Event related potentials elicited by violations of auditory regularities in patients with impaired consciousness.

International audienceImproving our ability to detect conscious processing in non communicating patients remains a major goal of clinical cognitive neurosciences. In this perspective, several functional brain imaging tools are currently under development. Bedside cognitive event-related potentials (ERPs) derived from the EEG signal are a good candidate to explore consciousness in these patients because: (1) they have an optimal time resolution within the millisecond range able to monitor the stream of consciousness, (2) they are fully non-invasive and relatively cheap, (3) they can be recorded continuously on dedicated individual systems to monitor consciousness and to communicate with patients, (4) and they can be used to enrich patients' autonomy through brain-computer interfaces. We recently designed an original auditory rule extraction ERP test that evaluates cerebral responses to violations of temporal regularities that are either local in time or global across several seconds. Local violations led to an early response in auditory cortex, independent of attention or the presence of a concurrent visual task, while global violations led to a late and spatially distributed response that was only present when subjects were attentive and aware of the violations. In the present work, we report the results of this test in 65 successive recordings obtained at bedside from 49 non-communicating patients affected with various acute or chronic neurological disorders. At the individual level, we confirm the high specificity of the 'global effect': only conscious patients presented this proposed neural signature of conscious processing. Here, we also describe in details the respective neural responses elicited by violations of local and global auditory regularities, and we report two additional ERP effects related to stimuli expectancy and to task learning, and we discuss their relations to consciousness

Survival and consciousness recovery are better in the minimally conscious state than in the vegetative state

BACKGROUND The prognosis value of early clinical diagnosis of consciousness impairment is documented by an extremely limited number of studies, whereas it may convey important information to guide medical decisions. OBJECTIVE We aimed at determining if patients diagnosed at an early stage (<90 days after brain injury) as being in the minimally conscious state (MCS) have a better prognosis than patients in the vegetative state/Unresponsive Wakefulness syndrome (VS/UWS), independent of care limitations or withdrawal decisions. METHODS Patients hospitalized in ICUs of the Pitié-Salpêtrière Hospital (Paris, France) from November 2008 to January 2011 were included and evaluated behaviourally with standardized assessment and with the Coma Recovery Scale-Revised as being either in the VS/UWS or in the MCS. They were then prospectively followed until 1July 2011 to evaluate their outcome with the GOSE. We compared survival function and outcomes of these two groups. RESULTS Both survival function and outcomes, including consciousness recovery, were significantly better in the MCS group. This difference of outcome still holds when considering only patients still alive at the end of the study. CONCLUSIONS Early accurate clinical diagnosis of VS/UWS or MCS conveys a strong prognostic value of survival and of consciousness recovery

Prominent Plasmacytosis Following Intravenous Immunoglobulin Correlates with Clinical Improvement in Guillain-Barré Syndrome

BACKGROUND: High doses of pooled polyclonal IgG are commonly used to treat numerous autoimmune diseases. Their mode of action nevertheless remains only partially explained. At the same time, until now, no early biological marker has been able to predict their efficacy. METHODOLOGY/PRINCIPAL FINDINGS: In a first pilot retrospective analysis, we reviewed white blood cell counts and blood smears in consecutive patients with autoimmune disease (n = 202) and non-autoimmune disease (n = 104). Autoimmune patients received either intravenous immunoglobulin (IVIg, n = 103), plasma exchange (n = 78) or no specific treatment (n = 21). We then prospectively monitored consecutive autoimmune patients with IVIg injection (n = 67), or without any specific treatment (n = 10) using the same routine laboratory tests, as well as flow cytometry. Both retrospective and prospective analyses identified large plasma-cell mobilization exclusively in IVIg-treated autoimmune patients 7 days after initiation of treatment. The majority of IVIg-mobilized plasma cells were immature HLA-DR(high)/CD138(low)/CXCR4(low) plasma cells expressing intracellular immunoglobulin G which were neither IVIg- nor human IgG-specific. Importantly, we found a strong negative correlation between the absolute number of IVIg-mobilized plasma cells and time to improve neurological function in both retrospective and prospective studies of Guillain-Barré syndrome (GBS), (r = -0.52, p = 0.0031, n = 30, r = -0.47, p = 0.0028, n = 40, respectively). CONCLUSIONS/SIGNIFICANCE: IVIg promotes immature plasma-cell mobilization in patients with GBS, chronic inflammatory demyelinating polyneuropathy, myasthenia gravis and inflammatory myopathy. Prominent day 7 plasma-cell mobilization is a favourable prognostic marker in patients with GBS receiving IVIg treatment

Manifestations oniriques au cours du Syndrome de Guillain-Barré

PARIS6-Bibl.Pitié-Salpêtrie (751132101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

e-Table 4 - RUDANT-884684

E-table 4. Association between surgery during the previous 60 days and GBS (case-crossover design), according to the standard duration of the procedure, for each main group of surgery

e-Table 5 - RUDANT-884684

E-Table 5: Association between Guillain-Barré syndrome (GBS) and surgery during the previous 60 days (case-crossover design), among patients treated with immunoglobulins or plasma exchange

e-Table 3 - RUDANT-884684

E-table 3. Association between Guillain-Barré syndrome (GBS) and surgery during the previous 60 days (case-crossover design), according to the presence of infection during hospitalization for each main group of surgery, and association with each subgroup of organs and tissues targeted by the procedure

e-Table 2 - RUDANT-884684

e-table 2. Procedures performed during the case and referent windows among the 8,364 GBS cases included in the present stud

Data from: Surgery and risk of Guillain-Barré syndrome: a French nationwide epidemiologic study

Objectives: To assess the association between Guillain-Barre syndrome (GBS) and recent surgery based on French nationwide data. Methods: Data were extracted from the French health administrative databases (SNIIRAM / PMSI). All patients hospitalized for GBS between 2009 and 2014 were identified by ICD-10 code G61.0 as main diagnosis. Patients previously hospitalized for GBS in 2006, 2007 and 2008 were excluded. Surgical procedures were identified from the hospital database. Hospitalizations for surgery with no infection diagnosis code entered while the hospital stay were also identified. The association between GBS and a recent surgical procedure was estimated using a case-crossover design. Case and referent windows were defined as 1–60 days and 366–425 days before GBS hospitalization, respectively. Analyses were adjusted for previous episodes of gastroenteritis and respiratory tract infection, identified by drug dispensing data. Results: Out of the 8,364 GBS cases included, 175 and 257 patients had undergone a surgical procedure in the referent and case windows, respectively (adjusted odds ratio (OR) =1.54, 95% confidence interval (CI): 1.26, 1.88). A slightly weaker association was observed for surgical procedures with no identified infection during the hospitalization (OR=1.40, 95%CI: 1.12, 1.73). In terms of the type of surgery, only surgical procedures on bones and digestive organs were significantly associated with GBS (OR and 95%CI=2.81 (1.70, 4.65) and 2.37 (1.32, 4.23), respectively). Conclusion: In this large nationwide epidemiological study, GBS was moderately associated with any type of recent surgery, and was more strongly associated with bone and digestive organ surgery