Van Ham L M, Nijs J, Vanderstraeten G G, Mattheeuws D R
Department of Small Animal Medicine and Clinical Biology, Faculty of Veterinary Medicine, University of Ghent, Belgium.
Am J Vet Res. 1996 Feb;57(2):142-6.
To compare 2 types of narcotic-induced anesthesia for recording of transcranial magnetic motor evoked potentials (TMMEP) in dogs.
The effect of different doses of sufentanil and midazolam and of sufentanil and nitrous oxide on onset latencies and peak-to-peak, amplitudes of TMMEP was evaluated and compared.
18 neurologically normal dogs.
Premedication with droperidol and fentanyl. Induction and maintenance of anesthesia either with sufentanil and midazolam or with sufentanil and nitrous oxide. Recording of TMMEP from the extensor carpi radialis muscle of the forelimb and from the cranial tibial muscle of the hind limb.
Both types of narcotic anesthesia induced dose-dependent suppression of TMMEP; compared with baseline recordings, latencies increased, amplitudes decreased, and reproducibility became poorer with increasing dose of the anesthetics. Using surgical-depth doses of the anesthetics, TMMEP could still be recorded in all dogs with sufentanil and nitrous oxide, but not with sufentanil and midazolam anesthesia.
Sufentanil and nitrous oxide anesthesia was superior to sufentanil and midazolam anesthesia for TMMEP recording.
In small animal medicine, and in dogs in particular, spinal cord diseases are among the most frequently encountered neurologic disorders. The development of techniques for recording TMMEP in anesthetized dogs allows noninvasive evaluation of transmission along descending motor pathways of the spinal cord.
