debilitating motor symptoms that leave them nearly incapable of performing activities of daily living can have the ability to move and function as they did before their diagnosis of PD. This is not to say that DBS does not have risks. It is a major surgical operation and results are not the same for each patient. The first step to determining whether or not DBS would be appropriate for any PD patient would be to discuss their options with a certified movement disorder clinician or neurologist.

Kinesia is a system for objectively monitoring and tracking the severity of Parkinson’s disease symptoms in conjunction with clinician evaluations using the Unified Parkinson’s Disease Rating Scale (UPDRS). The device uses tiny motion sensors (accelerometers and gyroscopes) to collect patient symptom data and, using a Bluetooth radio, wirelessly transmits that information to a PC. An addition to the system has just been released which includes automated tremor scoring based on the 0-4 scoring method of the UPDRS. Before Kinesia, there was no objective way to consistently track symptoms, making this a large advance in the way Parkinson’s disease patients are monitored.

The Kinesia patient unit is worn on the hand and wrist while patients follow video instruction for completing upper extremity motor tasks. After the completion of the tasks, algorithms in the software automatically score three tremor tasks for evaluating rest, postural and kinetic tremor on a 0-4 scale based on the UPDRS. In addition to the scoring being automated and repeatable, the scores are provided with better resolution than the whole numbers given with the UPDRS. Kinesia will assign scores such as 1.29, 3.75 or 0.84 to provide clinicians with a more exact picture of a patient’s symptoms. Reports can be generated and tremor symptom history can be viewed by their clinician, assisting them in making decisions regarding the progression of the disease, the patient’s current medication or other methods of treatment. A peer reviewed publication documenting clinical utility was accepted by The Movement Disorders Journal and is currently available online at http://www3.interscience.wiley.com/journal/121634261/abstract

There are many other symptoms that affect PD patients outside of tremor, including bradykinesia (slowed movements or hesitations), rigidity, gait and balance issues and dyskinesias (wild, involuntary movements caused by an overabundance of dopamine in the brain – the result of a patient being overmedicated). Automated tremor scoring is only the beginning of the development of Kinesia . Researchers at CleveMed are in the process of conducting a large clinical trial involving three movement disorders centers and one hundred fifty PD patients. The data collected during this study will aid in the development of algorithms for automated scoring of bradykinesia and dyskinesias. The overall goal is to include scoring for a large majority of the motor symptoms that affect PD patients.