Toward an Attention-Based Diagnostic Tool for Patients With Locked-in Syndrome.

Electroencephalography (EEG) has been proposed as a supplemental tool for reducing clinical misdiagnosis in severely brain-injured populations helping to distinguish conscious from unconscious patients. We studied the use of spectral entropy as a measure of focal attention in order to develop a motor-independent, portable, and objective diagnostic tool for patients with locked-in syndrome (LIS), answering the issues of accuracy and training requirement. Data from 20 healthy volunteers, 6 LIS patients, and 10 patients with a vegetative state/unresponsive wakefulness syndrome (VS/UWS) were included.

Electromyographic decoding of response to command in disorders of consciousness.

Objective: To propose a new methodology based on single-trial analysis for detecting residual response to command with EMG in patients with disorders of consciousness (DOC), overcoming the issue of trial dependency and decreasing the influence of a patient's fluctuation of vigilance or arousal over time on diagnostic accuracy.

Methods: Forty-five patients with DOC (18 with vegetative/unresponsive wakefulness syndrome [VS/UWS], 22 in a minimally conscious state [MCS], 3 who emerged from MCS [EMCS], and 2 with locked-in syndrome [LIS]) and 20 healthy controls were included in the study. Patients were randomly instructed to either move their left or right hand or listen to a control command ("It is a sunny day") while EMG activity was recorded on both arms.

Preserved covert cognition in noncommunicative patients with severe brain injury?

Background: Despite recent evidence suggesting that some severely brain-injured patients retain some capacity for top-down processing (covert cognition), the degree of sparing is unknown.

Objective: Top-down attentional processing was assessed in patients in minimally conscious (MCS) and vegetative states (VS) using an active event-related potential (ERP) paradigm.

Methods: A total of 26 patients were included (38 ± 12 years old, 9 traumatic, 21 patients >1 year postonset): 8 MCS+, 8 MCS-, and 10 VS patients.

Detection of visual pursuit in patients in minimally conscious state: a matter of stimuli and visual plane?

Objectives: The aim of this study was to determine whether the assessment of pursuit eye movements in patients in minimally conscious state (MCS) is influenced by the choice of the visual stimulus (study 1) and by the moving plane (study 2).

Methods: Patients with MCS (MCS- and MCS+) in the acute (<1 month post-injury) or chronic (>1 month) setting were assessed. The Coma Recovery Scale-Revised (CRS-R) procedure was used to test visual pursuit of a moving mirror, object and person (study 1, n = 88) and to test vertical and horizontal visual tracking (study 2, n = 94).

Volitional electromyographic responses in disorders of consciousness.

Objective: The aim of the study was to validate the use of electromyography (EMG) for detecting responses to command in patients in vegetative state/unresponsive wakefulness syndrome (VS/UWS) or in minimally conscious state (MCS).

Methods: Thirty-eight patients were included in the study (23 traumatic, 25 patients >1 year post-onset), 10 diagnosed as being in VS/UWS, eight in MCS- (no response to command) and 20 in MCS+ (response to command). Eighteen age-matched controls participated in the experiment.

Effect of zolpidem in chronic disorders of consciousness: a prospective open-label study.

Zolpidem has been reported as an "awakening drug" in some patients with disorders of consciousness (DOC). We here present the results of a prospective openlabel study in chronic DOC patients. Sixty patients (35±15 years; 18 females; mean time since insult ± SD: 4±5.

The auditory P300-based single-switch brain-computer interface: paradigm transition from healthy subjects to minimally conscious patients.

Objective: Within this work an auditory P300 brain-computer interface based on tone stream segregation, which allows for binary decisions, was developed and evaluated.

Methods And Materials: Two tone streams consisting of short beep tones with infrequently appearing deviant tones at random positions were used as stimuli. This paradigm was evaluated in 10 healthy subjects and applied to 12 patients in a minimally conscious state (MCS) at clinics in Graz, Würzburg, Rome, and Liège.