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To identify changes in the standard electroencephalograms (EEGs) of patients with unresponsive wakefulness syndrome (UWS) who did or did not recover consciousness 6 months after admission to a rehabilitation department.Prospective cohort study.Unit for severe acquired brain injuries.Consecutive patients with UWS (N=28).Not applicable.EEG amplitude (reduced or normal), dominant frequency (alpha, theta, or delta), and reactivity (absent or present) were scored at admission and 6 months later. The cumulative Amplitude-Frequency-Reactivity score was evaluated. Clinical assessments were made using the Coma Recovery Scale-Revised.Sixteen (57.1%) of the 28 patients with UWS recovered consciousness after 6 months, while 12 patients (42.9%) did not recover consciousness. EEG improvements occurred in 14 patients with consciousness recovery (87.5%) and 2 patients without consciousness recovery (16.7%) only. Improvements in EEG dominant frequency (from the theta to the alpha band or from the delta to the theta band), reappearance of EEG reactivity, and Amplitude-Frequency-Reactivity score increase (P.01) differentiated patients with consciousness improvement from those without consciousness improvement. Six months after admission for rehabilitation, patients with EEG improvements showed higher Coma Recovery Scale-Revised scores than did those without EEG changes (P.01).Most patients who emerge from UWS demonstrate improvement in basic EEG characteristics over time. EEG changes in patients with UWS may aid in the timely recognition of patients transitioning into a minimally conscious state.

The value of resting electroencephalogram (EEG) in revealing neural constitutes of consciousness (NCC) was examined. We quantified the dynamic repertoire, duration and oscillatory type of EEG microstates in eyes-closed rest in relation to the degree of expression of clinical self-consciousness. For NCC a model was suggested that contrasted normal, severely disturbed state of consciousness and state without consciousness. Patients with disorders of consciousness were used. Results suggested that the repertoire, duration and oscillatory type of EEG microstates in resting condition quantitatively related to the level of consciousness expression in brain-damaged patients and healthy-conscious subjects. Specifically, results demonstrated that (a) decreased number of EEG microstate types was associated with altered states of consciousness, (b) unawareness was associated with the lack of diversity in EEG alpha-rhythmic microstates, and (c) the probability for the occurrence and duration of delta-, theta- and slow-alpha-rhythmic microstates were associated with unawareness, whereas the probability for the occurrence and duration of fast-alpha-rhythmic microstates were associated with consciousness. In conclusion, resting EEG has a potential value in revealing NCC. This work may have implications for clinical care and medical-legal decisions in patients with disorders of consciousness.

Traumatic brain injury (TBI) is a major risk factor for Alzheimer disease (AD). Although the mechanisms that lead to AD after a TBI are largely unknown, changes in amyloid- β (A β ) metabolism and abnormal tau phosphorylation are probably involved. In this study, we evaluated A β 1 - 42 , total tau (t-tau), and phosphorylated tau (p-tau) levels in the cerebrospinal fluid (CSF) of 15 patients who developed a prolonged disorder of consciousness after a severe TBI (mean time from TBI 271.6 ± 176.5 days; range 92–578 days). Reduced A β 1 - 42 levels (cohort median value 258 pg/ml, range 90–833.6 pg/ml) were observed in 14/15 patients (93.3%) with severe post-TBI disorders of consciousness. Normal t-tau levels (median 95.2 pg/ml, range 52–256.9 pg/ml) were found in all patients. Normal p-tau levels (median 22.2 pg/ml, range 14–72 pg/ml) were observed in 14/15 patients, while 1 patient had a p-tau level slightly increased. In conclusion, the present findings show that reduced CSF A β levels are not paralleled by significant changes in t-tau and p-tau levels; these results suggest that treatments aimed to prevent chronic neurodegeneration and AD risk after a severe TBI may be better targeted on A β than tau.

The ability to recognize one’s own face, or “self-face”, is a hallmark of self-awareness. In healthy subjects, the sympathetic skin response (SSR) evoked by self-face recognition has a greater area than responses evoked by other visual stimuli. We evaluated the SSRs evoked by self-face images and by six other visual stimuli (conditions) in 15 patients with severe disorders of consciousness and in 15 age-matched healthy subjects. Under all conditions, the evoked area of the SSR was smaller in patients with unresponsive wakefulness syndrome (UWS), intermediate in patients in a minimally conscious state (MCS), and greater in healthy subjects. In patients with UWS, no differences were found between the SSR area evoked by self-face images and those evoked by other conditions. In patients in an MCS, the area of the SSR evoked by self-face presentation was greater than those evoked by other conditions, but statistical significance was reached only in the comparison to other stimuli not involving a real face. This finding may be due to the inability of these patients to differentiate their own face from those of others. These results probably reflect a varying level of self-awareness and suggest some diagnostic implications in patients with severe disorders of consciousness.

Recent findings suggest that EEG amplitude, frequency, and reactivity are related to clinical outcomes in patients with severe disorders of consciousness. Moreover, their prognostic value increases if they are combined with a new Amplitude–Frequency–Reactivity (AFR) score (Bagnato et al., Clin Neurophysiol, 2015). This study evaluated if changes in standard EEG descriptors parallel changes in the level of consciousness in patients in a vegetative state (VS). EEGs were scored in 25 patients in a VS at admission to a rehabilitation department and six months later. Amplitude was scored as 1 if reduced or 2 if normal. Dominant frequency was scored as 1, 2, or 3 for delta, theta, or alpha, respectively. Reactivity to stimuli was scored as 1 if absent or 2 if present. Therefore, the AFR score ranged from 3 to 7. Changes in these scores after six months were compared between patients who improved ( n =14) or not ( n =11) their level of consciousness. Patients who improved their level of consciousness showed significant changes in EEG frequency ( p =0.02) and reactivity ( p =0.001). Moreover, 85.7% of them showed an increase of the AFR score ( p

Although epileptiform abnormalities are a common electroencephalographic finding after a brain injury, not much is known about their prevalence and prognostic value in patients with severe disorders of consciousness. In this study, we evaluated the occurrence of epileptiform abnormalities in the electroencephalograms recorded at admission in 106 consecutive patients with unresponsive wakefulness syndrome (UWS, 59 patients), or in a minimally conscious state (MCS, 47 patients). Using the Coma Recovery Scale Revised (CRS-R), we compared the three-month outcome of patients with and without epileptiform abnormalities. Epileptiform abnormalities were found in 34 patients (32.1%), with a similar occurrence in patients with UWS (33.9%) or in a MCS (29.8%). The CRS-R score at admission was 7.5 ± 4.6 in patients with epileptiform abnormalities, and 7.4 ± 4.3 in patients without epileptiform abnormalities. After three months, the CRS-R score was 13.6 ± 8 in patients with epileptiform abnormalities, and 15.1 ± 7.7 3 in patients without epileptiform abnormalities. ANOVA showed no significant differences between groups in the three-months changes of the CRS-R score ( F 1,104 = 1.59; p = 0.2). In conclusion, epileptiform abnormalities are common in patients with UWS or MCS after a severe brain injury; yet, their occurrence does not seem to correlate with short term outcome.

Coma is usually a transient state occurring as a result of a severe brain injury; generally, patients with coma either progress to a full recovery of consciousness or die. A third and much less common mode of progression is the transition into a vegetative state. In this report we describe a patient who remained in a comatose state for more than one year after a traumatic and hypoxic brain injury. This state, which we refer to as long-lasting coma (LLC), may represent a disorder of consciousness with significantly different features from conventional coma, vegetative state, or brain death. Overall data are described. Clinical, neurophysiological, and neuroimaging data suggest that LLC may represent the most severe consciousness disorder. A multi-level involvement of the ascending reticular activating system (ARAS) is required in LLC. A new type of disorder of consciousness characterized by the persistence of a state similar to coma, resulting from a widespread disruption of the ascending arousal control system, is reported. This description may be useful for identification of other patients suffering from this severe disorder of consciousness and suggests important ethical implications.