Activation procedures in the electroencephalograms of healthy and epileptic cats under propofol anaesthesia

Abstract

The current study evaluated the diagnostic value of electroencephalographic recordings (EEG) in cats with epilepsy under special consideration of photic stimulation and hyperventilation. EEGs in six healthy cats were recorded under light (mean dose of 0.23 mg/kg/min) and deep (mean dose of 0.7 mg/kg/min) propofol anaesthesia, whereas EEGs in 13 diseased cats were recorded under a propofol anaesthesia which was kept as light as possible (mean dose of 0.39 mg/kg/min). Paroxysmal discharges were detected in six of 13 cats suffering from seizures (two cats with idiopathic epilepsy and four cats with symptomatic epilepsy). Activation techniques did not enhance the diagnostic value of the EEGs. Photic driving was detected in one of six healthy cats under light, in five of six healthy cats under deep propofol anaesthesia and in 11 of 13 cats with seizures. Systematic use of activation techniques does not seem to increase the diagnostic yield of the recorded EEGs and should not be used in a clinical setting until future studies indicate value. Further investigations into the origin of photic driving under propofol anaesthesia are needed and could lead to the development of a reliable animal model to research into drug effects on the EEG.

Clinical Characterization of Epilepsy of Unknown Cause in Cats

“…A high proportion of the cats with EUC in this study showed CPS with orofacial involvement and a good outcome, similar to what has been described recently in correlation with FHN . FHN previously has been described as a frequent etiology for seizures in cats whereas others only observed it infrequently . When reviewing and comparing the MRI scans from cats with EUC and cats without seizures, we were unable to confirm hippocampal signal alterations in any of the cats in the study.…”

“…Epilepsy of unknown cause was diagnosed in 22% of cats with recurrent seizures. This frequency is less than previously reported (25, 38, 41, and 54, 66%) by other authors, who had called this entity idiopathic or presumed idiopathic seizures, suspected idiopathic epilepsy, probable symptomatic epilepsy, or primary epilepsy . However, in this study, all cats with epilepsy of unknown cause and structural epilepsy were examined by 1.5 T MRI or underwent PME.…”

Meningoencephalomyelitis of Unknown Origin in Cats: A Case Series Describing Clinical and Pathological Findings

“…Brainstem auditory evoked response [modified according to Plonek et al ( 12 )] showed normal wave I, III and V latencies on both sides. Electroencephalography [modified according to Brauer et al ( 13 )] displayed sporadic spikes, a constant underlying beta rhythm and occasionally muscle artifacts caused by swallowing. The cat did not regain consciousness or spontaneous breathing within 12 h of mechanical hypocapnic ventilation and after mannitol bolus infusion (1 g/kg i. v.).…”

Epilepsy in Cats: Theory and Practice

“…There are only limited data relating to clinical EEG in healthy cats and cats with recurrent seizures . Recently encouraging EEG results were reported in cats . Under propofol restrain, 6 of 13 epileptic cats showed paroxysmal discharges (focal or generalized spikes), while such activity was not detected in any of 6 healthy control cats.…”