The collection and analysis of cerebrospinal fluid as an aid to diagnosis in ruminant neurological disease

Collection of cerebrospinal fluid in 50 adult healthy donkeys (Equus asinus): clinical complications, and cytological and biochemical constituents

Background

Diseases of the central nervous system are a well-recognized cause of morbidity and mortality in equine. Collection and analysis of cerebrospinal fluid (CSF) give information about the type and stage of degenerative and inflammatory diseases in central nervous system (CNS). The present research aimed to assess the clinical complications of CSF collections and to establish range values of cytological and biochemical parameters of CSF in adult healthy donkeys (Equus asinus). The CSF samples were collected from fifty healthy donkeys at the lumbosacral (LS) and atlanto-occipital (AO) sites.

Results

Hypothermia, tachycardia, ataxia and recumbency may develop post-puncture. Erythrocytes were noticed in 35 of 50 CSF samples. Total nucleated cell counts ranged from 0 to 6 cells/μL, and lymphocytes predominated the cells (61%). The concentration of glucose (1.2 to 5.3 mmol/L) was lower than that of serum (P < 0.05). The CSF sodium concentration (123 to 160 mmol/L) was approximately like that of serum, but potassium (1.5–3 mmol/L) was lower than that of serum (P < 0.01). Urea concentrations (1.1–2.9 mmol/L) were markedly lower than serum (P < 0.001). Concentrations of CSF total proteins, and albumin ranged from 0.1 to 0.6 g/dL, and from 0.002 to 0.013 g/dL, respectively. The albumin quotient ranged from 0.06 to 0.56.

Conclusions

Transient hypothermia, tachycardia, ataxia and recumbency may develop as clinical complications of CSF puncture procedures. The collection site has no impact on the constituents in CSF. Furthermore, this study presented the range values for normal cytological and biochemical constituents of CSF in donkeys (Equus asinus) that can provide a basis in comparison when evaluating CSF from donkeys with neurologic diseases.

Parâmetros citológicos e bioquímicos do líquido cefalorraquidiano coletado de bovinos sadios em dois momentos, com intervalo de 96 horas

RESUMO A análise do líquido cefalorraquidiano (LCR) é uma importante ferramenta no diagnóstico das doenças neurológicas dos bovinos. A coleta do LCR em diferentes momentos facilita o monitoramento do quadro clínico e/ou a avaliação da eficácia de tratamentos estabelecidos. Todavia, os efeitos de coletas consecutivas sobre os parâmetros citológicos e bioquímicos do LCR de bovinos saudáveis ainda não foram analisados. Dessa forma, o objetivo do presente estudo foi avaliar potenciais diferenças citológicas e bioquímicas no LCR de bovinos sadios, obtidos em dois momentos, com intervalo de 96 horas. O LCR foi submetido à análise citológica e à determinação do teor de proteína total. Na segunda coleta, verificou-se aumento significativo da celularidade, porém ainda dentro do intervalo de referência para a espécie, diminuição de linfócitos e elevação de células mononucleares em relação à primeira coleta. No entanto, os números de hemácias (/µL), células nucleadas (/µL), neutrófilos (%), eosinófilos (%) e a concentração da proteína total (mg/dL) continuaram dentro dos valores de referência 96 horas após a realização da primeira punção. Conclui-se que os procedimentos de coleta de LCR consecutivos não provocaram inflamação local detectável 96 horas após a primeira punção, o que sugere que, quando necessário, coletas de LCR seriadas, por si só, não interfeririam nos resultados do exame.

Cerebrospinal Fluid Analysis in Recumbent Adult Dairy Cows With or Without Spinal Cord Lesions

Background

Diagnosis of central nervous system (CNS) lesions in recumbent dairy cattle (RDC) is challenging because neurologic examination is limited and medical imaging often is challenging or unrewarding. Cerebrospinal fluid (CSF) analysis is useful in the diagnosis of CNS disorders in cattle. However, its utility in identifying spinal cord lesions in RDC remains to be evaluated.

Hypothesis/Objectives

We hypothesized that CSF analysis would discriminate between RDC with and without spinal cord lesions.

Animals

Twenty‐one RDC with spinal cord lesions (RDC+) and 19 without (RDC−) were evaluated.

Methods

Spinal cord lesions were confirmed at necropsy. Signalment, clinical findings, and CSF results were compared retrospectively. Total nucleated cell count and differential, protein concentration, and red blood cell count in RDC+ and RDC− were compared.

Results

Neoplasia, trauma, and infectious processes were the most frequent spinal cord lesions identified. Cerebrospinal fluid protein concentrations and TNCC were significantly higher in RDC+ compared to RDC− (P = .0092 and P = .0103, respectively). Additionally, CSF protein concentrations and TNCC in RDC− were lower than previously published reference ranges. Using an interpretation rule based on CSF protein concentration and TNCC, it was possible to accurately identify 13 RDC with spinal cord lesions and 6 RDC without lesions. It was not possible to determine spinal cord status in the remaining 18 RDC.

Conclusions and Clinical Importance

Cerebrospinal fluid analysis is valuable in the evaluation of spinal cord status in RDC. The prognosis associated with these findings remains to be determined.

Seizure Disorders in Goats and Sheep

Background

Goats and sheep are more likely to be presented for examination for seizures than are cattle, possibly as a consequence of their relatively smaller body size. Currently, no reports describing seizure disorders in goats and sheep are available.

Objectives

To describe clinical features and treatment outcomes of sheep and goats presented for seizures.

Animals

A total of 59 goats and 21 sheep presented for seizures.

Methods

Retrospective study. Medical records from 1994 to 2014 at the Veterinary Medical Teaching Hospital, University of California, Davis, were reviewed. Descriptive statistics were used to summarize data. Logistic regression was performed to determine whether variables were associated with mortality.

Results

The majority of seizures in goats and sheep had structural or metabolic causes. Polioencephalomalacia (PEM) secondary to ruminal lactic acidosis or PEM of undetermined cause was the most frequently diagnosed cause of seizures in goats and sheep. The proportions of mortality in goats and sheep were 49.2 and 42.9%, respectively. Age increased the odds mortality (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.07, 2.14) in goats. Goats with structural or metabolic causes of seizures had higher odds for mortality (OR, 37.48; 95% CI, 1.12, 99.10) than those with unknown causes. Age and etiological diagnosis were not significant (P > .05) predictors of mortality in affected sheep.

Conclusions and Clinical Relevance

Seizure disorders in goats and sheep are associated with high mortality, despite treatment. Current treatment in goats and sheep with seizures warrants further investigation to determine whether treatments are beneficial or detrimental to survival.

MAGNETIC RESONANCE IMAGING FINDINGS IN SMALL RUMINANTS WITH BRAIN DISEASE

Brain disease is an important cause of neurologic deficits in small ruminants, however few MRI features have been described. The aim of this retrospective, case series study was to describe MRI characteristics in a group of small ruminants with confirmed brain disease. A total of nine small ruminants (six sheep and three goats) met inclusion criteria. All had neurologic disorders localized to the brain and histopathologic confirmation. In animals with toxic-metabolic diseases, there were bilaterally symmetric MRI lesions affecting either the gray matter (one animal with polioencephalomalacia) or the white matter (two animals with enterotoxemia). In animals with suppurative inflammation, asymmetric focal brainstem lesions were present (two animals with listeric encephalitis), or lesions typical of an intra-axial (one animal) or dural abscess (one animal), respectively. No MRI lesions were detected in one animal with suspected viral cerebellitis and one animal with parasitic migration tracts. No neoplastic or vascular lesions were identified in this case series. Findings from the current study supported the use of MRI for diagnosing brain diseases in small ruminants.

Analysis of cerebrospinal fluid from cattle with central nervous system disorders after storage for 24 hours with autologous serum

BACKGROUND

We compared the changes in cell morphology, total and differential cell counts between cerebrospinal fluid (CSF) samples analyzed within an hour of collection (fresh sample) and after the addition of autologous serum and storage for 24 h (stored sample) in 27 cattle with central nervous system disorders.

RESULTS

There was a positive linear correlation between total and differential cell counts in the fresh and the stored samples. Cell morphology was preserved in all stored samples, except for increased vacuolization of mononuclear cells and cleaved nuclei of some small mononuclear cells. In the stored CSF samples, the total nucleated cell count and monocyte percentage were decreased (P = 0.01; P = 0.03), while the lymphocyte percentage was increased (P = 0.04). Mononuclear pleocytosis diagnosed in 20 fresh samples was cytologically confirmed in 12 of the 20 stored samples. In the remaining eight stored samples, the number of total nucleated cells was within the normal range. Neutrophilic pleocytosis was confirmed in all seven stored samples. The overall agreement rate between cytologic interpretation of the fresh and the stored CSF samples was 70 % (100 % for neutrophilic pleocytosis and 60 % for mononuclear pleocytosis).

CONCLUSIONS

Adding 11 % of autologous serum to CSF samples might allow delayed analysis with a good agreement rate for CSF cytological interpretation. Caution is nonetheless warranted, as animal age, anamnesis, and neurological presentation need to be considered when interpreting stored CSF without pleocytosis.

Alterações no SNC e morfometria cerebelar de bovinos intoxicados experimentalmente por Solanum paniculatum

Algumas espécies de Solanum causam intoxicações em ruminantes caracterizadas clinicamente por desordens cerebelares e microscopicamente como doença do depósito lisossomal. Não há lesões de necropsia específicas e microscopicamente ocorrem vacuolização e perda de neurônios de Purkinje. Por ser Solanum paniculatum a espécie de ocorrência na região Nordeste, sendo responsável pelos surtos de intoxicação espontânea descrito no Estado de Pernambuco foi realizado um delineamento experimental para caracterizar o quadro clínico-patológico da intoxicação. Foram usados cinco bovinos, sendo quatro no grupo experimental (GE) e um animal no controle (GC), de seis meses de idade, sem raça definida, com peso de 120 Kg, mantidos em baias durante cinco meses na Clínica de Bovinos de Garanhuns/UFRPE. Os animais receberam a planta, colhida nas propriedades em que ocorreram os surtos naturais, na dosagem de 5g/kg/PV/dia da planta dessecada misturada na ração por ingestão natural. Semanalmente realizou-se o Head Raising Test para determinar os sinais cerebelares e quando positivo os animais foram submetidos à colheita de sangue e do líquido céfalo-raquidiano e em seguida foi feito à eutanásia. O SNC e a rete mirabile foram fixados em formol a 10% tamponado, processados rotineiramente e corados pela hematoxilina e eosina para avaliação histopatológica. Foi realizada análise morfométrica das lesões cerebelares. Para avaliação dos resultados laboratoriais utilizou-se análise descritiva e em relação à morfometria, empregou-se o teste T de Student (p<0.05) na contagem de células de Purkinje e para a espessura da camada molecular do cerebelo o teste de Mann Whitney, com nível de 5% de significância. Três animais apresentaram sinais de intoxicação com tempo em média de 90 dias e um com 155 dias. Os sinais clínicos observados foram ataques convulsivos transitórios, e distúrbios do equilíbrio. Na necropsia não foram encontradas lesões específicas da intoxicação. Não houve alterações no hemograma e no líquido céfalo-raquidiano causado pela planta. No histopatológico havia principalmente vacuolização fina do pericário e perda de células de Purkinje, com degeneração Walleriana e esferóides axonais na camada granular e na substância branca medular, com proliferação dos astrócitos de Bergman. Vacuolização e necrose neuronal também foram observadas no óbex, pedúnculos cerebelares e colículos rostral e caudal e raramente no tálamo, núcleos da base, hipocampo e medula oblonga. Na análise morfométrica não houve diferença significativa (p<0,05) entre o número de células de Purkinje e a espessura da camada molecular entre o GE e GC, demonstrando que apesar dos bovinos desenvolverem quadro clínico da intoxicação e alterações histopatológicas acentuadas, mas nestas condições experimentais não ocorreram alteração morfométricas significativas em relação ao GC. Sugerindo que há necessidade de um tempo de administração maior da planta para o aparecimento de lesões mais acentuadas como as que ocorrem em casos naturais. Os resultados laboratoriais de sangue e do líquido céfalo-raquidiano não refletem alterações relacionadas à intoxicação pela planta.

Síndrome do abscesso pituitário em bezerros na Região Centro-Oeste

A síndrome do abscesso pituitário é uma doença neurológica responsável por casos esporádicos e surtos, principalmente em bezerros, ocasionando alto índice de mortalidade. Descreve-se a ocorrência e os achados clínicos, laboratoriais e anátomo-patológicos em três bezerros com síndrome do abscesso pituitário no Centro-Oeste do Brasil. Os animais tinham 8-11 meses de idade e os sinais clínicos mais marcantes relacionaram-se aos sinais nervosos de origem cerebral e do tronco encefálico com evolução clínica de 7-20 dias. A hematologia revelou leucocitose por neutrofilia e hiperfibrinogenemia. A análise do líquido céfalo-raquidiano apresentou pleocitose neutrofílica. Arcanobacterium pyogenes foi isolado do líquido céfalo-raquidiano. Um dos bezerros apresentou recuperação após antibioticoterapia. A mortalidade foi de 66,6% (2/3). Os achados de necropsia consistiram em um único abscesso de localização parapituitária ou situado no parênquima da glândula; um dos bezerros apresentou rinite necrosante e outro, broncopneumonia abscedativa. O exame histológico do sistema nervoso central revelou ausência quase completa do tecido hipofisário normal, devido à necrose extensa e infiltrado inflamatório neutrofílico difuso concomitante. Reitera-se a importância da realização de práticas de manejo adequadas a fim de reduzir a incidência de inúmeras enfermidades, principalmente em bezerros, dentre elas a síndrome do abscesso pituitário.

Cerebrospinal Fluid

This chapter discusses the anatomy, functions, and biochemistry of cerebrospinal fluid (CSF). CSF has four major functions: physical support of neural structures, excretion and “sink” action, intracerebral transport, and control of the chemical environment of the central nervous system. CSF provides a “water jacket” of physical support and buoyancy. The CSF is protective because its volume changes reciprocally with changes in the volume of intracranial contents, particularly blood. Thus, the CSF protects the brain from changes in arterial and central venous pressure associated with posture, respiration, and exertion. Acute or chronic pathological changes in intracranial contents can be accommodated, to a point, by changes in the CSF volume. The direct transfer of brain metabolites into the CSF provides excretory function. This capacity is important because the brain lacks a lymphatic system. The lymphatic function of the CSF is also manifested in the removal of large proteins and cells, such as bacteria or blood cells, by bulk CSF absorption. The “sink” action of the CSF arises from the restricted access of water-soluble substances to the CSF and the low concentration of these solutes in the CSF.

Cytology in food animal practice

Diagnostic cytology can greatly aid the clinician in determining a more refined diagnosis, prognosis, and treatment plan to serve the client and patient better. Sample collection is not difficult and can be done in the field as well as in a hospital setting. The collection and sample handling procedures described in this article can help the clinician to obtain diagnostically valuable samples. In many cases, preliminary cytologic evaluation can be performed by the general practitioner. Additional diagnostic evaluation and interpretation are readily available from trained pathologists at diagnostic laboratories.

Diagnostic techniques and clinicopathologic findings in ruminant neurologic disease

In ruminant species, cerebrospinal fluid (CSF) collection and analysis provide rapid (in some situations, instant) information to the veterinary clinician investigating a disease problem in the living animal. CSF analysis is particularly useful with respect to confirming the presence of an inflammatory lesion involving the leptomeninges,such as bacterial meningoencephalitis, and in investigating potential compressive lesions of the spinal cord. When correctly performed under local anesthesia, lumbar CSF collection in ruminants is a safe procedure and there are no harmful sequelae. Familiarity with the technique aids high extradural injection of lidocaine or xylazine, which has many applications in farm practice. There are few indications for cisternal CSF collection in food animals.