‘CatWalk’ automated quantitative gait analysis as a novel method to assess mechanical allodynia in the rat; a comparison with von Frey testing

Abstract

A characteristic symptom of neuropathic pain is mechanical allodynia. In animal models of neuropathic pain, mechanical allodynia is often assessed using von Frey filaments. Although the forces applied with these filaments are highly reproducible, there are various disadvantages of using this method. Testing paradigms and definitions of withdrawal threshold are not standardised. Moreover, measurements may be influenced by various conditions, such as ambient temperature, humidity, weight bearing of the limb and stress. We have therefore investigated another technique to assess mechanical allodynia, the 'CatWalk' automated quantitative gait analysis. With this computer-assisted method of locomotor analysis, it is possible to objectively and rapidly quantify several gait parameters, including duration of different phases of the step cycle and pressure applied during locomotion. We tested rats with a chronic constriction injury of the sciatic nerve, a model of neuropathic pain, both with von Frey filaments and the CatWalk method. We demonstrate that these rats minimise contact with the affected paw during locomotion, as demonstrated by a reduction in stance phase and pressure applied during stance. Moreover, these parameters show a high degree of correlation with mechanical withdrawal thresholds as determined by von Frey filaments. We therefore suggest that the CatWalk method might serve as an additional tool in the investigation of mechanical allodynia.

Progesterone Reduces Secondary Damage, Preserves White Matter, and Improves Locomotor Outcome after Spinal Cord Contusion

“…49 Accordingly, we did not find mechanical allodynia or thermal hyperalgesia in rats with SCI, and we assessed that PROG did not induce such behaviors either, neither measured by classical tests, such as hot and cold plate and the Hargreaves method, nor with CatWalk parameters normally decreased in animals in which allodynia is developing (Stance, Print Intensity, Print and Max area). 50,51 Data obtained in the present study demonstrate that PROG improved locomotor outcome after thoracic contusion. There is no general consensus about the functional effects of PROG after SCI, however.…”

“…Decreases in those parameters have been previously related to mechanical allodynia. 50,51 Thermal sensitivity. As for mechanical stimulation, no statistically significant differences were observed between groups, showing that our model did not produce thermal hyperalgesia and that PROG administration did not induce changes in the nociceptive behavior (Fig.…”

Prasugrel, a Platelet P2Y 12 Receptor Antagonist, Improves Abnormal Gait in a Novel Murine Model of Thrombotic Hindlimb Ischemia

“…In particular, maximum contact area and stance phase duration of the ischemic limb were reduced, and swing phase duration of the ischemic limb was increased, while stride length of the ischemic limb did not alter in our model. Vrinten and colleagues showed that paw placement‐related parameters of the injured limb such as contact area and contact intensity were reduced in their chronic constriction injury model, a neuropathic pain model 24. Their model also showed prolongation of swing phase duration and shortening of stance phase duration in the injured limb 24.…”

“…Vrinten and colleagues showed that paw placement‐related parameters of the injured limb such as contact area and contact intensity were reduced in their chronic constriction injury model, a neuropathic pain model 24. Their model also showed prolongation of swing phase duration and shortening of stance phase duration in the injured limb 24. Parvathy and colleagues evaluated gait disturbances in an inflammatory pain model 25.…”

The use of motion analysis to measure pain-related behaviour in a rat model of degenerative tendon injuries

“…A number of methods were developed to measure pain in small animals, including measurement of weight-bearing (Vrinten, 2003), mechanical sensitivity (Fernihough, 2004), vocalization (Han, 2005) and gait analysis such as footprint analysis (Marxen, 2004) and motion analysis [Coulthard, 2002;Coulthard, 2003;Varejao 2002]. As chronic tendinopathy is characterized with activity-related pain, it is more plausible to Page 5 of 37 A c c e p t e d M a n u s c r i p t 4 detect the pain-associated changes in dynamic state (walking) instead of static state (standing).…”