Gabriela Dumitrita Stanciu

Interictal cardiac autonomic nervous system disturbances in dogs with idiopathic epilepsy

Autonomic nervous system (ANS) activity in the interictal period (InIp) in dogs with presumed idiopathic epilepsy (pIE) was assessed using heart rate variability (HRV) analysis. The HRVs obtained from 28 pIE dogs with interictal epileptic discharges (InIEd; 11 with treatment and 17 without treatment) detected on electroencephalography (EEG) were compared with those obtained from 13 healthy dogs. On electrocardiographic (ECG) study, the P wave dispersion (PWD; P<0.001), P max (P=0.004) and corrected QT interval (QTc; P=0.025) were significantly increased in the pIE group. On the basis of HRV analysis, the pIE dogs had an increased activity of the parasympathetic component of the ANS, including the percentage of R-R interval (pNN50%) that differs more than 50ms (P=0.011) and high frequency band (HF; P=0.041). Administration of phenobarbitone had no influence on the ANS pattern when pIE subgroups were compared (P>0.05). In InIp, dogs elicited specific conductibility delays of the electrical impulses (increased PWD and QTc interval); these delays are considered to be risk factors for developing severe arrhythmias, such as atrial fibrillation and ventricular tachycardia. When compared with human beings, a different ANS pattern characterised by increased parasympathetic activity was observed, which may influence the therapeutic approach of IE in dogs.

Evaluation of central vestibular syndrome in dogs using brainstem auditory evoked responses recorded with surface electrodes

ABSTRACT The present study aimed to analyse the wave morphology, amplitude, latency, and intervals of the brainstem auditory evoked responses (BAERs) in dogs with central vestibular syndrome (CVS) recorded with surface electrodes. Ten dogs with CVS were examined by mono- and binaural stimulation, using the Neuropack electrodiagnostic system, with stimulus intensities of 90 dBSPL. BAERs examinations revealed morphological changes of waves I, II, III, and V and decreased amplitudes of all waves in 7/10 dogs. P values obtained were = 0.014 for wave I amplitude, 0.031 for II, and III and 0.032 for V. Comparing the latencies of waves I, II, III, and V generated by right and left monoaural stimulation in dogs with CVS, we did not observe significant differences (P>0.05). No statistical differences were observed for BAERs latencies of the waves recorded after binaural and monaural stimulation (left or right). As far as we know, this is the first study of BAERs using surface electrodes, obtained from dogs with CVS. Keywords: dog, brainstem auditory evoked responses, electrophysiology, central vestibular syndrome, surface electrodes RESUMO

Brainstem auditory evoked responses in healthy Argentine Mastiff dogs recorded with surface electrodes

RESUMOEvocado auditivo de respostas – BAER ) foi gravado utilizando eletrodos de superficie em sete caes Mastiff argentino saudaveis para estimulacoes monoaural e binaural em intensidades sonoras de 90 dB NPS . As latencias e amplitudes das ondas I, III e V bem como os intervalos InterWave I- III , III -V e IV foram calculados. As diferencas estatisticas foram obtidas para as ondas III e latencias V, amplitudes das ondas III e intervalos I- III e I-V entre mono e estimulacao binaural. Por serem uma das racas geneticamente predispostas a surdez congenita, obtendo valores de referencia BAER, os caes Mastiff argentino tem uma importância clinica especial.