TITLE:
Electroencephalographic Recordings in the Canine: Effects of Low Dose Medetomidine or Dexmedetomidine Followed by Atipamezole
AUTHORS:
Laura C. Tepper, Andy Shores
KEYWORDS:
Dog; Brain; Electroencephalogram; Medetomidine; Atipamezole; Dexmedetomidine
JOURNAL NAME:
Open Journal of Veterinary Medicine,
Vol.4 No.2,
February
10,
2014
ABSTRACT: Objectives: 1) To describe electroencephalogram (EEG)
appearance in the awake dog and compare these results with EEG recordings after
low dose medetomidine (2 μg/kg IV) followed by atipamezole (10 μg/kg, IM); 2) To
institute EEG recordings after low dose medetomidine or dexmedetomidine as a
standard of practice if focal abnormalities and amplitudes were not
significantly altered by pharmaceuticals in Phase 1 of this study. Methods:
Electroencephalograms were performed on eight clinical canine patients with
suspected intracranial disease involving the prosencephalon. A five lead montage
was used to record the EEGs. Each dog had an awake, baseline recording followed
by an EEG performed after administration of low dose medetomidine (2 μg/kg IV)
then atipamezole (10 μg/kg, IM). In the second phase of this study, the same
dose of medetomidine or dexmedetomidine at 1 μg/kg IV and atipamezole (10
μg/kg, IM) were used in the evaluation of 20 clinical patients with suspected
neurologic disease. Results: In Phase 1, awake recordings were laced with movement artifacts.
After medetomidine and atipamezole, EEG waveforms were slower. Following
atipamezole, however, the frequencies were observed to increase with time.
Statistical evaluation revealed significantly more artifacts in baseline
recordings. No statistically significant change was observed in focal
abnormalities or amplitude. In Phase 2, the a2-adrenoreceptor agonists followed by atipamezole without the use of
lidocaine produced clinically reliable results. Clinical Significance:
Quality and diagnostic electroencephalogram (EEG) recordings are frequently
inconvenient to obtain in the awake dog. Movement results in artifacts and
dislodged leads. Administration of low dose medetomidine or dexmedetomidine
followed by atipamezole reliably reduced the impact of movement artifacts and
produced clinically valid EEG recordings in dogs.