Which of the following conditions is NOT associated with low CSF glucose levels?

Low cerebrospinal fluid (CSF) glucose levels are often indicative of underlying conditions that affect the metabolism of glucose in the brain or the presence of infections or malignancies. In the context of the given conditions, septic meningitis typically presents with low glucose levels due to bacterial consumption and impaired transport into the CSF. Cancer, particularly leptomeningeal carcinomatosis, can also be associated with low CSF glucose due to similar factors affecting glucose transport and metabolism.

Multiple sclerosis is characterized by inflammation and demyelination, which does not generally lead to low CSF glucose levels. In fact, the CSF in patients with multiple sclerosis often shows normal glucose levels unless there is a coexisting infection or complication.

Diabetes mellitus, although it can lead to various neurological complications, typically does not cause significantly lower levels of glucose in the CSF. In diabetic patients, glucose levels in the CSF are often within normal ranges because the blood-brain barrier effectively regulates glucose transport regardless of the systemic glucose levels, unless there are other complicating factors or concurrent illnesses. Thus, diabetes mellitus is not associated with low CSF glucose levels, making it the correct answer for this question.