Should I be concerned about "volume loss in the brain"?

Question:
​Hi my question is regarding MRI reports. I have seen the term "volume loss in the brain" multiple times when obtaining a copy of the MRI report, but my doctor has never mentioned this as an issue to me. Should I be concerned?

Answer:

The term, “volume loss”, on an MRI report is usually accompanied by the phrase, “greater than expected for age.”  As you may know, we gradually lose brain tissue volume as part of the normal aging process. Certain diseases of the nervous system, such as MS, accelerate this volume loss. Even in the most benign cases of MS, we usually notice greater volume loss than expected for age after years of disease.

Few neurologists pay attention to this volume loss for several reasons:
1. Until recently there was no way to accurately measure this brain volume loss except in research studies or even determine if the amount of volume loss per interval of time (say a year) was greater than expected. Soon these techniques will be available in clinical practice.
2. We know of no therapies that halt this volume loss, although certain highly active therapies such as alemtuzumab (Lemtrada) and ocrelizumab (not available yet) slow down this loss of volume to near normal rates.
3. Most MS therapies are approved based on clinical trials that used relapse rates and the development of new T2 hyperintensities (the white spots on MRI) as the chief outcome measures. Therefore, most neurologists in clinical practice primarily use these outcome measures to determine if a drug is working.

Studies over the past 25 years have demonstrated that the brain is able to compensate for loss of brain tissue, in individuals with significant passive and active neuronal reserve (see prior blogs on this subject). Briefly, passive reserve refers to the amount of enrichment and education you receive during development and active reserve refers to ongoing mental and physical stimulation and learning through adulthood and old age. Therefore, the mere presence of volume loss should not concern you now. Continued volume loss, on the other hand, at rates greater than expected is associated with the development of both cognitive and physical disability. Therefore, it is increasingly important to measure this MRI metric to determine if your treatment is working adequately. This is particularly important in people who are over 50 or with longstanding MS, since they rarely have relapses or noticeable new MRI T2 lesions even when a treatment is not working adequately. In these individuals it is perhaps not accurate to say that everything is stable merely because these measure remain stable.

Stay tuned for more information on this important topic.

Revere (Rip) Kinkel MD
Director of the Multiple Sclerosis Program
Professor of Clinical Neurosciences
University of California San Diego