A tree of life? Multivariate logistic outcome-prediction in disorders of consciousness.

Background: Clinical outcome of patients with disorders of consciousness (DOC) is seen as generally very poor. Here, we specify individual outcome chances for patients with DOC on the basis of clinical and event-related-potentials (ERPs) data and identify subgroups, who vary substantially regarding their outcome chances.Methods: We employed data from 102 patients and used standard clinical protocol data (age, etiology, diagnosis, gender), sensory (N100, Mismatch-Negativity) and cognitive (P300, N400) ERPs to predict patients' recovery rates.Results: Two significant prediction models emerged: In both, subgroups of patients with good (51%, tree 1) to very good recovery chances (97%, tree 2) could be identified. The first model was obtained from standard clinical data. The second model included cognitive ERPs and resulted in considerably better patient classification. Moreover, when taking cognitive ERPs into account, the standard protocol data did not add further significant information, neither did sensory ERPs.Conclusion: The presented information about outcome chances of individual patients with DOC will be vital for these patients and critical for clinical professionals who have to direct specialized treatments and council relatives. Legal guardians and families, in turn, need to know what to expect in the future in order to prepare for the challenges ahead.

Against the odds: a case study of recovery from coma after devastating prognosis.

To demonstrate the possibility for hidden rehabilitation potential even following most severe brain injury and the uncertainty of current prognosis factors for coma and unresponsive wakefulness syndrome, we detail the rehabilitation of J. W., after coma from traumatic brain injury. Originally, with many negative prognosis factors and several medical complications, prognosis was devastating. But, with continuing treatment, J. W. improved to a high level of independence in everyday life. This shows the need for rehabilitation research to further specify the "prognostic power" of various combinations of prognosis factors, so that practitioners can come to accurate single-case recommendations when both positive and negative predictors are present.

Will time heal? A long-term follow-up of severe disorders of consciousness.

OBJECTIVE: Little is known about the long-term outcome of patients with disorders of consciousness (DOCs) such as unresponsive wakefulness syndrome (UWS) or minimally conscious state (MCS). We describe the disease course of a large group of DOC patients 2-14 years after brain damage. METHODS: In 102 patients (59 UWS, 43 MCS), clinical and demographic variables from disorder onset were related to the patients' outcomes 2-14 years after discharge. Etiology, age at event, time since onset, gender, and home care versus institutional care were assessed as predictors and similarities and differences between UWS and MCS determined. RESULTS: Seventy-one percent of the patients had passed away or showed no improvement in condition. Twenty-nine percent regained consciousness and developed some communicative capacities. The time a syndrome persisted did not predict clinical outcome in either condition. Six patients regained consciousness after more than 3 years. Of these, five had been UWS (42% of recovered UWS, three traumatic origins, one tumor, one hypoxia) and one MCS (5% of recovered MCS, traumatic origin). In UWS, younger patients, those cared for at home, and in tendency those with traumatic origins, were more likely to recover. In MCS, no reliable outcome predictors were found. INTERPRETATION: Current predictors are too vague for single patient predictions. This study identifies a subgroup of late-recovering patients, casting doubt on the 12-month boundary, after which UWS is stated to be permanent. Routine reexamination, use of more reliable outcome predictors and research determining optimal care settings are needed to inform the crucial decisions made for these patients.

N400 predicts recovery from disorders of consciousness.

OBJECTIVE: Patients with the unresponsive wakefulness syndrome (UWS; formerly vegetative state) or in a minimally conscious state (MCS) open their eyes spontaneously but show no (UWS) or only marginal (MCS) signs of awareness. Because these states can become permanent, residual information processing capacities need to be determined, and reliable outcome predictors need to be found. We assessed higher-order cortical information processing in UWS or MCS in a large group of patients using electroencephalographic event-related potentials (ERPs) and determined their long-term prognostic value for recovery. METHODS: Cognitive ERPs elicited by sound (P300) and speech (N400) were used to assess information processing in 92 behaviorally unresponsive patients diagnosed as in the state of either UWS (n=53) or MCS (n=39). ERPs were assessed with a clinical standard evaluation method and a computerized method, the t-continuous wavelet transform. The patients' clinical outcome was followed up between 2 and 14 years after discharge from the rehabilitation center. RESULTS: Within the first year of the disease, many patients showed an intact P300 and several also an N400, indicating considerable residual information processing. At clinical follow-up, about 25% of the patients recovered and regained communicative capabilities. A highly significant relationship between N400, but not P300, presence and subsequent recovery was found. INTERPRETATION: Results specify cognitive capabilities in disorders of consciousness, and determine their prognostic value. Specifically the N400 ERP is suggested as an important tool to assess information-processing capacities that can predict the likelihood of recovery of patients in UWS or MCS.

MRI brain lesion patterns in patients in anoxia-induced vegetative state.

The object of this study was to analyze magnetic resonance imaging data from patients with disorders of consciousness who were suffering from non-traumatically induced brain lesions with respect to the pattern of vulnerability and to examine the associations between the sizes of these lesions and the clinical outcome of the patients. To this end, T1- and T2-weighted brain images were examined in twelve patients in the post-anoxic vegetative state after a median of 21 days after the causative event. Predominant in the characteristic lesion patterns were regions of pathological white matter signals within the frontal and occipital lobes and in the periventricular regions. The total volumes of the lesions were found to be associated with the severity of the patients' clinical outcomes as measured by the Ranchos Los Amigos Cognitive Scale after a median of 25 months. These lesion patterns demonstrated damage to cerebral networks critical to higher cognitive processes ("consciousness") in both white and gray matter. The relevance of these findings for patients in anoxia-induced decreased levels of consciousness is discussed.