Alice I have multiple unspecified lesions too 'pre-ventricular and sub-cortical white matter' though, none in the grey matter, thankfully.
My private consultant says all my symptoms are explained by Autonomic Dysfunction and that the brain lesions were most likely caused by my severe/complex migraines. Apparently he sees quite a lot of them and there's increasing evidence for migraines causing lesions of the white matter if you Google. I also wonder about hypoperfusion, lack of blood to the brain, with POTs and if that has any potential to cause damage if it's prolonged.
I had all the standard MS tests, which turned up nothing, (LP, Visual, Evoked and Somatatory (sp?) potentals etc) then finally an EEG - at which point my Neuro said there was clearly something going on, but she hadn't a clue what, so would just keep me on 6 month review and to go back if I suddenly lost speech, sight or the use of half of my body! 
I then got upset that I still had no answers and was finding it hard to explain to people why I don't work and what illness I have and she told me: 'tell anyone who asks that you have one of those 'trendy' illnesses like ME/Fibro. Neurologists like myself don't believe they exist, but they would be useful for you to explain your symptoms when people ask.'
I was so shocked I was speechless.
A month later I collapsed, had two complete blackouts, complete with extensive bruising that occurred while I was out. The were suspected by A&E/Acute Medical Unit to be seizures I was sent for yet more MRIs and another EEG, by which time my Neuro was on Maternity Leave. I saw a Locum who told me my brain scans were normal and there was nothing wrong with me.
When I pressed him, he suggested I didn't actually have a blackout, as no-one saw it (I was in the bathroom at a hotel at the time) although dh got to me seconds after I came round the second time and that any other symptoms must be hormonal or anxiety based.
My dh then intervened and he agreed to do a 5 day ambulatory EEG, but he messed up that, as I didn't qualify to be funded for it, so it was cancelled. He sent me a letter telling me not to attend, I didn't, then received a week's worth of 'did not attend' letters and was struck off the neurology list. I contacted the EEG department to ask them to amend my notes to show I had been told not to attend, then the Locum's secretary to make sure I would be seen in clinic within 6 weeks as promised, she said I would. When I didn't get an appointment through I left her another message - aaaaand I've never heard from them since. That was Feb 2013.
Actually I haven't bothered with the NHS at all since, until I went to get my private referral in December. When I went to see my GP for my recent referral I was given a copy of the Locum's letter to the GP Surgery. It was absolutely full of inconsistencies and downright lies and clearly implied that he thought I was either depressed, hormonal, anxious or all three. 
Looking back, the difference between my usual Neuro and the Locum was that she had seen videos of my episodes and he hadn't, plus she'd been seeing me since 2006, when I first saw her about my migraines and had seen a progression of symptoms.
Also I screwed up and had my last MRI done in the open scanner, as I had vowed to never have another MRI, but was pressed to have it done after the big blackouts. Apparently the strength/quality of that scanner is a lot lower than the other ones I'd had MRIs on, so wouldn't have shown up as much - which might explain him saying my scan was normal, otherwise it's a bit odd that all my previous lesions, that my usual neuro was concerned about, had suddenly disappeared.
I've since found out that all my referrals are flagged at the top with reference to historical depression (PND almost 12 years ago and reactive depression 16 ish years ago to nursing my husband through a serious head injury) which predisposes any doctors that are so inclined to dismiss me as a hysterical female. 
I am so glad I finally plucked up the courage to go private, even if dh's job didn't have health insurance it would have been the best £250 I've ever spent.