Correlation between severity of clinical signs and motor evoked potentials after transcranial magnetic stimulation in large-breed dogs with cervical spinal cord disease.
OBJECTIVE
To evaluate use of transcranial magnetic motor evoked potentials for assessment of the functional integrity of the cervical spinal cord in large-breed dogs with cervical spinal cord disease.


METHODS
Randomized, controlled, masked study.


METHODS
10 healthy large-breed control dogs and 25 large-breed dogs with cervical spinal cord diseases.


METHODS
Affected dogs were allocated to 3 groups on the basis of neurologic status: signs of neck pain alone, ambulatory with ataxia in all limbs, or nonambulatory. Transcranial magnetic stimulation was performed on each dog with the same standard technique. Motor evoked potentials (MEP) were recorded from electrodes inserted in the tibialis cranialis muscle. Following the procedure, each dog was anesthetized and cervical radiography, CSF analysis, and cervical myelography were performed. The MEP latencies and amplitudes were correlated with neurologic status of the dogs after correction for neuronal path length.


RESULTS
Mean MEP latencies and amplitudes were significantly different between control dogs and dogs in each of the 3 neurologic categories, but were not significantly different among dogs in the 3 neurologic categories. A linear association was evident between MEP latencies and amplitudes and severity of neurologic deficits; the more severe the neurologic deficits, the more prolonged the latencies and the more decreased the amplitudes.


CONCLUSIONS
Transcranial magnetic MEP are useful to assess severity of cervical spinal cord disease in large-breed dogs. Impairment of the functional integrity of the cervical spinal cord was found even in dogs with neck pain alone.
Poma
Roberto
R
Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Canada.
Parent
Joane M
JM
Holmberg
David L
DL
Partlow
Gary D
GD
Monteith
Gabrielle
G
Sylvestre
Anne M
AM
D000818:Animals; D001259:Ataxia / Q000503:physiopathology / Q000662:veterinary; D002574:Cervical Vertebrae; D004283:Dog Diseases / Q000175:diagnosis* / Q000503:physiopathology; D004285:Dogs; D004558:Electric Stimulation; D004574:Electromagnetic Fields; D004576:Electromyography / Q000662:veterinary; D019054:Evoked Potentials, Motor; D005260:Female; D008297:Male; D009334:Neck Muscles / Q000503:physiopathology; D009460:Neurologic Examination / Q000662:veterinary; D012720:Severity of Illness Index; D013118:Spinal Cord Diseases / Q000175:diagnosis / Q000503:physiopathology / Q000662:veterinary*