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"What is delayed myelination?"

ZocdocAnswersWhat is delayed myelination?


My daughter, 11 months old, recently had an MRI to address some strange symptoms she's been showing. The doctor said that the scan revealed 'delayed myelination'. What does that mean?


Although it is not clear, the MRI your daughter had is presumably a brain mri to evaluate the symptoms she is displaying. This short vignette also does not describe the symptoms she has. In terms of delayed myelination, this is often a diagnosis seen in babies that are born prematurely. The myelin sheath is a covering that wraps around nerves in the brain and peripheral nervous system. The myelin sheath allows for the signal traveling down the nerve to not decrease in amplitude or speed. It is similar to the rubber covering electrical wiring. MRIs of the brain can look at specific parts of the brain and assess whether the amount of myelin covering the nerves is a normal amount or if there is a decreased amount of myelin visible. Unfortunately at this time, we do not know the long term significance of this finding as some patients who are found to have delayed myelination eventually go on to develop normal amounts of myelin, while other patients continue to have a diminished supply. At this time, it is also unclear what types of long term symptoms these patients may or may not develop. Your daughter's neurologist would be best able to assess your daughters clinical presentation, medical history, and further work up and possible treatment regimens if available.

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