Clinical characterization of epileptic seizures in Pomeranians with idiopathic epilepsy or epilepsy of unknown cause

Abstract

Background Focal epileptic motor seizures manifested by limb contraction have been recognized anecdotally in Pomeranians. Objectives To investigate clinical features of idiopathic epilepsy (IE) and epilepsy of unknown cause (EUC) in Pomeranians as well as the ADAM23 haplotype frequency previously reported as a common risk haplotype for epilepsy in several breeds of dogs. Animals Twenty‐eight Pomeranians, including 15 with IE and 13 with EUC. Nine Pomeranians with epilepsy and 8 control Pomeranians were used for ADAM23 risk haplotype analysis. Methods Case series study including both retrospectively and prospectively collected cases. The ADAM23 haplotype was determined by direct sequencing of PCR amplicons. Data were analyzed descriptively. Results Focal epileptic seizures (FS) were the predominant type of seizure in 22 of 28 dogs (78.6%). Among these, 12 of the IE dogs (80.0%) and 10 of the EUC dogs (76.9%) showed FS. Notably, 21 of 22 Pomeranians with FS (95.5%) showed limb contraction during ictal periods. Some dogs with FS also showed immobility, generalized tremors, difficulty walking or moving, autonomic signs, orofacial automatisms or some combination during ictal events. Ten dogs with FS and limb contraction had electroencephalography (EEG) performed, and interictal epileptiform discharges were identified in 9 dogs. The haplotype frequency of ADAM23 in cases was lower (27.8%) than that of the controls (56.3%). Conclusions and Clinical Importance In our study, FS was the predominant type of seizure in Pomeranians, and almost all cases with FS showed limb contraction, regardless of whether having IE or EUC.

The Potential of Bemegride as an Activation Agent in Electroencephalography in Dogs

“…For example, paroxysmal dyskinesia sometimes mimic focal epileptic seizures [ 32 ]. The importance of finding interictal EDs to distinguish between paroxysmal dyskinesia and focal epileptic seizures was recently reported in Pomeranians [ 33 ]. Bemegride may be used to help to make a diagnosis of epilepsy based on the dose required to activate EDs, especially in situations where a strict diagnosis is required.…”

“…It is observed in hypoxic encephalopathy and other brain dysfunctions or during deep anesthesia. A previous study showed that the burst activities of BS included spikes and sharp waves in dogs regardless of whether the dog had epilepsy, similar to humans [ 33 ]. To unify the depth of anesthesia, the concentration of sevoflurane was maintained at the point at which BS had just completely disappeared from the EEG trace in all dogs.…”

Epilepsia Idiopatica Focal Con Crisis Motoras en 50 Caniches en Argentina: Caracterizacion Electroclinica Y Respuesta a La Terapia

“…Existen puntos de contacto con la epilepsia focal motora del Pomerania (Yu et al, 2022). La mayoría de los Caniches presentaron CFM solamente (88%), y permanecieron en alerta durante las crisis (94%).…”

“…En 71% de los casos las DEIs fueron contralaterales al lado donde ocurría el inicio de la CFM; en el resto se observaron en ambos hemisferios cerebrales. Estos hallazgos fueron similares a los comunicados en la epilepsia focal motora del Pomerania (Yu et al, 2022). Las localizaciones de las DEIs en algunos perros no coincidieron con la región sugerida por la semiología de las crisis.…”

“…Las crisis focales caracterizadas por eventos moto-res elementales (contracciones musculares estereotipadas o automatismos) se denominan crisis focales motoras (CFM) (Chandler, 2006;Berendt et al, 2015). Se comunicaron unas pocas epilepsias focales con crisis motoras en Lagotto Romagnolo (Jokinen, Metsähonkala, Bergamasco et al, 2007;Seppälä, Jokinen, Fukata et al, 2011), Boerboel sudafricano (Stassen, Grinwis, van Rhijn et al, 2019) y Pomerania (Yu, Hasegawa, Kanazono et al, 2022), con sustrato genético probado o sospechado.…”