What else looks like Viral Encephalitis of the brain?

[Gina65]

My 13 year old son had a 1 year plus history of stomach issues with random nausea, but nothing consistant.  Had a GI workup this year and didn't see anything with the scope, but said mild gastritis and attributed it to stress.  

In March of this year, noticed his eyes were not turning together in equal movements.  When he would look to the side, the eye looking towards his nose would not roll as it should and would stop the same on both eyes looking inward. This sent us scambling to the Dr who sent us to an Opthamologist.  We immediately had an MRI of the brain done, but it was an open MRI and came back clear.  We then went to a Neuoroligst and a Neuro Opthomogolist who ordered an MRA and MRI and again, saw nothing, but this was again an Open MRI.  

Finally we went to a Pediactric Neuro Opthomologist who said this appeared to be a bilateral internuclear ophthalmoplegia and sent us to a closed MRI and for a spinal tap.  The Children's hospital immediately hospitalized him and said his MRI had the appearance of herpes encephalitis (abnormal bilateral temporal lobes, right caudate lobe, leptomeningeal enhancement in the inferior aspect of the optic shiasm, left sylvian fissure and interpeduncular cistern.)  They immediately started him on acyclovir.  His blood test came back twice with a positive to HS2 but with a recent exposure marker. This did not fit into the time line for his eye palsy symptoms or that he has ever had exposure to the HS virus.  He is not sexually active and hasn't even kissed a girl yet.  

His CSF came back negative for HS.    After two weeks on Acyclovir, the followup MRI and spinal showed no improvement.  They now want to do a brain biopsy and remove from three layers of areas that appear affected,  but sent him home to wait for a Von Willebrand bleeding disorder test to come back.  I wanted to test him on steriords but they said if he has some type of cancer, it would make it worse.  

Meanwhile, SINCE he was hospitalized and during that time after his spinal tap, he is now waking with a headache and nausea EVERY day and often vomits.  This was not happening every day prior to his spinal.  He has now started complaining of neck and coccyx pain.  He says his tailbone throbs and hurts to lay on.  He can put his head to his chest, but it hurts to lift his head up when he is laying down.  

His lumbar punctures both had elevated opening pressures and on 9/25 had a WBC of 62, RBC 2 and a protein of 186.  His CSF on 10/2 had a WBC of 42, RBC of 7 and Protein of 238.  He has no sign of papilledema.

While we are at home waiting, I also had the local Hospital Radiologist look at the MRI and his feeling was it was consistant with Infection, Eosinophililc Granuloma or Lymphoma.  BTW, Britt's Malignant Cell test from CSF came back negative.  

The doctors do not know what to make of his new symptoms of pain in his tailbone and neck.  I am worried about a complication from the spinal or it is a clue as to what he might have.  I do not want to do this brain biopsy if there is any other tests that can be run based on these symptoms.  Also, MS tests came back negative and he has no muscle weakness. They ran a bunch of encephalitis tests on him too that came back negative as did meningitis.  

Any suggestions?  Does this tailbone pain make sense?  Can eye palsy and irregularities on the brain MRI be caused by something else they are overlooking?  They did not see a tumor, but did see multiple lightups and leisions.  The final MRI said that Brain parenchymal and meningeal abnormalities identified consistent with meningoencephalitis.  

Concerned Mom