Sleep in the unresponsive wakefulness syndrome and minimally conscious stateCologan, Victor ; ; et alin Journal of Neurotrauma (2013), 30(5), 339-346 The goal of our study was to investigate different aspects of sleep, namely the sleep-wake cycle and sleep stages, in the vegetative state/unresponsive wakefulness syndrome (VS/UWS) and minimally ... [more ▼] The goal of our study was to investigate different aspects of sleep, namely the sleep-wake cycle and sleep stages, in the vegetative state/unresponsive wakefulness syndrome (VS/UWS) and minimally conscious state (MCS). 24h polysomnography was performed in 20 patients in a UWS (n=10) or in a MCS (n=10) due to brain injury. The data were first tested for the presence of a sleep-wake cycle and the observed sleep patterns were compared to standard scoring criteria. Sleep spindles, slow waves sleep and rapid eye movement sleep were quantified and their clinical value was investigated. According to our results, an electrophysiological sleep-wake cycle was identified in 5 MCS and 3 VS/UWS patients. Sleep stages did not always match the standard scoring criteria which therefore needed to be adapted. Sleep spindles were more present in patients who clinically improved within 6 months. Slow wave sleep was present in 8 MCS and 3 VS/UWS patients but never in the ischemic etiology. Rapid eye movement sleep, and therefore dreaming which is a form of consciousness, was present in all MCS and 3 VS/UWS patients. In conclusion, the presence of alternating periods of eyes-open/eyes-closed cycles does not necessarily imply preserved electrophysiological sleep architecture in the UWS and MCS, contrary to previous definition. The investigation of sleep is a little studied yet simple and informative way to evaluate the integrity of residual brain function in patients with disorders of consciousness with possible clinical diagnostic and prognostic implications. [less ▲] Detailed reference viewed: 163 (10 ULg)![]() The Day George Avellis Met Miller Fisher – About the Unsual Presentation of an Anti-GQ1b IgG Antibody SyndromePHAN BA, Remy ; Parmentier, Eric ; LIEVENS, Isabelle et alPoster (2013, March) Objective: OBJECTIVE: To describe the clinical, laboratory and electrophysiological features of a patient who presented an Avellis syndrome as the initial feature of Miller Fisher syndrome (MFS ... [more ▼] Objective: OBJECTIVE: To describe the clinical, laboratory and electrophysiological features of a patient who presented an Avellis syndrome as the initial feature of Miller Fisher syndrome (MFS). Background: BACKGROUND: Anti-GQ1b Ig antibodies are associated with an increasing spectrum of neurological disorders, including MFS and Guillain-Barre syndrome (GBS). Design/Methods: DESIGN/METHODS: Clinical case description. Results: RESULTS: A 67-year old woman was seen for subacute dysphagia and dysphonia, preceded by rapidly worsening paresthesia of the extremities and face, with a history of upper respiratory tract infection two weeks before admission. Nasotracheal examination showed a left velopalatine and left vocal cord paresis. Twelve hours later, sensory ataxia appeared and deep tendon reflexes weakened. Diffuse paresis affecting predominantly the axial muscles developped. Oculomotricity was preserved. Brain MRI was normal, while EMG suggested a mild sensory neuropathy. Within hours, dysphagia worsened and dyspnea appeared, prompting ICU admission for airway support. She developed a proximal paresis and dysautonomia, global areflexia. CSF findings were unremarkable. IVIg were administered at a dose of 0.2g/kg per day during five days. Control EMG showed signs of polyradiculoneuropathy. She gradually recovered and was discharged at home after 32 days, with only a slight velopalatal paresis and a mild fatigue. Anti-ganglioside antibodies screen was positive for IgG-GM3, GD1b, GD3, GQ1b, GT1a and GT1b. In front of this clinical and biological picture, the diagnosis of atypical MFS was retained. Thirty day after discharge, both clinical and electrophysiological parameters were normalised. Conclusions: CONCLUSIONS: This case highlights that (i) MFS can show atypical presentation (here a pure Avellis syndrome, never reported in the context of the anti-GQ1b syndrome to our knowledge) and should be considered in front of an isolated impaired cranial nerve function, even in the absence of the classical triad of ophtalmoplegia, areflexia and ataxia, and (ii) that the boundaries between MFS and GBS are usually neater in textbooks than in real life. [less ▲] Detailed reference viewed: 35 (8 ULg) Deciphering Distance-Induced Deceleration of Gait and Ataxia in People with Multiple SclerosisPHAN BA, Remy ; Pierard, Sébastien ; Moonen, Gustave et alPoster (2012, October 12) Detailed reference viewed: 40 (3 ULg) Detection and Quantification of Efficiency and Quality of Gait Impairment in Multiple Sclerosis through Foot Path AnalysisPHAN BA, Remy ; Pierard, Sébastien ; MOONEN, Gustave et alPoster (2012, October 11) Introduction: Walking speed is generally considered as the best outcome measure in trials for people with multiple sclerosis (pMS). We recently designed a device based on range laser scanner capable to ... [more ▼] Introduction: Walking speed is generally considered as the best outcome measure in trials for people with multiple sclerosis (pMS). We recently designed a device based on range laser scanner capable to track feet paths of walking subjects. Our purpose was to explore gait descriptors of pMS and compare them with those of healthy volunteers (HV). Methods: Fourty-four pMS (considered as moderatly or highly disabled according to a cut-off EDSS value of 3.0) and 28 HV performed 4 walking tasks along 2 trajectories in 3 walking modes. Twenty-six gait descriptors crudely dichotomized in « efficiency» and « quality » of gait were compared in the 2 populations using unpaired t-tests. Results: (i) apart from an older age in pMS, the two populations were comparable, (ii) efficiency of gait descriptors including walking speed distinguished HV from pMS, and pMS with moderate from pMS with high disability, (iii) quality of gait descriptors were also significantly altered in pMS, including in walking tasks where their walking speed was comparable to that of HV. Conclusions: RLS technology can distinguish pMS from HV according to (i) more efficiency of gait descriptors than the sole walking speed and (ii) quality of gait descriptors, including in subjects with a « normal » walking speed. [less ▲] Detailed reference viewed: 49 (6 ULg) L’image du mois: Pli fessier anormal révélant un syndrome de Currarino.Jedidi, Zayd ; Moonen, Gustave ![]() in Revue Médicale de Liège (2012), 67(10) We briefly report the case of a man carrying an abnormal intergluteal cleft as an isolated manifestation of Currarino's syndrome. Detailed reference viewed: 15 (0 ULg) The earlier the smaller the better for natalizumab-associated PML: in MRI vigilance veritas ?PHAN BA, Remy ; Belachew, Shibeshih ; et alin Neurology (2012), 79 Natalizumab-associated progressive multifocal leukoencephalopathy (N-PML) in multiple sclerosis (MS) is due to CNS infection by the opportunistic JC virus (JCV). As of december 2011, 193 confirmed cases ... [more ▼] Natalizumab-associated progressive multifocal leukoencephalopathy (N-PML) in multiple sclerosis (MS) is due to CNS infection by the opportunistic JC virus (JCV). As of december 2011, 193 confirmed cases of N-PML have been observed, giving rise to an overall risk of approximately 0,202%. N-PML pathogenesis remains partially elusive although risk factors have now been clearly delineated. In patients with prior JCV infection detected by serum anti-JCV antibodies, duration of therapy and prior use of immunosuppressants (IS) increase the risk of N-PML. The clinical outcome of MS patients who developed N-PML was highly variable, ranging from asymptomatic case to varying degrees of neurological disability or even death. It was also observed in real life setting that the earlier N-PML was diagnosed and treated, the better was the clinical outcome. Clinical vigilance is now considered as the established cornerstone of PML risk-management algorithm. Here we present early MRI features of 4 out of 8 N-PML cases, which were observed in Wallonia-Brussels and Northern France in more than 4 years of post-marketing utilization of natalizumab for both regions. We are not aware of the specific context and outcome of the 4 other N-PML cases, which were diagnosed and treated in other centers. The reported cases emphasize that (i) N-PML can have a long presymptomatic course while still being clearly detectable with MR imaging, (ii) N-PML can have a benign outcome provided it is diagnosed and treated early, (iii) a clinically symptomatic N-PML may be a further advanced infection with a poorer prognosis, and (iv) periodic brain MR scans, particularly in high risk situations, are likely to provide earlier detection of N-PML and better outcomes. [less ▲] Detailed reference viewed: 81 (13 ULg) Motor fatigue measurement by distance-induced slow down of walking speed in multiple sclerosisPHAN BA, Remy ; CALAY, Philippe ; GRODENT, Patrick et alin PLoS ONE (2012), 7(4), 34744 Background: Motor fatigue and ambulation impairment are prominent clinical features of people with multiple sclerosis (pMS). We hypothesized that a multimodal and comparative assessment of walking speed ... [more ▼] Background: Motor fatigue and ambulation impairment are prominent clinical features of people with multiple sclerosis (pMS). We hypothesized that a multimodal and comparative assessment of walking speed on short and long distance would allow a better delineation and quantification of gait fatigability in pMS. Objectives: To compare 4 walking paradigms: the timed 25-foot walk (T25FW), a corrected version of the T25FW with dynamic start (T25FW+), the timed 100-meter walk (T100MW) and the timed 500-meter walk (T500MW). Methods: Thirty controls and 81 pMS performed the 4 walking tests in a single study visit. Results: The 4 walking tests were performed with a slower WS in pMS compared to controls even in subgroups with minimal disability. The finishing speed of the last 100-meter of the T500MW was the slowest measurable WS whereas the T25FW+ provided the fastest measurable WS. The ratio between such slowest and fastest WS (Deceleration Index, DI) was significantly lower only in pMS with EDSS 4.0-6.0, a pyramidal or cerebellar functional system score reaching 3 or a maximum reported walking distance !4000m. Conclusion: The motor fatigue which triggers gait deceleration over a sustained effort in pMS can be measured by the WS ratio between performances on a very short distance and the finishing pace on a longer more demanding task. The absolute walking speed is abnormal early in MS whatever the distance of effort when patients are unaware of ambulation impairment. In contrast, the DI-measured ambulation fatigability appears to take place later in the disease course. [less ▲] Detailed reference viewed: 42 (10 ULg) Pain perception in disorders of consciousness: Neuroscience, clinical care, and ethics in dialogueDemertzi, Athina ; ; Bruno, Marie-Aurélie et alin Neuroethics (2012) Pain, suffering and positive emotions in patients in vegetative state/unresponsive wakefulness syndrome (VS/UWS) and minimally conscious states (MCS) pose clinical and ethical challenges. Clinically, we ... [more ▼] Pain, suffering and positive emotions in patients in vegetative state/unresponsive wakefulness syndrome (VS/UWS) and minimally conscious states (MCS) pose clinical and ethical challenges. Clinically, we evaluate behavioural responses after painful stimulation and also emotionally-contingent behaviours (e.g., smiling). Using stimuli with emotional valence, neuroimaging and electrophysiology technologies can detect subclinical remnants of preserved capacities for pain which might influence decisions about treatment limitation. To date, no data exist as to how healthcare providers think about end-of-life options (e.g., withdrawal of artificial nutrition and hydration) in the presence or absence of pain in non-communicative patients. Here, we aimed to better clarify this issue by re-analyzing previously published data on pain perception (Prog Brain Res 2009 177, 329–38) and end-of-life decisions (J Neurol 2010 258, 1058–65) in patients with disorders of consciousness. In a sample of 2259 European healthcare professionals we found that, for VS/UWS more respondents agreed with treatment withdrawal when they considered that VS/UWS patients did not feel pain (77%) as compared to those who thought VS/UWS did feel pain (59%). This interaction was influenced by religiosity and professional background. For MCS, end-of-life attitudes were not influenced by opinions on pain perception. Within a contemporary ethical context we discuss (1) the evolving scientific understandings of pain perception and their relationship to existing clinical and ethical guidelines; (2) the discrepancies of attitudes within (and between) healthcare providers and their consequences for treatment approaches, and (3) the implicit but complex relationship between pain perception and attitudes toward life-sustaining treatments. [less ▲] Detailed reference viewed: 195 (12 ULg) Immune Reconstitution Inflammatory Syndrome in Natalizumab-Associated PMLPhan-Ba, Rémy ; LOMMERS, Emilie ; Moonen, Gustave et alin Neurology (2012), 78(1), 73 Detailed reference viewed: 30 (13 ULg) La vignette diagnostique de l'étudiant.Syndrome du trou déchiré postérieur(foramen jugulaire); PHAN BA, Remy ; et alin Revue Médicale de Liège (2012), 67(4), 210-214 Detailed reference viewed: 19 (0 ULg)![]() p27(Kip1) Is a Microtubule-Associated Protein that Promotes Microtubule Polymerization during Neuron Migration.Godin, Juliette ; ; Laguesse, Sophie et alin Developmental Cell (2012), 23(4), 729-44 The migration of cortical interneurons is characterized by extensive morphological changes that result from successive cycles of nucleokinesis and neurite branching. Their molecular bases remain elusive ... [more ▼] The migration of cortical interneurons is characterized by extensive morphological changes that result from successive cycles of nucleokinesis and neurite branching. Their molecular bases remain elusive, and the present work describes how p27(Kip1) controls cell-cycle-unrelated signaling pathways to regulate these morphological remodelings. Live imaging reveals that interneurons lacking p27(Kip1) show delayed tangential migration resulting from defects in both nucleokinesis and dynamic branching of the leading process. At the molecular level, p27(Kip1) is a microtubule-associated protein that promotes polymerization of microtubules in extending neurites, thereby contributing to tangential migration. Furthermore, we show that p27(Kip1) controls actomyosin contractions that drive both forward translocation of the nucleus and growth cone splitting. Thus, p27(Kip1) cell-autonomously controls nucleokinesis and neurite branching by regulating both actin and microtubule cytoskeletons. [less ▲] Detailed reference viewed: 27 (9 ULg) Cycling or not cycling: cell cycle regulatory molecules and adult neurogenesis.Beukelaers, Pierre ; ; Caron, Nicolas et alin Cellular and Molecular Life Sciences : CMLS (2012), 69(9), 1493-1503 The adult brain most probably reaches its highest degree of plasticity with the lifelong generation and integration of new neurons in the hippocampus and olfactory system. Neural precursor cells (NPCs ... [more ▼] The adult brain most probably reaches its highest degree of plasticity with the lifelong generation and integration of new neurons in the hippocampus and olfactory system. Neural precursor cells (NPCs) residing both in the subgranular zone of the dentate gyrus and in the subventricular zone of the lateral ventricles continuously generate neurons that populate the dentate gyrus and the olfactory bulb, respectively. The regulation of NPC proliferation in the adult brain has been widely investigated in the past few years. Yet, the intrinsic cell cycle machinery underlying NPC proliferation remains largely unexplored. In this review, we discuss the cell cycle components that are involved in the regulation of NPC proliferation in both neurogenic areas of the adult brain. [less ▲] Detailed reference viewed: 36 (11 ULg) MicroRNAs tune cerebral cortical neurogenesis.; ; Moonen, Gustave et alin Cell Death & Differentiation (2012), 19(10), 1573-81 MicroRNAs (miRNAs) are non-coding RNAs that promote post-transcriptional silencing of genes involved in a wide range of developmental and pathological processes. It is estimated that most protein-coding ... [more ▼] MicroRNAs (miRNAs) are non-coding RNAs that promote post-transcriptional silencing of genes involved in a wide range of developmental and pathological processes. It is estimated that most protein-coding genes harbor miRNA recognition sequences in their 3' untranslated region and are thus putative targets. While functions of miRNAs have been extensively characterized in various tissues, their multiple contributions to cerebral cortical development are just beginning to be unveiled. This review aims to outline the evidence collected to date demonstrating a role for miRNAs in cerebral corticogenesis with a particular emphasis on pathways that control the birth and maturation of functional excitatory projection neurons. [less ▲] Detailed reference viewed: 2 (1 ULg) Functional neuroanatomy underlying the clinical subcategorization of minimally conscious state patients.Bruno, Marie-Aurélie ; Majerus, Steve ; Boly, Mélanie et alin Journal of Neurology (2012), 259(6), 1087-98 Patients in a minimally conscious state (MCS) show restricted signs of awareness but are unable to communicate. We assessed cerebral glucose metabolism in MCS patients and tested the hypothesis that this ... [more ▼] Patients in a minimally conscious state (MCS) show restricted signs of awareness but are unable to communicate. We assessed cerebral glucose metabolism in MCS patients and tested the hypothesis that this entity can be subcategorized into MCS- (i.e., patients only showing nonreflex behavior such as visual pursuit, localization of noxious stimulation and/or contingent behavior) and MCS+ (i.e., patients showing command following).Patterns of cerebral glucose metabolism were studied using [(18)F]-fluorodeoxyglucose-PET in 39 healthy volunteers (aged 46 +/- 18 years) and 27 MCS patients of whom 13 were MCS- (aged 49 +/- 19 years; 4 traumatic; 21 +/- 23 months post injury) and 14 MCS+ (aged 43 +/- 19 years; 5 traumatic; 19 +/- 26 months post injury). Results were thresholded for significance at false discovery rate corrected p < 0.05.We observed a metabolic impairment in a bilateral subcortical (thalamus and caudate) and cortical (fronto-temporo-parietal) network in nontraumatic and traumatic MCS patients. Compared to MCS-, patients in MCS+ showed higher cerebral metabolism in left-sided cortical areas encompassing the language network, premotor, presupplementary motor, and sensorimotor cortices. A functional connectivity study showed that Broca's region was disconnected from the rest of the language network, mesiofrontal and cerebellar areas in MCS- as compared to MCS+ patients.The proposed subcategorization of MCS based on the presence or absence of command following showed a different functional neuroanatomy. MCS- is characterized by preserved right hemispheric cortical metabolism interpreted as evidence of residual sensory consciousness. MCS+ patients showed preserved metabolism and functional connectivity in language networks arguably reflecting some additional higher order or extended consciousness albeit devoid of clinical verbal or nonverbal expression. [less ▲] Detailed reference viewed: 86 (10 ULg) A corrected version of the Timed-25 Foot Walk Test with a dynamic start to capture the maximum ambulation speed in multiple sclerosis patientsPhan-Ba, Rémy ; CALAY, Philippe ; GRODENT, Patrick et alin NeuroRehabilitation (2012), 30(4), 261-266 Background : No clinical test is currently available and validated to measure the maximum walking speed (WS) of multiple sclerosis (MS) patients. Since the Timed 25-Foot Walk Test (T25FW) is performed ... [more ▼] Background : No clinical test is currently available and validated to measure the maximum walking speed (WS) of multiple sclerosis (MS) patients. Since the Timed 25-Foot Walk Test (T25FW) is performed with a static start, it takes a significant proportion of the distance for MS patients to reach their maximum pace. Objectives : In order to capture the maximum WS and to quantify the relative impact of the accelerating phase during the first meters, we compared the classical T25FW with a modified version (T25FW+) allowing a dynamic start after a 3 meters run-up. Methods : Sixty-four MS patients and 30 healthy subjects performed successively the T25FW and the T25FW+. Results : The T25FW+ was performed faster than the T25FW for the vast majority of MS and healthy subjects. In the MS population, the mean relative gain of speed due to the dynamic start on T25FW+ was independent from the EDSS and from the level of ambulation impairment. Compared to healthy subjects, the relative difference between dynamic versus static start was more important in the MS population even in patients devoid of apparent gait impairment according to the T25FW. Conclusion : The T25FW+ allows a more accurate measurement of the maximum WS of MS patients, which is a prerequisite to reliably evaluate deceleration over longer distance tests. Indirect arguments suggest that the time to reach the maximum WS may be partially influenced by the cognitive impairment status. The maximum WS and the capacity of MS patients to accelerate on a specific distance may be independently regulated and assessed separately in clinical trials and rehabilitation programs. [less ▲] Detailed reference viewed: 95 (33 ULg) Vitamin D tweets light to genes in multiple sclerosisLOMMERS, Emilie ; Lecrompe, Laurence ; Moonen, Gustave et alin Revue Médicale de Liège (2012), 67(5-6), 359-365 The relationship between sunlight exposure and the incidence of multiple sclerosis and the understanding of immunomodulatory effects of vitamin D triggered, in recent years, a broad range of ... [more ▼] The relationship between sunlight exposure and the incidence of multiple sclerosis and the understanding of immunomodulatory effects of vitamin D triggered, in recent years, a broad range of investigations. Immunological studies performed in vitro and in vivo have demonstrated how tolerogenic vitamin D can be. Epidemiological studies confirmed an increased incidence of multiple sclerosis in vitamin D deficient subjects and signs of increased disease activity in such MS patients. Although small-scale observational studies have suggested a beneficial impact of vitamin D supplementation on the incidence and severity of multiple sclerosis, large scale clinical trials remain warranted to confirm these preliminary results. [less ▲] Detailed reference viewed: 54 (13 ULg) Partial trisomy 4q associated with young-onset dopa-responsive parkinsonism.Garraux, Gaëtan ; CABERG, Jean-Hubert ; et alin Archives of Neurology (2012), 69(3), 398-400 OBJECTIVE: To describe a patient who developed a young-onset, dopa-responsive parkinsonism linked to a de novo heterozygous interstitial duplication 4q. DESIGN: Case report. SETTING: Movement Disorder ... [more ▼] OBJECTIVE: To describe a patient who developed a young-onset, dopa-responsive parkinsonism linked to a de novo heterozygous interstitial duplication 4q. DESIGN: Case report. SETTING: Movement Disorder Outpatient Clinic at the University Hospital Centre, Liege, Belgium. Patient A 31-year-old woman. MAIN OUTCOME MEASURES: Clinical, neuroimaging, and genetic data. RESULTS: The duplicated region contains 150 known genes, including the alpha-synuclein (SNCA) gene locus. Motor and 6-[(18)F]fluoro-L-dopa positron emission tomography features are similar to those previously reported in heterozygote SNCA duplication carriers. Altered expression of other genes contained in the duplicated region may contribute to clinical features that are uncommon in the phenotypic spectrum of SNCA multiplications such as delayed developmental psychomotor milestones during infancy and musculoskeletal abnormalities. CONCLUSION: This case report provides new insights on the genetic basis of parkinsonism. [less ▲] Detailed reference viewed: 25 (8 ULg) MRI preclinical detection and asymptomatic course of a progressive multifocal leucoencephalopathy (PML) under natalizumab therapy.Phan-Ba, Rémy ; LOMMERS, Emilie ; TSHIBANDA, Luaba et alin Journal of Neurology, Neurosurgery & Psychiatry (2012), 83 Early detection of progressive multifocal leucoencephalopathy (PML) in the setting of natalizumab therapy currently is performed by rapid evaluation of new symptoms occurring in treated patients. The role ... [more ▼] Early detection of progressive multifocal leucoencephalopathy (PML) in the setting of natalizumab therapy currently is performed by rapid evaluation of new symptoms occurring in treated patients. The role of MR scanning has not been investigated but holds promise since MR detection is highly sensitive for PML lesions. The authors report a case of presymptomatic PML of the posterior fossa detected by MR scans. Immediate suspension of natalizumab and plasma exchanges resulted in a rapid decline of natalizumab serum concentration. Intravenous steroids started together with plasma exchanges followed by an oral tapering course were used to minimise the immune reconstitution inflammatory syndrome. No symptoms (beyond mild headache) developed, and the repeat PCR for JC Virus (JCV) DNA detection performed 10 weeks later was negative. This case suggests that: (1) periodic brain MR scans may detect signs of presymptomatic PML in MS patients treated with natalizumab, (2) corticosteroid management of inflammatory reaction may contribute to optimal control of the immune reconstitution inflammatory syndrome routinely seen with natalizumab-associated PML and (3) early radiological detection of PML can have an excellent outcome even in a clinically critical region and despite prior immunosuppressant exposure. The potential benefit of regular MR scanning just using the T2/FLAIR modalities could be further investigated in order to detect early natalizumab-associated PML, leading to benign outcomes. [less ▲] Detailed reference viewed: 31 (6 ULg) Primary central nervous system lymphoma in a patient treated with Natalizumab.Phan-Ba, Rémy ; Bisig, Bettina ; Deprez, Manuel et alin Annals of Neurology (2011), 69(6), 1060-1 Detailed reference viewed: 32 (12 ULg) Automated EEG entropy measurements in coma, vegetative state/unresponsive wakefulness syndrome and minimally conscious stateGosseries, Olivia ; Schnakers, Caroline ; LEDOUX, Didier et alin Functional Neurology (2011) Monitoring the level of consciousness in brain injured patients with disorders of consciousness is crucial as it provides diagnostic and prognostic information. Behavioral assessment remains the gold ... [more ▼] Monitoring the level of consciousness in brain injured patients with disorders of consciousness is crucial as it provides diagnostic and prognostic information. Behavioral assessment remains the gold standard for assessing consciousness but previous studies have shown a high rate of misdiagnosis. This study aimed to investigate the usefulness of electroencephalography (EEG) entropy measurements in differentiating unconscious (coma or vegetative) from minimally conscious patients. Left fronto-temporal EEG recordings (10-minute resting state epochs) were prospectively obtained in 56 patients and 16 age-matched healthy volunteers. Patients were assessed in the acute (≤1 month post-injury;n=29) or chronic (>1 month post-injury; n=27) stage. The etiology was traumatic in 23 patients. Automated online EEG entropy calculations (providing an arbitrary value ranging from 0 to 91) were compared with behavioral assessments (Coma Recovery Scale-Revised) and outcome. EEG entropy correlated with Coma Recovery Scale total scores (r=0.49). Mean EEG entropy values were higher in minimally conscious (73±19; mean and standard deviation) than in vegetative/unresponsive wakefulness syndrome patients (45±28). Receiver operating characteristic analysis revealed an entropy cut-off value of 52 differentiating acute unconscious from minimally conscious patients (sensitivity 89% and specificity 90%). In chronic patients, entropy measurements offered no reliable diagnostic information. EEG entropy measurements did not allow prediction of outcome. User-independent time-frequency balanced spectral EEG entropy measurements seem to constitute an interesting diagnostic – albeit not prognostic – tool for assessing neural network complexity in disorders of consciousness in the acute setting. Future studies are needed before using this tool in routine clinical practice, and these should seek to improve automated EEG quantification paradigms in order to reduce the remaining false negative and false positive findings. [less ▲] Detailed reference viewed: 162 (9 ULg) |
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