The Mechanism of Volume Regulation by Cervical Neuroforaminal Veins as was Previously Demonstrated for the Internal Vertebral Venous Plexus (IVVP) in the Cervical and Lumbar Region / Mecanismo de Regulación del Volumen por las Venas Neuroforaminales Cervicales como se Demostró Previamente para el Plexo Venoso Vertebral Interno (PVVI) en la Regiones Cervical y Lumbar

SUMMARY: Head and cervical spine movements cause narrowing or widening of neuroforamina. In healthy individuals these movements do not cause symptoms of radiculopathy. This implies a compensating volume-regulating mechanism of the neuroforamina. Such a mechanism has been postulated in the years before CT and MRI for the neuroforaminal veins. Dural sac indentations with emptying and refilling of the internal vertebral venous plexus (IVVP) were postulated in the lumbar region using myelography. Emptying of the IVVP occurs in the lumbar spine when moving towards maximal extension and refilling while moving towards maximal flexion. Such indentations have not been shown in the cervical region. With MRI this mechanism has been demonstrated during axial rotation in the C1-C2 segment. It consists of emptying and refilling of the IVVP and thus prevents dural sac compression. During spinal surgery, the IVVP and connecting neuroforaminal veins may be damaged. Because the clinical implications of dysfunction of this protecting mechanism of the IVVP and its neuroforaminal venous connections are not clear, the consequences of such damage are unknown. Therefore, these venous structures should be examined by studying the cervical spine in supine position and, if possible, in different postures (flexion, extension and axial rotation) using MRI with contrast-enhancement and fat suppression. These images may be a basis for future advancement of clinical care.

Los movimientos de la cabeza y la columna cervical provocan un estrechamiento o ensanchamiento de las neuroforaminas. En individuos sanos estos movimientos no causan síntomas de radiculopatía. Esto implica un mecanismo compensador de regulación del volumen de las neuroforaminas. Este mecanismo se ha postulado en los años anteriores a la TC y la RM para las venas neuroforaminales. Mediante mielografía se postularon hendiduras del saco dural con vaciado y llenado del plexo venoso vertebral interno (PVVI) en la región lumbar. El vaciado del PVVI se produce en la columna lumbar cuando se mueve hacia la máxima extensión y se rellena mientras se mueve hacia la máxima flexión. En la región cervical no se han observado tales depresiones. Con resonancia magnética se ha demostrado este mecanismo durante la rotación axial en el segmento C1-C2. Consiste en vaciar y rellenar la PVVI y así evitar la compresión del saco dural. Durante la cirugía de columna, la PVVI y las venas neuroforaminales que las conectan pueden dañarse. Debido a que las implicaciones clínicas de la disfunción de este mecanismo protector de la PVVI y sus conexiones venosas neuroforaminales no están claras, se desconocen las consecuencias de dicho daño. Por tanto, estas estructuras venosas deben examinarse estudiando la columna cervical en decúbito supino y, si es posible, en diferentes posturas (flexión, extensión y rotación axial) mediante resonancia magnética con contraste y supresión grasa. Estas imágenes pueden ser una base para futuros avances de la atención clínica.

Non-invasive monitoring of intracranial pressure waveforms using Braincare® BCMM 2000 monitor in dogs with myelopathies undergoing myelography / Monitoramento não invasivo do formato das ondas de pressão intracraniana usando o monitor Braincare® BCMM 2000 em cães com mielopatias submetidos à mielografia

Intracranial pressure (ICP) monitoring is considered the gold standard for optimizing the treatment of humans in intensive care units. However, this procedure is not commonly performed in veterinary medicine because of the limitations and complications of the method. There are some new promising non-invasive techniques for monitoring ICP, but they have not been validated in veterinary medicine. This study aimed to correlate the non-invasive intracranial pressure (NI-ICP) waveforms obtained with the BCMM-2000 Brain4care monitor during myelography in dogs with myelopathies undergoing this exam for diagnostic purposes with the waveforms obtained through invasive monitoring of the subarachnoid pressure (SP). The NI-ICP waveform was monitored in six dogs with myelopathies before (M1), during (M2), and after (M3) contrast medium injection into the subarachnoid space. Cerebrospinal fluid (CSF) was collected before contrast injection. The SP waveform was simultaneously monitored in three of the six dogs. Correlations between the two methods were performed using Pearson's coefficient. The analysis of the morphology and amplitude of the waves at each moment was performed, and at M2, an increase in the P2:P1 ratio (p<0.05) was observed in both monitoring methods. In M3, the values were similar to those of M1, demonstrating the return of cerebral compliance. The comparison of the NI-ICP and SP had a positive correlation in those moments (Pearson's coefficient r=0.76; p=0.027). The speed of contrast administration, degree of spinal cord compression, and volume of CSF previously collected may affect P2:P1 and ICP dynamics. The BCMM-2000 Brain4care monitor was effective in detecting changes in ICP dynamics and abnormal pulse waveforms in dogs with meningoencephalitis of unknown origin, vertebral neoplasm and intervertebral disc disease with and without hemorrhagic myelomalacia, suggesting increased ICP induced by myelography.

A monitorização da pressão intracraniana (PIC) é considerada o padrão ouro para otimizar o tratamento de humanos em unidades de terapia intensiva, entretanto, esse procedimento não é comumente realizado na medicina veterinária devido às limitações e complicações do método. Existem algumas técnicas não invasivas promissoras de monitoramento da PIC, mas elas não foram validadas na medicina veterinária. Este estudo teve como objetivo correlacionar os formatos das ondas não invasivas da PIC (NI-PIC), obtidas com o monitor BCMM-2000 Brain4care, antes e após a injeção de meio de contraste no espaço subaracnóideo de cães com mielopatias submetidos à mielografia para fins diagnósticos, com as formas de onda obtidas por meio de monitoração invasiva da pressão subaracnóidea (PS). O formato das ondas NI-PIC foram monitoradas em seis cães com mielopatias antes (M1), durante (M2) e após (M3) injeção de meio de contraste no espaço subaracnóideo. O líquido cefalorraquidiano (LCR) foi coletado antes da injeção de contraste. A forma da onda da PS foi monitorada simultaneamente em três dos seis cães. As correlações entre os dois métodos foram feitas usando o coeficiente de Pearson. Foi realizada a análise da morfologia e amplitude das ondas em cada momento, e em M2 observou-se aumento da relação P2:P1 (p<0,05) em ambos os métodos de monitoramento. Em M3, os valores foram semelhantes aos de M1, demonstrando o retorno da complacência cerebral. A comparação do NI-PIC e PS apresentou correlação positiva nesses momentos (coeficiente de Pearson r=0,76; p=0,027). A velocidade de administração do contraste, o grau de compressão da medula espinhal e o volume de LCR coletado anteriormente podem afetar a dinâmica P2:P1 e PIC. O monitor BCMM-2000 Brain4care foi eficaz na detecção de alterações na dinâmica da PIC e dos formatos das ondas de pulso anormais em cães com meningoencefalite de origem desconhecida, neoplasia vertebral e doença do disco intervertebral com e sem mielomalácia hemorrágica, sugerindo aumento da PIC induzida pela mielografia.

Arachnoiditis ossifications in the spine / Aracnoidite ossificante na coluna vertebral / Aracnoiditis osificante en la columna vertebral

ABSTRACT Introduction: Arachnoiditis ossificans (AO) in the spine is a rare entity characterized by progressive calcification of the arachnoid and dural sac, with consequent neurological involvement. Objective: Review the causes, clinical manifestations, and complementary studies for their correct diagnosis. Method: Systematic review under PRISMA guidelines, with search in Pubmed, Lilacs, and Embase. Patient demographics (sex and age), history reported as a cause of AO and time elapsed between cause and diagnosis of AO, clinical manifestations, and complementary studies used for diagnosis were collected. Results: 38 articles, of which we collected 46 patients (25 women, 21 men), mean age of 52 years. The most frequent cause was previous spine surgery and myelography with fat-soluble contrast. The most frequent symptoms were insufficient muscle strength (74%) and pain (69%). CT was used in 76%. The most frequent location was thoracic (35%). Conclusion: Its pathogenesis is unclear; described as the final cause of a chronic inflammatory process in the arachnoid with the consequent bone metaplasia. Diagnosis usually precedes a long period of pain and progressive neurological symptoms. The most sensitive and specific complementary study for the diagnosis is the tomography without contrast, which should be requested in case of clinical suspicion. Level of Evidence II; Systematic Review.

Resumo: Introdução: A aracnoidite ossificante (AO) na coluna vertebral é uma entidade rara caracterizada por calcificação progressiva do saco aracnóideo e dural, com consequente envolvimento neurológico. Objetivo: revisar as causas, manifestações clínicas e estudos complementares para o seu correto diagnóstico. Método: Revisão sistemática sob as diretrizes do PRISMA, com busca no Pubmed, Lilacs e Embase. Foram coletados dados demográficos dos pacientes (sexo e idade), história relatada como causa de AO e tempo decorrido entre a causa e o diagnóstico de AO, manifestações clínicas e estudos complementares utilizados para o diagnóstico. Resultados: 38 artigos, dos quais foram coletados 46 pacientes (25 mulheres, 21 homens), com idade média de 52 anos. A causa mais frequente foi cirurgia prévia da coluna vertebral e mielografia com contraste lipossolúvel. Os sintomas mais frequentes foram comprometimento da força muscular (74%) e dor (69%). A TC foi utilizada em 76%. A localização mais frequente foi torácica (35%). Conclusões: Sua patogênese não é clara, é descrita como a causa final de um processo inflamatório crônico na aracnoide com a consequente metaplasia óssea. O diagnóstico é geralmente precedido por um longo período de dor acompanhado por sintomas neurológicos progressivos. O estudo complementar mais sensível e específico para o seu diagnóstico é a tomografia sem contraste, que deve ser solicitada em caso de suspeita clínica. Nível de Evidência II; Revisão sistemática.

Resumen: Introducción: La aracnoiditis osificante (AO) en la columna vertebral es una entidad rara que se caracteriza por la calcificación progresiva de la aracnoides y el saco dural, con la consecuente afectación neurológica. Objetivo: revisar las causas, manifestaciones clínicas y los estudios complementarios para su correcto diagnóstico. Método: Revisión sistemática bajo las directrices PRISMA, con búsqueda en Pubmed, Lilacs y Embase. Se recolectaron los datos demográficos de los pacientes (sexo y edad), el antecedente reportado como causa de AO y el tiempo transcurrido entre causa y el diagnóstico de AO, las manifestaciones clínicas y los estudios complementarios utilizados para el diagnóstico. Resultados: 38 artículos, de los cuales recolectamos 46 pacientes (25 mujeres, 21 hombres), promedio de edad 52 años. La causa más frecuente fue la cirugía previa de columna vertebral y la mielografía con contraste liposoluble Los síntomas más frecuentes fueron la alteración de la fuerza muscular (74%) y dolor (69%). Se utilizó TC en un 76%. La ubicación más frecuente fue torácica (35%). Conclusiones: Su patogenia no es clara, se describe como causa final de un proceso inflamatorio crónico en la aracnoides con la consecuente metaplasia ósea. El diagnóstico generalmente se precede de un largo periodo de dolor acompañado de síntomas neurológicos progresivos. El estudio complementario más sensible y específico para su diagnóstico es la tomografía sin contraste, que debe ser solicitado ante la sospecha clínica. Nivel de Evidencia II; Revisión sistemática.

Effects of lumbar myelography on subarachnoid pressure and cardiorespiratory parameters in healthy sheep / Efeitos da mielografia lombar na pressão subaracnoidea e nos parâmetros cardiorrespiratórios em ovelhas saudáveis

The purpose of this study was to evaluate the effects of lumbar myelography on subarachnoid pressure, cardiorespiratory parameters and pressure-volume index in sheep. Eight sheep were evaluated. The animals were submitted to puncture of the cisterna magna for monitoring of subarachnoid pressure (SaP). Lumbar myelography was performed through applying Iohexol (0.4mL/kg). ToC, PAS, PAD, MAP, InspISO, FeISO, SaP and CPP were recorded immediately after anesthetic stabilization (M0), during lumbar puncture (M1), and two, four and six minutes after contrast application (M2, M3 and M4, respectively). Blood pressure initially increased, then decreased, returning to basal level, similarly observed for InspISo and FeISo. The SaP rose initially thereafter remaining stable. Despite of the effect on subarachnoid pressure, lumbar myelography can be considered safe in sheep.(AU)

O objetivo foi avaliar os efeitos da mielografia lombar na pressão subaracnóidea, parâmetros cardiorrespiratórios e índice pressão-volume em ovinos. Oito ovelhas foram avaliadas. Os animais foram submetidos à punção da cisterna magna para monitoramento da pressão subaracnoidea (SaP). A mielografia lombar foi realizada com a aplicação de Iohexol (0,4mL/kg). Os momentos estudados foram: imediatamente após a estabilização anestésica (M0), durante a punção lombar (M1), dois, quatro e seis minutos após a aplicação do contraste (M2, M3 e M4, respectivamente), para avaliar as seguintes variáveis: ToC, PAS, PAD, MAP, InspISO, FeISO, Sap e CPP. A pressão arterial aumentou inicialmente, depois diminuiu, retornando aos valores iniciais, padrão também observado para o InspISo e o FeISo. O SaP subiu inicialmente, posteriormente, permanecendo estável. A mielografia lombar, apesar de influenciar a pressão subaracnoidea, pode ser considerada segura em ovinos.(AU)

Effects of lumbar myelography on subarachnoid pressure and cardiorespiratory parameters in healthy sheep

ABSTRACT: The purpose of this study was to evaluate the effects of lumbar myelography on subarachnoid pressure, cardiorespiratory parameters and pressure-volume index in sheep. Eight sheep were evaluated. The animals were submitted to puncture of the cisterna magna for monitoring of subarachnoid pressure (SaP). Lumbar myelography was performed through applying Iohexol (0.4mL/kg). ToC, PAS, PAD, MAP, InspISO, FeISO, SaP and CPP were recorded immediately after anesthetic stabilization (M0), during lumbar puncture (M1), and two, four and six minutes after contrast application (M2, M3 and M4, respectively). Blood pressure initially increased, then decreased, returning to basal level, similarly observed for InspISo and FeISo. The SaP rose initially thereafter remaining stable. Despite of the effect on subarachnoid pressure, lumbar myelography can be considered safe in sheep.

RESUMO: O objetivo foi avaliar os efeitos da mielografia lombar na pressão subaracnóidea, parâmetros cardiorrespiratórios e índice pressão-volume em ovinos. Oito ovelhas foram avaliadas. Os animais foram submetidos à punção da cisterna magna para monitoramento da pressão subaracnoidea (SaP). A mielografia lombar foi realizada com a aplicação de Iohexol (0,4mL/kg). Os momentos estudados foram: imediatamente após a estabilização anestésica (M0), durante a punção lombar (M1), dois, quatro e seis minutos após a aplicação do contraste (M2, M3 e M4, respectivamente), para avaliar as seguintes variáveis: ToC, PAS, PAD, MAP, InspISO, FeISO, Sap e CPP. A pressão arterial aumentou inicialmente, depois diminuiu, retornando aos valores iniciais, padrão também observado para o InspISo e o FeISo. O SaP subiu inicialmente, posteriormente, permanecendo estável. A mielografia lombar, apesar de influenciar a pressão subaracnoidea, pode ser considerada segura em ovinos.

Effects of lumbar myelography on subarachnoid pressure and cardiorespiratory parameters in healthy sheep / Efeitos da mielografia lombar na pressão subaracnoidea e nos parâmetros cardiorrespiratórios em ovelhas saudáveis

The purpose of this study was to evaluate the effects of lumbar myelography on subarachnoid pressure, cardiorespiratory parameters and pressure-volume index in sheep. Eight sheep were evaluated. The animals were submitted to puncture of the cisterna magna for monitoring of subarachnoid pressure (SaP). Lumbar myelography was performed through applying Iohexol (0.4mL/kg). ToC, PAS, PAD, MAP, InspISO, FeISO, SaP and CPP were recorded immediately after anesthetic stabilization (M0), during lumbar puncture (M1), and two, four and six minutes after contrast application (M2, M3 and M4, respectively). Blood pressure initially increased, then decreased, returning to basal level, similarly observed for InspISo and FeISo. The SaP rose initially thereafter remaining stable. Despite of the effect on subarachnoid pressure, lumbar myelography can be considered safe in sheep.(AU)

O objetivo foi avaliar os efeitos da mielografia lombar na pressão subaracnóidea, parâmetros cardiorrespiratórios e índice pressão-volume em ovinos. Oito ovelhas foram avaliadas. Os animais foram submetidos à punção da cisterna magna para monitoramento da pressão subaracnoidea (SaP). A mielografia lombar foi realizada com a aplicação de Iohexol (0,4mL/kg). Os momentos estudados foram: imediatamente após a estabilização anestésica (M0), durante a punção lombar (M1), dois, quatro e seis minutos após a aplicação do contraste (M2, M3 e M4, respectivamente), para avaliar as seguintes variáveis: ToC, PAS, PAD, MAP, InspISO, FeISO, Sap e CPP. A pressão arterial aumentou inicialmente, depois diminuiu, retornando aos valores iniciais, padrão também observado para o InspISo e o FeISo. O SaP subiu inicialmente, posteriormente, permanecendo estável. A mielografia lombar, apesar de influenciar a pressão subaracnoidea, pode ser considerada segura em ovinos.(AU)

Proposta de sequenciamento das projeções mielográficas na identificação de compressão da medula espinhal em cães com doença do disco intervertebral cervical / [Sequential proposal in the myelographic views for detection of spinal cord compression in dogs with cervical intervertebral disc disease]

O objetivo deste trabalho foi verificar em quais projeções foi possível identificar compressão da medula espinhal em cães com doença do disco intervertebral (DDIV) cervical e propor um sequenciamento das projeções a ser realizado no exame mielográfico dessa região. Foram avaliadas quatro projeções mielográficas (lateral, ventrodorsal e oblíquas esquerda e direita) de 41 pacientes diagnosticados com DDIV cervical. Em 40 pacientes (97,5%), foi possível identificar compressão da medula espinhal na projeção lateral; em 22 (53,6%), nas oblíquas; e em 11 (26,8%), na ventrodorsal (P<0,05). Havia lateralização da compressão em 22 (53,6%) pacientes; 100% delas (n=22) foram detectadas pelas projeções oblíquas e 50% (n=11) pela ventrodorsal. Em 10 (24,4%) cães, foi observado mais que um local de compressão, tendo as projeções ventrodorsal e oblíquas auxiliado na definição do local de compressão em 50% e 70%, respectivamente. Pode-se concluir que todas as projeções mielográficas estudadas permitem identificar compressão na medula espinhal em cães com DDIV cervical, sendo a incidência lateral a que mais a revelou, seguida das oblíquas e da ventrodorsal, estabelecendo-se, assim, uma proposta de sequenciamento das projeções mielográficas a serem realizadas para essa região.(AU)

The aim of this study was to verify in which of the myelographic views it was possible to identify spinal cord compression in dogs with cervical intervertebral disc disease (IVDD), and to establish a sequence in which myelographic views should be obtained for this region. Four myelographic views (lateral, ventrodorsal, left oblique and right oblique) of 41 patients diagnosed with cervical IVDD were evaluated. In 40 patients (97.5%) it was possible to identify spinal cord compression by lateral view, 22 (53.6%) by the oblique view, and 11 (26.8%) by the ventrodorsal view (P< 0.05). There were lateralized compressions in 22 (53.6%) patients, detected by all oblique views (100%) and by 11 (50%) of the ventrodorsal views. In 10 (24.4%) dogs, more than one compression site was observed, where the ventrodorsal view helped to decide the site in 50% of the cases and oblique in 70%. It can be concluded that all the tested myelographic views allow the identification of spinal cord compressions in dogs with cervical IVDD, the lateral view being the most relevant, followed by the oblique and ventrodorsal view, therefore establishing a sequence of myelographic views should be obtained for this region.(AU)

Proposta de sequenciamento das projeções mielográficas na identificação de compressão da medula espinhal em cães com doença do disco intervertebral cervical / [Sequential proposal in the myelographic views for detection of spinal cord compression in dogs with cervical intervertebral disc disease]

O objetivo deste trabalho foi verificar em quais projeções foi possível identificar compressão da medula espinhal em cães com doença do disco intervertebral (DDIV) cervical e propor um sequenciamento das projeções a ser realizado no exame mielográfico dessa região. Foram avaliadas quatro projeções mielográficas (lateral, ventrodorsal e oblíquas esquerda e direita) de 41 pacientes diagnosticados com DDIV cervical. Em 40 pacientes (97,5%), foi possível identificar compressão da medula espinhal na projeção lateral; em 22 (53,6%), nas oblíquas; e em 11 (26,8%), na ventrodorsal (P<0,05). Havia lateralização da compressão em 22 (53,6%) pacientes; 100% delas (n=22) foram detectadas pelas projeções oblíquas e 50% (n=11) pela ventrodorsal. Em 10 (24,4%) cães, foi observado mais que um local de compressão, tendo as projeções ventrodorsal e oblíquas auxiliado na definição do local de compressão em 50% e 70%, respectivamente. Pode-se concluir que todas as projeções mielográficas estudadas permitem identificar compressão na medula espinhal em cães com DDIV cervical, sendo a incidência lateral a que mais a revelou, seguida das oblíquas e da ventrodorsal, estabelecendo-se, assim, uma proposta de sequenciamento das projeções mielográficas a serem realizadas para essa região.(AU)

The aim of this study was to verify in which of the myelographic views it was possible to identify spinal cord compression in dogs with cervical intervertebral disc disease (IVDD), and to establish a sequence in which myelographic views should be obtained for this region. Four myelographic views (lateral, ventrodorsal, left oblique and right oblique) of 41 patients diagnosed with cervical IVDD were evaluated. In 40 patients (97.5%) it was possible to identify spinal cord compression by lateral view, 22 (53.6%) by the oblique view, and 11 (26.8%) by the ventrodorsal view (P< 0.05). There were lateralized compressions in 22 (53.6%) patients, detected by all oblique views (100%) and by 11 (50%) of the ventrodorsal views. In 10 (24.4%) dogs, more than one compression site was observed, where the ventrodorsal view helped to decide the site in 50% of the cases and oblique in 70%. It can be concluded that all the tested myelographic views allow the identification of spinal cord compressions in dogs with cervical IVDD, the lateral view being the most relevant, followed by the oblique and ventrodorsal view, therefore establishing a sequence of myelographic views should be obtained for this region.(AU)

Intradural extramedullary plasmacytoma in a dog

Background: Plasmacytoma is a neoplasm originating in plasma cells, derived from B lymphocytes. Extramedullary presentation is the most common form of plasmacytoma, mainly in the skin and rarely in other tissues, including the vertebral canal. Extramedullary plasmacytoma (EMP) occurs more frequently in senile dogs and rarely in cats and some dog breeds have predisposition for this type of neoplasm. The aim of this study was to report plasmacytoma in a dog located adjacent to the thoracic vertebrae. Case: An approximately 5-year-old mongrel male with sudden paraplegia resulting from upper motor neuron injury was admitted to a University Hospital. The dog presented a six-centimeter diameter mass in the dorsal region, adjacent to the thoracic vertebrae. The leucogram presented mild leukopenia by eosinopenia and lymphopenia. Myelogram associated with epidurography showed a fill failure in the contrast column between the seventh and ninth thoracic vertebrae, and there were no osteolysis points in the thoracic vertebrae, adjacent to the neoplastic mass. The evaluation of the intervertebral spaces between the fourth to ninth thoracic vertebrae presented no increase in radiopacity, nor alterations in the size of intervertebral spaces, indicating intervertebral disc extrusion. The laterolateral radiographs showed an alignment of the vertebrae and vertebral canal, without presence of bone neoformations on the ventral face of the vertebral bodies. The animal was euthanized and fragments of mass were collected for histological analysis. Macroscopic findings presented a non-encapsulated well-delimited mass, with color ranging from white to reddish. Microscopically, there was proliferation of moderately differentiated round cells in bone and muscle tissues, arranged in mantle…(AU)

Intradural extramedullary plasmacytoma in a dog

Background: Plasmacytoma is a neoplasm originating in plasma cells, derived from B lymphocytes. Extramedullary presentation is the most common form of plasmacytoma, mainly in the skin and rarely in other tissues, including the vertebral canal. Extramedullary plasmacytoma (EMP) occurs more frequently in senile dogs and rarely in cats and some dog breeds have predisposition for this type of neoplasm. The aim of this study was to report plasmacytoma in a dog located adjacent to the thoracic vertebrae. Case: An approximately 5-year-old mongrel male with sudden paraplegia resulting from upper motor neuron injury was admitted to a University Hospital. The dog presented a six-centimeter diameter mass in the dorsal region, adjacent to the thoracic vertebrae. The leucogram presented mild leukopenia by eosinopenia and lymphopenia. Myelogram associated with epidurography showed a fill failure in the contrast column between the seventh and ninth thoracic vertebrae, and there were no osteolysis points in the thoracic vertebrae, adjacent to the neoplastic mass. The evaluation of the intervertebral spaces between the fourth to ninth thoracic vertebrae presented no increase in radiopacity, nor alterations in the size of intervertebral spaces, indicating intervertebral disc extrusion. The laterolateral radiographs showed an alignment of the vertebrae and vertebral canal, without presence of bone neoformations on the ventral face of the vertebral bodies. The animal was euthanized and fragments of mass were collected for histological analysis. Macroscopic findings presented a non-encapsulated well-delimited mass, with color ranging from white to reddish. Microscopically, there was proliferation of moderately differentiated round cells in bone and muscle tissues, arranged in mantle

Micro-CT myelography using contrast-enhanced digital subtraction: feasibility and initial results in healthy rats.

PURPOSE: The spinal subarachnoid space (SSAS) is vital for neural performance. Although models of spinal diseases and trauma are used frequently, no methods exist to obtain high-resolution myelograms in rodents. Thereby, our aim was to explore the feasibility of obtaining high-resolution micro-CT myelograms of rats by contrast-enhanced dual-energy (DE) and single-energy (SE) digital subtraction. METHODS: Micro-CT contrast-enhanced DE and SE imaging protocols were implemented with live adult rats (total of 18 animals). For each protocol, contrast agents based on iodine (Iomeron® 400 and Fenestra® VC) and gold nanoparticles (AuroVist™ 15 nm) were tested. For DE, images at low- and high-energy settings were acquired after contrast injection; for SE, one image was acquired before and the other after contrast injection. Post-processing consisted of region of interest selection, image registration, weighted subtraction, and longitudinal alignment. RESULTS: High-resolution myelograms were obtained with contrast-enhanced digital subtraction protocols. After qualitative and quantitative (contrast-to-noise ratio) analyses, we found that the SE acquisition protocol with Iomeron® 400 provides the best images. 3D contour renderings allowed visualization of SSAS and identification of some anatomical structures within it. CONCLUSION: This in vivo study shows the potential of SE contrast-enhanced myelography for imaging SSAS in rat. This approach yields high-resolution 3D images without interference from adjacent anatomical structures, providing an innovative tool for further assessment of studies involving rat SSAS.

Myelography and residual contrast in panoramic radiography: case report / Presença de contraste residual de mielografia em radiografia panorãmica: relato de caso

ABSTRACT Myodil or pantopaque is an oil-based contrast solution often used up to 1980 for myelography, cisternography, and ventilography. Oilbased contrasts have a very slow clearance time in the cerebrospinal fluids and may encapsulate for decades and remain in the central nervous system and the interior of the spine. The knowledge of the existence of this rare condition coming from other radiographictests of the past, described in this clinical case, is essential when atypical radiographic images are found.

RESUMO O myodil ou o Pantopaque é uma solução de contraste a base de óleo usada frequentemente até 1980 para mielografia, cisternografia e ventilografia. Os contrastes à base de óleo têm um tempo de liberação muito lento nos fluidos cefalorraquidianos e podem encapsular por décadas e permanecer no sistema nervoso central e no interior da coluna vertebral. O conhecimento da existência dessa condição rara proveniente de outros exames radiográficos do passado, descritos neste caso clínico, é essencial quando são encontradas imagens radiográficas atípicas, principalmente em radiografia panorâmicas.

Idiopathic Spinal Cord Herniation­Case Report

Idiopathic spinal cord herniation is a rare cause of progressivemyelopathy, especially in the absence of a history of spinal or surgical trauma. The radiological diagnosis ismade through a myelography or an MRI exam. The spinal cord is pushed anteriorly, buffering the dural defect and leading inmost cases to Brown-Séquard syndrome. The present study describes the case of a male patient with a clinical picture of progressive thoracicmyelopathy. In the clinical and radiological investigation, an idiopathic spinal cord herniation on the chest level was identified. During the surgery, the spinal cord was reduced to the natural site, taking its usual elliptical shape, and the dural defect was repaired with a dural substitute. The numbness of the patient improved, and the shocks in the lower limbs disappeared. A postoperative MRI confirmed the surgical reduction of the herniation and the restoration of the anterior cerebrospinal fluid (CSF) column to the spinal cord. The authors describe the clinical, radiological, intraoperative, and postoperative evolution.

Patterns of Brachial Plexus Stretch Palsy in a Prospective Series of 565 Surgically Treated Patients.

PURPOSE: To report the distribution of the different patterns of stretch brachial plexus injuries (BPIs) in a retrospective cohort of patients operated at our institution during an 11-year period. METHODS: From September 2002 to June 2012, we evaluated and operated on 565 patients with traction injuries of the brachial plexus. Average age was 26.8 years (SD ±9.3 years); the interval between the injury and surgery was 5.4 months (SD ±2.8 months). The pattern of injury was defined based on data obtained from a standardized clinical examination, preoperative helical computed tomography myelography after intradural contrast injection, surgical findings, and intraoperative electric stimulation. RESULTS: Supraclavicular injuries accounted for 91% of all cases (N = 512) whereas 9% of injuries were infraclavicular. Within the supraclavicular injuries, 50% of cases involved the entire plexus and in 12% there was avulsion of all 5 roots. Among them, 94% involved the upper plexus (C5 to C6 ± C7 ± C8), and 6% the lower plexus (C8 to T1 ± C7). C5 to C6 injuries accounted for 23% of partial BPI, C5 to C7 19%, C5 to C8 52%, C7 to T1 4%, and C8 to T1 2%. CONCLUSIONS: The most relevant findings of this study were that most panplexal BPIs showed at least one graftable root, there was a high prevalence of C5 to C8 BPI, C7 to T1 root injury was the most common pattern of lower type of injury, and infraclavicular BPI was uncommon. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.

Comparative neurotoxicity of iobitridol with iohexol by intracisternal administration in Wistar rats / Neurotoxicidade comparativa do iobitridol com o iohexol, por via intracisternal, em ratos Wistar

Iobitridol is a tri-iodinated contrast agent, and neurotoxicologic studies of the intracisternal administration are scarce and inconclusive. The purpose of this study was to compare the neurotoxicity of iobitridol with iohexol, by intracisternal administration in Wistar rats, for a pre-clinical evaluation of its use as a myelographic agent. The animals, a total of 75, were divided into three experimental groups, iobitridol, iohexol and cerebral artificial fluid (control group), with 25 animals per group. Then, these were divided into five subgroups of five animals each, and given doses of 200, 400, 600, 800 and 1000 mg kg-1, while the control group received the equivalent volumes of contrast media tested. The animals were evaluated after 5, 15, 30, 60, 120, 180 and 240 min of intracisternal administration of these substances, for signs of depression and excitement, tactile palmar grasp, flexor, extensor, palpebral, papillary and pinna reflexes, surface righting and placing reactions, and with an auditory startle test. The evaluations were assessed daily for seven days with these parameters and their body weight, food, and water intake were also measured. There were no statistically significant differences between groups tested with respect to any of the evaluated parameters. In other words, in this animal model, the iobitridol demonstrated a low neurotoxicologic potential, comparable to that observed with iohexol. Further study with dogs and cats, as an alternative, is suggested.(AU)

O iobitridol é um meio de contraste tri-iodado, e estudos referentes à neurotoxicidade, com administração subaracnóide são escassos e inconclusivos. O objetivo deste trabalho foi comparar a neurotoxicidade do iobitridol com a do iohexol, por via intracisternal, em ratos Wistar, como avaliação pré-clínica da utilização deste como agente mielográfico. Foram utilizados 75 animais divididos em três grupos experimentais com 25 animais: iobitridol, iohexol e líquido cerebroespinhal artificial (grupo controle). Estes foram subdivididos em cinco subgrupos com cinco animais cada, com doses distintas de 200, 400, 600, 800 e 1000 mg kg-1, sendo utilizado no grupo controle o volume equivalente aos meios de contraste testados. Os animais foram avaliados após 5, 15, 30, 60, 120, 180 e 240 min da administração intracisternal dessas substâncias, quanto a sinais de depressão e excitação, reflexos tátil de agarramento palmar, flexor, extensor, palpebral, pupilar e da pina, reação de endireitamento e posicionamento e resposta auditiva. Nos sete dias subsequentes, os animais foram avaliados diariamente quanto a estes parâmetros, e ainda a massa corporal, a ingestão de ração e de água, foram mensuradas. Não foram observadas diferenças estatisticamente significativas entre os grupos testados com meios de contraste, em nenhum dos parâmetros avaliados. Dessa forma, nesse modelo animal, o iobitridol demonstrou baixa neurotoxicidade, comparável a observada com o iohexol. Sugerem-se mais estudos com cães e gatos para utilização do iobitridol como alternativa.(AU)

Comparative neurotoxicity of iobitridol with iohexol by intracisternal administration in Wistar rats / Neurotoxicidade comparativa do iobitridol com o iohexol, por via intracisternal, em ratos Wistar

Iobitridol is a tri-iodinated contrast agent, and neurotoxicologic studies of the intracisternal administration are scarce and inconclusive. The purpose of this study was to compare the neurotoxicity of iobitridol with iohexol, by intracisternal administration in Wistar rats, for a pre-clinical evaluation of its use as a myelographic agent. The animals, a total of 75, were divided into three experimental groups, iobitridol, iohexol and cerebral artificial fluid (control group), with 25 animals per group. Then, these were divided into five subgroups of five animals each, and given doses of 200, 400, 600, 800 and 1000 mg kg-1, while the control group received the equivalent volumes of contrast media tested. The animals were evaluated after 5, 15, 30, 60, 120, 180 and 240 min of intracisternal administration of these substances, for signs of depression and excitement, tactile palmar grasp, flexor, extensor, palpebral, papillary and pinna reflexes, surface righting and placing reactions, and with an auditory startle test. The evaluations were assessed daily for seven days with these parameters and their body weight, food, and water intake were also measured. There were no statistically significant differences between groups tested with respect to any of the evaluated parameters. In other words, in this animal model, the iobitridol demonstrated a low neurotoxicologic potential, comp

O iobitridol é um meio de contraste tri-iodado, e estudos referentes à neurotoxicidade, com administração subaracnóide são escassos e inconclusivos. O objetivo deste trabalho foi comparar a neurotoxicidade do iobitridol com a do iohexol, por via intracisternal, em ratos Wistar, como avaliação pré-clínica da utilização deste como agente mielográfico. Foram utilizados 75 animais divididos em três grupos experimentais com 25 animais: iobitridol, iohexol e líquido cerebroespinhal artificial (grupo controle). Estes foram subdivididos em cinco subgrupos com cinco animais cada, com doses distintas de 200, 400, 600, 800 e 1000 mg kg-1, sendo utilizado no grupo controle o volume equivalente aos meios de contraste testados. Os animais foram avaliados após 5, 15, 30, 60, 120, 180 e 240 min da administração intracisternal dessas substâncias, quanto a sinais de depressão e excitação, reflexos tátil de agarramento palmar, flexor, extensor, palpebral, pupilar e da pina, reação de endireitamento e posicionamento e resposta auditiva. Nos sete dias subsequentes, os animais foram avaliados diariamente quanto a estes parâmetros, e ainda a massa corporal, a ingestão de ração e de água, foram mensuradas. Não foram observadas diferenças estatisticamente significativas entre os grupos testados com meios de contraste, em nenhum dos parâmetros avaliados. Dessa forma, nesse modelo animal, o iobitridol de

Comparative neurotoxicity of iobitridol with iohexol by intracisternal administration in Wistar rats / Neurotoxicidade comparativa do iobitridol com o iohexol, por via intracisternal, em ratos Wistar

Iobitridol is a tri-iodinated contrast agent, and neurotoxicologic studies of the intracisternal administration are scarce and inconclusive. The purpose of this study was to compare the neurotoxicity of iobitridol with iohexol, by intracisternal administration in Wistar rats, for a pre-clinical evaluation of its use as a myelographic agent. The animals, a total of 75, were divided into three experimental groups, iobitridol, iohexol and cerebral artificial fluid (control group), with 25 animals per group. Then, these were divided into five subgroups of five animals each, and given doses of 200, 400, 600, 800 and 1000 mg kg-1, while the control group received the equivalent volumes of contrast media tested. The animals were evaluated after 5, 15, 30, 60, 120, 180 and 240 min of intracisternal administration of these substances, for signs of depression and excitement, tactile palmar grasp, flexor, extensor, palpebral, papillary and pinna reflexes, surface righting and placing reactions, and with an auditory startle test. The evaluations were assessed daily for seven days with these parameters and their body weight, food, and water intake were also measured. There were no statistically significant differences between groups tested with respect to any of the evaluated parameters. In other words, in this animal model, the iobitridol demonstrated a low neurotoxicologic potential, comparable to that observed with iohexol. Further study with dogs and cats, as an alternative, is suggested.

O iobitridol é um meio de contraste tri-iodado, e estudos referentes à neurotoxicidade, com administração subaracnóide são escassos e inconclusivos. O objetivo deste trabalho foi comparar a neurotoxicidade do iobitridol com a do iohexol, por via intracisternal, em ratos Wistar, como avaliação pré-clínica da utilização deste como agente mielográfico. Foram utilizados 75 animais divididos em três grupos experimentais com 25 animais: iobitridol, iohexol e líquido cerebroespinhal artificial (grupo controle). Estes foram subdivididos em cinco subgrupos com cinco animais cada, com doses distintas de 200, 400, 600, 800 e 1000 mg kg-1, sendo utilizado no grupo controle o volume equivalente aos meios de contraste testados. Os animais foram avaliados após 5, 15, 30, 60, 120, 180 e 240 min da administração intracisternal dessas substâncias, quanto a sinais de depressão e excitação, reflexos tátil de agarramento palmar, flexor, extensor, palpebral, pupilar e da pina, reação de endireitamento e posicionamento e resposta auditiva. Nos sete dias subsequentes, os animais foram avaliados diariamente quanto a estes parâmetros, e ainda a massa corporal, a ingestão de ração e de água, foram mensuradas. Não foram observadas diferenças estatisticamente significativas entre os grupos testados com meios de contraste, em nenhum dos parâmetros avaliados. Dessa forma, nesse modelo animal, o iobitridol demonstrou baixa neurotoxicidade, comparável a observada com o iohexol. Sugerem-se mais estudos com cães e gatos para utilização do iobitridol como alternativa.

Epidemiological aspects of myelography in dogs: 61 cases (2003–2012) / Aspectos epidemiológicos de cães avaliados mielograficamente: 61 casos (2003-2012)

Myelography is a radiological contrast examination technique frequently used in the diagnosis of vertebral spine and spinal cord disorders. The procedure involves inserting a needle with subsequent injection of contrast medium, which delimits the spinal cord. The main indication is suspected spinal injuries not visualized on plain radiographs. Myelography is effective in the identification of the location of the lesion but is contraindicated in patients with infectious diseases or who have recently experienced trauma. Advantages of myelography are cost effectiveness in both the examination procedure and maintenance of equipment, and delivery of quality images, compared with other imaging methods in dogs. Disadvantages include a relatively long examination procedure, the need for general anesthesia, and the risk of seizures or death. The aim of this study was to characterize a population of dogs undergoing myelography according to the following factors: severity of injury, breed, age, sex, reproductive status, diet, weight, previous illnesses, vertebral region evaluated, lesion location in spinal cord or meninges, cause of radiographic signs, and possible complications. The database was created from information in medical records, and included 61 dogs with suspected disorders of the vertebral spine, spinal cord, and/or meninges that underwent myelography at the Unidade Hospitalar para Animais de Companhia of Pontifícia Universidade Católica do Paraná from January 2003 through December 2012. The results indicate that the most common degree of injury severity was Grade 2 (39.34% of the patients). The most prevalent breeds were mixed breed dogs (22.58%) and the dachshund (18.03%). Ages with higher frequency were 6 and 10 years (average, 7.6 years).[...](AU)

A mielografia é utilizada no diagnóstico de doenças da coluna vertebral e medula espinhal. As indicações são suspeitas de lesões medulares não visualizadas em radiografias simples. Suas contraindicações são em pacientes com doenças infecciosas ou que sofreram trauma recente. Se comparada a outros métodos imaginológicos em cães, apresenta a vantagem de ter baixo custo do exame e de manutenção. Como desvantagem, apresenta maior tempo para a realização do exame, risco de convulsão e óbito. O objetivo deste trabalho foi caracterizar a população de cães submetidos à mielografia de acordo com os fatores: gravidade da lesão, raça, idade, sexo, estado reprodutivo, dieta, peso, doenças anteriores, região do canal vertebral acometido, localização na medula espinhal/meninge, causas dos sinais radiográficos e possíveis implicações. A base de dados foi a análise de prontuários e mielografias de 61 cães com suspeita de doença da coluna vertebral, medula espinhal e/ou meninges no período de janeiro de 2003 à dezembro de 2012. Os resultados mostram que a maioria dos pacientes apresentaram lesão grau 1. Cães sem raça definida foram os de maior prevalência. As idades com maior frequência foram 6 e 10 anos (média = 7,6 anos). Em relação ao sexo e estado reprodutivo, os machos não castrados foram mais acometidos. A ração comercial foi a mais frequente. O peso corpóreo entre 6 a 15 kg foi o mais significativo. A maioria não apresentou doenças anteriores. A região toracolombar foi a mais avaliada. A maioria das lesões eram extramedulares, e as causas em sua maior parte foram discopatias. As implicações da mielografia não foram significativas. Pode-se constatar que os dados em nosso meio tendem a se assemelhar com a literatura consultada, porém a literatura internacional tem pesquisado exames mais sensíveis, como tomografia computadorizada e ressonância magnética.(AU)

Compressive myelopathy in a free-ranging red brocket (Mazama americana) caused by a lumbar paraspinal abscess with accompanying spondylodiscitis

Background: Spondylodiscitis is an inflammation that is characterized by the involvement of one and more intervertebral discs and adjacent vertebral bodies. The clinical manifestations of spondylodiscitis are nonspecific and vary with the site and extent of injury, however this kind of lesion is poorly known between free-ranging cervids. In this sense, the presente study aimed to describe the occurrence, clinical, radiographic and anatomopathological findings related to a lumbar abscess accompanied by spondylodiscitis in a free-ranging female red brocket (Mazama americana) from Eastern Brazilian Amazon. Case: An approximately five-month old, 3,7 kg, female red brocket (Mazama americana), was received at the Veterinary Hospital of the Federal Rural University of Amazônia, in the municipality of Belém, in the State of Pará (Northern Brazil) for clinical care. The animal was rescued from the wild by the Brazilian Institute of Environment and Renewable Natural and presented lethargy, pelvic limb paralysis with proprioceptive deficits. The clinical signs observed suggested a spinal cord injury in the thoracolumbar region and the animal was sent to radiographic examination and myelography performed on the ventrodorsal and lateral projections of the vertebrae and spinal cord. The hemogram revealed anemia (8.74 × 106 cells/mm3) and leukocytosis (29.65 × 103 cells/mm3) with...(AU)

Compressive myelopathy in a free-ranging red brocket (Mazama americana) caused by a lumbar paraspinal abscess with accompanying spondylodiscitis

Background: Spondylodiscitis is an inflammation that is characterized by the involvement of one and more intervertebral discs and adjacent vertebral bodies. The clinical manifestations of spondylodiscitis are nonspecific and vary with the site and extent of injury, however this kind of lesion is poorly known between free-ranging cervids. In this sense, the presente study aimed to describe the occurrence, clinical, radiographic and anatomopathological findings related to a lumbar abscess accompanied by spondylodiscitis in a free-ranging female red brocket (Mazama americana) from Eastern Brazilian Amazon. Case: An approximately five-month old, 3,7 kg, female red brocket (Mazama americana), was received at the Veterinary Hospital of the Federal Rural University of Amazônia, in the municipality of Belém, in the State of Pará (Northern Brazil) for clinical care. The animal was rescued from the wild by the Brazilian Institute of Environment and Renewable Natural and presented lethargy, pelvic limb paralysis with proprioceptive deficits. The clinical signs observed suggested a spinal cord injury in the thoracolumbar region and the animal was sent to radiographic examination and myelography performed on the ventrodorsal and lateral projections of the vertebrae and spinal cord. The hemogram revealed anemia (8.74 × 106 cells/mm3) and leukocytosis (29.65 × 103 cells/mm3) with...