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Acta Scientiae Veterinariae, 2019. 47: 1704
Renato Tavares Conceição, Karina Keller Marques da Costa Flaiban , Fernanda Catacci Guimarães & Mônica Vicky Bahr Arias
ABSTRACT
Background: Cerebrospinal fluid (CSF) analysis is of great importance for evaluation of patients with central nervous
system problems, because it helps to confirm or exclude many diseases when evaluated together with other relevant clinical and ancillary laboratory tests. As there are few studies in Brazil describing results of CSF analysis in dogs and cats,
the objective of the present study was to evaluate results of CSF analysis in a period of ten years, grouping the changes
observed, mainly total and differential cell count and total protein concentration, according to the following etiological
categories of diseases: inflammatory, degenerative, traumatic, neoplastic and vascular disorders.
Materials, Methods & Results: Medical records of dogs and cats with neurological diseases that had CSF collected and
analyzed at a Veterinary Teaching Hospital between 2008 and 2017 were retrospectively reviewed. Patient data included
breed, sex, body weight, age at presentation, findings of clinical and neurological examination, results of CSF analysis,
diagnostic imaging and other laboratory tests results including PCR and serologies for infectious diseases. A total of 245
CSF exams were studied (240 dogs and five cats). The established normal range for protein concentration was less than
25 mg/dL for cisternal collection and less than 45 mg/dL for lumbar puncture. Total nucleated cell count was considered
normal when less than 5 cells/µL, with a predominance of mononuclear cells. Both pleocytosis and increased concentration
of the protein level were classified as discrete, moderate and marked, and the pleocytosis was further classified as mononuclear, neutrophilic and mixed cell pleocytosis. The information obtained was analyzed in relation to the neurological
syndromes and etiological categories of neurological diseases. The most frequent syndrome was thoracolumbar and the less
frequent was cerebellar. Regarding the etiological categories, the most frequent in decreasing order were inflammatory,
infectious, degenerative, neoplastic, traumatic, vascular and episodic. CSF examination was abnormal in 72% of cases.
In viral infectious diseases, there was predominantly mononuclear pleocytosis with a slight increase of protein, whereas
in dogs with presumptive diagnosis of meningoencephalitis of unknown origin (MUO), marked mononuclear and mixed
pleocytosis predominated with moderate to marked protein increase. In degenerative diseases, however, the absence of
pleocytosis or mild pleocytosis, with normal to slightly increased protein was most observed. In neoplastic diseases there
was a high frequency of mild to moderate pleocytosis, with and without albuminocytological dissociation, while in spinal
trauma there was mainly mononuclear pleocytosis. A slight increase in protein was observed mainly in infectious, degenerative, neoplastic and traumatic diseases, while moderate to marked increase was more observed in cases of presumptive
diagnosis of MUO. Albuminocytological dissociation was observed in half of the cases of neoplasia and less frequently
in degenerative, infectious and traumatic diseases.
Discussion: The exam was altered in a considerable number of patients and provided important information even when normal.
The diseases with more abnormalities were inflammatory/infectious and neoplastic diseases. When the exam was normal,
the most frequent condition was degenerative diseases. Although the changes were not specific for each class of neurological
disease, there were certain trends regarding pleocytosis type and protein increase in some of them. Based on the results of this
retrospective study, result of CSF analysis, when interpreted along with signalment, etiological categories of diseases, neurological syndromes, and results of other complementary tests, provided support for the diagnosis of various neurological diseases.
