Introduction

• Cerebrospinal fluid (CSF) produced by active secretion as well as selective filtration from blood by choroid plexus.
• It should be clear and transparent (or colorless) and should not clot.
• CSF normally has a low protein content and contains few cells.
• Pathology in the CNS is often reflected in the CSF when there is compromise of the blood-brain barrier, the blood-CSF barrier or the CSF's interface with the brain and spinal cord.
• CNS disease does not consistently cause alterations in the CSF - abnormalities depend on the location and extent of the CNS lesion.
  General anesthesia is mandatory for CSF collection.

Uses

• Diagnosis of central nervous system disease Cerebrospinal fluid: cell count and differential and evaluation of therapy.
• Therapeutic drainage of CSF at high pressure, or blood or exudate.

Advantages

• Easy to collect.
• Full fluid analysis can be performed Cerebrospinal fluid: cell count and differential.
• Enables injection of contrast material for imaging.

Disadvantages

• Best results obtained during acute phase of disease.
• Requires general anesthesia.
• Life-threatening complications.
• May be associated with technique, eg tentorial herniation Brain: tentorial herniation associated with sudden release of pressure.

Contraindications for CSF collection

• Patient unstable for general anesthesia.
• Evidence of coagulopathy.
• Instability or pathology suspected at the site of collection (eg atlanto-axial instability).
• Severe hydrocephalus Hydrocephalus Hydrocephalus: congenital.
• Recent head trauma Brain: trauma.
• Imaging evidence of intracranial mass lesion or edema/hemorrhage causing mass effect.
• Clinical indication of increased intracranial pressure Intracranial pressure measurement.

Requirements

Preparation

Procedure

Outcomes

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.

Other sources of information

• How to perform a cerebral spinal fluid (CSF) tap in a dog. VETgirl, LLC Veterinary Continuing Education Video: www.youtube.com/watch?v=pqgV5G0kpl0
• Walmsley H (2013)Clinical pathology.In:Manual of Canine and Feline Neurology.Platt S R, Olby N J (eds). British Small Animal Veterinary Association, Gloucester, pp 36-58.
• Crow S E & Walshaw S O (1997)Manual of Clinical Procedures in the Dog, Cat, and Rabbit.2nd edition. Lippincott-Raven Publications, Philadelphia.
• Rusbridge C (1997)Collection and interpretation of cerebrospinal fluid in cats and dogs.In Practice19(6), 322-324, 327-331.
• Braund K G (1994)Clinical Syndromes in Veterinary Neurology.2nd edition. Mosby Year Book, St. Louis. pp 368-376.