Magnesium, cerebrospinal fluid (CSF) concentration
This test measures the amount of magnesium, a mineral, in your cerebrospinal fluid (the fluid surrounding your brain and spinal cord). It helps assess mineral balance and potential issues in the central nervous system.
["CSF magnesium levels can indicate nerve or fluid-related health concerns."]
Key facts at a glance
- LOINC
- 11861-2
- Short code
- Fet Cisterna magna Diam Est from GA
- Synonyms
- Fet Cisterna magna Diam Est from GA
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- estimated-from-gestational-age
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test if you have symptoms like muscle weakness, seizures, or neurological problems. It can also be part of a broader evaluation for conditions affecting the brain or spinal cord, such as meningitis, brain tumors, or metabolic disorders.
What to Expect Before the Test
No special preparation is usually needed. You may receive a local anesthetic to numb the area where the fluid is collected. The procedure involves inserting a needle into your back to draw a small amount of CSF.
What Happens During the Test?
The test involves a quick, minor procedure called a lumbar puncture (spinal tap). A healthcare professional will carefully insert a needle into your lower spine to collect a small sample of CSF. The sample is then sent to the lab for analysis.
What Are the Possible Results?
Results are interpreted by your healthcare provider based on your symptoms, medical history, and lab findings. Abnormal levels may suggest conditions like electrolyte imbalances, nerve damage, or infections.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Magnesium in CSF can reflect underlying neurological or metabolic conditions. Low levels may indicate nerve dysfunction or certain infections, while elevated levels could suggest metabolic disorders or other systemic issues. Always discuss results with your doctor.
Short name
CSF Magnesium
Frequently asked questions
How long does it take to get results from this test?
What are common reasons for abnormal magnesium levels in CSF?
Can diet affect magnesium levels in CSF?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy