Electroencephalographic Recordings in the Canine: Effects of Low Dose Medetomidine or Dexmedetomidine Followed by Atipamezole

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 α2-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.

EEG Patterns Orienting to Lafora Disease Diagnosis—A Case Report in Two Beagles

“…Third, all reported improvement following antiepileptic treatment was based solely on the accounts of the owners, and therefore the risk of recall bias cannot be completely eliminated. Finally, in both cases EEG was performed under sedation, which could have potentially influenced the recordings; however, sedation of dogs with a low dose of medetomidine has been shown to reduce movement artifacts while allowing clinically valid EEG recordings to be obtained (28).…”

Effect of prior general anesthesia or sedation and antiseizure drugs on the diagnostic utility of wireless video electroencephalography in dogs

“…Electroencephalography is rarely used clinically to differentiate epileptic seizures from nonepileptic paroxysmal episodes in dogs, mostly because of technical difficulties and lack of a standardized protocol. [6][7][8][9][10][11][12][13][14][15][16] More specifically, the confounding factors that influence the diag- with AEEG. [27][28][29] Three dogs in our population received 4 to 6 ASD (1 dog received These data support further questions about the potential use of AEEG as a monitoring tool for epileptic patients.…”

“…Electroencephalography is rarely used clinically to differentiate epileptic seizures from nonepileptic paroxysmal episodes in dogs, mostly because of technical difficulties and lack of a standardized protocol 6‐16 . More specifically, the confounding factors that influence the diagnostic capability of electroencephalography are not known.…”

“…This impractical clinical application of EEG in veterinary medicine partly may explain the lack of protocol standardization, which makes it difficult to compare findings between different recordings. [6][7][8][9][10][11][12][13][14][15][16] Nonetheless, EEG has proven useful in veterinary medicine to detect epileptic activity that was not clinically observable. 17,18 In recent years, the use of ambulatory video EEG (AEEG) has been reported in dogs.…”

Effects of concurrent perioperative use of marbofloxacin and cimicoxib or carprofen in dogs

“…In this study an EEG was recorded because it is an established tool to detect seizure activity in dogs (Berendt et al ). A disadvantage of EEG monitoring in dogs is the need to sedate or anaesthetise the animal to avoid muscle artefacts (Tepper & Shores ). Various anaesthetics dose‐dependently dampen the EEG (Bergamasco et al , Ambrisko et al ) and anaesthesia probably had an impact on the baseline EEG monitoring in our study.…”