A horrible sensation deep in my son's brain following Epstein Barr

A Plea for Help

In 1994, at the age of twenty-one, our son, a Cambridge university graduate, was diagnosed with ME, having fallen ill while reading Social and Political Science. Recently I wonder if he suffers from a different undiagnosed illness and write to see if I can find a desperately needed answer.
Originally he suffered extreme fatigue to the point of being unable sit up or speak, classic symptoms. In 1996 I discovered a unit in the National Hospital of Neurology and Neurosurgery, London, treating people with ME and other rare conditions. In 1997 he spent ten weeks there, by the end of which he could walk, talk to other patients and begin to rebuild his life. Walking was essential, six times a day for half an hour each time.
By 2003 he was 50% recovered: driving, teaching music, studying again, working in an Oxfam bookshop, until he was struck down with glandular fever / Epstein-Barr virus, medically verified.
He immediately developed a weird indescribable headache sensation, deep within the skull or brain which makes him feel very ill, and which limits him to many hours lying down. He has tinnitus and chronic constant vertigo, which started at the National Hospital. Has recently developed vestibular migraine, diagnosed by Mark Kellett at Salford Royal. All ‘brain symptoms.’
He’s consulted well-known UK doctors treating ME. Had antivirals, LDN (causing headaches) and every alternative medicine possible. Spent a fortune at the Breakspear Hospital, Hemel Hempstead. Nothing has changed these symptoms He believes this indescribable ‘headache’ is his version of ME. But if he no longer has the classic symptoms, what else can it be?
He continues to persevere, but is more and more incapacitated, the head sensation worsens if he applies his mind to tasks. He feels constantly very ill, though he does not experience the original fatigue. I’d read about intra cranial hypertension but he feels this is not the cause. We contacted Dr Higgins, Cambridge, but he no longer treats patients.
If anyone reading this can recognise what this truly is, can advise us or suggest medication or some process, we would be immensely grateful.