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John D Pickard - One of the best experts on this subject based on the ideXlab platform.

  • residual auditory function in Persistent Vegetative State a combined pet and fmri study
    Neuropsychological Rehabilitation, 2005
    Co-Authors: Adrian M Owen, David K Menon, Ingrid S Johnsrude, Martin R Coleman, Jennifer M Rodd, Matthew H Davis, Karen Taylor, John D Pickard
    Abstract:

    In recent years, a number of studies have demonstrated an important role for functional neuroimaging in the identification of residual cognitive function in Persistent Vegetative State. Such studies, when successful, may be particularly useful where there is concern about the accuracy of the diagnosis and the possibility that residual cognitive function has remained undetected. Unfortunately, functional neuroimaging in Persistent Vegetative State is extremely complex and subject to numerous methodological, clinical and theoretical difficulties. Here, we describe the strategy used to study residual auditory and speech processing in a single patient with a clinical diagnosis of Persistent Vegetative State. Identical positron emission tomography studies, conducted nine months apart, revealed preserved and consistent responses in predicted regions of auditory cortex in response to intelligible speech stimuli. Moreover, a preliminary functional magnetic resonance imaging examination at the time of the second s...

  • Residual auditory function in Persistent Vegetative State: A combined PET and fMRI study
    NEUROPSYCHOLOGICAL REHABILITATION, 2005
    Co-Authors: John D Pickard
    Abstract:

    In recent years, a number of studies have demonstrated an important role for functional neuroirnaging in the identification of residual cognitive function in Persistent Vegetative State. Such studies, when successful, may be particularly useful where there is concern about the accuracy of the diagnosis and the possibility that residual cognitive function has remained undetected. Unfortunately, functional neuroirnaging in Persistent Vegetative State is extremely complex and subject to numerous methodological, clinical and theoretical difficulties. Here, we describe the strategy used to study residual auditory and speech processing in a single patient with a clinical diagnosis of Persistent Vegetative State. Identical positron emission tomography studies, conducted nine months apart, revealed preserved and consistent responses in predicted regions of auditory cortex in response to intelligible speech stimuli. Moreover, a preliminary functional magnetic resonance imaging examination at the time of the second session revealed partially intact responses to semantically ambiguous stimuli, which are known to tap higher aspects of speech comprehension. In spite of the multiple logistic and procedural problems involved, these results have major clinical and theoretical implications and provide a strong basis for the systematic study of possible residual cognitive function in patients diagnosed as being in a Persistent Vegetative State.

  • Using a hierarchical approach to investigate residual auditory cognition in Persistent Vegetative State
    BOUNDARIES OF CONSCIOUSNESS: NEUROBIOLOGY AND NEUROPATHOLOGY, 2005
    Co-Authors: John D Pickard
    Abstract:

    Persistent Vegetative State is arguably one of the least understood and most ethically troublesome neurological conditions in modern medicine. The term describes a rare disorder in which patients who emerge from coma appear to be awake, but show no signs of awareness. In recent years, a number of studies have demonstrated an important role for functional neuroimaging in the identification of residual cognitive function in patients meeting the clinical criteria for Persistent Vegetative State. Such studies, when successful, may be particularly useful where there is a concern about the accuracy of the diagnosis and the possibility that residual cognitive function has remained undetected. Unfortunately, functional neuroimaging in Persistent Vegetative State is extremely complex and subject to numerous methodological, clinical and theoretical difficulties. In this chapter, we argue that in order to most effectively define the degree and extent of preserved cognitive function in Persistent Vegetative State, a hierarchical approach to cognition is required. To illustrate this point, a series of functional neuroimaging paradigms in the auditory domain are described, which systematically increase in complexity in terms of the auditory and/or linguistic processes required and, therefore, the degree of preserved cognition that can be inferred from "normal" patterns of activation in Persistent Vegetative patients. Preliminary results in a small series of patients provide a strong basis for the systematic study of possible residual cognitive function in Persistent Vegetative State.

  • detecting residual cognitive function in Persistent Vegetative State
    Neurocase, 2002
    Co-Authors: Adrian M Owen, David K Menon, Ingrid S Johnsrude, Sophie K Scott, Tom Manly, Emma Williams, Catherine J Mummery, John D Pickard
    Abstract:

    Despite converging agreement about the definition of Persistent Vegetative State, recent reports have raised concerns about the accuracy of diagnosis in some patients, and the extent to which, in a selection of cases, residual cognitive functions may remain undetected. Objective assessment of residual cognitive function can be extremely difficult as motor responses may be minimal, inconsistent, and difficult to document in many patients, or may be undetectable in others because no cognitive output is possible. Here we describe strategies for using H 2 15 O positron emission tomography activation studies to study covert cognitive processing in patients with a clinical diagnosis of Persistent Vegetative State. Three cases are described in detail. Of these, two exhibited clear and predicted regional cerebral blood flow responses during well-documented activation paradigms (face recognition and speech perception) which have been shown to produce specific, robust and reproducible activation patterns in normal volunteers. Some months after scanning, both patients made a significant recovery. In a third case, blood flow data were acquired during a speech perception task, although methodological difficulties precluded any systematic interpretation of the results. In spite of the multiple logistic and procedural problems involved, these results have major clinical and scientific implications and provide a strong basis for the systematic study of possible residual cognitive function in patients diagnosed as being in a Persistent Vegetative State.

Dorothee Lule - One of the best experts on this subject based on the ideXlab platform.

  • Persistent Vegetative State and minimally conscious State
    Deutsches Arzteblatt International, 2015
    Co-Authors: Andreas Bender, Eva Grill, A Straube, Dorothee Lule
    Abstract:

    Background: Acute brain damage can cause major disturbances of consciousness, ranging all the way to the Persistent Vegetative State (PVS), which is also known as ”unresponsive wakefulness syndrome”. PVS can be hard to distinguish from a State of minimal preserved consciousness (“minimally conscious State,” MCS); the rate of misdiagnosis is high and has been estimated at 37–43%. In contrast, PVS is easily distinguished from brain death. We discuss the various diagnostic techniques that can be used to determine whether a patient is minimally conscious or in a Persistent Vegetative State.

Adrian M Owen - One of the best experts on this subject based on the ideXlab platform.

  • residual auditory function in Persistent Vegetative State a combined pet and fmri study
    Neuropsychological Rehabilitation, 2005
    Co-Authors: Adrian M Owen, David K Menon, Ingrid S Johnsrude, Martin R Coleman, Jennifer M Rodd, Matthew H Davis, Karen Taylor, John D Pickard
    Abstract:

    In recent years, a number of studies have demonstrated an important role for functional neuroimaging in the identification of residual cognitive function in Persistent Vegetative State. Such studies, when successful, may be particularly useful where there is concern about the accuracy of the diagnosis and the possibility that residual cognitive function has remained undetected. Unfortunately, functional neuroimaging in Persistent Vegetative State is extremely complex and subject to numerous methodological, clinical and theoretical difficulties. Here, we describe the strategy used to study residual auditory and speech processing in a single patient with a clinical diagnosis of Persistent Vegetative State. Identical positron emission tomography studies, conducted nine months apart, revealed preserved and consistent responses in predicted regions of auditory cortex in response to intelligible speech stimuli. Moreover, a preliminary functional magnetic resonance imaging examination at the time of the second s...

  • detecting residual cognitive function in Persistent Vegetative State
    Neurocase, 2002
    Co-Authors: Adrian M Owen, David K Menon, Ingrid S Johnsrude, Sophie K Scott, Tom Manly, Emma Williams, Catherine J Mummery, John D Pickard
    Abstract:

    Despite converging agreement about the definition of Persistent Vegetative State, recent reports have raised concerns about the accuracy of diagnosis in some patients, and the extent to which, in a selection of cases, residual cognitive functions may remain undetected. Objective assessment of residual cognitive function can be extremely difficult as motor responses may be minimal, inconsistent, and difficult to document in many patients, or may be undetectable in others because no cognitive output is possible. Here we describe strategies for using H 2 15 O positron emission tomography activation studies to study covert cognitive processing in patients with a clinical diagnosis of Persistent Vegetative State. Three cases are described in detail. Of these, two exhibited clear and predicted regional cerebral blood flow responses during well-documented activation paradigms (face recognition and speech perception) which have been shown to produce specific, robust and reproducible activation patterns in normal volunteers. Some months after scanning, both patients made a significant recovery. In a third case, blood flow data were acquired during a speech perception task, although methodological difficulties precluded any systematic interpretation of the results. In spite of the multiple logistic and procedural problems involved, these results have major clinical and scientific implications and provide a strong basis for the systematic study of possible residual cognitive function in patients diagnosed as being in a Persistent Vegetative State.

Andreas Bender - One of the best experts on this subject based on the ideXlab platform.

  • Persistent Vegetative State and minimally conscious State
    Deutsches Arzteblatt International, 2015
    Co-Authors: Andreas Bender, Eva Grill, A Straube, Dorothee Lule
    Abstract:

    Background: Acute brain damage can cause major disturbances of consciousness, ranging all the way to the Persistent Vegetative State (PVS), which is also known as ”unresponsive wakefulness syndrome”. PVS can be hard to distinguish from a State of minimal preserved consciousness (“minimally conscious State,” MCS); the rate of misdiagnosis is high and has been estimated at 37–43%. In contrast, PVS is easily distinguished from brain death. We discuss the various diagnostic techniques that can be used to determine whether a patient is minimally conscious or in a Persistent Vegetative State.

Adam Zeman - One of the best experts on this subject based on the ideXlab platform.

  • The Persistent Vegetative State: Conscious of Nothing?
    Practical Neurology, 2002
    Co-Authors: Adam Zeman
    Abstract:

    The Persistent Vegetative State (PVS) was described in the Lancet exactly 30 years ago by Bryan Jennett, a neurosurgeon, and the neurologist Fred Plum (Jennett & Plum 1972). Jennett has recently reviewed the subject (Jennett 2002). Sometimes described as a condition of wakefulness without awareness, it can follow a range of severe insults to the brain. Often misdiagnosed, frequently misunderstood, the syndrome provides a useful shorthand for a diverse but distinctive set of clinical phenomena. Although it has withstood the scrutiny of ethicists and lawyers, it assumes a concept of awareness that may not stand the test of time. In this article I will sketch its key features and end by asking how confident we can really be that a patient in the PVS is wakeful, but conscious of nothing. Many of us will remember our first encounter with a patient in the Vegetative State (VS), as the condition is

  • Persistent Vegetative State
    The Lancet, 1997
    Co-Authors: Adam Zeman
    Abstract:

    SIR—Adam Zeman (Sept 13, p 795) is to be congratulated on his excellent discussion of the concept of Persistent Vegetative State (PVS). As he points out, this concept is based on a particular model of consciousness and wakefulness that has certain shortcomings. The shortcomings are well illustrated by two consecutive sentences in his conclusion: “Consciousness [or awareness], in all its aspects, is a matter of degree”, and “The Vegetative State [is] a condition of wakefulness without awareness”. The first correctly identifies awareness as a continuum rather than a quality that is either present or absent. The second should therefore define PVS as a State of wakefulness without a set amount of awareness. This definition makes the concept less superficially attractive (and begs the question how awareness is measured and how much is allowed in 5-HT2A receptor gene polymorphisms, anorexia nervosa, and obesity