A PET Scan of a Normal Brain In what can only be described as a harrowing instance of misdiagnosis, a Belgian man presumed comatose for 23 years after a near-fatal car crash was actually conscious and paralyzed the entire time. Rom Houben, whose real state was discovered three years ago but only now made public , could be one of many falsely diagnosed coma cases, raising serious questions about those diagnosed as "vegetative" and, even more frighteningly, the process by which vegetative people are removed from life support. Houben, now in a facility in Brussels and communicating via a computer controlled by his minimally functioning right hand, came around after his 1983 car accident. But while he could hear every word his doctors spoke, he could not speak to them, nor could he move his body to communicate with them in any way. For years researchers and doctors tried to coax a response from Houben, who all along was trapped within his own body, living a life of frustration with his inability to interact. "I screamed, but there was nothing to hear," he told the Guardian via his computer. For over two decades Houben remained in what doctors thought was an unconscious state, though he was fully conscious of the world going by around him. It wasn't until three years ago when doctors wanted to try a new state-of-the-art PET scanning system on Houben that they made a startling discovery: the "comatose" man's brain was functioning almost normally. For Houben, the discovery of his consciousness by the outside world has been like a "second birth," to put it in his own words. But for science, while the news of Houben's "discovery" is heartening, it will likely rehash the debate over when, if ever, a patient who by all indications of modern science is vegetative should be terminated. Belgian neurologist Steven Laureys has published a paper on Houben's ordeal suggesting that his case is not isolated. According to his study, as many as 40 percent of cases
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A PET Scan of a Normal Brain
In what can only be described as a harrowing instance of misdiagnosis, a Belgian man presumed comatose for 23
years after a near-fatal car crash was actually conscious and paralyzed the entire time. Rom Houben, whose real
state was discovered three years ago but only now made public, could be one of many falsely diagnosed coma
cases, raising serious questions about those diagnosed as "vegetative" and, even more frighteningly, the process by
which vegetative people are removed from life support.
Houben, now in a facility in Brussels and communicating via a computer controlled by his minimally functioning right
hand, came around after his 1983 car accident. But while he could hear every word his doctors spoke, he could not
speak to them, nor could he move his body to communicate with them in any way. For years researchers and doctors
tried to coax a response from Houben, who all along was trapped within his own body, living a life of frustration with
his inability to interact.
"I screamed, but there was nothing to hear," he told the Guardian via his computer.
For over two decades Houben remained in what doctors thought was an unconscious state, though he was fully
conscious of the world going by around him. It wasn't until three years ago when doctors wanted to try a new state-
of-the-art PET scanning system on Houben that they made a startling discovery: the "comatose" man's brain
was functioning almost normally.
For Houben, the discovery of his consciousness by the outside world has been like a "second birth," to put it in his own words. But for science, while the news of Houben's "discovery" is heartening, it will likely rehash the debate over when, if ever, a patient who by all indications of modern science is vegetative should be terminated.
Belgian neurologist Steven Laureys has published a paper on Houben's ordeal suggesting that his case is not
isolated. According to his study, as many as 40 percent of cases diagnosed as vegetative may indeed possess
enough consciousness to not only communicate, but to actually make considerable progress with the right treatment.
Of 44 "vegetative" patients Laureys analyzed, 18 ended up responding to communication.
The idea of losing the ability to communicate with the outside world is terrifying enough, but to then be misdiagnosed
and forgotten -- or deemed a lost cause and slotted for termination -- all while possessing fully functioning mental
capacities is downright unthinkable. The question "how many times have we been wrong?" is one the medical
community is likely loath to ask, but if Houben's case is any indication, it's one that needs to be addressed. If Laureys
analysis is to be believed, there should be many more Houben's out there screaming in silence.
Vegetative state.
Classification[edit]
There are several definitions that vary by technical versus laymen's usage, and by legal implications in different
countries.
The vegetative state is a chronic or long-term condition. This condition differs from a coma: a coma is a state
that lacks both awareness and wakefulness. Patients in a vegetative state may have awoken from a coma, but
still have not regained awareness. In the vegetative state patients can open their eyelids occasionally and
demonstrate sleep-wake cycles, but completely lack cognitive function. The vegetative state is also called a
"coma vigil". The chances of regaining awareness diminish considerably as the time spent in the vegetative
state increases.[8]
The persistent vegetative state is the standard usage (except in the UK) for a medical diagnosis, made after
numerous neurological and other tests, that due to extensive and irrevocable brain damage a patient is highly
unlikely ever to achieve higher functions above a vegetative state. This diagnosis does not mean that a doctor
has diagnosed improvement as impossible, but does open the possibility, in the US, for a judicial request to
end life support.[4] Informal guidelines hold that this diagnosis can be made after four weeks in a vegetative
state. US caselaw has shown that successful petitions for termination have been made after a diagnosis of a
persistent vegetative state, although in some cases, such as that of Terri Schiavo, such rulings have generated
widespread controversy.
In the UK, the term 'persistent vegetative state' is discouraged in favor of two more precisely defined terms that
have been strongly recommended by the Royal College of Physicians (RCP). These guidelines recommend
using a continuous vegetative state for patients in a vegetative state for more than four weeks. A medical
definition of a permanent vegetative state can be made if, after exhaustive testing and a customary 12
months of observation,[9] a medical diagnosis that it is impossible by any informed medical expectations that the
mental condition will ever improve.[10] Hence, a "continuous vegetative state" in the UK may remain the
diagnosis in cases that would be called "persistent" in the US or elsewhere.
While the actual testing criteria for a diagnosis of "permanent" in the UK are quite similar to the criteria for a
diagnosis of "persistent" in the US, the semantic difference imparts in the UK a legal presumption that is
commonly used in court applications for ending life support.[9] The UK diagnosis is generally only made after 12
months of observing a static vegetative state. A diagnosis of a persistent vegetative state in the US usually still
requires a petitioner to prove in court that recovery is impossible by informed medical opinion, while in the UK
the "permanent" diagnosis already gives the petitioner this presumption and may make the legal process less
individuals are indeed trapped in their bodies, they may be living in great torment and will request to have their
care terminated or e
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The Radical Restructuring of Brain Networks in Comatose PatientsDec. 4, 2012 — Researchers from Inserm, CNRS and the Université Joseph Fourier in Grenoble, in collaboration with Cambridge university, Strasbourg university and clinical practitioners from the Strasbourg University Hospital Centre, have analysed data from 17 comatose patients using functional MRI data. Their research reveals that the brain networks of these patients have been restructured. The results, published in PNAS on 26 November 2012, could help clinical practitioners diagnose comatose patients.
The researchers are focusing on analysing brain networks of brain-damaged comatose (non-traumatised) patients, a state where the individual is considered to be unconscious.The authors of the study used an original graph theory-based methodology, where images were constructed using functional MRI data at rest and using robust statistical signal-processing methods. Local and overall effectiveness indices of functional brain networks were obtained for 17 brain-damaged patients and 20 healthy volunteers.Correlations in 417 brain regions were extracted to produce brain connection graphs using the statistically significant correlations.Inserm unit 836 "Grenoble Institut des neurosciences," CNRS researchers from the "GIPSA lab" and from the Behavioural and Clinical Neuroscience Institute in Cambridge, in collaboration with clinical practitioners from the Strasbourg University Hospital Centre, have been able to highlight restructured brain networks in brain-damaged (non-traumatized) comatose patients.Through comparisons with the healthy subjects, the results demonstrate that the overall cerebral connectivity is preserved in comatose patients. By analysing the connectivity at a local level, the authors of the study have observed that some brain regions ("hubs"), which are highly connected in healthy volunteers, are less well connected in comatose patients. Conversely, the less densely connected regions in the network in healthy subjects become "hubs" in comatose patients.Brain imaging obtained from connectivity graphsThe connectivity graph method is used to summarize in a single image data acquired through MRI scanning. It translates the effectiveness of connections in a single region compared to all the others. By grouping the most interconnected regions, modules are revealed (each represented by a different colour). Patients and healthy volunteers both have different models in their spatial location, representing radical alterations to the brain connections.According to current hypotheses, consciousness disorders in persistently comatose patients could be linked to disconnection phenomena between specific cortical regions, particularly the precuneus. The results of this study also point in this direction. "From an overall perspective, the topology of brain connections resists well to traumatism by reorganising the most interconnected regions in the network. It therefore seems that comas may be linked to changes in the location of "hubs" among the brain networks" suggests Chantal Delon Martin, an Inserm researcher.An assessment of brain injury and comasPatients with brain injury may go through various clinically-defined states: vegetative state that ischaracterized by the preserved sleep-wake cycle (eyes opening spontaneously, autonomous breathing, etc.); minimally conscious state where patients have partially preserved environmental consciousness (eye movement capacity, reaction to stimulation); locked in syndrome where the patient is paralysed but conscious (communication using eyes); brain death when the coma is irreversible flat line EEG, no blood flow).Coma (from the Greek κῶμα kôma meaning "deep sleep") is one of the different states where self awareness and consciousness of the outside world is eradicated further to an accident (cerebral, cardiac, etc.). There are two coma phases: the "acute" coma phase (a few days after the accident) and the "chronic" phase (one month or more). Brain restructuring was observed by researchers during the "acute" phase, when it is not known which coma type the patient will develop.Assessments of brain injuries in comatose patients are currently conducted through clinical examination, morphological MRI, evoked potentials and by SPECT (Single-photon emission computed tomography) or TEP (Positron emission tomography (PET). "The results of this study could help clinical practitioners in the difficult diagnosis process for comatose patients, since this method makes it possible to characterize each patient individually", conclude the researchers.
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New Test for Consciousness in 'Comatose' Patients
he Coma Science Group (CRCyclotron, University of Liège /Liège University Hospital), led by Dr Steven Laureys, has developed, along with its partners in London, Ontario, (Canada) and Cambridge (England), a portable test which will permit a simpler and less expensive diagnosis of 'vegetative' patients who still have consciousness, despite the fact that they do not have the means to express it.
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The researchers' conclusions are published this week in The Lancet.The desire to develop this simple test of consciousness, at the patient's bedside, follows on from previous research carried out by the Coma Science Group. Professor Steven Laureys and his colleagues had in effect already demonstrated, in 2009, that 40% of so-called 'vegetative' patients had been badly diagnosed and that in reality they retained a certain degree of consciousness. Following on from this
study Laureys' team at the University Hospital of Liège, on the recommendation of the Federal Health Service, was able to prescribe the compulsory use of a specially designed scale of consciousness (the coma recovery scale), now used in every coma specialist centre in Belgium.In 2010 the Coma Science Group researchers and their colleagues at Cambridge (England) made another fundamental breakthrough in showing that it was possible to communicate with 'vegetative' patients through the means of scanners whose technology was based on functional magnetic resonance imaging (fMRI). Classically, the clinical evaluation of coma always proceeded via a muscular response to a stimulus. This study showed that, thanks to fMRI, a doctor could detect traces of consciousness and even communicate with so-called 'vegetative' patients due to the fact that they mentally responded in an appropriate manner to a task suggested by the evaluator. Scientifically revolutionary, using functional magnetic resonance imaging in the evaluation of comas is nevertheless very expensive, and not every hospital is equipped with or has access to it.The new test described this week in The Lancet should change this situation. "As doctors, we as a rule ask the patient to respond to a simple command, such as 'pinch my hand,' to assure us that the patient is conscious. When we obtain a response, everything is fine, but if we cannot detect a response that does not necessarily mean to say that the patient is unconscious. Sometimes he or she cannot move because injuries have affected the nerves, the spinal cord or the brain," explains Dr Laureys. "With our new test, we also ask patients to move their hand or their foot, but we no longer have confidence in the muscular response. We measure the activity of the motor cortex directly using electroencephalography (EEG), a cheaper method which is widespread throughout the hospital centres.""That means that this portable test can be carried out in every health care centre and even at home!" states Camille Chatelle, a neuropsychologist and one of the new study's co-authors.……………………………………
Functional neuroimagingFrom Wikipedia, the free encyclopedia
Functional magnetic resonance imaging data
Functional neuroimaging is the use of neuroimaging technology to measure an aspect of brain function, often
with a view to understanding the relationship between activity in certain brain areas and specific mental
functions. It is primarily used as a research tool in cognitive neuroscience, cognitive
Functional neuroimaging of interesting phenomena often gets cited in the press. In one case a group of
prominent functional neuroimaging researchers felt compelled to write a letter to New York Times in response
to an op-ed article about a study of so-calledneuropolitics.[3]
They argued that some of the interpretations of the study were "scientifically unfounded".[4]
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Patients in a Minimally Conscious State Remain Capable of Dreaming During Their SleepAug. 30, 2011 — The question of sleep in patients with seriously altered states of consciousness has rarely been studied. Do 'vegetative' patients (now also called patients in a state of unresponsive wakefulness) or minimally conscious state patients experience normal sleep? Up until now the distinction between the two patient populations had not been taken into account by electrophysiological studies. Yet if the vegetative state opens no conscious door onto the external world, the state of minimal consciousness for its part assumes a residual consciousness of the environment, certainly fluctuating but real.
It is this difference which has led a group of researchers at the Coma Science Group (University of Liège and CHU Liège) and the universities of Wisconsin and Milan to compare the sleep of these two types of brain damaged patients. The results of their study are published this week in the journal Brain. They demonstrate once again the necessity of an adapted and specific medical care for each of these states.The researchers' work rested on a sample of 11 subjects (6 in a state of minimal consciousness and 5 in a vegetative state) and made use of high density (256 electrodes) electroencephalography (EEG). The goal was to determine the structure of sleep within the two types of patient. 'We used as a marker of arousal the fact that the subject had his/her eyes open and muscle tone, and as a marker of sleep the fact that the patient had closed eyes and muscle inactivity,' points out Dr Steven Laureys, the Director of the Coma Science Group.The high density EEG revealed that the brain's electrical activity differed very little between sleep and wake states in patients in a vegetative state. On the other hand the sleep of patients in a minimally conscious state had characteristics very close to that of normal sleep in a healthy subject. They showed changes in "slow wave" activity in the front of the brain considered important for learning and neural plasticity. It also appeared that these patients produced NREM (non rapid eye movement) slow wave sleep and REM (rapid eye movement) sleep, which is the support for dream activity.'Everything thus indicates that they have access to dreaming,' emphasises Steven Laureys. 'As a result, we can legitimately suppose that they still have a form of consciousness of self in addition to a certain consciousness of the external world.'The study published in Brain brings to light a relationship between the electrophysiology of sleep and the degree of consciousness in severely brain damaged patients. Thus, once validated, the method used could constitute an additional tool to evaluate, in a routine clinical setting, the potential maintenance of a residual consciousness in these patients.……………………………….
Misdiagnosis Of Disorders Of Consciousness Still CommonplaceJuly 21, 2009 — A sixteen-month study of consensus-based diagnosis of patients with disorders of consciousness has shown that 41% of cases of minimally conscious state (MCS) were misdiagnosed as vegetative state (VS), a condition associated with a much lower chance of recovery. Researchers have demonstrated that standardized neurobehavioral assessment is more sensitive than diagnoses determined by clinical consensus.
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Steven Laureys, from the University of Liege, Belgium, worked with a team of researchers, including Caroline Schnakers and Joseph Giacino, to compare consensus-based diagnoses of VS and MCS to those based on the JFK Coma Recovery Scale-Revised (CRS-R), a well-established standardized neurobehavioral rating scale. Laureys said, "Differentiating the vegetative from the minimally conscious state is often one of the most challenging tasks facing clinicians involved in the care of patients with disorders of consciousness. Misdiagnosis can lead to grave consequences, especially in end-of-life decision-making".The researchers prospectively followed 103 patients with mixed etiologies and compared the clinical consensus diagnosis provided by the physician on the basis of the medical staff's daily observations to diagnoses derived from the CRS-R. They found that of the 44 patients diagnosed with VS based on the clinical consensus of the medical team, 18 (41%) were found to be in MCS following standardized assessment with the CRS-R. According to Laureys, "It is likely that the examiners' reliance on unstructured bedside observations contributed to the high rate of misdiagnosis of VS patients. Unlike traditional bedside assessment, the CRS-R guards against misdiagnosis by incorporating items that directly reflect the existing diagnostic criteria for MCS, and by operationalizing scoring criteria for the identification of behaviors associated with consciousness".The researchers conclude, "The results of this study suggest that the systematic use of a sensitive standardized neurobehavioral assessment scale may help decrease diagnostic error and limit diagnostic uncertainty".……………………………………
In a recent study of patients in vegetative and minimally conscious states, researchers played a tone immediately prior to blowing air into a patient's eye. After some time training, the patients would start to blink when the tone played but before the air puff to the eye. (Credit: iStockphoto/Eric Hood)
Individuals In Vegetative States Can Learn, Scientists FindSep. 21, 2009 — Scientists have found that some individuals in the vegetative and minimally conscious states, despite lacking the means of reporting awareness themselves, can learn and thereby demonstrate at least a partial consciousness. Their findings are reported in the online edition of Nature Neuroscience.
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It is the first time that scientists have tested whether patients in vegetative and minimally conscious states can learn. By establishing that they can, it is believed that this simple test will enable practitioners to assess the patient's consciousness without the need of imaging.This study was done as a collaborative effort between the University of Buenos Aires (Argentina), the University of Cambridge (UK) and the Institute of Cognitive Neurology (Argentina). By using classical Pavlonian conditioning, the researchers played a tone immediately prior to blowing air into a patient's eye. After some time training, the patients would start to blink when the tone played but before the air puff to the eye.This learning requires conscious awareness of the relation between stimuli -- the tone precedes and predicts the puff of air to the eye. This type of learning was not seen in the control subjects, volunteers who had been under anaesthesia.
The researchers believe that the fact that these patients can learn associations shows that they can form memories and that they may benefit from rehabilitation.Lead author Dr Tristan Bekinschtein, from the University of Cambridge's Wolfson Brain Imaging Unit, said: "This test will hopefully become a useful, simple tool to test for consciousness without the need for imaging or instructions. Additionally, this research suggests that if the patient shows learning, then they are likely to recover to some degree."In 2006, the Cambridge Impaired Consciousness Group at the Wolfson Brain Imaging Unit showed, using functional imaging, showed that patients in vegetative states (as defined by behavioural assessment in the clinic) can in fact be conscious despite being unable to show consistent voluntary movements.The paper 'Classical conditioning in the vegetative and minimally conscious state' will be published in the Advanced Online Publication of Nature Neuroscience on 20 September 2009.This study was funded by an Antorchas Foundation grant (T.A.B.), a Marie Curie IIF grant (T.A.B.), a StartUp grant (F.F.M.), the Human Frontiers Science Program (M.S.) and a Medical Research Council Acute Brain Injury Collaborative grant.……………………………
Traumatic Brain Injury Patients Treated With Anti-Spasm Agent Partially Recover from Disorders of ConsciousnessJune 12, 2013 — At the International Neuromodulation Society's 11th World Congress, Dr. Stefanos Korfias of the Department of Neurosurgery at the University of Athens will present the results of a clinical study led by Professor Damianos Sakas, which showed that two of six in-patients studied at Evangelismos Hospital in Athens steadily emerged from minimally conscious state after receiving intrathecal baclofen (ITB) after traumatic brain injury.
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The drug relaxes spasticity that can result from brain injury and may be used to facilitate care, but is not normally used to restore function. The patients, a 24-year-old man and a 29-year-old man, had been in minimally conscious states for three years and 18 months, respectively. Their scores on a revised coma recovery scale (with a maximum of 23) increased from 10 -- 19 and 11 -- 22, respectively.Minimally conscious state is defined as a consciousness disorder in which a patient shows fluctuating, but not reproducible, signs of self-awareness and the surroundings. Most patients in a minimally conscious state also have moderate to severe spasticity as a result of their injuries.Dr. Konstantinos Margetis, who contributed significantly to this study, notes that some sporadic case reports have suggested a potential beneficial effect of ITB in recovery from disorders of consciousness. He and colleagues decided to search for the effect in a systematic way. ITB was indicated in this study, he said, and in the previous case series, to reduce spasticity since it facilitates care and probably minimizes some spasticity complications."The improvement in the level of consciousness was a very pleasant observation for us," he said. "It might have been due to an additional beneficial effect of receiving intrathecal baclofen in this group of patients." All six patients improved spasticity scores with treatment, and the two who also made gains in recovering consciousness apparently retained some ability, despite their brain injury, to sustain an awake, alert, and oriented state that might have been enhanced by the treatment. He hypothesizes the mechanism of this observed effect could be associated with the action of baclofen on receptors in the orexin system, which plays a role in maintaining wakefulness, and in the thalamic reticular nucleus, a brain structure associated with consciousness.Next he would like to see a larger, multi-center study evaluate such factors as brain and nervous system activity observed in functional and neural pathway imaging (fMRI and DTI MRI respectively); analysis of
changes in neurotransmitters in the cerebrospinal fluid; and tracking electrical activity in neural networks or response to a stimulus (EEG and evoked potential recordings)."A complete research protocol designed with input from other disciplines will attempt to investigate every facet of this complex subject," he remarked. "A study like that will allow for definite conclusions about the role of intrathecal baclofen in the recovery of the disorders of consciousness. While we feel that the current results might lower the threshold for intrathecal baclofen treatment in spasticity patients with disorders of consciousness, should a multi-center a study establish a definite role for intrathecal baclofen in disorders of consciousness, then the potential will be very promising indeed."
Glasgow Coma Scale
This gives a reliable, objective way of recording the conscious state of a person.[1] It can be used by medical and nursing staff for initial and continuing assessment. It has value in predicting ultimate outcome. Three types of response are independently assessed and are recorded on an appropriate chart (and the overall score is made by summing the scores).The calculator has been adapted to estimate the Glasgow verbal score from the Glasgow eye and motor scores in intubated patients.[2]
There is a Paediatric Glasgow Coma Scale applicable to infants too young
pain: The stimulus causes limb extension (abduction, internal rotation of shoulder, pronation of forearm, wrist extension) - decerebrate posture.
3. Abnormal flexor response to pain: Stimulus causes abnormal flexion of limbs (adduction of arm, internal rotation of shoulder, pronation of forearm, wrist flexion - decorticate posture.
4. Withdraws to pain: Pulls limb away from painful stimulus.Infant: withdraws from pain.
5. Localizing response to pain: Purposeful movements towards changing painful stimuli is a 'localizing' response.Infant: withdraws from touch
6. Obeying command: The patient does simple things you ask (beware of
1 pt - No response to pain2 pts - Extensor posturing to pain3 pts - Abnormal Flexor response to pain4 pts - Withdraws to pain5 pts - Localizing response to pain6 pts - Obeying commands
accepting a grasp reflex in this category).Infant: moves spontaneously or purposefully
2. Best Verbal Response (V) - 5 gradesRecord best level of speech. If patient is intubated, a "derived verbal score" is calculated via a linear regression prediction.
1. No verbal response.2. Incomprehensible
speech: Moaning but no words.Infant: Inconsolable, agitated.
3. Inappropriate speech: Random or exclamatory articulated speech, but no conversational exchange.Infant: Inconsistantly inconsolable, moaning.
4. Confused conversation: Patient responds to questions in a conversational manner but some disorientation and confusion.Infant: Cries but consolable, inappropriate interactions.
5. Orientated: Patient 'knows who he is, where he is and why, the year, season, and month.Infant: Smiles, orientated to sounds, follows objects, interacts.
R, Fakhry SM, et al; The conundrum of the Glasgow Coma Scale in intubated patients: a linear regression prediction of the Glasgow verbal
score from the Glasgow eye and motor scores. J Trauma. 1998 May; 44(5):839-44.
Some centres score GCS out of 14, not 15, omitting "withdrawal to pain". As well as the total figure the GCS can be expressed as subscores: GCS=15; M6,V5,E4 (motor, verbal and eye-opening responses)
Abbreviated coma scale (AVPU)
This sometimes used in the initial assessment ('primary survey') of the critically ill.
1 pt - No eye opening2 pts - Eye opening in response to pain3 pts - Eye opening in response to speech4 pts - Spontaneous eye opening
Reset
A = alert V = responds to vocal stimuli P = responds to pain U = unresponsive