Free brain scans for All!

Earlier today I was attending a talk by Nick Fox from the Institute of Neurology (UCL) on dementia and imaging techniques. I've calmed down now, but at first his talk got me quite upset.
For one, watching those videos of some of his patients were quite sad. You'd get the tragically funny disinhibited lady with frontotemporal dementia; the man who couldn't remember such mundane words as rose bush or thorn, and would continue losing most of his vocabulary thanks to his left temporal lobe resembling a crumpet (half eaten); another man who couldn't whistle, blow out a candle or cough on command anymore - not because there was something wrong with his mouth, but because he just didn't remember how to.

The patient who had the biggest impact on me, however, was a woman, maybe in her late fourties, who was complaining of small glitches in everyday memory. She was subject of Fox' attention because early-onset dementia ran heavily in her family (I've forgotten if they had identified the gene(s) responsible). This woman still seemed pretty normal, and one could forgive her for exaggerating her troubles with memory given her family history. However, she was a prime example for what Fox called 'registration' - the process of performing yearly MRI scans and letting a computer program figure out volumetric changes in brain matter. And sure enough, over the course of about 7 years one could easily see how her hippocampi shriveled up and her ventricles ballooned. First - albeit very mild - symptoms became noticable to her husband about 2-3 years into that process. Someone asked if the woman herself had gained insight into her disorder and loss of memory. "Yes, she did. And then she lost it again." was the answer and at this point I could feel my eyes getting wet. Needless to say said patient is long gone.

You see, Fox is a great speaker and he gets his point across. The point being that various imaging techniques (not just MRI, but also PET and fMRI) could and should be used to facilitate diagnosis, measurement of disease progression and maybe even enable detection of pre-symptomatic changes.

There's Alzheimer's disease, vascular dementia, dementia with Lewy bodies (which I've touched on before), frontotemporal dementia and others, but often enough the real diagnosis is not confirmed until after death and patients get labelled as merely demented. I can imagine that it takes a specialised neurologist to distinguish the symptoms properly, and as long as good reliable biomarkers are lacking, imaging could help to figure out which kind of dementia is eating away at the patient's brain. After all, the 'topography of loss' depends at least partially on the disease at hand, even if we don't fully understand yet why we see selective hippocampal loss and cortical thinning in Alzheimer's, while frontotemporal dementia does what it says on the tin (although it comes in different flavours), and DLB can affect the basal ganglia to varying degrees. (Actually, it would be probably be pretty insightful in terms of molecular mechanisms if we knew what causes certain areas to be selectively affected, what exactly makes some neuronal populations more vulnerable than others, but for that as well, we have to catalogue which areas are hit first in a given disease etc).

And apart from making for good material for sad videos, tracking progression of brain atrophy could also be quite informative. I wouldn't be surprised if familial dementias would be accompanied by accelerated deterioration or maybe different patterns of progression or something similar. Or - in a better world - imaging could allow clinicians to see if a given medication is halting neurodegeneration on the gross structural and not just symptomatic level..

Early detection, though, is what stuck with me the most. In Parkinson's disease, up to 90% of neurons in the substantia nigra are lost before the onset of symptoms. Ninety Percent!!! While this suggests on one hand that the brain is surprisingly plastic and can make do with a substantial amount of damage, it also means that the factors responsible for cell death start quietly wrecking havoc years and years before anyone could notice. I don't know about you, but I find the idea that my parents' brains could be quietly turning to mush right this instant without anyone knowing about it quite distressing. My first reaction was: Why can't we all have MRI scans for all (or PET scans for that matter, which can predict whether people with mild cognitive impairment will progress to Alzheimer's disease based on amyloid binding)? Every 5 years from 30 onwards, and every two years once you turn 50? Is that too much to ask? I guess it is. In most countries even basic healthcare is a luxury, and even those fortunate enough to live in countries like the UK or the USA probably will have to wait quite a bit till they start getting invitations for brains scans the way women are recruited for pap smears these days. All the things Fox talked about didn't seem to be exactly breaking news, yet implementation of routine brain scanning beyond research and severe/suspicious (eg familial) cases seems to be anything but widespread (He did mention that it's more common in the US than in the UK, though). I have no idea how much various imaging techniques cost. I just really hope the cost will come down and the quality will continue to go up. It would be nice to get a prediction of some sort, like - in 20 years time everyone will undergo routine MRI scans - or at least my children will, or at least everyone with basic health care insurance will, or whatever..

Now obviously early detection alone isn't gonna do much. "Uh, sorry Sir, but your hippocampal volume is decreasing at a steady rate of 4% per year". That's not very helpful (apart from it making for a good excuse for why you keep on forgetting that you wife asked you to take out the trash). No, what we ultimately need are new treatments that can effectively prevent or at least slow down brain atrophy. With the stuff that's out there at the moment, L-dopa for Parkinson's, NMDA antagonists or acetylcholinergics for Alzheimer's, we're just retrospectively trying to make up for the lost cells and their original function. How crude. How much better would it be if we could develop neuroprotective drugs and stop these cells from dying in the first place? I know that's exactly what scientists all over the world are trying to do. I just get really impatient sometimes...


PS: Incidentally I couldn't remember for the life of me why Fox' talk seemed so familiar until I googled him and consequently my harddrive - and voilá: it turns out he gave a lecture during my Masters back at UCL. Hrmm. (Just kidding, I know I'm not demented - yet.)

PPS: Probably gonna spice this post up with references and links sometime within the next few days, so if you made it this far, check back again. For now I'm off to bed, got a whole day of mingling with PD researchers in London ahead of me (which by virtue of me living in the Diff means catching a train at stupid o'clock).