Brain-Computer Interfaces for Communication: Preferences of Individuals With Locked-in Syndrome.

BACKGROUND: Brain-computer interfaces (BCIs) have been proposed as an assistive technology (AT) allowing people with locked-in syndrome (LIS) to use neural signals to communicate. To design a communication BCI (cBCI) that is fully accepted by the users, their opinion should be taken into consideration during the research and development process. OBJECTIVE: We assessed the preferences of prospective cBCI users regarding (1) the applications they would like to control with a cBCI, (2) the mental strategies they would prefer to use to control the cBCI, and (3) when during their clinical trajectory they would like to be informed about AT and cBCIs. Furthermore, we investigated if individuals diagnosed with progressive and sudden onset (SO) disorders differ in their opinion. METHODS: We interviewed 28 Dutch individuals with LIS during a 3-hour home visit using multiple-choice, ranking, and open questions. During the interview, participants were informed about BCIs and the possible mental strategies. RESULTS: Participants rated (in)direct forms of communication, computer use, and environmental control as the most desired cBCI applications. In addition, active cBCI control strategies were preferred over reactive strategies. Furthermore, individuals with progressive and SO disorders preferred to be informed about AT and cBCIs at the moment they would need it. CONCLUSIONS: We show that individuals diagnosed with progressive and SO disorders preferred, in general, the same applications, mental strategies, and time of information. By collecting the opinion of a large sample of individuals with LIS, this study provides valuable information to stakeholders in cBCI and other AT development.

Dorsolateral prefrontal cortex-based control with an implanted brain-computer interface.

The objective of this study was to test the feasibility of using the dorsolateral prefrontal cortex as a signal source for brain-computer interface control in people with severe motor impairment. We implanted two individuals with locked-in syndrome with a chronic brain-computer interface designed to restore independent communication. The implanted system (Utrecht NeuroProsthesis) included electrode strips placed subdurally over the dorsolateral prefrontal cortex. In both participants, counting backwards activated the dorsolateral prefrontal cortex consistently over the course of 47 and 22 months, respectively. Moreover, both participants were able to use this signal to control a cursor in one dimension, with average accuracy scores of 78 ± 9% (standard deviation) and 71 ± 11% (chance level: 50%), respectively. Brain-computer interface control based on dorsolateral prefrontal cortex activity is feasible in people with locked-in syndrome and may become of relevance for those unable to use sensorimotor signals for control.

Electroencephalogram based communication system for locked in state person using mentally spelled tasks with optimized network model.

Due to growth in population, Individual persons with disabilities are increasing daily. To overcome the disability especially in Locked in State (LIS) due to Spinal Cord Injury (SCI), we planned to design four states moving robot from four imagery tasks signals acquired from three electrode systems by placing the electrodes in three positions namely T1, T3 and FP1. At the time of the study we extract the features from Continuous Wavelet Transform (CWT) and trained with Optimized Neural Network model to analyze the features. The proposed network model showed the highest performances with an accuracy of 93.86 % then that of conventional network model. To confirm the performances we conduct offline test. The offline test also proved that new network model recognizing accuracy was higher than the conventional network model with recognizing accuracy of 97.50 %. To verify our result we conducted Information Transfer Rate (ITR), from this analysis we concluded that optimized network model outperforms the other network models like conventional ordinary Feed Forward Neural Network, Time Delay Neural Network and Elman Neural Networks with an accuracy of 21.67 bits per sec. By analyzing classification performances, recognizing accuracy and Information Transformation Rate (ITR), we concluded that CWT features with optimized neural network model performances were comparably greater than that of normal or conventional neural network model and also the study proved that performances of male subjects was appreciated compared to female subjects.

Ethics of life-sustaining treatment in locked-in syndrome: A Chinese survey.

BACKGROUND: Locked-in syndrome (LIS) characterizes individuals who have experienced pontine lesions, who have limited motor output but with preserved cognitive abilities. Despite their severe physical impairment, individuals with LIS self-profess a higher quality of life than generally expected. Such third-person expectations about LIS are shaped by personal and cultural factors in western countries. OBJECTIVE: We sought to investigate whether such opinions are further influenced by the cultural background in East Asia. We surveyed attitudes about the ethics of life-sustaining treatment in LIS in a cohort of medical and non-medical Chinese participants. RESULTS: The final study sample included 1545 respondents: medical professionals (n=597, 39%), neurologists (n=303, 20%), legal professionals (n=276, 18%) and other professionals (n=369, 24%), including 180 family members of individuals with LIS. Most of the participants (70%), especially neurologists, thought that life-sustaining treatment could not be stopped in individuals with LIS. It might be unnecessary to withdraw life-sustaining treatment, because the condition involved is not terminal and irreversible, and physical treatment can be beneficial for the patient. A significant proportion (59%) of respondents would like to be kept alive if they were in that condition; however, older people thought the opposite. Families experience the stress of caring for individuals with LIS. The mean (SD) quality of life score for relatives was 0.73 (2.889) (on a -5, +5 scale), which was significantly lower than that of non-relatives, 1.75 (1.969) (P<0.001). CONCLUSIONS: Differences in opinions about end of life in LIS are affected by personal characteristics. The current survey did not identify a dissociation between personal preferences and general opinions, potentially because of a social uniformity in China where individualism is less pronounced. Future open-ended surveys could identify specific needs of caregivers so that strategic interventions to reduce ethical debasement are designed.

Locked-in syndrome in Sweden, an explorative study of persons who underwent rehabilitation: a cohort study.

OBJECTIVE: Locked-in syndrome (LiS) is a rare condition, characterised by a complete paresis except for vertical eye movements and blinking with cognitive functions intact, commonly caused by ischaemia in the ventral pons. Previous studies have indicated that persons with LiS can live on for many years and have a good quality of life (QoL). To our knowledge, LiS has never been studied in Sweden. The aim was to explore LiS in Sweden; describing population characteristics, living situation, mortality/cause of death and health-related QoL/impact on participation. DESIGN: Explorative, nationwide study with two parts (quantitative and qualitative). Persons registered in the national quality register WebRehab during 2007-2014 were eligible. PARTICIPANTS: Ten persons were identified in part 1, four participated in part 2. During part 1, data were collected from WebRehab, medical charts and registers, while questionnaires and interviews were used during part 2. RESULTS: Seven out of 10 were men, median age at onset was 49 years and the cause of LiS was in all cases stroke, 70% of which ischaemic. Three were deceased with a median time of survival of 1.9 years. Seven were still alive, with a median time elapsed since onset of 5.8 years. Three participants experienced good QoL. Information, respect from professionals and more specialised technical devices were three areas containing unfulfilled needs. CONCLUSION: This was the first study conducted in Sweden and the characteristics of this population were like those studied abroad. In this study, the persons with LiS who were interviewed expressed the need for proper care, appropriate technical aids and a supportive environment in order to have QoL. However, there is still much room for improvements.

Transient Incomplete Locked-In Syndrome Secondary to Supratentorial Gunshot Wound.

BACKGROUND: Locked-in syndrome (LIS) is a rare neurologic disorder characterized as quadriplegia with anarthria. The diagnosis of LIS is challenging and requires a high index of suspicion. The syndrome is typically caused by an infratentorial lesion to the ventral pons, regardless of etiology. LIS secondary to supratentorial injury is extremely rare, and to our knowledge, this is the first reported case. CASE DESCRIPTION: We report the case of a 26-year-old woman who sustained a gunshot to the left suboccipital area, with supratentorial extension. A diagnosis of incomplete LIS was made on the day of admission, with eye movement preservation. Imaging studies confirmed bilateral injury of the motor homunculus. The clinical course was that of progressive improvement, aided by intensive care unit (ICU) supportive care and early physiotherapy rehabilitation. Her condition improved, and she was discharged to a rehabilitation facility at the end of week 7 postadmission. CONCLUSIONS: This is a unique case of incomplete LIS after supratentorial injury. Initial ICU care and early rehabilitation likely played a major role in the full recovery of this patient. The influence of etiology and site of injury on outcome prognosis is also suggested. Although severe diffuse brain injury may occur in the face of an unremarkable computed tomography (CT) scan, the emerging role of magnetic resonance imaging in optimally evaluating traumatic brain injury with discordant clinical and CT information is highlighted and is useful in cases of LIS where prognosis prediction is important.

Comprehensive, technology-based, team approach for a patient with locked-in syndrome: A case report of improved function & quality of life.

One of the most severe types of stroke is locked-in syndrome (LIS) due to the loss of almost all voluntary motor functions and a high mortality rate. The majority of the literature regarding LIS is based on case reports that utilized multidisciplinary interventions focused on improving functional communication and respiratory care with minimal focus on motor retraining. These reports were neither dynamic nor multi-sensory, and the only technology utilized was in the form of augmentative communication. There are additional types of technology frequently used in the general stroke population that can address similar motor deficits that occur in the LIS population. This case report explains an interdisciplinary approach using motor and communication interventions that are multisensory, progressive, multi-modal, and technology- based. The length of stay was 153 days in acute rehabilitation, after which the patient returned home making significant gains in overall function. In this patient, the FIM changes in motor (+42), cognitive (+29) and total change score of (+71) surpassed what was determined to be a minimal clinically important difference. These results suggest that this treatment program and approach may be a key reason why this patient was able to achieve significant functional gains and report improved quality of life.