Its unlikely that further neuroimaging will be useful, if 3 MRIs have already been done. The problem is more likely to be on a more diffuse level ie an imbalance of hormones such as serotonin in thebrain. This can manifest in several ways, and can be treated by for example SSRI drugs. There may also be subclinical depression which is a common cause for memory complaints - consider having him evaluetd by an adolescent psychologist or psychiatrist (there are some at CCF), to root this out. An MMPI - a detailed psychological/personality questionnaire would be useful also .
While memory problems can be as a result of frequent or uncontrolled seizures, it would be unusaul not tohave had any witnessed seizures, unless he is alone for long periods of time. An EEG is not unreasonable, although is only useful if it is positive, as a single normal EEG does not rulout epilepsy. Repeat neuropsych testing at a later date, will help determine if this is progressive and warrant testing for rarer disorders - some rare disorders can cause intellectual decline at his age, but usually present with other signs and symptoms, for example myoclonus, loss of vision/hearing etc
The inconsistant memory problems shown on neuropsych testing seems typical of Mild Traumatic Brain Injury. But, ADD/ADHD may have overlapping qualities making it difficult to find a difinitive MTBI diagnoses. What I mean is, I have a MTBI and neuropsych testing shows I have cognitive difficulties in 'inconsistant' areas of functioning. Though I do not have ADD/ADHD, I am being treated with Ritilan to try to improve areas of attention, consentration, and memory. That being said, I still think MTBI is the horse here. It is often underdiagnosed. (I went 14 yrs with no dx) But there are symptoms you haven't mentioned that often young males fail to report that may aid you in finding the problem. You may want to pointedly ask about any/all physicall things going on because in my case, for a long time, I just thought they were small things that would go away, or were unrelated to anything. So, unmentioned. Such as headache. These will aid you and your Doc to narrow the field. The memory problems alone leaves a broad playing field.
This is a long shot but maybe check his neck.
I read somewhere about a boy with poor grades and diagnosed with ADD. After extensive tests they gave him physiotherapy due to a small neck misalignment that was caused when he was a baby. After this all his grades improved.
I thought that a neurologist from Cleveland Clinic was responding to these postings? I see that there hasn't been a response from CCF since late November. Don't they staff this site anymore?
I read your situation with interest. I have a dear friend whom I have known since he was 18-19 yrs old who suffered from some memory loss issues for nearly 15 years... lost keys, missed appts..etc.. as you mention. He was treated with ritalyn as a young person and is also athsmatic... Last year he was bothered by continuing symptomology as an adult... He made appointment at the Mayo Clinic in MN... was ultimately diagnosed with improper fluid levels in certain areas of the brain... which the doctors say most certainly has been occuring since childhood. He was initially a candidate for a shunt to be inserted into the Brain to drain the excess fluid but a second doctor's suggestion was to medicate with an oral medication proven to decrease the fluid production.... I am not certain what the medication is called... I can find out if you would like... or you can look into this as a possible course of action...