Analysis of cerebrospinal fluid from the cerebellomedullary and lumbar cisterns of dogs with focal neurologic disease: 145 cases (1985-1987)

Data were obtained from 158 CSF samples from 145 dogs with focal, noninfectious/noninflammatory neurologic disease. The effect of lesion location and the duration and severity of clinical signs were studied. One hundred and twenty-five samples were obtained from the cerebellomedullary cistern (CMC), and 33 were obtained from the lumbar cistern (LC). Intracranial and cervical disease affected the CSF from the CMC more often than did thoracolumbar disease. However, lumbar CSF was more frequently affected by disease anywhere along the neuraxis. For compressive spinal cord disease, the protein concentration at both cisterns was more often high in acute, clinically severe lesions. Intracranial lesions consistently caused abnormalities in CSF from both the CMC (7 of 7; 100%) and LC (2 of 2; 100%). Abnormalities were identified in 16 of 38 (42%) and 5 of 7 (71%) CMC and LC samples, respectively, in dogs with cervical disease. In dogs with thoracolumbar lesions, only 22 of 80 (27.5%) CMC samples were abnormal, compared with 21 of 24 (87.5%) LC samples. These findings suggest that CSF collected cranial to the lesion may be normal or only mildly altered by focal neurologic disease. Fluid obtained caudal to the lesion presumably is more substantially altered because of the predominant caudal flow of CSF. To maximize the yield of diagnostic information from CSF analysis, the fluid should preferably be obtained caudad to the disease site; however, because of problems associated with lumbar puncture, we suggest that CSF from the CMC also be obtained.     

Measurement of myelin basic protein in the cerebrospinal fluid of dogs with degenerative myelopathy

BACKGROUND: Analysis of cerebrospinal fluid (CSF) is part of a routine clinical workup in veterinary patients when neurologic disease is suspected. However, knowledge of particular protein markers of disease in CSF is limited. The concentration of myelin basic protein (MBP) in CSF is used as a biochemical marker in humans to evaluate demyelinating lesions in the central nervous system (CNS). OBJECTIVE: The purpose of this study was to evaluate an ELISA for determination of MBP concentration in the CSF of German shepherd dogs with degenerative myelopathy (GSDM). METHODS: Cross-reactivity of the anti-human polyclonal antibody used in a commercial ELISA (Active MBP ELISA, Diagnostic Systems Laboratories Inc, Webster, TX, USA) was tested with canine MBP by immunoblotting. CSF samples were collected from both the cisterna magna and the lumbar cistern of 8 clinically healthy control dogs and 8 German shepherd dogs clinically diagnosed with GSDM. MBP concentrations were measured in all CSF samples using the ELISA. RESULTS: The mean MBP concentration in CSF from the lumbar cistern of dogs with GSDM (3.13 -/+ 0.46 ng/mL) was significantly higher than that in the cisterna magna (0.70 -/+ 0.06 ng/mL) and from both cisternal (0.47 -/+ 0.07 ng/mL) and lumbar (0.94 -/+ 0.37 ng/mL) samples from control dogs. CONCLUSION: The MBP ELISA has potential as a supplemental test of CSF to diagnose demyelinating disorders in dogs.     

Canine intervertebral disc disease: Changes in the cerebrospinal fluid

Data was obtained from 118 cerebrospinal fluid (CSF) samples from dogs with intervertebral disc disease. The effect of lesion location and the severity and duration of clinical signs was studied. Ninety-seven samples were obtained from the cerebellomedullary cistern and 21 from the lumbar cistern. Changes in CSF were identified in 84.7 per cent of the lumbar samples, compared with only 37.1 per cent of the cerebellomedullary samples. More pronounced pleocytosis and protein level increases were seen in dogs with acute and clinically severe lesions. The protein concentration was more commonly elevated than the total white blood cell count. These results indicate that marked protein and white blood cell count elevations can occur in association with intervertebral disc extrusion. Such findings, therefore, should not necessarily preclude myelographic examination in dogs presented for paralysis.     

小型犬脊髓穿刺技术

对 30只小型犬 (京叭 2 8只 ,杂种小型犬 2只 )进行了不同部位的脊髓穿刺。以穿刺技术的难度、造影的效果比较、脑脊液 (CSF)压力的测定和 CSF的分析结果为判断标准 ,得出如下结论 :进行 CSF收集或者测量 CSF压力时的穿刺部位 ,应选择在小脑延髓池处 ;怀疑颈部或前胸部脊髓有病变时 ,应在小脑延髓池处进行脊髓穿刺造影 ;怀疑为胸腰椎脊髓有病变时 ,脊髓造影应选择在腰椎 L 5～ 6之间 ,L 6～ 7也可以作为一种选择部位 ;穿刺过程中试验犬可以俯卧操作。另外 ,对穿刺器械的选择和使用也进行了分析     

Association of cerebrospinal fluid analysis findings with clinical signs and outcome in acute nonambulatory thoracolumbar disc disease in dogs

Background: Cerebrospinal fluid (CSF) pleocytosis recently was associated with the severity of neurologic signs in dogs with intervertebral disc disease (IVDD). Hypothesis/Objectives: To look for an association among CSF cell counts, total protein concentration, and severity of neurologic signs at presentation with outcome in dogs with acute thoracolumbar IVDD. Our hypothesis was that CSF total nucleated cell count (TNCC) and percentage cell types would be associated with the severity of spinal cord damage and therefore with both the presenting clinical signs and the prognosis of affected dogs. Animals: Fifty‐four dogs with acute nonambulatory thoracolumbar IVDD were evaluated. Methods: Retrospective study. Signalment, neurologic grade, CSF TNCC, protein concentration, red blood cells count and differential cell percentages, and short‐ and long‐term outcomes were evaluated. Results: CSF pleocytosis (>5 cells/μL) was present in 54% of dogs and was positively associated with neurologic grade at presentation and with postoperative time to regaining ambulation. Neutrophils were observed most frequently. The percentage of CSF macrophages and macrophage to monocyte ratio were higher (P= .001, for both) in dogs presented without deep pain sensation (DPS) that did not regain ambulation. Receiver operator characteristics curve analysis yielded a cut‐off point of 13% macrophages with a sensitivity and specificity of 100 and 83%, respectively, for prediction of a negative outcome. Conclusions and Clinical Importance: CSF pleocytosis is positively associated with the severity of spinal cord damage in dogs with thoracolumbar IVDD. The percentage of CSF macrophages can be used as a prognostic indicator for regaining ambulation in dogs that have lost DPS.     

Blood–brain‐barrier disruption in chronic canine hypothyroidism

Background: Central nervous system (CNS) manifestations of hypothyroidism have been associated with cerebrovascular complications. Reports of cerebrospinal fluid (CSF) abnormalities are rare in hypothyroid dogs. Objective: The aim of this study was to determine if chronic hypothyroidism causes blood–brain‐barrier (BBB) abnormalities that are detectable using indirect CSF biomarkers. Methods: The study included 18 normal, euthyroid, female mixed‐breed dogs. Hypothyroidism was induced by ¹³¹iodine administration in 9 dogs; 9 served as untreated controls. Evaluations included physical and neurologic examination, complete CSF analysis, serum and CSF protein electrophoresis, measurement of plasma vascular endothelial growth factor (VEGF) and serum S‐100B concentrations, and calculation of CSF albumin quota (AQ) and were conducted at baseline and 6, 12, and 18 months after induction of hypothyroidism. Data were analyzed using repeated measures ANOVA. Results: At baseline, differences between groups were not detected for any variable. Throughout the study, controls dogs remained free of neurologic disease and had test variables that remained within reference intervals. Two hypothyroid dogs developed CNS signs during the study, and evidence of cerebrovascular disease was found at necropsy. At 12 and 18 months, the CSF total protein, VEGF, S‐100B, and fractional albumin concentrations, and AQ were significantly higher (P<.04) in hypothyroid dogs than controls. Among test variables assayed in serum or plasma, the only significant difference was a higher S‐100B concentration in hypothyroid dogs (P=.003) at 18 months. Conclusions: BBB integrity is disrupted in chronic hypothyroidism. Significant increases in CSF concentrations of VEGF and S100‐B in hypothyroid dogs indicate dysfunction in both endothelial and glial elements of the BBB.     

Cerebrospinal fluid analysis and magnetic resonance imaging in the diagnosis of neurologic disease in dogs: a retrospective study

BACKGROUND: Diagnosis of central nervous system (CNS) abnormalities in dogs can be challenging antemortem. Historically, cerebrospinal fluid (CSF) analysis has been used for routine diagnostic evaluation of animals with suspected neurologic disease; however, with increasing availability of magnetic resonance (MR) imaging, the need for concurrent CSF analysis may be questioned. OBJECTIVE: The purpose of this study was to retrospectively assess and compare the diagnostic information contributed from MR imaging and CSF analysis in a population of dogs presenting with neurologic disease. METHODS: Results of concurrent MR imaging and CSF analysis were evaluated in dogs presented for neurologic diseases. Based on clinical diagnosis, the sensitivity of CSF analysis and MR imaging for detecting a nervous system abnormality was calculated. Dogs with diagnoses confirmed by other diagnostic modalities were also evaluated separately. RESULTS: A total of 256 dogs were included in the study. For clinical diagnoses in which abnormalities were expected, MR imaging abnormalities were found in 89% and CSF abnormalities in 75% of dogs; CSF abnormalities were more common than MR imaging abnormalities only in inflammatory CNS disease. The majority of CSF abnormalities were nonspecific; an etiologic diagnosis was determined in only 2% of CSF samples. MR imaging excelled in detecting structural disorders, revealing 98% of vertebral abnormalities. In confirmed cases (n = 55), 76% of MR images and 9% of CSF samples were diagnostic. When intervertebral disk disease (IVDD) and vertebral malformation were excluded from analysis (n = 16 remaining), 25% of MR images and 6% of CSF cytology results were highly indicative of the confirmed diagnoses; CSF titer results provided the diagnosis in 25% of these cases. CONCLUSION: CSF analysis may not be necessary when MR findings of IVDD or vertebral malformation/instability are obvious; however, when the cause of neurologic disorder is uncertain, concurrent MR imaging and CSF analysis provides the greatest assistance in establishing a clinical diagnosis.     

Composition of cerebrospinal fluid in clinically normal adult ferrets

OBJECTIVE: To determine the protein and cellular composition of CSF in healthy adult ferrets. ANIMALS: 42 clinically normal adult ferrets. PROCEDURE: CSF samples were collected from the cerebellomedullary cistern of anesthetized ferrets by use of disposable 25-gauge, 1.6-cm-long hypodermic needles. Samples were processed within 20 minutes after collection. The number of WBCs and RBCs per microliter of CSF was counted by use of a hemacytometer. The total protein concentration was determined by use of an automated chemistry analyzer. RESULTS: Total WBC counts (range, 0 to 8 cells/microL; mean, 1.59 cells/microL) in CSF of ferrets were similar to reference range values obtained for CSF from other species. Twenty-seven CSF samples had <100 RBCs/microL (mean, 20.3 RBCs/microL). A small but significant effect of blood contamination on WBC counts was found between the 27 CSF samples with <100 RBCs/microL and the remaining samples. Protein concentrations in CSF of ferrets (range, 28.0 to 68.0 mg/dL; mean, 31.4 mg/dL) were higher than has been reported for the CSF of dogs and cats. A significant effect of blood contamination on the CSF protein concentration was not found. CONCLUSION AND CLINICAL RELEVANCE: We have established reference range values for WBC counts and protein concentrations in CSF from healthy adult ferrets that may be useful in the clinical investigation of CNS disease. Results of our study indicate that the WBC count is significantly affected by blood contamination of the CSF sample.     

Analysis of cerebrospinal fluid from dogs and cats after 24 and 48 hours of storage

OBJECTIVE: To compare differential cell counts and cell characteristics of CSF samples analyzed immediately or after storage for 24 and 48 hours at 4 C with and without the addition of autologous serum. DESIGN: Prospective study. ANIMALS: 36 dogs and 6 cats. PROCEDURE: CSF samples were collected from the cerebellomedullary cistern and divided into 250-microliter aliquots. Slides of CSF samples were prepared by use of cytocentrifugation immediately and after 24 and 48 hours of storage with addition of autologous serum (final concentrations, 11 and 29%). Differential cell counts and number of unrecognizable cells were compared among preparations. RESULTS: Significant differences in the differential cell counts were not detected among samples analyzed before or after storage. Although the number of unrecognizable cells increased with storage time, this did not result in a significant effect on cell distribution or diagnosis. Cells in CSF samples stored with 11% serum more closely resembled cells in fresh samples than did cells in samples stored with 29% serum. CONCLUSIONS AND CLINICAL RELEVANCE: CSF samples collected at veterinary clinics remote from a diagnostic laboratory or during nonoperational hours may be preserved through the addition of autologous serum. Evaluation of such samples is likely to result in an accurate diagnosis for at least 48 hours after collection.     

Evaluation of the ADVIA 120 for analysis of canine cerebrospinal fluid

BACKGROUND: Conventional techniques for canine cerebrospinal fluid (CSF) analysis require large sample volumes and are labor intensive and subject to operator variability. Objective: The purpose of this study was to evaluate the ADVIA120 CSF assay for analysis of canine CSF samples. METHODS: CSF samples collected from 36 healthy control dogs and 17 dogs with neurologic disease were processed in parallel using the automated assay and established manual methods using a hemocytometer and cytocentrifugation. Results for WBC (total nucleated cell) count, RBC count, and differential nucleated cell percentages were compared using Spearman rank correlation coefficients and Bland-Altman bias plots. RESULTS: Correlation coefficients for WBC and RBC counts were 0.57 and 0.83 for controls, and 0.92 and 0.94 for ill dogs, respectively. Coefficients for the percentages of neutrophils, lymphocytes, and monocytes were 0.53, 0.26, and 0.12 for controls and 0.77, 0.92, and 0.70 for dogs with neurologic disease. When data were combined (n=53), correlation coefficients were 0.86 and 0.91 for WBC and RBC counts, and 0.63, 0.43, and 0.30 for neutrophil, lymphocyte, and monocyte percentages. A 9.5% positive bias and 7.0% negative bias were obtained for the ADVIA 120 CSF assay for lymphocytes and macrophages in dogs with neurologic disease with Bland-Altman analysis. A 12.2% positive bias was found for lymphocyte percentage in dogs with neurologic disease. CONCLUSIONS: Manual and automated CSF assays had moderate to excellent correlation for WBC and RBC concentrations, but results were more variable for differential cell percentages. The ADVIA assay may be more useful for assessment of canine CSF with adjustment of cell differentiation algorithms.     

Cerebrospinal Fluid Myelin Basic Protein as a Prognostic Biomarker in Dogs with Thoracolumbar Intervertebral Disk Herniation

Background: Release of myelin basic protein (MBP) into the cerebrospinal fluid (CSF) is associated with active demyelination and correlates with outcome in various neurological diseases. Hypothesis/Objectives: To describe associations among CSF MBP concentration, initial neurological dysfunction, and long‐term ambulatory outcome in dogs with acute thoracolumbar intervertebral disk herniation (IVDH). Animals: Five hundred and seventy‐four dogs with acute thoracolumbar IVDH and 16 clinically normal dogs. Methods: Prospective case series clinical study. Signalment, initial neurological dysfunction as determined by a modified Frankel score (MFS), and ambulatory outcome at >3‐month follow‐up were recorded. Cisternal CSF MBP concentration was determined by an ELISA. Associations were estimated between CSF MBP concentration and various clinical parameters. Results: Dogs with thoracolumbar IVDH that did not ambulate at follow‐up had a higher CSF MBP concentration (median, 3.56 ng/mL; range, 0.59–51.2 ng/mL) compared with control dogs (median, 2.22 ng/mL; range, 0–3.82 ng/mL) (P= .032). A CSF MBP concentration of ≥3 ng/mL had a sensitivity of 78% and specificity of 76% to predict an unsuccessful outcome based on receiver‐operating characteristics curve analysis (area under the curve =0.688, P= .079). Affected dogs with a CSF MBP concentration ≥3 ng/mL had 0.09 times the odds of ambulation at follow‐up compared with affected dogs with CSF MBP concentration <3 ng/mL when adjusted for initial MFS (95% confidence interval 0.01–0.66, P= .018). Conclusions and Clinical Importance: These results would suggest that CSF MBP concentration may be useful as an independent prognostic indicator in dogs with thoracolumbar IVDH.     

Iatrogenic brainstem injury during cerebellomedullary cistern puncture

Cerebrospinal fluid collection is fundamental to the investigation of central nervous system disorders although it carries potential risks. Herein we report the clinical signs and magnetic resonance (MR) imaging findings associated with needle injury to the brainstem during cerebellomedullary cistern puncture in four dogs. Three dogs were nonambulatory tetraparetic with cranial nerve deficits and one dog had unexplained left thoracic limb paresis. In MR images, there were conspicuous T2 hyperintensities in the myelencephalon in all dogs. In T2* gradient echo images, the lesions were hypointense in two dogs with multiple cranial nerve deficits, and hyperintense in another dog. One dog was euthanized due to sudden neurologic deterioration 12 days later, one died shortly after MR imaging, and a third was euthanized due to concurrent cervical spondylomyelopathy. The fourth dog recovered gradually. Diagnosis was confirmed histopathologically in one dog and was presumptive based on clinical signs and MR findings in three dogs. None of the dogs with cranial nerve deficits recovered, only the one dog with left thoracic limb paresis and concurrent syringomyelia.     

Evaluation of the success of medical management for presumptive cervical intervertebral disk herniation in dogs

Objective— To determine the success of medical management of presumptive cervical disk herniation in dogs and variables associated with treatment outcome. Design— Retrospective case series. Animals— Dogs (n=88) with presumptive cervical disk herniation. Methods— Dogs with presumptive cervical and thoracolumbar disk herniation were identified from medical records at 2 clinics and clients were mailed a questionnaire related to the success of therapy, clinical recurrence of signs, and quality of life (QOL) as interpreted by the owner. Signalment, duration and degree of neurologic dysfunction, and medication administration were determined from medical records. Results— Ninety‐seven percent of dogs (84/87) with complete information were described as ambulatory at initial evaluation. Successful treatment was reported for 48.9% of dogs with 33% having recurrence of clinical signs and 18.1% having therapeutic failure. Bivariable logistic regression showed that non‐steroidal anti‐inflammatory drug (NSAID) administration was associated with success (P=.035; odds ratio [OR]=2.52). Duration of cage rest and glucocorticoid administration were not significantly associated with success or QOL. Dogs with less‐severe neurologic dysfunction were more likely to have a successful outcome (OR=2.56), but this association was not significant (P=.051). Conclusions— Medical management can lead to an acceptable outcome in many dogs with presumptive cervical disk herniation. Based on these data, NSAIDs should be considered as part of the therapeutic regimen. Cage rest duration and glucocorticoid administration do not appear to benefit these dogs, but this should be interpreted cautiously because of the retrospective data collection and use of client self‐administered questionnaire follow‐up. Clinical Relevance— These results provide insight into the success of medical management for presumptive cervical disk herniation in dogs and may allow for refinement of treatment protocols.     

Cytologic examination of fine‐needle aspirates from mammary gland tumors in the dog: diagnostic accuracy with comparison to histopathology and association with postoperative outcome

Background: Mammary tumors are the most common neoplasms in female dogs. Malignant tumors may carry a poor prognosis and necessitate surgery. Few data are available on the value of cytologic examination as a diagnostic or prognostic tool for mammary tumors in dogs. Objectives: The objectives of this study were to determine whether cytologic findings in fine‐needle aspirate specimens of canine mammary tumors correlate with histopathologic results and whether the cytologic diagnosis is associated with postoperative outcome. Methods: In this prospective study, fine‐needle aspirate samples were obtained from 50 mammary tumors in 50 dogs. Results of cytologic and histopathologic examination were compared, using the histologic diagnosis as the reference method. Kaplan–Meier log rank analysis was used to evaluate univariate association of the cytologic diagnosis with duration of survival, local control, and metastasis‐free interval. Results: Adequate cytologic samples were obtained in 43/50 (86%) cases. The cytologic diagnosis correlated with the histologic diagnosis for benign and malignant tumors in 40/43 (93%) and 35/43 (81%) cases, respectively. Cytologic examination had a sensitivity of 88% and a specificity of 96% for the diagnosis of malignancy. The cytologic diagnosis had significant univariate association with duration of survival (P=.016), recurrence‐free interval (P=.003), and metastasis‐free interval (P=.014). Conclusions: Cytologic examination of mammary tumors in the dog has satisfactory accuracy, sensitivity, and specificity for the diagnosis of malignancy and is associated with postoperative outcome. Further studies on the diagnostic accuracy of cytology as well as multivariate analysis of its preoperative prognostic value in mammary tumors in the dog are warranted.     

Cerebrospinal fluid from a dog with hind limb ataxia

A 9-year-old spayed female German Shepherd dog with a history of orthopedic disease was presented to the North Carolina State University Veterinary Teaching Hospital for evaluation of recent, progressive, bilateral, hindlimb ataxia. Analysis of cisternal and lumbar cerebrospinal fluid (CSF) samples revealed normal total nucleated cell counts and a mild increase in protein concentration in the lumbar sample. In cytocentrifuged specimens of both CSF samples, aggregates of refractile, angular to irregular, pale blue to colorless, crystalline material were observed in the background. Some of the material appeared birefringent under polarized light. Differentials for the material included contrast agent, epidural anesthetics or other pharmacologic agents, or artifact introduced through sample processing, collection, or handling. Based on investigation of clinical and laboratory processes it was determined that tubes used to collect CSF in the hospital recently had been changed from additive-free glass tubes to silica-coated shatter-resistant plastic tubes (BD Vacutainer Plus serum tubes, silicone-coated, Becton Dickinson). A cytocentrifuged preparation of saline placed in a silica-coated tube contained crystalline material identical to that observed in the CSF samples; saline placed in an additive-free glass tube contained no material. In this case, we document the microscopic appearance of highly concentrated silica particles in cytocentrifuged preparations of CSF and underscore the importance of recognizing and identifying this artifact in cytologic preparations.     

Cytologic interpretation of canine cerebrospinal fluid samples with low total nucleated cell concentration,with and without blood contamination

Background: Cerebrospinal fluid (CSF) is potentially altered by iatrogenic blood contamination at the time of sampling due to the addition of blood‐associated leukocytes and protein. Objectives: The objective of this study was to assess whether protein concentration, neutrophil percentage, and the presence of activated macrophages, reactive lymphocytes, or eosinophils in CSF samples with low total nucleated cell concentration (TNCC) are affected by blood contamination or associated with central nervous system (CNS) disease. Methods: Case records from the Royal Veterinary College Diagnostic Laboratory were searched retrospectively for dogs with CSF having ≤5 TNCC/μL. TNCC, RBC, and protein concentrations; neutrophil percentage; and the presence of activated macrophages, reactive lymphocytes, and eosinophils were recorded. Results of magnetic resonance imaging (MRI) also were recorded as a marker of CNS disease. Results: Of 906 cases evaluated, 106 (12%) had blood contamination (>500 RBCs/μL) in CSF. Protein concentration and neutrophil percentage were significantly higher and the presence of eosinophils was more likely in blood contaminated vs noncontaminated samples. Non‐blood‐contaminated samples with activated macrophages or reactive lymphocytes had higher protein concentrations and neutrophil percentages, and those with activated macrophages were more likely to have a positive finding on MRI. Conclusions: Protein concentration, neutrophil percentage, and the presence of eosinophils are significantly affected by blood contamination in canine CSF having low TNCC. Activated macrophages and reactive lymphocytes are not affected by blood contamination, however, and may be useful in identifying dogs with CNS abnormalities.     

Beta-2-microglobulin levels in the cerebrospinal fluid of normal dogs and dogs with neurological disease

BACKGROUND: Cerebrospinal fluid (CSF) analysis is the basis for establishing a diagnosis of central nervous system (CNS) inflammation. However, the information provided by routine CSF analysis is limited. Determination of CSF beta-2-microglobulin (beta2m) concentration has been used diagnostically in humans to identify inflammatory CNS disease; we hypothesized that it may have similar value in dogs. OBJECTIVES: The objective of this study was to measure (beta2m concentration in the CSF of clinically healthy dogs and compare the values to those observed in dogs with inflammatory CNS disease and intervertebral disc disease (IVDD). METHODS: CSF was collected from 10 clinically healthy laboratory dogs and 11 dogs each with inflammatory CNS disease and IVDD. Routine CSF analysis was performed, and (beta2m concentration was measured by ELISA. CSF (beta2m concentration and CSF:serum (beta2m ratio were compared between groups by ANOVA. Linear relationships between CSF total nucleated cell count (TNCC), RBC count, total protein concentration, and (beta2m concentration were assessed by regression analysis. RESULTS: The mean (+/- SD) CSF (beta2m concentration in clinically healthy dogs was 0.36 (+/- 0.05 microg/mL (cisternal) and 0.40 (+/- 0.07 microg/mL (lumbar). Median CSF (beta2m concentration in dogs with IVDD (0.46 microg/mL) and inflammatory CNS disease (0.85 microg/mL) differed from that of controls (0.36 microg/mL; P=.002). The concentration also differed between the 2 disease groups (P=.01). Five dogs with inflammatory CNS disease had CSF:serum (beta2m ratios >1. A correlation was identified between TNCC and (beta2m concentration (r=0.69, P=.0003). CONCLUSIONS: CSF (beta2m concentration is higher in dogs with IVDD and inflammatory CNS disease, with highest values seen with inflammatory disease. This may be attributed in part to the correlation between CSF (beta2m concentration and TNCC, but also may reflect intrathecal immune activation.     

Results of cerebrospinal fluid analysis, neurologic examination findings, and age at the onset of seizures as predictors for results of magnetic resonance imaging of the brain in dogs examined because of seizures: 115 cases (1992-2000)

OBJECTIVE: To determine whether neurologic examination findings, results of CSF analysis, or age at the onset of seizures could be used to predict whether results of magnetic resonance imaging (MRI) would be normal or abnormal in dogs with seizures. DESIGN: Retrospective study. ANIMALS: 115 dogs. PROCEDURE: Information on results of neurologic examination, results of CSF analysis, age at the onset of seizures, and results of MRI was obtained from the medical records. RESULTS: Results of MRI were abnormal in 61 dogs and normal in 54. Sensitivity and specificity of neurologic examination alone were 77 (47/61) and 91% (49/54), respectively. Sensitivity and specificity of CSF analysis alone were 79 (48/61) and 69% (37/54), respectively. Results of MRI were abnormal for 12 of 28 (43%) dogs with abnormal CSF analysis results and normal neurologic examination results but for only 2 of 35 (6%) dogs with normal CSF analysis and normal neurologic examination results. Similarly, results of MRI were abnormal for 36 of 37 (97%) dogs with abnormal CSF analysis and abnormal neurologic examination results but for only 11 of 15 (73%) dogs with normal CSF analysis results and abnormal neurologic examination results. Age at the onset of seizures (< 6 vs > or = 6 years old) was not significantly associated with results of MRI. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that neurologic examination findings and results of CSF analysis are useful in predicting whether results of MRI will be abnormal in dogs examined because of seizures, but age at the onset of seizures is not.