Toward a coherent structuration of disorders of consciousness expertise at a country scale: A proposal for France.

Probing consciousness and cognitive abilities in non-communicating patients is one of the most challenging diagnostic issues. A fast growing medical and scientific literature explores the various facets of this challenge, often coined under the generic expression of 'Disorders of Consciousness' (DoC). Crucially, a set of independent converging results demonstrated both (1) the diagnostic and prognostic importance of this expertise, and (2) the need to combine behavioural measures with brain structure and activity data to improve diagnostic and prognostication accuracy as well as potential therapeutic intervention. Thus, probing consciousness in DoC patients appears as a crucial activity rich of human, medical, economic and ethical consequences, but this activity needs to be organized in order to offer this expertise to each concerned patient. More precisely, diagnosis of consciousness differs in difficulty across patients: while a minimal set of data can be sufficient to reach a confident result, some patients need a higher level of expertise that relies on additional behavioural and brain activity and brain structure measures. In order to enable this service on a systematic mode, we present two complementary proposals in the present article. First, we sketch a structuration of DoC expertise at a country-scale, namely France. More precisely, we suggest that a 2-tiers network composed of local (Tier-1) and regional (Tier-2) centers backed by distant electronic databases and algorithmic centers could optimally enable the systematic implementation of DoC expertise in France. Second, we propose to create a national common register of DoC patients in order to better monitor this activity, to improve its performance on the basis of nation-wide collected evidence, and to promote rational decision-making.

[Is there any obstruction other than prostatic obstruction in Idiopathic Parkinson's Disease?] / Existe-t-il une obstruction autre que prostatique dans la Maladie de Parkinson Idiopathique ?

OBJECTIVE: To highlight the existence of pseudo-dyssynergia in Idiopathic Parkinson's Disease (IPD) constituting a functional bladder outlet obstruction. MATERIALS AND METHODS: A retrospective study was conducted by including men with a confirmed diagnose of IPD who participated in the SIROCCO rehabilitation program. Patients included clinically exhibited overactive bladder and voiding dysfunction without prostatic hypertrophy ultrasounded. They have been clinically assessed by the Urinary Symptoms Profile (USP) urinary symptom score. Bladder outlet obstruction was assessed by the pressure-flow study. Urodynamic obstruction has been quantified by the bladder obstruction index which depends on detrusor pressure at maximum flow rate and maximum flow rate. It has been defined by a BOOI>40. RESULTS: The pressure-flow profile was analyzed in 5 patients who met the inclusion criteria. In this group of 5 patients with IPD, the diagnosis was made on average 10.6 years (7-14) before the pressure-flow studies were performed. Our results objectified 4 patients obstructive among 5 and one equivocal patient. A striated pseudo-dyssynergia was found in the 3 obstructive patients and associated with a smooth pseudodyssynergia in one patient. CONCLUSION: We have observed, in this short series, a pseudo-dyssynergia by subjects suffering from IPD. LEVEL OF EVIDENCE: 3.

Effects of preference and sensory modality on behavioural reaction in patients with disorders of consciousness.

BACKGROUND: Reliable evaluation of patients with unresponsive wakefulness syndrome (UWS) or in a minimally conscious state (MCS) remains a major challenge. It has been suggested that the expression of residual cerebral function could be improved by allowing patients to listen to their favourite music. However, the potential effect of music on behavioural responsiveness, as well as the effect of preferred stimuli in other sensory modalities (e.g. olfaction), remain poorly understood. OBJECTIVE: The aim of our study was to investigate the effect of sensory modality (auditory versus olfactory) and preference (preferred versus neutral) of the test stimuli on patients' subsequent performance on the Coma Recovery Scale-Revised (CRS-R). RESEARCH DESIGN: Within-subject design because of inter-individual differences between patients. METHODS AND PROCEDURES: We studied four items from the CRS-R (visual pursuit using a mirror, auditory localization of the own name and two movements to command) in 13 patients (7 MCS; 6 UWS). MAIN OUTCOMES AND RESULTS: Auditory stimuli triggered higher responsiveness compared to olfactory stimuli, and preferred stimuli were followed by higher scores than did neutral stimuli. CONCLUSIONS: Findings suggest that preferred auditory stimuli at the bedside contribute to the expression of residual function and could improve the diagnostic assessment.

[Impact of pharmaceutical interventions on antibiotic therapy of urinary tract infections in rehabilitation center]. / Impact des interventions pharmaceutiques sur l'antibiothérapie des infections urinaires en service de soins de suite et de réadaptation.

BACKGROUND: The aim of this study was to assess the impact of medico-pharmaceutical partnership on the quality of antibiotic treatment in urinary tract infection (UTI) within rehabilitation center. MATERIAL: All antibiotic prescriptions were validated by the pharmacist at the start of treatment and twice a week. All patients with symptomatic urinary tract infection between January 1, 2014 to December 31, 2015 were included in this study. Addition to awareness among specifiers to promoting the appropriate use of antibiotics, the pharmacist suggested pharmaceutical interventions (PI) in order to improve the quality of antibiotic treatments. At the same time, 3 quality indicators (QI) were followed: duration, dosage, antibiotic susceptibility. The compliance rates of this 3 QI allowed to assess the quality of the antibiotic treatment in urinary tract infection. RESULTS: The study population included 154 patients corresponding to 252 UTI. Sixty-eight PI were made by pharmacist about urinary tract infection treatment (overdosage or under-dosing, duration unknown, inadequate route of administration). These QI achieved 96.4% compliance with duration, 98.8% compliance with dosage and 99.2% with the antibiotic susceptibility. CONCLUSION: This study allowed showing the medico-pharmaceutical impact on the quality of antibiotic treatments in UTI. The awareness among specifiers with a daily validation of prescription by the pharmacist allowed to improve urinary tract infections care in rehabilitation center. LEVEL OF EVIDENCE: 4.

[Beneficial effect of preferred music on cognitive functions in minimally conscious state patients]. / Effets bénéfiques de la musique préférée sur les capacités cognitives des patients en état de conscience minimale.

Several studies have shown that music can boost cognitive functions in normal and brain-damaged subjects. A few studies have suggested a beneficial effect of music in patients with a disorder of consciousness but it is difficult to conclude since they did not use quantified measures and a control condition/group. The aim of the present study was to compare the effect of music to that of a continuous sound on the relational behavior of patients in a minimally conscious state (MCS). Behavioral responses of six MCS patients were evaluated using items from the Coma Recovery Scale-Revised. Weekly evaluation sessions were carried out, over four weeks, under two conditions: following the presentation of either the patient's preferred music, or following a continuous sound (control condition). Qualitative and quantitative analyses showed that twelve of the eighteen sessions (66.6%) showed a better result for the music condition than for the control condition. This new protocol suggests that preferred music has a beneficial effect on the cognitive abilities of MCS patients. The results further suggest that cerebral plasticity may be enhanced in autobiographical (emotional and familiar) contexts. These findings should now be further extended with an increased number of patients to further validate the hypothesis of the beneficial effect of music on cognitive recovery.

Bladder dysfunction in hereditary spastic paraplegia: a clinical and urodynamic evaluation.

OBJECTIVES: Hereditary spastic paraplegia (HSP) is a degenerative central nervous system disorder characterized by progressive spasticity and hyperreflexia of the lower limbs. Often, patients with HSP experience symptoms of voiding dysfunction. Urodynamic evaluations of these patients are rarely reported in the literature and the etiology of voiding dysfunction remains unclear. The present study characterizes lower urinary tract dysfunction in a large series of patients. METHODS: The medical records of 29 HSP patients who underwent urodynamic evaluation were retrospectively analyzed. The history of lower urinary tract symptoms was noted and the urodynamic findings analyzed. RESULTS: Urgency was the most dominant complaint (72.4%), followed by frequency (65.5%), urinary incontinence (55.2%) and hesitancy (51.7%). The urodynamic findings showed signs of central neurogenic bladder in 24 patients (82.7%), with detrusor overactivity (DO) in 15 patients (51.7%) and detrusor sphincter dyssynergia (DSD) in 19 (65.5%). Post-void residual (PVR) of >10% of the voided volume was found in 12 patients (41.4%). There were significant relationships between detrusor overactivity and PVR (P=0.005), frequency (P=0.046) and nocturia (P=0.045). Ultrasound examination revealed no upper urinary tract complications. CONCLUSION: Despite the presence of DO and DSD, HSP patients do not seem to have a high risk of developing ultrasonographically-assessed upper urinary tract complications after a mean follow-up of 22 years, contrary to spinal cord injury population. These results may guide practitioners in their decision-making about the appropriate evaluation and treatment of bladder disturbances that accompany hereditary spastic paraplegia.

An intensive exercise-based training program reduces prefrontal activity during usual walking in patients with Parkinson's disease.

INTRODUCTION: Parkinson's disease (PD) leads to a progressive loss of locomotor automaticity. Consequently, PD patients rely more on executive resources for the control of gait, resulting in increased prefrontal activity while walking. Exercise-based training programs may improve automaticity of walking and reduce prefrontal activity in this population. This study aimed to assess the effect of an intensive multidisciplinary exercise-based training program on prefrontal activity and gait performance during usual walking in PD patients. METHOD: Fourteen patients (mean age: 67 ± 9; disease duration: 6 ± 5 years; Hoehn and Yahr score: 1.9 ± 0.6) were included in this study. They were assessed in ON stage at three different times at 5-week intervals: two times before the training program (T0 and T1) and once after the training program (T2). Gait performance (stride time, speed, stride length, cadence, and their respective coefficient of variation) and cortical activity in the dorsolateral prefrontal cortex (DLPFC) using functional near infrared spectroscopy (fNIRS) were measured during usual walking. RESULTS: Patients had reduced cortical activity of the DLPFC at T2 compared to T1 (p = 0.003). Patients had shorter stride time at T2 compared to T1 (p = 0.025) and tended to have longer stride length at T2 than at T1 (p = 0.056). CONCLUSION: The training program led to positive effects on prefrontal activity and gait performance. Reduced prefrontal activity during usual walking after training program suggests that patients may have a greater reserve capacity to face more challenging walking conditions. Further studies will investigate the effect of this training on cortical activity during dual-task walking..

Effect of long-term oral treatment with L-arginine and idebenone on the prevention of stroke-like episodes in an adult MELAS patient.

INTRODUCTION: Mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is a maternally-inherited multisystem disorder. Mitochondrial angiopathy mediated by nitric oxide, a metabolite of L-arginine, is among the proposed pathophysiologic mechanisms of stroke-like episodes (SLEs) in MELAS. There are very few reports on long-term prevention of SLEs with oral L-arginine and idebenone treatment in MELAS adult patients. CASE REPORT: A 38-year-old patient with MELAS and SLEs was treated with oral L-arginine and idebenone for 27months. She remained free of attacks throughout the treatment period except when she stopped her treatment on two occasions during which she had recurrent cerebral metabolic attacks. The patient experienced no side effect of treatment with L-arginine and idebenone. CONCLUSION: Our observation suggests long-term safety and potential benefit of oral L-arginine and idebenone in the prevention of recurrence of SLEs in adult MELAS patients.

Parietal damage dissociates saccade planning from presaccadic perceptual facilitation.

A well-known theory in the field of attention today is the premotor theory of attention which suggests that the mechanisms involved in eye movements are the same as those for spatial attention shifts. We tested a parietal damaged patient with unilateral optic ataxia and 4 controls on a dual saccade/attentional task and show a dissociation between saccadic eye movements and presaccadic perceptual enhancement at the saccade goal. Remarkably, though the patient was able to make the appropriate saccades to the left, impaired visual field (undistinguishable from saccades to his right, intact visual field), he was unable to discriminate the letter at the saccade goal (whereas his performance was like controls for letter discrimination in his right visual field). This suggests that saccade planning and presaccadic perceptual facilitation are separable--planning a saccade to a location does not necessitate that the processing of this location is enhanced. Based on these results, we suggest that the parietal cortex is necessary for the coupling between saccade planning and presaccadic perceptual facilitation.

Optic ataxia errors depend on remapped, not viewed, target location.

Optic ataxia is a disorder associated with posterior parietal lobe lesions, in which visually guided reaching errors typically occur for peripheral targets. It has been assumed that these errors are related to a faulty sensorimotor transformation of inputs from the 'ataxic visual field'. However, we show here that the errors observed in the contralesional field in optic ataxia depend on a dynamic gaze-centered internal representation of reach space.

Indicators of long-term return to work after severe traumatic brain injury: A cohort study.

BACKGROUND: Return to work (RTW) is a major objective in the rehabilitation of individuals with severe traumatic brain injury (TBI). Implications for long-term occupational integration (beyond 5 years) have rarely been studied. OBJECTIVE: The objective was to assess long-term RTW and the associated factors after severe TBI. MATERIAL AND METHODS: Retrospective analysis of a cohort of individuals 16 to 60 years old admitted to hospital after severe TBI from 2005 to 2009 and followed prospectively. Medical and occupational data were collected from medical files and by systematic telephone interview to assess outcome at a minimum of 6 years post-trauma. Factors associated with RTW were investigated by multivariable regression analysis, estimating prevalence ratios (PRs) and 95% confidence intervals (CIs). A proportional hazards model was used to study RTW delay, estimating hazard ratios (HRs). RESULTS: Among the 91 individuals included (mean [SD] age 28.5 [11.3] years; 79% male), 63.7% returned to work after a mean of about 20 months, and 57.1% were still working at the time of the survey. Factors significantly associated with RTW on multivariable analysis were higher educational level (adjusted PR, 1.53; 95% CI, 1.15 to 2.03), absence of motor disability (adjusted PR, 1.82; 1.12 to 2.95) and behavioural disorder (adjusted PR, 1.26; 1.01 to 1.60), as well as disabled worker status (adjusted PR, 1.26; 1.01 to 1.60) (likelihood of the multivariate analysis model 53.1). Delayed RTW was associated with health insurance payments (adjusted HR, 0.40; 95% CI, 0.22 to 0.71), motor disability (adjusted HR, 0.34; 0.15 to 0.76), low educational level (adjusted HR, 2.20; 1.06 to 4.56) and moderate disability on the Extended Glasgow Outcome Scale (adjusted HR, 0.49; 0.27 to 0.91) (likelihood of the multivariate analysis model 335.5). CONCLUSION: Individuals with the most severe TBI are able to RTW and remain in work. This study highlights the multiple determinants involved in RTW and the role of socioenvironmental factors.

Capgras Syndrome and Other Delusional Misidentification Syndromes.

The delusional misidentification syndromes (DMS) are a group of disorders, characterized by patients mistaking the identity of people they know, although they recognize them physically. The term DMS is an umbrella term which may cover disorders whose definition extends to objects other than people, such as animals, places, or familiar material objects. The most common and best known DMS is Capgras syndrome. In this disorder, the misidentification leads to the delusional conviction that a close friend or relative has been replaced by an identical - or almost identical - "double," whose original has disappeared. This double is an imposter without name or identity. Most often considered as a persecutor, the double may be subjected to aggression, which may be very violent. Neuropsychological hypotheses based on cerebral dysfunctions are now commonly considered to be at the origin of the disorder. They have been elaborated from achievements in the neurosciences, particularly the facial recognition models. In return, knowledge about the normal cognitive processes involved in recognition and familiarity has benefited from the work that cognitive neuropsychiatry has invested in these disorders. The DMS are observed in various contexts of morbidity: primary psychiatric diagnosis, or secondary to various organic disorders, particularly in neurodegenerative disease; they are rarely met in isolated form. Most often, they develop in line with the associated pathology. In the absence of consensual clinical description, the epidemiology of DMS is uncertain; they may be more frequent than previously supposed. There is no specific treatment for these disorders; neuroleptics are generally used in association with treatment of the concomitant disorder. The frequent association of DMS with organic disorders which may be curable and the particularly dangerous profile of these patients are factors that underline the need for better screening.

Construction and feasibility study of the SOFMER Activity Score (SAS), a new assessment of physical and cognitive activity.

OBJECTIVES: For hospitalizations in rehabilitation centers (RCs) in France, the quantification of healthcare givers' activity is based on the dependency of the patients, defined as a total or partial inability to perform activities required for daily living without help. The tools currently used to quantify dependency are not sufficiently precise. Here we describe the construction of a new tool, the SOFMER Activity Score (SAS scoring), which allows for a good description of the level of activity of patients hospitalized in RCs, and a feasibility study of the tool. METHODS: After a study group proposed the first version of the SAS, the validity of its content was studied by the Delphi consensus method: 26 physicians or healthcare professionals known for their expertise in PMR responded to the first round. The feasibility study was prospective and involved multi-site professionals. Data related to the SAS determined by a multidisciplinary team were collected and compared to the Activité de la Vie Quotidienne (AVQ) scale, which is administered to all patients and included in medical and administrative data. RESULTS: We included 81 patients in the feasibility study. The mean (SD) time to obtain the SAS was 4.5 (3.3) min. For 97.5% of scorings, the participating professionals judged that the SAS was compatible or fairly compatible with clinical practice. The internal structure of the SAS scale seemed better than that of the AVQ scale, for which the present study confirmed a floor effect for all items. CONCLUSIONS: The SAS allows for measuring the level of physical and cognitive activity of a patient hospitalized in an RC. If validation studies for the SAS, exploring its reliability, construct validity or criterion validity, confirm the tool's good metrological qualities, the SAS will allow for a good quantification of the burden of care.

Drugs for behavior disorders after traumatic brain injury: Systematic review and expert consensus leading to French recommendations for good practice.

OBJECTIVE: There are no handbook or recommendations for the use of pharmacological agents to treat neurobehavioral disorders after traumatic brain injury (TBI). This work proposes a systematic review of the literature and a user guide on neuroleptics, antidepressants, beta-blockers, mood stabilizers and other medications for irritability, aggressiveness, agitation, impulsivity, depression, apathy… METHOD: Steering, working and reading groups (62 people) were formed under the control of the French High Authority for Health (HAS) in collaboration with the SOFMER scientific society (French Society of Physical and Rehabilitation Medicine). Articles were searched by HAS officers in the Medline database from 1990 to 2012, crossing TBI and pharmacological agents. The HAS method to select, read and analyze papers is close to the PRISMA statements. RESULTS: Out of 772 references, 89 were analyzed, covering a total of 1306 people with TBI. There is insufficient evidence to standardize drug treatments for these disorders. There are however some elements to establish consensus recommendations for good clinical practice. Propranolol can improve aggression (B grade). Carbamazepine and valproate seem effective on agitation and aggression and are recommended as first line treatment (Expert Consensus [EC]). There is no evidence of efficacy for neuroleptics. Their prescription is based on emergency situation for a crisis (loxapine) but not for long-term use (EC). Antidepressants are recommended to treat depression (EC) with a higher standard of proof for Selective Serotonin Reuptake Inhibitors (SSRI, grade B). Other products are described. CONCLUSION: The choice of treatment depends on the level of evidence, target symptoms, custom objectives, clinical experience and caution strategies.

Behavioral and affective disorders after brain injury: French guidelines for prevention and community supports.

OBJECTIVE: The purpose of this study was to elaborate practice guidelines for the prevention of behavioral and affective disorders in adult outpatients after traumatic brain injury (TBI); but also to identify the support systems available for family, caregivers of patients with TBI within the community. METHODS: The elaboration of these guidelines followed the procedure validated by the French health authority for good practice recommendations, close to the Prisma statement. This involved a systematic and critical review of the literature looking for studies that investigated the impact of programs in community settings directed to behavioral and affective disorders post-TBI. Recommendations were than elaborated by a group of professionals and family representatives. RESULTS: Only six articles were found comprising 4 studies with a control group. Two studies showed a beneficial effect of personalized behavior management program delivered within natural community settings for persons with brain injury and their caregivers. Two other studies showed the relevance of scheduled telephone interventions to improve depressive symptoms and one study emphasized the usefulness of physical training. One study investigated the relevance of an outreach program; this study showed an improvement of the patients' independence but did not yield any conclusions regarding anxiety and depression. DISCUSSION AND RECOMMENDATIONS: In addition to the application of care pathways already established by the SOFMER, prevention of behavioral and affective disorders for brain-injured outpatients should involve pain management, as well as development of therapeutic partnerships. It is recommended to inform patients, their family and caregivers regarding the local organization and facilities involved in the management of traumatic brain injury. The relevance of therapeutic education for implementing coping strategies, educating caregivers on behavioral disorder management, follow-up telephone interventions, and holistic therapy seems established. The level of evidence is low and preliminary studies should be confirmed with larger controlled trials.

[Assessment of disability and quality of life in patients with cognitive disorders]. / Evaluation des incapacités et de la qualité de vie des patients présentant des troubles cognitifs.

OBJECTIVE: To identify disability, handicap and quality of life questionnaires available for patients with cognitive impairment. MATERIALS AND METHODS: We systematically reviewed the literature in Medline using the keywords assessment, evaluation, deficiency, disability, disadvantage, handicap, quality of life, scale, index, questionnaire, ICIDH-1, and ICIDH-2, combined with the cognitive deficits dysexecutive syndrome, memory deficits, attention deficits, neglect, apraxia, aphasia, agnosia and mood disorders. We focused on validated scales and distinguished scales dedicated to assess disability, handicap and quality of life. RESULTS: At the level of disability, global and specific scales are available. Specific scales exist for dysexecutive syndrome, memory deficits, attention deficits, unilateral neglect, aphasia and mood disorders. French adaptations of foreign language tests and original tests developed in French have been validated in these areas. No specific tool is available for isolated apraxia or agnosia. Generic scales and pathology-specific scales (for stroke, traumatic brain injury, and multiple sclerosis) are available for quality of life. For aphasia, specific tools are available for incapacity handicap and quality of life. CONCLUSION: Previous results show the impact of the ICIDH-1 framework on functional outcome assessment of cognitive impairments. This approach is often limited by the lack of theoretical background and by the difficulty to assess the involvement of environment and anosognosia.

Long-term sensorimotor and therapeutical effects of a mild regime of prism adaptation in spatial neglect. A double-blind RCT essay.

Spatial neglect (SN) is commonly associated with poor functional outcome. Adaptation to a rightward optical deviation of vision has been shown to benefit to SN rehabilitation. The neurophysiological foundations and the optimal modalities of prism adaptation (PA) therapy however remain to be validated. This study is aimed at exploring the long-term sensory-motor, cognitive and functional effects produced by weekly PA sessions over a period of four weeks. A double-blind, monocentric randomized and controlled trial (RCT) was carried out. Twenty patients with left SN secondary to stroke were included, 10 in the "prism" group and 10 in the "control" group. The sensory-motor effects of PA were evaluated by measurement of manual and visual straight-ahead, and also by precision of pointing without visual feedback before and after each PA session. The functional independence measure (FIM) was evaluated before and at 1, 3 and 6 months after PA, while SN severity was assessed using the Behavioural Inattention Test (BIT) before and 6 months after PA. Before the intervention, only manual straight-ahead pointing constituted a reproducible sensory-motor measurement. During prism exposure, a questionnaire showed that not a single patient were aware of the direct effects of optical deviation on pointing movement performance. The sensory-motor after-effects produced by the PA produced a more rapid reduction of the rightward manual straight-ahead, which was secondarily followed by visual straight-ahead. These sensory-motor effects helped to clarify the action mechanisms of PA on SN. At the conclusion of the 6-month follow-up, the two groups showed similar improvement, indicating that a weekly PA session over 4 weeks was not sufficient to produce long-term functional benefit. This improvement was correlated with the evolution of visual straight-ahead, which can be proposed as a marker for patients outcome.

Bilateral vestibular stimulation does not improve visual hemineglect.

This work compared the effect of unilateral (right and left) and bilateral vestibular stimulation in a right-brain-damaged patient with neglect. Neglect was improved following left caloric vestibular stimulation, and worsened following right vestibular stimulation. On the other hand, no modification of neglect was observed after bilateral vestibular stimulation. These results support the idea that caloric vestibular stimulation may improve neglect through a specific effect; bilateral stimulation making the putative activation bilateral and symmetrical does not affect the lateral bias of neglect.

Mismatch negativity and late auditory evoked potentials in comatose patients.

OBJECTIVES: The purpose of this study was to assess the patterns of mismatch negativity (MMN) and N100 component in comatose patients and to evaluate their prognostic value vis-à-vis return of consciousness. METHODS: MMN and auditory (early, middle-latency and late) evoked potentials were recorded in 52 normals and in 128 comatose patients (comas due to neurosurgical and neurological problems). At the time of recording, all patients scored lower than 8 on the Glasgow scale. RESULTS: Visually detected N100 and MMN were confirmed by cross-correlation of sub-averages. The MMN was present in 33/128 patients and the N100 component in 84/128. The amplitudes of MMN and N100 waves detected in comatose patients were statistically different from those of normal subjects. By 3 months after the onset of coma, 95 patients had returned to consciousness, most of them with moderate to severe disability. A ratio of 30/33 patients with MMN and 70/84 with N100 had regained consciousness. The presence of a MMN together with a N100 component was more specific (90.9%) than the presence of a N100 component irrespective of MMN (57.6%) in terms of predicting return to consciousness, but its sensitivity was lower (respectively 31.6% for MMN and 73.7% for N100). The mean period that elapsed between the recording of evoked potentials and a return to consciousness was 6.3+/-4 days. MLAEPs were also highly specific, but BAEPs were not. CONCLUSION: MMN and auditory evoked potentials provide a reliable assessment of the functional status of comatose patients. When present, MMN and the N100 differ from those found in normal subjects in terms of latencies and amplitudes. As a predictor of return of consciousness MMN had high specificity and low sensitivity, whereas the N100 had high sensitivity and low specificity. This study demonstrates that the recording of MMN and the auditory N100 can be a very useful aid in the assessment of coma and in predicting whether or not a patient will regain consciousness.