Flow chart of inclusion of CSF samples.

<p>N – number of CSF samples.</p

Age-specific CSF glucose, CSF/plasma glucose ratio and CSF lactate values.

<p>(A) CSF glucose concentration in 8,871 samples. CSF samples with CSF glucose >10.0 mmol/L (n = 4) are not shown; (B) CSF/plasma glucose in 4,516 samples. CSF samples with CSF/plasma glucose >1.5 (n = 5) are not shown; (C) CSF lactate concentration in 7,614 samples. CSF samples with CSF lactate >5000 µmol/L (n = 22) are not shown. Lines indicate 5^th and 95^th percentile values.</p

Summary of literature search for reference ranges of CSF glucose, CSF/plasma glucose ratio and CSF lactate.

<p>N - number of CSF samples included in study; wk(s) – week(s); dys – days; yrs- years; P – percentile.</p

Relation between plasma glucose and CSF glucose.

<p>(A) Relation between plasma glucose and CSF/plasma glucose ratio in 4,508 CSF samples. CSF samples with CSF/plasma glucose ratio >1.5 (n = 5) are not shown. (B) Relation between plasma glucose and CSF glucose in 4,513 CSF samples. The grey areas indicates normoglycemia (plasma glucose >3.0 and <7.8 mmol/L).</p

Age-specific reference values for CSF glucose, CSF/plasma glucose ratio and CSF lactate.

<p>Reference values are based on the 5^th to 95^th percentile values. The subgroups from the original data (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042745#pone.0042745.s001" target="_blank">Tables S1</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042745#pone.0042745.s002" target="_blank">S2</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042745#pone.0042745.s003" target="_blank">S3</a>) were clustered into age groups which are commonly used in daily clinical practice (as used by MeSH, Pubmed).</p>*<p>Reference range after exclusion of CSF samples of patients with an unknown or abnormal plasma glucose (<3.0 mmol/L or >7.8 mmol/L) at the moment of lumbar puncture (only represented if >10% different from to the original value). Numbers between brackets represent values without correction for plasma glucose. ‡Reference range after exclusion of CSF samples with CSF lactate >3000 µmol/L (only represented if >10% different from the original value). Number between brackets represents upper limit without exclusion of CSF samples with CSF lactate >3000 µmol/L.</p