Uncovering Awareness

Medical and Ethical Challenges in Diagnosing and Treating the Minimally Conscious State

Comments

Misdiagnosis in Vegetative State

Daria Dinacci

10/31/2010 5:27:46 PM

Differential Diagnosis in Vegetative State, Minimal Conscious State, and Locked In Syndrome are still difficult for physicians. The diffusion in the clinical practice of a standardized scale could be very useful. I think that the Coma Recovery Scale Revised could be a good instrument, but it is not clear to me if in the "visual function" examination of this scale, are included written order to patient. The administration instruction, in my opinion, are not enough clear. Since many patients with major disability or disturb of consciousness arrive in rehabilitation clinics, even not deeply specialized in this area, I think that clear guidelines and deep explanation of clinical instruments (as Coma Recovery Scale Revised) should be diffused in wide scale. In particular, does the CRS-R include written order to patient?

A 'NULL' RESPONSE AS SAYING SOMETHING

GORDON HAROLD DOWTON

9/22/2010 5:53:16 PM

A most interesting, interesting article. But, I must add a caveat to this enthusiasm. Neuroscience still seems to regard, or hold to 'consciousness', the activity of 'I am', 'I exist', to be the primary, most salient feature of the brain and that this 'feature' must in some way be exhibited before declaring that there is activity within the brain. What I mean by this can be demonstrated by the 'one-way telephone conversation', in which the person speaking into one end of the phone line, does so without the expectation of a response from the other end. Some will then ask..'Is this a conversation'? That depends on an agreement come to by the individual who is speaking. One does it because there is a potential receiver at the other end. This is a known.

We must seriously consider that the brain has its reasons for doing and not doing. I tend to view it much like an animal, as it does exhibit a number of familiar responses that we see in all manner of animal Life. As such, the understanding of such a complex animal, is very little understood as to why A exhibits a particular response, yet B does not, even though the two perhaps exhibit the same 'grosso modo' insult. Is this 'one way conversation' predicated on faith? No. It is simply an unknown, and as such, awaits discovery, validation, whatever. But the latter seems determined by what is considered 'normal' brain function, signs and signals associated with such as thus, so far demonstrated'. Consciousness, memory, thought...the 'higher brain functions', are what psychiatry, psychology, pop neurology, and to some degree mainstream neurology act on as the criteria for 'function'.

What might a 'null' state indicate? What do brain cells not emitting visible signals say to the observer? Can the human brain appear to be inactive, yet be perceptually alert, yet this alertness not register under any degree of measurement? I am thinking of a zebra herd surrounded by a reclining pride of lions. The zebra will tolerate this situation and will go about eating. Once the pride begins to move, the zebra exhibit a state of alert, eyes, ears, defecation, urination, the flight or fight response. It would be most interesting to see the 'state of the zebra brain' under such conditions.

I will close if I might, with a small part of an opening discussion given by Donald O. Hebb at a symposium given in 1959 (the Darwin Centennial Year)*, Dr. Hebb's paper entitled...Distinctive Features Of Learning In The Higher Animal...where on pg. 38, 2nd paragraph, he begins with...'If we assume that many of the neurones in the brain of a waking mammal are firing at any given time, and especially if we further assume that some of these are inhibitory, there are certain consequences which have sometimes been overlooked in physiological discussions of learning. The possession of a large brain capable of learning a great many different things inevitably means that there are far more neurones present than is necessary for learning one specific task. Any random activity in these excess neurones (the ones not needed for the task being learned) is 'noise', which must tend to interfere with learning. (If the activity is oraganized instead of random it is not noise, technically speaking, but the effect may still tend to be adverse.) It seems obvious that the number of excess neurones must be very much greater - perhaps thousands of times greater in the brain of the higher animal- than those needed for the learning going on at the moment. It therefore seems that the rate of learning, as observed in the behaviour of the whole animal, may not be an index of capacity for adding new synaptic connections so much as an index of the noise level, and that learning will be fast or slow according as one is successful in establishing an environmental control of the excess neural activity, in order to prevent or minimize interference'. *Taken from BRAIN MECHANISMS AND LEARNING..A SYMPOSIUM..CHARLES C. THOMAS, PUBLISHER.