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Updated: Jul 19, 2026
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Assessment and Communication for People with Disorders of Consciousness
Published on: August 1, 2017
Chronic disorders of consciousness
1Dartmouth Medical School, Hanover, NH, USA. bernat@dartmouth.edu
Lancet (London, England)
|April 18, 2006
Summary
Disorders of consciousness, such as vegetative state (VS) and minimally conscious state (MCS), involve impaired awareness. Functional imaging differentiates these states, with VS showing limited network activation, while MCS may retain some awareness, impacting treatment decisions.
Area of Science:
- Neuroscience
- Neurology
- Medical Imaging
Background:
- Disorders of consciousness (DOC), including vegetative state (VS) and minimally conscious state (MCS), represent significant clinical challenges.
- These conditions arise from diffuse brain lesions affecting thalamic, cortical, or white-matter pathways.
- Distinguishing between VS (wakefulness without awareness) and MCS (intermittent awareness) is crucial for prognosis and management.
Purpose of the Study:
- To differentiate between vegetative state and minimally conscious state using functional neuroimaging.
- To elucidate the neural correlates of awareness in disorders of consciousness.
- To inform prognosis and treatment strategies for patients with DOC.
Main Methods:
- Utilizing functional imaging techniques such as Positron Emission Tomography (PET) and functional Magnetic Resonance Imaging (fMRI).
- Assessing cortical activation patterns in response to stimuli.
- Correlating imaging findings with behavioral assessments of awareness.
Main Results:
- Patients in VS demonstrated activation of primary cortical areas but lacked activation in secondary areas or distributed networks indicative of awareness.
- Preliminary studies suggest that some patients in MCS exhibit substantially intact awareness, despite poor responsiveness.
- Prognosis for VS is poor, especially after prolonged periods ( >1 year traumatic, >3 months non-traumatic).
Conclusions:
- Functional neuroimaging aids in distinguishing VS from MCS by revealing differences in neural network activation.
- While stimulation treatments are largely ineffective for VS, they may offer some benefit in MCS.
- Ethical and legal principles, alongside medical guidelines, should guide treatment decisions for patients with VS and MCS.
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