Quantification of movement in normal and parkinsonian macaques using video analysis

BACKGROUND

Quantification of spontaneous animal movement can be achieved using analysis of video recordings of the animals. Previous reports of video-based methods are based on outdated computer platforms or require the use of specialized equipment.

NEW METHOD

We developed a video analysis algorithm to quantify movement based on the commonly used MATLAB programming language. The algorithm is based on pixel differences between frames of video footage acquired with a standard video camera.

RESULTS

The new algorithm was validated, analyzing the amount of movements made by monkeys undergoing treatment with the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to induce parkinsonism. We compared the movement quantification generated by the new system of analysis with results obtained with a conventional infrared beam break counting system, a parkinsonism rating scale, and accelerometry-based motion quantification in three rhesus macaques. The information provided by our video analysis method was consistent with that obtained with the first two methods, and more detailed than the third.

COMPARISON WITH EXISTING METHODS

The new method can replace other methods to quantify movement. Although other video analysis methods have been described, some have since been deprecated, or involve the use of specialized hardware. The new method provides a straightforward and fast approach of analyzing the amount of movement in caged experimental animals, using conventional off-the-shelf equipment and moderate computing resources.

CONCLUSIONS

This video analysis method provides an affordable, open access platform to quantify animal movement.

A low-cost solution for quantification of movement during DBS surgery

BACKGROUND

During the deep brain stimulation (DBS) electrode implantation operation with microelectrode recordings (MER) in awake patients, somatotopic testing and test stimulation are performed to improve electrode placement and provide the most beneficial symptom reduction possible, while minimizing side effects. As this procedure is commonly used to alleviate abnormal movements associated with Parkinson's disease (PD) and Essential Tremor (ET), intraoperative assessment of a patient's movements is critical to optimizing surgical benefit. However, despite its importance, movement assessment is typically subjective and qualitative.

NEW METHOD

Here, we present a detailed description of a low-cost, open-source system as a solution.

RESULTS

The described system measures movements intraoperatively and in synchrony with neurophysiological recordings for both online visualization and offline analysis.

COMPARISON WITH EXISTING METHOD(S)

Few movement quantification systems are designed to interface with intraoperative neurophysiological recordings; the widespread application of such systems may be limited by their cost and proprietary, closed-source nature. The system presented provides a low-cost, open-source alternative.

CONCLUSIONS

The system outlined in this work may improve the DBS procedure by adding valuable objectivity in movement quantification.