The effect of prior thecal puncture on cerebrospinal fluid analytes in normal adult horses.

Abstract

BACKGROUND: Serial cerebrospinal fluid (CSF) analysis might be required in clinical neurologic disease. The effect of lumbosacral (LS) or cervical (C1-C2) centesis on subsequent CSF cytologic analyses has not been investigated in horses. OBJECTIVE: To evaluate the effect of thecal puncture on subsequent CSF analyses ANIMALS: Ten healthy adult horses. METHODS: Prospective study. Horses were randomly assigned to undergo CSF collection twice, 14&#x2009;days apart, from either the C1-C2 or LS space. After a 4-month washout period, CSF collection was repeated from the alternate site. Continuous data were analyzed using linear mixed-effects models and count data using mixed-effects negative binomial regression. Statistical significance was set at P&#x2009;<&#x2009;.05. RESULTS: There was no significant effect of collection day (day 0 or day 14) for any CSF analytes, including protein concentration (C1-C2: 45 [95% CI: 33-57] mg/dL day 0 vs 49 [95% CI: 39-62] mg/dL day 14, P = .12; LS: 64 [95% CI: 41-100] mg/dL day 0 vs 83 [95% CI: 53-129] mg/dL day 14, P = .37), or nucleated cell count (C1-C2: 2 [95% CI: 1-4] cells/&#x3bc;L day 0 vs 3 [95% CI: 1-4] cells/&#x3bc;L day 14, P = .65; LS: 3 [95% CI: 2-5] cells/&#x3bc;L day 0 vs 5 [95% CI: 3-8] cells/&#x3bc;L day 14, P = .10). There was no significant difference in EPM titer or EPM serum : CSF ratio between days 0 and 14. CONCLUSIONS AND CLINICAL IMPORTANCE: Repeat thecal puncture from the LS or C1-C2 space 2&#x2009;weeks apart does not appear to impact CSF analytes.