Diagnosed Of Pervasive Developmental Disorder, Lacks Adaptive Functioning. MRI Shows Septum Pellucidum Is Absent. Meaning ?

Hi, My 12 year old son was adopted from Russia in 2001 at 15 months old. He has been diagnosed with significant developmental delays, Pervasive Developmental Disorder and suspected Fetal Alcohol Sydrome (source unconfirmed). He was found abandoned in the street at a few days old and nothing is known about the biological parents. He does do well in some areas academically (he is in a special needs classroom) he is very sociable but is lacking in adaptive functioning. His recent brain MRI states the septum pellucidum is absent, but the midline structures are otherwise normal. It also states the ventricular system , cerebullum and brainstem are normal in size and morphology. What I was wondering about was it states there are multiple punctate nonspecific foci of increased flair signal in the subcortical white matter noted in the right parieral and left parieto-occipital lobes, right corona radiata and centrum semiovale and the splenium of the corpus callosum. What does that mean? His neurologist office just said the MRI is abnormal (although some areas were normal). Could the punctate foci be related to fetal alcohol syndrome? Thanks, AAAAA