cerebral metabolic disorder and encephalopathy dx

At one time my son had a dx of ADD.  Now dx is unspecified encephalopathy and cerebral metabolic disorder.  What are these two conditions and are they related to ADD?  He has a severe dyscalculia and has no concept of number at 15.  Your help is appreciated.

[CCF-Neuro-M.D.-CS]

Metabolic disorders are a group of disorders involving abnormal metabolism in the body. There are many different processes which need to function normally inorder to generate energy and normal function. Some groups within this category could include mitochondrial disease, disorders of sugar metabolism, disorders of fat metabolism, disorders of protein or enzyme synthesis, and disorders of processes which breakdown byproducts. I know this is rather vague, but this area of disorders is quite large. I would encourage you to ask your doctor to provide a more specific diagnosis, and perhaps inquire about a second opinion. If you are in the area we have several wonderful physicians who specialize in neurometabolism, their names are Drs. Marvin Natowicz and Bruce Cohen. These disorders are diagnosed with a combination of imaging, lab tests, and occasionally biopsies (muscle or skin). Encephalopathy is a term used to describe a state when the brain is not functioning properly. I hope this helps.