THE DIAGNOSTIC UTILITY OF CEREBROSPINAL-FLUID CREATINE-KINASE ACTIVITY IN THE HORSE

We evaluated creatine kinase (CK) activity in the cerebrospinal fluid (CSF) of 128 horses with various neurological disorders, No associatio n was found between CSF CK activity and CSF red blood cell count, CSF nucleated cell count, CSF total protein concentration, or serum CK act ivity. The sensitivity and specificity of CSF CK activity as a diagnos tic test for protozoal myelitis in horses (61% and 56%, respectively) was higher than for cervical stenotic myelopathy, degenerative myelopa thy, or motor neuron disease, but was considered to be inadequate to b e of use diagnostically. Contamination of CSF with whole blood, hemoly zed red blood cells, or serum did not substantially contribute to incr eases in CSF CK activity. Addition of epidural fat or dura to CSF sign ificantly increased CSF CK activity in all cases. We suggest that the use of CSF CK activity as a diagnostic indicator of neurological disea se in the horse is unreliable, and that CSF CK activity may be falsely increased by contamination of CSF with epidural fat or dura during CS F collection. Copyright (C) 1996 by the American College of Veterinary Internal Medicine.