Peter B. Forgacs

Preservation of electroencephalographic organization in patients with impaired consciousness and imaging‐based evidence of command‐following

Standard clinical characterization of patients with disorders of consciousness (DOC) relies on observation of motor output and may therefore lead to the misdiagnosis of vegetative state or minimally conscious state in patients with preserved cognition. We used conventional electroencephalographic (EEG) measures to assess a cohort of DOC patients with and without functional magnetic resonance imaging (fMRI)‐based evidence of command‐following, and correlated the findings with standard clinical behavioral evaluation and brain metabolic activity.

Isolation Syndrome after Cardiac Arrest and Therapeutic Hypothermia

Here, we present the first description of an isolation syndrome in a patient who suffered prolonged cardiac arrest and underwent a standard therapeutic hypothermia protocol. Two years after the arrest, the patient demonstrated no motor responses to commands, communication capabilities, or visual tracking at the bedside. However, resting neuronal metabolism and electrical activity across the entire anterior forebrain was found to be normal despite severe structural injuries to primary motor, parietal, and occipital cortices. In addition, using quantitative electroencephalography, the patient showed evidence for willful modulation of brain activity in response to auditory commands revealing covert conscious awareness. A possible explanation for this striking dissociation in this patient is that altered neuronal recovery patterns following therapeutic hypothermia may lead to a disproportionate preservation of anterior forebrain cortico-thalamic circuits even in the setting of severe hypoxic injury to other brain areas. Compared to recent reports of other severely brain-injured subjects with such dissociation of clinically observable (overt) and covert behaviors, we propose that this case represents a potentially generalizable mechanism producing an isolation syndrome of blindness, motor paralysis, and retained cognition as a sequela of cardiac arrest and therapeutic hypothermia. Our findings further support that highly-preserved anterior cortico-thalamic integrity is associated with the presence of conscious awareness independent from the degree of injury to other brain areas.

Dynamic regimes of neocortical activity linked to corticothalamic integrity correlate with outcomes in acute anoxic brain injury after cardiac arrest

Recognition of potential for neurological recovery in patients who remain comatose after cardiac arrest is challenging and strains clinical decision making. Here, we utilize an approach that is based on physiological principles underlying recovery of consciousness and show correlation with clinical recovery after acute anoxic brain injury.

A proposed role for routine EEGs in patients with consciousness disorders

ing consensus for inclusion of standard EEG in the neurophysiological evaluation of patients with DOC, several questions remain to be answered. In particular, it has not been clarified whether we should refer to common EEG patterns or combine classic EEG descriptors. Also, it has not been settled whether sleep architecture study adds significant information. Moreover, it remains to be resolved whether a prolonged EEG recording is required to obtain essential data or whether a standard-duration recording is adequate. Data acquired from patients in a coma are scarcely useful because the pathophysiology of coma is different from that of UWS or MCS. Accordingly, it is our view that specific standardized criteria should be defined in the evaluation of EEG data obtained from these patients. Otherwise, neither patients nor clinicians will benefit fully from the advantages of EEG.

Preservation of EEG organization in patients with impaired consciousness and imaging-based evidence of command-following

Standard clinical characterization of patients with disorders of consciousness (DOC) relies on observation of motor output and may therefore lead to the misdiagnosis of vegetative state or minimally conscious state in patients with preserved cognition. We used conventional electroencephalographic (EEG) measures to assess a cohort of DOC patients with and without functional magnetic resonance imaging (fMRI)‐based evidence of command‐following, and correlated the findings with standard clinical behavioral evaluation and brain metabolic activity.

A proposed role for routine EEGs in patients with consciousness disorders: Reply to Letter

ing consensus for inclusion of standard EEG in the neurophysiological evaluation of patients with DOC, several questions remain to be answered. In particular, it has not been clarified whether we should refer to common EEG patterns or combine classic EEG descriptors. Also, it has not been settled whether sleep architecture study adds significant information. Moreover, it remains to be resolved whether a prolonged EEG recording is required to obtain essential data or whether a standard-duration recording is adequate. Data acquired from patients in a coma are scarcely useful because the pathophysiology of coma is different from that of UWS or MCS. Accordingly, it is our view that specific standardized criteria should be defined in the evaluation of EEG data obtained from these patients. Otherwise, neither patients nor clinicians will benefit fully from the advantages of EEG.

Reply: A proposed role for routine EEG evaluations in patients with disorders of consciousness

ing consensus for inclusion of standard EEG in the neurophysiological evaluation of patients with DOC, several questions remain to be answered. In particular, it has not been clarified whether we should refer to common EEG patterns or combine classic EEG descriptors. Also, it has not been settled whether sleep architecture study adds significant information. Moreover, it remains to be resolved whether a prolonged EEG recording is required to obtain essential data or whether a standard-duration recording is adequate. Data acquired from patients in a coma are scarcely useful because the pathophysiology of coma is different from that of UWS or MCS. Accordingly, it is our view that specific standardized criteria should be defined in the evaluation of EEG data obtained from these patients. Otherwise, neither patients nor clinicians will benefit fully from the advantages of EEG.

Preservation of electroencephalographic organization in patients with impaired consciousness and imaging-based evidence of command-following: EEG in Consciousness Disorders

Standard clinical characterization of patients with disorders of consciousness (DOC) relies on observation of motor output and may therefore lead to the misdiagnosis of vegetative state or minimally conscious state in patients with preserved cognition. We used conventional electroencephalographic (EEG) measures to assess a cohort of DOC patients with and without functional magnetic resonance imaging (fMRI)‐based evidence of command‐following, and correlated the findings with standard clinical behavioral evaluation and brain metabolic activity.