Hi, My Father Is 66 And Has Schizophrenia. Recently He

hi, my father is 66 and has schizophrenia. recently he forgets things and doesn't understand what is going on around him. his MRI shows these:
evidence of small vessel ischemic changes in deep and periventricular white matter is detected.
mild senile cortical brain atrophy is seen.
i literally don't know what it means, i wonder if you could help me about this.