[5] Hypoglycorrhachia (low CSF glucose levels) can be caused by CNS infections, inflammatory conditions, subarachnoid hemorrhage, hypoglycemia (low blood sugar),[3] impaired glucose transport (e.g. GLUT1 deficiency syndrome), increased CNS glycolytic activity and metastatic carcinoma.
[4] CSF glucose levels can be useful in distinguishing among 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.
Decrease in glucose levels during a CNS infection is caused due to glycolysis by both white cells and the pathogen, and impaired CSF glucose transport through the blood-brain barrier.
[3][6] 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.
In addition, damage to small blood vessels during lumbar puncture (traumatic tap) can lead to an increased CSF glucose since the blood that enters the collected CSF sample contains higher levels of glucose.