50 Shades of Measuring Damage

.In the United States almost half a million people a year survive stroke, but as many of us know only too well many are left with long term disabilities.

This is where I feel patient input, from those of us further down the line and willing to be as involved as possible, is paramount. The reason being options for treatment are limited. Also, predicting who will recover appears so vague. The messages most of us are given are, ‘its as good as it’s going to get’, or ‘you will not recover after twelve months’. I am not portioning any blame when I say this, simply saying that when we have proved otherwise surely it’s vital to pass that on to fellow survivors. Medical professionals fortunately cannot speak from experience, so are forced to give us a general and as we know negative forecast for the future. 

There is however some hope of change on the horizon. Two new studies in Washington, from the Washington University School of Medicine indicate that current clinical practices maybe missing a key element in stroke injured brain damage. An example of what they are saying is those of us struggling with cognitive functions, such as memory and concentration. This is caused because the brain’s communication network has been disturbed, yet this is not measured on most brain scans. To read more on this, a study was published online W/C 11th July in the proceedings of the National Academy of Sciences.

“The holy grail of predicting stroke recovery is to develop an individualised algorithm that will reliably inform your consultant, for example a patient will recover 85% of their abilities, while another 55% ” said Maurizio Corbetta, MD, the Norman J Stupp Professor of Neurology.

If on the other hand a consultant is assessing difficulties with sensory, motor or visual difficulties, the current scans provide a lot of information. If this is so, personally I feel it is a pity that such percentages cannot be calculated and then used as inspiration/ encouragement for the stroke survivor. Is this because, as I’ve read in a different report recently, not all consultants read scans in the same way. Is it different teaching I wonder, but the report suggested things are missed as not everyone can read MRI scans to the full, same degree.  

Back to the original study, they used fcMRI to assess communication between brain areas in 130 stroke survivors and 31 people who had not experienced a stroke. This allowed them to identify large areas disrupted in the brain that occurred as a result of stroke. They also gave every participant neuropsychological tests to measure vision, motor function, visual memory, language ability, attention and verbal memory. All of which are an upward struggle for me! 

The findings illustrate that the size and location of brain lesions correlated with vision and motor impairments but problems with memory were better explained by changes to the networks of the brain connections. Predicting language and attention deficits required knowing something about both the lesions and the networks. It did highlight that the 130-year-old system doctors use of mapping brain lesions to symptoms only gets you so far.

For memory, it turns out that it is not damage to a specific location that really matters but whether the connections between locations are intact. Currently fcMRI scans are not used clinically and the kinds of MRI and CT scans used to assess stroke damage do not measure how well different brain regions work. Obviously my question is, will fcMRI scanners replace the current ones used? Functional MRI hasn’t been used in clinics because prior to this study there was not convincing evidence of their value.

They say moving forward, they will need to conduct additional studies on many more patients, to show that having functional scans in the first hours, or days following stroke, could provide valuable blue information for predicting their outcome and recovery programme.

The work also suggests the possibility of treating brain damage by coaxing networks towards the normal pattern of connections. Currently treatment for stroke is centred on the first few hours with either drugs or surgery preventing brain tissue from dying. However, once the damage is already done, as we already know too, treatments are limited such as physiotherapy, which is limited in its allowed time frame due to costs/ budgets.

This is where there could be more hope too, TMS (Transcranial magnetic stimulation) has been used experimentally to aid stroke recovery. These are magnetic waves sent through the skull and into the brain. This causes an electrical current to stimulate neurons in the required area. It is then thought that TMS may be able to restore normal connectivity by stimulating neurons to make more connections with one another.

Those of you who have read my book will know only too well how this excites me, and is in fact similar to the scanner device I talk of and have benefited from. I for one, would be prepared to take part in trials of TMS.

I promise next week my blog will be on a much lighter subject.


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