A clinical and diagnostic approach to the patient with seizures

Idiopathic Epilepsy Risk Allele Trends in Belgian Tervuren: A Longitudinal Genetic Analysis

Idiopathic epilepsy (IE) has been known to be inherited in the Belgian Tervuren for many decades. Risk genotypes for IE in this breed have recently been identified on Canis familiaris chromosomes (CFA) 14 and 37. In the current study, the allele frequencies of these loci were analyzed to determine whether dog breeders had employed a purposeful selection against IE, leading to a reduction in risk-associated allele frequency within the breed over time. The allele frequencies of two generational groupings of Belgian Tervuren with and without IE were compared. Allele frequencies for risk-associated alleles on CFA14 were unchanged between 1985 and 2015, whereas those on CFA37 increased during that time in the control population (p < 0.05). In contrast, dogs with IE showed a decrease (p < 0.05) in the IE risk-associated allele frequency at the CFA37 locus. Seizure prevalence in the Belgian Tervuren appears to be increasing. These results suggest that, despite awareness that IE is inherited, selection against IE has not been successful.

Protein profiling and assessment of amyloid beta levels in plasma in canine refractory epilepsy

Introduction

The relationship between epilepsy and cognitive dysfunction has been investigated in canines, and memory impairment was prevalent in dogs with epilepsy. Additionally, canines with epilepsy have greater amyloid-β (Aβ) accumulation and neuronal degeneration than healthy controls. The present study investigated plasma Aβ42 levels and performed proteomic profiling in dogs with refractory epilepsy and healthy dogs.

Methods

In total, eight dogs, including four healthy dogs and four dogs with epilepsy, were included in the study. Blood samples were collected to analyze Aβ42 levels and perform proteomic profiling. Changes in the plasma proteomic profiles of dogs were determined by nano liquid chromatography tandem mass spectrometry.

Results and discussion

The plasma Aβ42 level was significantly higher in dogs with epilepsy (99 pg/mL) than in healthy dogs (5.9 pg/mL). In total, 155 proteins were identified, and of these, the expression of 40 proteins was altered in epilepsy. Among these proteins, which are linked to neurodegenerative diseases, 10 (25%) were downregulated in dogs with epilepsy, whereas 12 (30%) were upregulated. The expression of the acute phase proteins haptoglobin and α2-macroglobulin significantly differed between the groups. Complement factor H and ceruloplasmin were only detected in epilepsy dogs, suggesting that neuroinflammation plays a role in epileptic seizures. Gelsolin, which is involved in cellular processes and cytoskeletal organization, was only detected in healthy dogs. Gene Ontology annotation revealed that epilepsy can potentially interfere with biological processes, including cellular processes, localization, and responses to stimuli. Seizures compromised key molecular functions, including catalytic activity, molecular function regulation, and binding. Defense/immunity proteins were most significantly modified during the development of epilepsy. In Kyoto Encyclopedia of Genes and Genomes pathway analysis, complement and coagulation cascades were the most relevant signaling pathways affected by seizures. The findings suggested that haptoglobin, ceruloplasmin, α2-macroglobulin, complement factor H, and gelsolin play roles in canine epilepsy and Aβ levels based on proteomic profiling. These proteins could represent diagnostic biomarkers that, after clinical validation, could be used in veterinary practice as well as proteins relevant to disease response pathways. To determine the precise mechanisms underlying these relationships and their implications in canine epilepsy, additional research is required.

Efficacy of medium chain triglyceride oil dietary supplementation in reducing seizure frequency in dogs with idiopathic epilepsy without cluster seizures: a non-blinded, prospective clinical trial

BACKGROUND

Despite appropriate antiseizure drug (ASD) treatment, around two-thirds of dogs with idiopathic epilepsy (IE) have seizures long-term and 20-30per cent of affected dogs remain poorly controlled.

METHODS

The current study aim is to test in a field trial the efficacy and tolerability of a commercially available diet enriched with 6.5per cent medium chain triglyceride (MCT) oil in dogs (n=21) with at least a tier 1 idiopathic epilepsy diagnosis, without cluster seizures, in 10 veterinary practices across Europe. Each dog's quality of life (QoL), ataxia, sedation and frequency and severity of seizures were recorded by owners throughout the study.

RESULTS

The mean seizure frequency per month, averaged over the entire 84-day study, significantly (P=0.04) decreased 32per cent compared with the baseline monthly seizure frequency recorded during the month immediately before feeding the diet. Similarly, the seizure days rate (days/month) also declined (P<0.001) by 42per cent. QoL was reported as very good to excellent (>8.5/10) in 20 of the 21 dogs before starting the diet and this remained unchanged during the trial.

CONCLUSIONS

This study demonstrates the use of a diet enriched with MCTs as an adjunct to ASD treatment may have some antiseizure properties for dogs diagnosed with IE, as demonstrated in previous studies.

Antiepileptic Drug Use Patterns in Suspect Epileptic Dogs Among Neurology and Emergency Specialists

This study used a cross-sectional survey designed to inquire about antiepileptic drug (AED) use in newly diagnosed idiopathic epileptic dogs among board-certified emergency and neurology specialists. Results were obtained from 300 completed surveys by 128 board-certified neurologists and 172 board-certified emergency and critical care (ECC) specialists. Case volume was slightly different between groups, with 36% of neurologists and 18% of ECC specialists managing >50 cases of first-time canine seizure patients yearly. The initial AED of choice was similar between the groups, with 66% of neurologists and 64% of ECC specialists using phenobarbital and 16% of neurologists and 26% of ECC specialists using levetiracetam. Although most respondents gave a loading dose of phenobarbital, roughly one-fourth of neurologists did not load the drug versus 6% of ECC specialists. The total loading dose was similar between respondents (16 mg/kg) but varied in administration protocol. Approximately half of neurologists and nearly two-thirds of ECC specialists gave a higher initial dose of levetiracetam than recommended. Almost all the respondents who gave a higher initial dose of levetiracetam used 60 mg/kg IV once. Understanding the common practices in AED use may promote future discussions regarding best practices in the management of canine idiopathic epilepsy.

Recurrent seizures in cats: Diagnostic approach - when is it idiopathic epilepsy?

Practical relevance: Seizures are one of the most common neurologic problems recognized in cats, affecting approximately 1-3% of the general population. Treatment options and prognosis are closely related to the underlying cause, so it is important that veterinarians are familiar with the diagnostic approach to cats with seizures and options for medical management. Series outline: This is the first of a two-part article series that reviews the diagnosis and treatment of seizures in cats. Part 1 outlines the classification and terminology used to describe epilepsy and epileptic seizures in cats, and discusses some of the most common and unique causes of recurrent seizures in cats. The diagnostic approach to cats with recurrent seizures is addressed, as are criteria for the diagnosis of idiopathic epilepsy.

AUDIENCE

This review of recurrent seizures in cats is intended for all veterinarians who are facing the challenges of seizure diagnosis and management in the feline patient. Evidence base: Recommendations for diagnosis and management of feline seizure disorders have historically been extrapolated from the canine and human literature. The information and guidance provided in this two-part series is based on a review of the recent published literature addressing seizure disorders and antiepileptic treatment in cats, as well as the authors' clinical experience.

A Review: Emergency Management of Dogs With Suspected Epileptic Seizures

Dogs with seizure disorders are commonly presented to the general practitioner for initial evaluation. The most common diagnosis provided is idiopathic epilepsy. As witnessing seizures is often traumatic for owners, it is important for the practitioner to understand seizure classification, know when to initiate antiepileptic drug therapy and be comfortable with client education regarding seizures. This review briefly discusses the most up-to-date classification of seizures, the necessity to obtain accurate histories and complete examinations, base-line diagnostics to perform, the importance of owner education, and when to start medications. This is not intended to discuss detailed differential lists, in-depth information on antiepileptic drug therapy, long-term management of epileptics or those refractory to their current treatment.

Survival in 76 cats with epilepsy of unknown cause: a retrospective study

Survival of cats with epilepsy of unknown cause (EUC) has not been reported. Seizure semiology and its relationship to treatment outcome and survival was studied in a population of 76 cats. A questionnaire for seizure semiology was developed based on experimental data. Seizure semiology was characterised by owner interviews at least one year after discharge. Seizures were classified as (1) primary generalised and (2) focal without and (3) with secondary generalisation. Median age at seizure onset was four (range 0.3-18) years. One-third of cats with EUC presented with primary generalised seizures and 78 per cent of those with initially focal seizures progressed to secondary generalised seizures. Clinical signs of generalised seizures included sudden onset of loss of consciousness and tonic-clonic seizures, while cats with focal seizures had unilateral signs. Antiepileptic drug (AED) therapy was initiated in 62 cats. Complete remission rate was 42 per cent and the median survival time was 3.2 (range 1-11) years with or without AED, and 91 per cent were still alive at the time of interview. Neither semiology nor seizure type predicted survival, response to treatment and outcome in cats with EUC. A seizure-free status of more than 12 months was observed in 79 per cent of cats without AED.

Magnetic resonance imaging and computed tomography findings of Dyke-Davidoff-Masson-like syndrome in a cat

CASE REPORT

A 3.5-year-old spayed female Domestic Shorthair cat was evaluated for new onset seizures and lateralising signs indicative of a lesion in the right prosencephalon. Magnetic resonance imaging and computed tomography of the head revealed hypoplasia of the right cerebral hemisphere and changes in the overlying cranium, including hyperostosis and expansion of the diploic space, resulting in an increased pneumatisation of the rostral bones of the cranium. A congenital injury to the cerebral hemisphere and secondary changes of the cranium in response to the decreased brain parenchyma was presumed. Similar changes have been previously recognised in human patients with unilateral anomalies of the cerebral hemispheres, termed Dyke-Davidoff-Masson syndrome (DDMS).

CONCLUSION

The case presented is the first clinical and imaging description of a cat with a syndrome that closely resembles DDMS in humans. The description of the syndrome allows recognition of an additional differential for seizures in a young patient and informs the clinician of the imaging characteristics of the cranium seen with early loss of brain parenchyma.

International Veterinary Epilepsy Task Force's current understanding of idiopathic epilepsy of genetic or suspected genetic origin in purebred dogs

Canine idiopathic epilepsy is a common neurological disease affecting both purebred and crossbred dogs. Various breed-specific cohort, epidemiological and genetic studies have been conducted to date, which all improved our knowledge and general understanding of canine idiopathic epilepsy, and in particular our knowledge of those breeds studied. However, these studies also frequently revealed differences between the investigated breeds with respect to clinical features, inheritance and prevalence rates. Awareness and observation of breed-specific differences is important for successful management of the dog with epilepsy in everyday clinical practice and furthermore may promote canine epilepsy research. The following manuscript reviews the evidence available for breeds which have been identified as being predisposed to idiopathic epilepsy with a proven or suspected genetic background, and highlights different breed specific clinical features (e.g. age at onset, sex, seizure type), treatment response, prevalence rates and proposed inheritance reported in the literature. In addition, certain breed-specific diseases that may act as potential differentials for idiopathic epilepsy are highlighted.

Seizures and epilepsy in cats

Seizures are a common presenting complaint in cats, although causes and options for the treatment of seizures in this species have been historically poorly described in the veterinary literature. Seizure manifestation in cats may be different than what is typically seen in dogs, but the underlying causes of seizure activity are the same. These include primary epilepsies, structural epilepsies, and reactive seizures. Although primary epilepsy was once believed to be rare in cats, we now commonly appreciate this syndrome, albeit at a lower frequency than in dogs. Because of this, a complete diagnostic work-up is recommended for all cats presenting for initial evaluation of seizures. Symptomatic treatment of seizures in cats is similar to dogs, with only a few limitations related to species-specific antiepileptic drug toxicities. The goal of this review is to summarize the recent veterinary literature related to feline seizures, with a focus on seizure classification, clinical manifestation, diagnostic evaluation, and treatment options.