Hello, I hope you can help! I've been trying to learn about delayed myelination, dysmyelination, and hypomyelination. My son is 2 and a half, with microcephaly, mental retardation, cortical vision impairment, motor skills of 4 month old. Cannot walk, crawl, sit up on own, or roll over. Nonverbal, cannot feed himself. Athetoid movements
My son's MRI reports at age 5 months and age 1 year showed "delayed myelination". Then his neurologist said he had "dysmyelination". Later, at a different appointment he called it "hypomyelination".
I am confused as to all these terms that the neurologist seems to be using interchangeably. Then when I asked him if this meant that he has a type of leukodystrophy, he said that he doesn't have a leukodystrophy, because that would mean regression/DEmyelination (and my son is not regressing). When I read about leukodystrophies, most were about DEmyelinating, BUT some said that they could be about DYSmyelination and not progressive.
First question: Could you please tell me the difference between delayed myelination, dysmyelination, and hypomyelination?
Second question: are there some leukodystrophies that involve delayed, dys-, or hypo- as opposed to DEmyelination?
Third question: are there any leukodystrophies that do not involve regression, or do they always have regression as a feature? (My son is not regressing)
Last question: all leukodystrophies mean a myelin problem. Is the opposite also true, that all myelin problems mean leukodystrophy?
THANK YOU very, very much for taking the time to answer these questions.