Traumatic and iatrogenic sciatic nerve injury in 38 dogs and 10 cats: Clinical and electrodiagnostic findings.

BACKGROUND: Reports describing sciatic nerve injuries (SNI) and their outcome are scarce in veterinary medicine. HYPOTHESIS: Describe the causes of traumatic and iatrogenic SNI and evaluate which clinical and electrodiagnostic findings predict outcome. ANIMALS: Thirty-eight dogs and 10 cats with confirmed SNI referred for neurologic and electrodiagnostic evaluation. METHODS: Clinical and electrodiagnostic examination results, including electromyography (EMG), motor nerve conduction studies, muscle-evoked potential (MEP), F-waves, sensory nerve conduction studies, and cord dorsum potential (CDP), were retrospectively evaluated. Quality of life (QoL) was assessed based on owner interviews. RESULTS: Surgery (42%) and trauma (33%) were the most common causes of SNI; in dogs, 24% were caused by bites from wild boars. Ability to flex and extend the tarsus was significantly associated with positive outcome in dogs. Mean time from onset of clinical signs until electrodiagnostic evaluation was 67 ± 65 (range, 7-300) days and 65 ± 108 (range, 7-365) days for dogs and cats, respectively. A cut-off amplitude of 1.45 mV for compound motor action potentials (CMAP) was predictive of positive outcome in dogs (P = .01), with sensitivity of 58% and specificity of 100%. CONCLUSIONS AND CLINICAL IMPORTANCE: Clinical motor function predicts recovery better than sensory function. Electrodiagnostic findings also may play a role in predicting the outcome of SNI. Application of the proposed CMAP cut-off amplitude may assist clinicians in shortening the time to reassessment or for earlier suggestion of salvage procedures. Owners perceived a good quality of life (QoL), even in cases of hindlimb amputation.

Evaluation of central vestibular syndrome in dogs using brainstem auditory evoked responses recorded with surface electrodes / Avaliação da síndrome vestibular central em cães usando respostas evocadas auditivas do tronco cerebral gravadas com eletrodos de superfície

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.(AU)

Este estudo destina-se à análise da morfologia, da amplitude, da latência e do intervalo das ondas das respostas evocadas auditivas no tronco cerebral (BAERs) em cães com síndrome vestibular central (CVS) registrados com eletrodos de superfície. Dez cães com CVS foram examinados por estimulação mono e binaural usando um sistema de eletrodiagnóstico Neuropack, com intensidade do estímulo de 90 dBSPL. Os exames BAERs relevaram alterações morfológicas das ondas I, II, III e V, bem como baixas amplitudes para todas as ondas no caso dos 7/10 cães. Os valores de P obtidos foram = 0.014 para ampitude da onda I, 0.031 para a II e 0.032 para a V. Compararam-se as latências das ondas I, II, III e V geradas pelo estímulo monoaural direito e esquerdo em cães com CVS e não foram constatadas diferenças significativas (P > 0.05). Igualmente não foram observadas diferenças estatísticas no caso das latências BAERs no que diz respeito às ondas gravadas depois de estímulos binaural e monoaural (esquerdo ou direito). Pelo que é de conhecimento dos autores da presente pesquisa, este é o primeiro estudo sobre BAERs usando eletrodos de superfície obtidos em cães com CVS.(AU)

Brainstem auditory-evoked potential in Boxer dogs / Potencial evocado auditivo de tronco encefálico em cães da raça Boxer

Brainstem auditory-evoked potential (BAEP) has been widely used for different purposes in veterinary practice and is commonly used to identify inherited deafness and presbycusis. In this study, 43 Boxer dogs were evaluated using the BAEP. Deafness was diagnosed in 3 dogs (2 bilateral and 1 unilateral) allowing the remaining 40 Boxers to be included for normative data analysis including an evaluation on the influence of age on the BAEP. The animals were divided into 2 groups of 20 Boxers each based on age. The mean age was 4.54 years (range, 1-8) in group I, and 9.83 years (range, 8.5-12) in group II. The mean latency for I, III, and V waves were 1.14 (±0.07), 2.64 (±0.11), and 3.48 (±0.10) ms in group I, and 1.20 (±0.12), 2.73 (±0.15), and 3.58 (±0.22) ms in group II, respectively. The mean inter-peak latencies for the I-III, III-V and I-V intervals were 1.50 (±0.15), 0.84 (±0.15), and 2.34 (±0.11) ms in group I, and 1.53 (±0.16), 0.85 (±0.15), and 2.38 (±0.19) ms in group II, respectively. Latencies of waves I and III were significant different between group I and II. For the I-III, III-V and I-V intervals, no significant differences were observed between the 2 groups. As far as we know, this is the first normative study of BAEP obtained from Boxer dogs.

O potencial evocado auditivo de tronco encefálico (PEATE) tem sido amplamente utilizado com diferentes finalidades na prática veterinária e é comumente usado para identificar a surdez hereditária e a presbiacusia. No presente estudo, 43 cães da raça Boxer foram pelo teste PEATE. Foi diagnosticada surdez em 3 cães (2 bilaterais e 1 unilateral), e 40 Boxers foram usados no estudo normativo incluindo avaliação da influência da idade no PEATE. Os animais foram divididos de acordo com a idade em 2 grupos de 20 Boxers cada. A idade media foi 4,54 anos (variação de 1-8) no grupo I e 9,83 anos (variação de 8,5-12) no grupo II. A latência media das ondas I, III e V foram: 1,14 (±0,07); 2,64 (±0,11) e 3,48 (±0,10) ms no grupo I; e 1,20 (±0,12); 2,73 (±0,15) e 3,58 (±0,22) ms no grupo II, respectivamente. A latência media para os intervalos I-III, III-V e I-V foram 1,50 (±0,15); 0,84 (±0,15) e 2,34 (±0,11) ms no grupo I; e 1,53 (±0,16); 0,85 (±0,15) e 2,38 (±0,19) ms no grupo II, respectivamente. As latências das ondas I e III foram estatisticamente diferentes entre os grupos I e II. Não foram observadas diferenças estatísticas entre os dois grupos para os intervalos I-III, III-V e I-V. De acordo com a revisão realizada, este é o primeiro estudo normativo de BAEP realizado em cães da raça Boxer.

Brainstem auditory evoked potential testing in Dalmatian dogs in Brazil / Potencial evocado auditivo de tronco encefálico em cães da raça Dálmata no Brasil

The brain stem auditory-evoked potential (BAEP) is an electrophysiologic test that detects and records the electrical activity in the auditory system from cochlea to midbrain, generated after an acoustic stimulus applied to the external ear. The aim of this study is to obtain normative data for BAEP in Dalmatian dogs in order to apply this to the evaluation of deafness and other neurologic disorders. BAEP were recorded from 30 Dalmatian dogs for a normative Brazilian study. Mean latencies for waves I, III, and V were 1.14 (±0.09), 2.62 (±0.10), and 3.46 (±0.14) ms, respectively. Mean inter-peak latencies for I-III, III-V, and I-V intervals were 1.48 (±0.17), 0.84 (±0.12), and 2.31 (±0.18) ms, respectively. Unilateral abnormalities were found in 16.7% of animals and bilateral deafness was seen in one dog. The normative data obtained in this paper is compatible with other published data. As far as we know this is the first report of deafness occurrence in Dalmatian dogs in Brazil...

O potencial evocado auditivo de tronco encefálico (BAEP) é um teste eletrodiagnóstico que detecta e registra a atividade elétrica do sistema auditivo desde a cóclea até o tronco encefálico, gerada após a emissão de um estímulo acústico na orelha externa. O objetivo deste estudo é obter dados normativos para o BAEP em cães da raça Dálmata para usá-lo para detecção de surdez e de outras alterações neurológicas. BAEP foi obtido de 30 cães da raça Dálmata para um estudo normativo no Brasil. As latências médias para as ondas I, III e V foram 1,14ms (±0,09); 2,62ms (±0,10) e 3,46ms (±0,14), respectivamente. A média das latências dos intervalos I-III, III-V e I-V foi 1,48ms (±0,17); 0,84ms (±0,12) e 2,31ms (±0,18), respectivamente. Alteração unilateral foi observada em 16,7% dos animais, e surdez bilateral foi observada em um cão. Os dados normativos obtidos neste trabalho são compatíveis com outros dados já publicados. Segundo a revisão realizada, este é o primeiro relato da ocorrência de surdez em cães da raça Dálmata no Brasil...

Probable trigeminal nerve schwannoma in a dog.

A 7-year-old male Husky dog developed atrophy of the right masseter muscle and pruritus of the right side of the face. A myogenic origin was excluded using muscular biopsy. Electrophysiologically, there was involvement of the motor and sensory fibers of the trigeminal nerve, suggesting a lesion located between the brainstem and the trigeminal ganglion. On MRI examination, a nodular mass was detected in the right caudal fossa. This mass was characterized by intense enhancement after injection of contrast medium. Because of the progressive clinical signs, electrophysiology, and MRI results, a presumptive diagnosis of a trigeminal nerve schwannoma was made. The animal's condition improved slightly with corticosteroids. The dog underwent euthanasia 3 months after initial presentation. Necropsy was not performed.

Neuromuscular disease in a dog.

Diffuse neuromuscular disease occurs sporadically in dogs. The most commonly reported diffuse neuromuscular diseases are polyradiculoneuritis (coonhound paralysis), tick paralysis, botulism, and myasthenia gravis (1,2,12). This clinical report describes an atypical presentation of a diffuse neuromuscular disease in a dog.

Disseminated protothecosis causing acute blindness and deafness in a dog.

A 3-year-old Collie bitch was euthanatized two weeks after the onset of blindness and deafness. The hearing deficit had been localized by clinical signs, brain stem auditory evoked responses, and impedance audiometry. Protothecosis was diagnosed by cytologic and histologic examinations. The organism was identified as Prototheca zopfii . Organisms and granulomatous lesions were found in kidney, heart, liver, skeletal muscle, thyroid gland, colon, bronchial lymph node, brain, and cochlea.