Confirming a Diagnosis

Cerebrospinal fluid collection and its analysis in equine neurological disease

“…In addition, AO collection requires general anaesthesia in adults. Larger volumes of CSF are readily obtained from the AO site in comparison with the LS site, although large volumes are rarely required (except when performing myelography), but removing a large volume can lead to brain herniation and death in animals with increased intracranial pressure (Lorenz and Kornegay 2004). As a result, AO taps are usually contraindicated when the clinician considers that intracranial pressure may be raised (e.g.…”

“…Usually though, slight turbidity is appreciated with as few as 200 WBC/µl or 400 RBC/µl (Hayes 1987). CSF may clot if it contains increased fibrinogen (occasionally seen in suppurative meningitis or if the sample is significantly blood contaminated (De Lahunta 1983; Lorenz and Kornegay 2004).…”

“…Xanthochromia (a slight yellow tinge), that persists after centrifugation is usually due to previous RBC lysis, and appears within 2-4 h following subarachnoid haemorrhage (De Lahunta 1983;Smith and George 2002). Mild xanthochromia is also seen in neonates -a reflection of their higher CSF protein concentration (Furr and Bender 1994) or in pathological conditions associated with elevated CSF protein concentration, such as herpes (EHV1) myeloencephalitis, or during hyperbilirubinaemia (De Lahunta 1983;Lorenz and Kornegay 2004).…”

“…The pressure of CSF can be measured but is not specific (De Lahunta 1983;Hayes 1987;Lorenz and Kornegay 2004) and is influenced by the technique, anaesthesia and systemic blood pressure (De Lahunta 1983). It is rarely measured in the clinical setting.…”

“…If bacterial infection is suspected from clinical signs or after detecting turbid CSF, low CSF glucose concentration or neutrophilic pleocytosis, a sample should be cultured. Prior to receiving antibacterial sensitivity results, a Gram stain can aid in early choice of antibiotic therapy (De Lahunta 1983;Lorenz and Kornegay 2004).…”