Assessment of dorsal nerve root and spinal cord dorsal horn function in clinically normal dogs by determination of cord dorsum potentials.
OBJECTIVE
To establish normal predictive values for cord dorsum potential (CDP) onset latency after thoracic and pelvic limb sensory or mixed nerve stimulation in adult dogs.


METHODS
26 clinically normal adult dogs.


METHODS
Sensory nerve action potentials (SNAP) were recorded proximally from tibial and lateral superficial radial nerves after distal stimulation. The CDP were recorded from the L4-L5 interarcuate ligament for the tibial nerve and from the C7-T1 interarcuate ligament for the radial nerve. Linear regression analyses were performed for CDP onset latency, and mean +/- SD was calculated for CDP onset to peak latency differences and sensory nerve conduction velocities (SNCV).


RESULTS
For the tibial nerve, expected CDP onset latency (CDPOL) = -1.194 + 0.014 X pelvic limb length (mm; R2 = 0.912); CDPOL = -2.156 + 0.011 X pelvic limb/spinal length (mm; R2 = 0.911); and CDPOL = 0.941 + 2.197 X tibial nerve SNAP latency (milliseconds; R2 = 0.903). For the radial nerve, CDPOL = -0.9 + 0.014 x thoracic limb length (mm; R2 = 0.873); and CDPOL = 1.454 + 1.874 X radial nerve SNAP latency (milliseconds; R2 = 0.903). Mean +/- SD for CDP onset to peak latency difference for tibial and radial nerves was 3.1+/-0.3 and 3.0+/-0.4 milliseconds, respectively.


CONCLUSIONS
Strong linear associations exist between CDPOL and a number of easily measured peripheral independent variables in dogs. There is also a narrow range of normal values for CDP onset to peak latency differences that is independent of limb length.


CONCLUSIONS
CDP evaluation can be used to accurately assess functional severity and distribution of abnormalities in proximal sensory nerves, dorsal nerve roots, and spinal cord dorsal horns in dogs with suspected neuropathy, radiculopathy, or myelopathy involving the brachial or lumbosacral intumescences.
Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523, USA.
P A
PA
Cuddon
A J
AJ
Delauche
J M
JM
Hutchison
D000818:Animals; D004285:Dogs / Q000502:physiology*; D004576:Electromyography / Q000662:veterinary; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D016014:Linear Models; D008297:Male; D011826:Radial Nerve / Q000502:physiology; D012016:Reference Values; D013116:Spinal Cord / Q000502:physiology*; D013126:Spinal Nerve Roots / Q000502:physiology*