“Resistance Is Futile”: A Pilot Study into Pseudoresistance in Canine Epilepsy
1
Department of Small Animal Medicine and Surgery, University of Veterinary Medicine, 30559 Hannover, Germany
2
Clinic for Internal Diseases, Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia
*
Author to whom correspondence should be addressed.
Animals 2023, 13(19), 3125; https://doi.org/10.3390/ani13193125
Submission received: 19 August 2023
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Revised: 30 September 2023
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Accepted: 3 October 2023
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Published: 6 October 2023
(This article belongs to the Section Veterinary Clinical Studies)
Simple Summary
We introduce the term and evaluate the phenomenon of pseudoresistance to antiseizure-medication in canine epilepsy cases initially diagnosed with medication-resistant epilepsy. Our study shows that around one third of the patients initially diagnosed with medication-resistant epilepsy had in fact other underlying reasons for their drug resistance (they were in fact pseudoresistant) and all but one of these cases responded to modification of the initial therapy protocol.
Abstract
Epilepsy is a common neurological disorder in veterinary practice, complicated by frequent occurrence of medication-resistant epilepsy. In human medicine, it has been noted that some patients with medication-resistant epilepsy have in fact other reasons for their apparent medication-resistance. The aim of this retrospective study was to describe the issue of pseudoresistance using as an example a population of dogs presented with presumed medication-resistant epilepsy and provide an in-depth review of what is known in human medicine about pseudoresistant epilepsy. One-hundred fifty-two cases were identified with medication-resistant epilepsy, of which 73% had true medication-resistant epilepsy and 27% patients had pseudoresistance. Low serum anti-seizure medication levels were the most common cause of pseudoresistance, present in almost half of the cases (42%), followed by inadequate choice of drugs or dosages (22%), misclassification (22%) or misdiagnosis (9%) of epilepsy and poor compliance (9%). All cases of pseudoresistance, except for one, responded to a modification of the initial therapy protocol. Pseudoresistance can bias clinical trials, misinform the clinical decision-making process, delay diagnosis and treatment, and misinform owners about their pets’ prognosis. A substantial proportion of these cases can have improvement of their seizure frequency or achieve seizure freedom upon modification of their therapeutic protocol.
Keywords:
seizures; dog; pseudoresistance; refractory epilepsy
