Reduced brain N-acetyl aspartate level by MRS

What it means

A decrease in the level of N-acetyl aspartate in the brain identified by magnetic resonance spectroscopy (MRS).

N-Acetyl Aspartate (NAA) is an amino acid found exclusively in neurons. It is regarded as a non-specific marker and is thought to be involved in Coenzyme A interactions and lipogenesis within the brain. It is a marker of neuronal viability. Normal NAA concentration is in the range of 8-9 mmol/kg in healthy adult brain. Concentrations are decreased in conditions leading to axonal injury or neuronal loss. NAA is also decreased in other conditions such as neoplasm, infarction, and inflammatory conditions such as multiple sclerosis. NAA peak is seen at 2.0 ppm (parts per million) on MR spectra.

Rare diseases that can present with this6

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: MR Spectroscopy: N-acetylaspartate low in brain · Reduced brain N-acetyl aspartate level by magnetic resonance spectroscopy