Risk factors for cluster seizures in canine idiopathic epilepsy

Factors affecting seizure recurrence in the emergency department

Background

Information on Emergency Department (ED) follow-up of patients presenting with epileptic seizures is limited.

Objectives

It was planned to investigate the factors affecting the recurrence of epileptic seizures in the follow-up of patients presenting to the ED with the complaint of epileptic seizures.

Materials and methods

This prospective, observational, single-center study was carried out in an adult population presenting to the ED. The study included patients older than 18 years of age presenting to the ED with the complaint of epileptic seizures.

Results

Of the 205 patients included in the study, 68 (33.2%) had seizure recurrence during the 6 h. In the univariable analysis, advanced age, prolonged post-ictal duration, increased seizure duration, generalized tonic clonic seizure, alcohol consumption within past 24 h, hypertension, coronary artery disease, Alzheimer's disease, prior ischemic cerebrovascular disease, low Glascow Coma Scale (GCS), high glucose, high C-Reactive Protein, high phosphorus, low potassium, high blood urea nitrogen, high lactate, increased anion gap, high osmolarity were statistically significant in predicting recurrent seizure recurrence within 6 h. According to the logistic regression, postictal duration, GCS score, and age were independent predictors in our model. The cut-off value of postictal duration in predicting seizure recurrence at the highest sensitivity (66.2%) and specificity (89.8%) was 22.5 min.

Conclusion

A prolonged postictal state, low GCS score, advanced age may be an indication of seizure recurrence. Therefore, patients with a long postictal duration, low GCS score, advanced age should be followed up more carefully in terms of recurrent seizures in the ED.

Prevalence of nonconvulsive seizures and nonconvulsive status epilepticus in dogs and cats with a history of cluster seizures: A retrospective study

BACKGROUND

Nonconvulsive seizures (NCS) and nonconvulsive status epilepticus (NCSE) are frequently observed in human patients. Diagnosis of NCS and NCSE only can be achieved by the use of electroencephalography (EEG). Electroencephalographic monitoring is rare in veterinary medicine and consequently there is limited data on frequency of NCS and NCSE.

OBJECTIVES

Determine the prevalence of NCS and NCSE in dogs and cats with a history of cluster seizures.

ANIMALS

Twenty-six dogs and 12 cats.

METHODS

Retrospective study. Medical records of dogs and cats with cluster seizures were reviewed. Electroencephalography was performed in order to identify electrographic seizure activity after the apparent cessation of convulsive seizure activity.

RESULTS

Nonconvulsive seizures were detected in 9 dogs and 2 cats out of the 38 patients (29%). Nonconvulsive status epilepticus was detected in 4 dogs and 2 cats (16%). Five patients had both NCS and NCSE. A decreased level of consciousness was evident in 6/11 patients with NCS, 3/6 also had NCSE. Mortality rate for patients with NCS (73%) and NCSE (67%) was much higher than that for patients with no seizure activity on EEG (27%).

CONCLUSION AND CLINICAL IMPORTANCE

Prevalence of NCS and NCSE is high in dogs and cats with a history of cluster seizures. Nonconvulsive seizures and NCSE are difficult to detect clinically and are associated with higher in hospital mortality rates. Results indicate that prompt EEG monitoring should be performed in dogs and cats with cluster seizures.

Approach to initial management of canine generalised epileptic seizures in primary-care veterinary practices in the United Kingdom

OBJECTIVES

To investigate how primary care clinicians in the UK approach initial management of canine generalised epileptic seizures, including factors potentially associated with prescription and choice of anti-seizure drugs (ASDs).

MATERIALS AND METHODS

Electronic health records concerning 3,150,713 consultations (917,373 dogs) were collected from 224 veterinary practices by the Small Animal Veterinary Surveillance Network. Free-text clinical narratives were reviewed to identify those consistent with generalised epileptic seizure activity, including only those recording the first presentation for seizures. Dogs older than 6 years were excluded.

RESULTS

Five hundred and seventeen cases were included. Sixty-seven dogs (13.0%) received anti-seizure drugs at first presentation; this was significantly more likely in dogs presented with cluster seizures (CS) (odds ratio 13.8, 95% confidence interval 7.3 to 26.1). Phenobarbital (n=36) and imepitoin (n=29) were the most frequently chosen anti-seizure drugs. Presentation for a single epileptic seizure occurred in 321 dogs; seven were prescribed anti-seizure drugs. Eighty-six dogs were presented with cluster seizures; 38 were prescribed anti-seizure drugs, most frequently imepitoin (n= 19) and phenobarbital (n=17). Of the dogs presenting with a single seizure and at least 6-month follow-up (n=165), 33 (20%) did not have subsequent seizures recorded.

CLINICAL SIGNIFICANCE

Primary care clinicians rarely prescribed anti-seizure drugs following a single epileptic seizure in accordance with International Veterinary Epilepsy Task Force recommendations. Less than half of dogs initially presenting with cluster seizures were prescribed anti-seizure drugs. Imepitoin was frequently selected in the treatment of cluster seizures despite no authorisation for this purpose. These findings may ultimately contribute to improved cohesion in the management of canine epileptic seizures between primary care and referral institutions.

Cross Sectional Survey of Canine Idiopathic Epilepsy Management in Primary Care in the United Kingdom

The aims of this study are to gain insight on how primary care veterinarians in the UK diagnose and treat canine idiopathic epilepsy (IE) and what they perceive as challenges in the management of canine IE. Two hundred and thirty-five primary care veterinarians took part in this survey. The questionnaire asked about the type of practice the respondent worked in, any relevant post-graduate qualifications, how many years' experience they had in practice and the participant's canine IE caseload. Participants were asked how they diagnose canine IE, how they select antiseizure drugs (ASDs) and how they assess outcome. The questionnaire also explored which information sources they have access to for deciding on canine IE treatment, challenges that may be faced when managing these cases and areas in which more support can be provided. 94.5% of participants (n = 222/235) managed <10 canine IE cases in a year and 87.8% (n = 206/235) used phenobarbital as their first line ASD. The reported mean initial phenobarbital dose was 2.1 mg/kg (standard deviation = 0.71) every 12 h. When considering how closely participants aligned with IVETF guidelines on the topics of diagnosis, ASD initiation and outcome assessment, on average participants would score around half of the available points. 53.2% (n = 125/235) of respondents recommended neutering in canine IE and 46.8% (n = 110/235) did not. 53.2% (n = 125/235) did not recommend any additional treatments for canine IE beyond use of ASDs. 23.4% recommended Purina Neurocare diet (n = 55/235), 12.8% recommended environmental modification (n = 30/235), and 6.8% (n = 16/235) recommend medium chain triglyceride supplements. In this study participants found managing client expectations to be most challenging alongside canine IE emergency management. The main limitation of this study is the relatively low response rate and therefore the results may not reflect the entire small animal veterinary profession in the UK. However, the results of this study represent a starting point to inform educational resources and support strategies to improve quality care of canine IE in primary care.

A Review of the Impact of Neuter Status on Expression of Inherited Conditions in Dogs

Gonadectomy is an important reproductive management tool employed in many countries, and is highly prevalent in the US with an estimated 85% of dogs being neutered. Despite the societal benefits in pet population control, negative associations between neuter status, and health conditions have been reported in recent years. Most particularly observed are the consequences of early age neutering. Knowing that different physiological systems rely upon gonadal steroids during development and physiological maintenance, studies have been undertaken to assess the impact of neuter status on multiple body and organ systems. For some inherited conditions, neutering is associated with an increased risk of expression. Neutering has also been associated with altered metabolism and a predisposition for weight gain in dogs, which may confound the detected risk association between neutering and disease expression. This review summarizes the effects of neutering on cancer, orthopedic, and immune disorders in the dog and also explores the potentially exacerbating factor of body weight.

Associations between neutering and idiopathic epilepsy in Labrador retrievers and Border collies under primary veterinary care in the UK

There are sparse published scientific data on associations between neutering and the severity and survival of dogs with idiopathic epilepsy. This study aimed to explore the timing of neutering with respect to onset of seizures in dogs with idiopathic epilepsy. Associations between neutering and both age of onset of seizures and the occurrence of cluster seizures or status epilepticus were examined. Survival analysis investigated the effects of sex-neuter categories. The median survival time of Border collies was compared with data previously reported in literature. The study included veterinary primary-care clinical data on 117 Labrador retrievers and 57 Border collies diagnosed with idiopathic epilepsy from the VetCompass project in the UK. The majority (74.2%; P≤0.001) of neutered cases were neutered before the onset of seizures. Age (years) at onset of seizures did not differ between dogs intact at time of onset and dogs neutered before onset of seizures (males 3.6 vs. 3.7; P=0.468 and females 3.4 vs. 4.1; P=0.154). Neuter status was not associated with the occurrence of cluster seizures (males P=0.947 and females P=0.844). Dogs intact at onset of seizures had longer median survival times than dogs neutered before onset of seizures (males, 1436 days vs. 1234 days; P=0.019; females, 1778.5 days vs. 1261 days; P=0.027). Median survival time of 1393 days for Border collies was longer than previously reported (P≤0.001). These results do not support recommendations to neuter dogs with idiopathic epilepsy within an evidence-based treatment plan.

Retrospective epidemiological study of canine epilepsy in Japan using the International Veterinary Epilepsy Task Force classification 2015 (2003-2013): etiological distribution, risk factors, survival time, and lifespan

Background

Epilepsy is the most common neurological disease in veterinary practice. However, contrary to human medicine, epilepsy classification in veterinary medicine had not been clearly defined until recently. A number of reports on canine epilepsy have been published, reflecting in part updated proposals from the human epilepsy organization, the International League Against Epilepsy. In 2015, the International Veterinary Epilepsy Task Force (IVETF) published a consensus report on the classification and definition of canine epilepsy. The purpose of this retrospective study was to investigate the etiological distribution, survival time of dogs with idiopathic epilepsy (IdE) and structural epilepsy (StE), and risk factors for survival time, according to the recently published IVETF classification. We investigated canine cases with epilepsy that were referred to our teaching hospital in Japan during the past 10 years, and which encompassed a different breed population from Western countries.

Results

A total of 358 dogs with epilepsy satisfied our etiological study criteria. Of these, 172 dogs (48 %) were classified as IdE and 76 dogs (21 %) as StE. Of these dogs, 100 dogs (consisting of 65 with IdE and 35 with StE) were included in our survival study. Median survival time from the initial epileptic seizure in dogs with IdE and StE was 10.4 and 4.5 years, respectively. Median lifespan of dogs with IdE and StE was 13.5 and 10.9 years, respectively. Multivariable analysis demonstrated that risk factors for survival time in IdE were high seizure frequency (≥0.3 seizures/month) and focal epileptic seizures.

Conclusions

Focal epileptic seizures were identified as a risk factor for survival time in IdE. Clinicians should carefully differentiate seizure type as it is difficult to identify focal epileptic seizures. With good seizure control, dogs with IdE can survive for nearly the same lifespan as the general dog population. Our results using the IVETF classification are similar to previous studies, although some features were noted in our Japanese canine population (which was composed of mainly small-breed dogs), including a longer lifespan in dogs with epilepsy and a larger percentage of meningoencephalomyelitis of unknown origin in dogs with StE.