Mechanical sensory threshold in Cavalier King Charles spaniels with syringomyelia-associated scratching and control dogs

TY - JOUR

T1 - Mechanical sensory threshold in Cavalier King Charles spaniels with syringomyelia-associated scratching and control dogs

AU - Thoefner, M. S.

AU - Westrup, U.

AU - Toft, N.

AU - Bjerrum, O. J.

AU - Berendt, M.

PY - 2019

Y1 - 2019

N2 - It is assumed that Cavalier King Charles spaniels with Chiari-like malformation and syringomyelia experience central neuropathic pain. An association between spinal cord parenchymal lesions and specific clinical signs (e.g. spontaneous and evoked scratching, withdrawal, and paroxysmal pain manifestations with vocalisation) has been suggested. This led to the hypothesis that mechanical sensory threshold is altered in clinical cases. The aim of this study was to quantify the cervical mechanical sensory threshold using Semmes-Weinstein monofilaments in nine Cavalier King Charles spaniels with Chiari-like malformation and assumed syringomyelia-associated central neuropathic pain compared to eight control dogs. Clinical and neurological examination including magnetic resonance imaging was undertaken. Mean mechanical sensory threshold was not significantly different between case and control dogs (t-test on log10 transformed data; P = 0.25). Substantial variation within and between dogs was seen, with individual thresholds ranging from 0.04 to 26 g in case dogs and from 0.02 to 10 g in control dogs. Based on these results, it is unlikely that Cavalier King Charles spaniels with Chiari-like malformation and syringomyelia have increased mechanical sensation characterised by lower mechanical sensory threshold when quantified with Semmes-Weinstein monofilaments. Whether clinical cases experience central neuropathic pain remains unknown. The assessment of sensory function in dogs with assumed central neuropathic pain should be multimodal and include not only mechanical but also tactile and thermal threshold quantification. The use of threshold quantification in a clinical setting is challenging due to an insufficient signal relative to the biological background noise within and between dogs.

AB - It is assumed that Cavalier King Charles spaniels with Chiari-like malformation and syringomyelia experience central neuropathic pain. An association between spinal cord parenchymal lesions and specific clinical signs (e.g. spontaneous and evoked scratching, withdrawal, and paroxysmal pain manifestations with vocalisation) has been suggested. This led to the hypothesis that mechanical sensory threshold is altered in clinical cases. The aim of this study was to quantify the cervical mechanical sensory threshold using Semmes-Weinstein monofilaments in nine Cavalier King Charles spaniels with Chiari-like malformation and assumed syringomyelia-associated central neuropathic pain compared to eight control dogs. Clinical and neurological examination including magnetic resonance imaging was undertaken. Mean mechanical sensory threshold was not significantly different between case and control dogs (t-test on log10 transformed data; P = 0.25). Substantial variation within and between dogs was seen, with individual thresholds ranging from 0.04 to 26 g in case dogs and from 0.02 to 10 g in control dogs. Based on these results, it is unlikely that Cavalier King Charles spaniels with Chiari-like malformation and syringomyelia have increased mechanical sensation characterised by lower mechanical sensory threshold when quantified with Semmes-Weinstein monofilaments. Whether clinical cases experience central neuropathic pain remains unknown. The assessment of sensory function in dogs with assumed central neuropathic pain should be multimodal and include not only mechanical but also tactile and thermal threshold quantification. The use of threshold quantification in a clinical setting is challenging due to an insufficient signal relative to the biological background noise within and between dogs.

KW - Central neuropathic pain

KW - Chiari-like malformation

KW - Quantitative sensory test

KW - Spinal cord

KW - Syrinx

U2 - 10.1016/j.tvjl.2019.01.011

DO - 10.1016/j.tvjl.2019.01.011

M3 - Journal article

C2 - 30902196

AN - SCOPUS:85062811694

SN - 1090-0233

VL - 246

SP - 92

EP - 97

JO - Veterinary Journal

JF - Veterinary Journal

ER -