Glucose, CSF
Clinical Background:
The glucose level in CSF is proportional to the blood glucose level and corresponds to 60-70% of the concentration in blood. Therefore, normal CSF glucose levels lie between 2.2 and 4.4 mmol/L. Hyp...
The glucose level in CSF is proportional to the blood glucose level and corresponds to 60-70% of the concentration in blood. Therefore, normal CSF glucose levels lie between 2.2 and 4.4 mmol/L. Hypoglycorrhachia (low CSF glucose levels) can be used in the investigation of CNS infections, inflammatory conditions, subarachnoid hemorrhage, hypoglycemia (low blood sugar), impaired glucose transport, increased CNS glycolytic activity and metastatic carcinoma. It is useful in distinguishing causes of meningitis as more than 50% of patients with bacterial meningitis have decreased CSF glucose levels while patients with viral meningitis usually have normal CSF glucose levels.
There is no pathologic process that directly leads to hyperglycorrhachia (high CSF glucose levels) and therefore, high CSF glucose levels have no specific diagnostic importance
Test Details
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Discipline:
Biochemistry
Biochemistry
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Specimen Container Adult:
Fluoride oxalate tube
Fluoride oxalate tube
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Specimen Container Paediatric:
Fluoride oxalate tube
Fluoride oxalate tube
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Minimum Volume Adult:
0.5 mL CSF
0.5 mL CSF
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Minimum Volume Paediatric:
0.5 mL CSF
0.5 mL CSF
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Sample Stability:
5 hours at 15-25°C, 3 days at 4-8°C, >1 month at -20°C
5 hours at 15-25°C, 3 days at 4-8°C, >1 month at -20°C
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Interpretation:
Provided that CSF for glucose estimation has been mixed with fluoride a low glucose concentration occurs in:
1. Infection
CSF glucose is normally metabolised only by cerebral cells. If many leucocy...Read MoreProvided that CSF for glucose estimation has been mixed with fluoride a low glucose concentration occurs in:
1. Infection
CSF glucose is normally metabolised only by cerebral cells. If many leucocytes and bacteria are present these also utilise the sugar and abnormally low levels are obtained. If obvious pus is present the estimation of CSF glucose adds nothing to diagnostic precision. It is most useful when the CSF is clear and tuberculous meningitis is suspected, although levels are not as low in this condition as in pyrogenic meningitis.
2. Hypoglycaemia
CSF glucose concentration parallels that of blood, although there is a lag before changes in blood glucose are reflected in the CSF. In the presence of hypoglycaemia (which may cause coma) CSF glucose levels may be low although there is no primary cerebral abnormality. In case of doubt both blood and CSF concentrations should be measured. In hyperglycaemia CSF glucose levels will be high.
Low CSF glucose and decreased CSF glucose to blood glucose ratio may also be seen in GLUT1 deficiency syndrome. -
Reference Ranges:
Up to 18 years: 3.33 – 4.44 mmol/L
18 years and over: 2.22 – 3.89 mmol/L
Up to 18 years: 3.33 – 4.44 mmol/L
18 years and over: 2.22 – 3.89 mmol/L
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Routine Contact Name:
Duty Biochemist
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Routine Telephone:
Freeman: 0191 244 8889
RVI: 0191 282 9719Freeman: 0191 244 8889
RVI: 0191 282 9719 -
Routine Email: