The prevalence and characteristics of patients with classic locked-in syndrome in Dutch nursing homes

Neural Decoding of Spontaneous Overt and Intended Speech

PURPOSE

The aim of this study was to decode intended and overt speech from neuromagnetic signals while the participants performed spontaneous overt speech tasks without cues or prompts (stimuli).

METHOD

Magnetoencephalography (MEG), a noninvasive neuroimaging technique, was used to collect neural signals from seven healthy adult English speakers performing spontaneous, overt speech tasks. The participants randomly spoke the words yes or no at a self-paced rate without cues. Two machine learning models, namely, linear discriminant analysis (LDA) and one-dimensional convolutional neural network (1D CNN), were employed to classify the two words from the recorded MEG signals.

RESULTS

LDA and 1D CNN achieved average decoding accuracies of 79.02% and 90.40%, respectively, in decoding overt speech, significantly surpassing the chance level (50%). The accuracy for decoding intended speech was 67.19% using 1D CNN.

CONCLUSIONS

This study showcases the possibility of decoding spontaneous overt and intended speech directly from neural signals in the absence of perceptual interference. We believe that these findings make a steady step toward the future spontaneous speech-based brain-computer interface.

Update on How to Approach a Patient with Locked-In Syndrome and Their Communication Ability

Locked-in syndrome (LIS) is a rare and challenging condition that results in tetraplegia and cranial nerve paralysis while maintaining consciousness and variable cognitive function. Once acute management is completed, it is important to work with the patient on developing a plan to maintain and improve their quality of life (QOL). A key component towards increasing or maintaining QOL within this population involves the establishment of a functional communication system. Evaluating cognition in patients with LIS is vital for evaluating patients' communication needs along with physical rehabilitation to maximize their QOL. In the past decade or so, there has been an increase in research surrounding brain-computer interfaces to improve communication abilities for paralyzed patients. This article provides an update on the available technology and the protocol for finding the best way for patients with this condition to communicate. This article aims to increase knowledge of how to enhance and manage communication among LIS patients.

Demographic, Medical, and Clinical Characteristics of a Population-Based Sample of Patients With Long-lasting Locked-In Syndrome

BACKGROUND AND OBJECTIVES

Patients with classic locked-in syndrome (LIS), typically caused by ventral pontine stroke, present with quadriplegia, mutism, intact consciousness, and communication skills limited to vertical gazing and/or blinking. Clinical presentations and definitions of LIS differ, especially regarding incomplete LIS. In our study, we explored the functional diversity of LIS, its outcomes, and the complexity of its course along with variations in the location of lesions and their potential significance for outcomes.

METHODS

A national cohort of patients with vascular LIS who remained in the LIS state for at least 6 weeks according to a functional definition of LIS was studied. Demographic, medical, and follow-up data, collected between 2012 and 2022, were obtained from the quality register of the Norwegian National Unit for Rehabilitation of Locked-In Syndrome. Outcomes in verbal communication, motor function, and dependency were evaluated according to criteria for being in or not in the LIS state. The modified Rankin scale and LIS motor recovery scale were applied. Descriptive analysis was performed. The relationship between lesion location and functional outcome was investigated.

RESULTS

The sample included 51 patients (median age: 55.7 years, 36 male individuals), 43 of whom had follow-up data. Ischemic stroke was the most common etiology (n = 35). Twenty-three patients had emerged from the LIS state, mostly within 2 years after onset. All but 1 patient achieved some motor improvement, whereas only 3 achieved full motor recovery, and 88% had a persistently high level of dependence. The 3-year survival rate was 87%. Five patients had an isolated pontine lesion, whereas 80% showed various lesions outside the brain stem. Patients who emerged from the LIS state had a significantly lower prevalence of lesions outside the brain stem than patients who remained in the LIS state did.

DISCUSSION

Investigating an unselected population-based sample of patients with vascular LIS offers important insights into the functional diversity of LIS. Although most patients remained severely disabled, even small improvements in function can substantially increase the potential for activity and participation. Additional lesions outside the brain stem seem to be common in long-lasting LIS and might be prognostic for remaining in the LIS state.

Locked-in syndrome revisited

The locked-in syndrome (LiS) is characterized by quadriplegia with preserved vertical eye and eyelid movements and retained cognitive abilities. Subcategorization, aetiologies and the anatomical foundation of LiS are discussed. The damage of different structures in the pons, mesencephalon and thalamus are attributed to symptoms of classical, complete and incomplete LiS and the locked-in plus syndrome, which is characterized by additional impairments of consciousness, making the clinical distinction to other chronic disorders of consciousness at times difficult. Other differential diagnoses are cognitive motor dissociation (CMD) and akinetic mutism. Treatment options are reviewed and an early, interdisciplinary and aggressive approach, including the provision of psychological support and coping strategies is favoured. The establishment of communication is a main goal of rehabilitation. Finally, the quality of life of LiS patients and ethical implications are considered. While patients with LiS report a high quality of life and well-being, medical professionals and caregivers have largely pessimistic perceptions. The negative view on life with LiS must be overthought and the autonomy and dignity of LiS patients prioritized. Knowledge has to be disseminated, diagnostics accelerated and technical support system development promoted. More well-designed research but also more awareness of the needs of LiS patients and their perception as individual persons is needed to enable a life with LiS that is worth living.

Understanding the Psychological Well-being of Patients With Locked-in Syndrome: A Scoping Review

Locked-in syndrome (LiS) is a neurological disorder caused by lesions affecting the ventral pons and midbrain and is characterized by loss of physical function, but with perceived consciousness intact. Despite severely limited function, previous studies have shown the quality of life (QoL) in patients to be more positive than naturally assumed by caregivers and relatives. The present review aims to synthesize the broad scientific literature focused on the psychological well-being of LiS patients. A scoping review was performed to synthesize the available evidence on the psychological well-being of LiS patients. Eligible studies included those that target individuals with LiS as the study population, evaluated psychological well-being, and explored the factors related to it. We extracted study population details, type of QoL methods, method of communication, and primary findings from the studies. We summarized the findings categorized into health-related QoL (HRQoL), global QoL, and other tools for assessing psychological status. Across the 13 eligible studies, we observed that patients with LiS had reasonable or similar psychological well-being as the standard based on HRQoL and global QoL assessment. Caregivers and healthcare professionals seem to rate the psychological QoL of LiS patients lower than patients themselves. Studies showed evidence that the longer duration of LiS is a factor that positively affects QoL, and augmentative and alternative communication tools and recovery of speech production showed positive effects as well. Studies reported a range of 27% to 68% of patients experiencing thoughts of suicide and euthanasia. The evidence shows that LiS patients had reasonable psychological well-being. There appear to be differences between patients' assessed well-being and the negative perceptions by caregivers. Response shift and adaptation to disease by patients are considered potential reasons. A sufficient moratorium period and provision of information to support patients' QoL and appropriate decision-making seems necessary.

Methodological Recommendations for Studies on the Daily Life Implementation of Implantable Communication-Brain-Computer Interfaces for Individuals With Locked-in Syndrome

Implantable brain-computer interfaces (BCIs) promise to be a viable means to restore communication in individuals with locked-in syndrome (LIS). In 2016, we presented the world-first fully implantable BCI system that uses subdural electrocorticography electrodes to record brain signals and a subcutaneous amplifier to transmit the signals to the outside world, and that enabled an individual with LIS to communicate via a tablet computer by selecting icons in spelling software. For future clinical implementation of implantable communication-BCIs, however, much work is still needed, for example, to validate these systems in daily life settings with more participants, and to improve the speed of communication. We believe the design and execution of future studies on these and other topics may benefit from the experience we have gained. Therefore, based on relevant literature and our own experiences, we here provide an overview of procedures, as well as recommendations, for recruitment, screening, inclusion, imaging, hospital admission, implantation, training, and support of participants with LIS, for studies on daily life implementation of implantable communication-BCIs. With this article, we not only aim to inform the BCI community about important topics of concern, but also hope to contribute to improved methodological standardization of implantable BCI research.

Stimulation-related modifications of evolving functional brain networks in unresponsive wakefulness

Recent advances in neurophysiological brain network analysis have demonstrated novel potential for diagnosis and prognosis of disorders of consciousness. While most progress has been achieved on the population-sample level, time-economic and easy-to-apply personalized solutions are missing. This prospective controlled study combined EEG recordings, basal stimulation, and daily behavioral assessment as applied routinely during complex early rehabilitation treatment. We investigated global characteristics of EEG-derived evolving functional brain networks during the repeated (3–6 weeks apart) evaluation of brain dynamics at rest as well as during and after multisensory stimulation in ten patients who were diagnosed with an unresponsive wakefulness syndrome (UWS). The age-corrected average clustering coefficient C* allowed to discriminate between individual patients at first (three patients) and second assessment (all patients). Clinically, only two patients changed from UWS to minimally conscious state. Of note, most patients presented with significant changes of C* due to stimulations, along with treatment, and with an increasing temporal distance to injury. These changes tended towards the levels of nine healthy controls. Our approach allowed to monitor both, short-term effects of individual therapy sessions and possibly long-term recovery. Future studies will need to assess its full potential for disease monitoring and control of individualized treatment decisions.

Locked-In Syndrome: A Systematic Review of Long-Term Management and Prognosis

Locked-in syndrome (LIS) is a neurological disorder in which there is damage to the ventral pons and caudal midbrain. An ischemic cause, such as basilar artery occlusion, can often lead to LIS. LIS has three subtypes: classical, partial, and total. There is loss of motion in the four extremities in classical LIS, loss of horizontal gaze, and aphasia. In partial LIS, the patient still has some motor function. Complete LIS has the worst outcome because patients cannot blink or have vertical gaze, thus rendering them incapable of communicating. Most cases of LIS occur due to ischemic infarcts. These patients require a great deal of physical rehabilitation to regain partial motor ability and a means to communicate. While the clinical features and pathophysiology are known, the prognosis and long-term treatment remain unknown. We conducted a systematic review using the Meta-Analysis Of Observational Studies in Epidemiology (MOOSE) protocol. We use an advanced PubMed strategy using the inclusion criteria of observational studies or clinical trials conducted in the last 20 years, written in English, and conducted on humans. We excluded systematic reviews, literature reviews, metanalysis, and studies that did not meet the outcomes of our objectives. The prognosis of LIS is not good, and most patients remain locked in, with poor quality of life, especially motor functions. Respiratory failure and depression are big comorbidities. In the acute setting, patients benefit from rapid intervention. The subacute treatment needs to manage aggressively to improve functional scores best. The long-term treatment focus is on the quality of life and managing comorbidities.

The prevalence and determinants of inappropriate sexual behaviour in people with acquired brain injury in nursing homes

AIMS

Establishing the prevalence of inappropriate sexual behaviour, concurrent challenging behaviours and the determinants of inappropriate sexual behaviour among patients with acquired brain injury ≤65 years of age in Dutch nursing homes.

DESIGN

Cross-sectional, observational study in acquired brain injury special care units spreads throughout the country.

METHODS

Nursing homes were recruited through the national expertise network for patients with severe acquired brain injury, regional brain injury teams and by searching the Internet. Patient characteristics were collected through digital questionnaires. Inappropriate sexual behaviour was assessed with the St. Andrews Sexual Behaviour Assessment, concurrent challenging behaviours with the NeuroPsychiatric Inventory-Nursing Home Version and the Cohen-Mansfield Agitation Inventory, cognition with the Mini-Mental State Examination and activities of daily living with the Disability Rating Scale. Psychotropic drug use was retrieved from the electronic prescription system. Associations between determinants and inappropriate sexual behaviour were examined using multilevel multivariate linear regression model analyses. Data collection started in June 2017 and ended in April 2019.

RESULTS

Of the 118 included patients, 38.1% had one or more inappropriate sexual behaviours. Verbal comments (30.1%) and non-contact behaviour (24.8%) were the most prevalent types of inappropriate sexual behaviour. Less severe behaviours were more common than more severe behaviours. The most frequent concurrent challenging behaviours were agitation, aggression and hyperactivity. Physical aggression was associated with more inappropriate sexual behaviour. Being married and pain were associated with less inappropriate sexual behaviour.

CONCLUSION

Inappropriate sexual behaviour is prevalent in patients with acquired brain injury ≤65 years of age residing in nursing homes.

IMPACT

Inappropriate sexual behaviour may have impact not only on the patients themselves but also on nursing staff. Insight into the magnitude, severity, course and concurrent challenging behaviours, sexuality and quality of life could give direction to the kind of interventions and education that is needed. The ultimate goal is to develop appropriate care for this vulnerable group of patients, specifically psychosocial interventions and appropriate use of psychotropic drugs.

Locked-In Syndrome: Practical Rehabilitation Management

Locked-in syndrome is a rare and devastating condition that results in tetraplegia, lower cranial nerve paralysis, and anarthria with preserved cognition, vertical gaze, and upper eyelid movements. Although acute management is much like that of any severe stroke, rehabilitation and recovery of these patients have not been previously described. Challenges relevant to this population include blood pressure management and orthostasis, timing and appropriateness of reinstating oral feeding, ventilatory support, decannulation after tracheostomy, bowel and bladder management, vestibular dysfunction, and eye care. Targeted rehabilitation of head, neck, and trunk stability to improve function, and proper fit in an appropriate wheelchair are essential to assist with mobility. Rehabilitation interventions should include a focus on distal motor control and upright tolerance training followed by balance and mobility exercises. In addition, special considerations must be given to developing early methods of communication through use of augmentative systems to call for help and express needs. These systems along with additional technology provide the basis to promote connectivity to family and friends through the use of social media and the internet. Establishment of communication, mobility, and connectivity is essential in promoting independence, autonomy, and improving quality of life. Overall, with specialized rehabilitative care and access to the proper equipment, long-term outcomes and quality of life in these patients can be favorable.

MEG Sensor Selection for Neural Speech Decoding

Direct decoding of speech from the brain is a faster alternative to current electroencephalography (EEG) speller-based brain-computer interfaces (BCI) in providing communication assistance to locked-in patients. Magnetoencephalography (MEG) has recently shown great potential as a non-invasive neuroimaging modality for neural speech decoding, owing in part to its spatial selectivity over other high-temporal resolution devices. Standard MEG systems have a large number of cryogenically cooled channels/sensors (200 - 300) encapsulated within a fixed liquid helium dewar, precluding their use as wearable BCI devices. Fortunately, recently developed optically pumped magnetometers (OPM) do not require cryogens, and have the potential to be wearable and movable making them more suitable for BCI applications. This design is also modular allowing for customized montages to include only the sensors necessary for a particular task. As the number of sensors bears a heavy influence on the cost, size, and weight of MEG systems, minimizing the number of sensors is critical for designing practical MEG-based BCIs in the future. In this study, we sought to identify an optimal set of MEG channels to decode imagined and spoken phrases from the MEG signals. Using a forward selection algorithm with a support vector machine classifier we found that nine optimally located MEG gradiometers provided higher decoding accuracy compared to using all channels. Additionally, the forward selection algorithm achieved similar performance to dimensionality reduction using a stacked-sparse-autoencoder. Analysis of spatial dynamics of speech decoding suggested that both left and right hemisphere sensors contribute to speech decoding. Sensors approximately located near Broca's area were found to be commonly contributing among the higher-ranked sensors across all subjects.

Decoding Imagined and Spoken Phrases From Non-invasive Neural (MEG) Signals

Speech production is a hierarchical mechanism involving the synchronization of the brain and the oral articulators, where the intention of linguistic concepts is transformed into meaningful sounds. Individuals with locked-in syndrome (fully paralyzed but aware) lose their motor ability completely including articulation and even eyeball movement. The neural pathway may be the only option to resume a certain level of communication for these patients. Current brain-computer interfaces (BCIs) use patients' visual and attentional correlates to build communication, resulting in a slow communication rate (a few words per minute). Direct decoding of imagined speech from the neural signals (and then driving a speech synthesizer) has the potential for a higher communication rate. In this study, we investigated the decoding of five imagined and spoken phrases from single-trial, non-invasive magnetoencephalography (MEG) signals collected from eight adult subjects. Two machine learning algorithms were used. One was an artificial neural network (ANN) with statistical features as the baseline approach. The other was convolutional neural networks (CNNs) applied on the spatial, spectral and temporal features extracted from the MEG signals. Experimental results indicated the possibility to decode imagined and spoken phrases directly from neuromagnetic signals. CNNs were found to be highly effective with an average decoding accuracy of up to 93% for the imagined and 96% for the spoken phrases.

Brain-computer interfaces for communication

Locked-in syndrome (LIS) is characterized by an inability to move or speak in the presence of intact cognition and can be caused by brainstem trauma or neuromuscular disease. Quality of life (QoL) in LIS is strongly impaired by the inability to communicate, which cannot always be remedied by traditional augmentative and alternative communication (AAC) solutions if residual muscle activity is insufficient to control the AAC device. Brain-computer interfaces (BCIs) may offer a solution by employing the person's neural signals instead of relying on muscle activity. Here, we review the latest communication BCI research using noninvasive signal acquisition approaches (electroencephalography, functional magnetic resonance imaging, functional near-infrared spectroscopy) and subdural and intracortical implanted electrodes, and we discuss current efforts to translate research knowledge into usable BCI-enabled communication solutions that aim to improve the QoL of individuals with LIS.

Prevalence and characteristics of neuropsychiatric symptoms, quality of life and psychotropics in people with acquired brain injury in long-term care

Aim

Establishing the prevalence of neuropsychiatric symptoms (NPS), quality of life and psychotropic drug use in people aged ≤65 years with acquired brain injury in nursing homes.

Design

Cross‐sectional, observational study among patients aged 18–≤65 years with acquired brain injury admitted to special care units in Dutch nursing homes.

Methods

According to the Committee on Research Involving Human Subjects in January 2017 this study did not require ethics approval. Nursing homes will be recruited through the national acquired brain injury expertise network for patients with severe brain injury, the regional brain injury teams and by searching the internet. Patient characteristics will be collected through digital questionnaires. Neuropsychiatric symptoms will be assessed with the NeuroPsychiatric Inventory‐Nursing Home version, the Cohen–Mansfield Agitation Inventory and the St. Andrews Sexual Behaviour Assessment; cognition with the Mini‐Mental State Examination, quality of life with the Quality of Life after Brain Injury Overall Scale and activities of daily living with the Disability Rating Scale. Medication will be retrieved from the electronic prescription system. Data collection commenced in 2017 and will be followed by data analysis in 2019. Reporting will be completed in 2020.

Discussion

Little is known about NPS among patients with acquired brain injury in nursing homes. In patients up to the age of 65 years, only six studies were found on prevalence rates of NPS.

Impact

Patients with severe acquired brain injury experience lifelong consequences, that have a high impact on them and their environment. Although there is increasing attention for the survival of this vulnerable group of patients, it is also important to enlarge awareness on long‐term consequences, specifically the NPS, quality of life and psychotropic drug use in acquired brain injury. Insight into the magnitude of these issues is necessary to achieve appropriate care for these patients.

Prevalence of neuropsychiatric symptoms and psychotropic drug use in patients with acquired brain injury in long-term care: a systematic review

OBJECTIVE

Little is known about the prevalence of neuropsychiatric symptoms (NPS) and psychotropic drug use (PDU) in patients below the age of 65 years with acquired brain injury (ABI) in long-term care. The objective of this study was to review the literature about the prevalence of NPS and PDU.

METHODS

A systematic literature search of English, Dutch and German articles in Pubmed, EMBASE, PsycINFO and CINAHL was performed with the use of MeSH and free-text terms.

RESULTS

Six articles met the inclusion criteria. The place of residence was mainly a nursing home and most studies were conducted in a population of patients with traumatic brain injury. Sample sizes varied from 40 to 26,472 residents and NPS were assessed with different assessment instruments. Depressive symptoms were most common with a prevalence ranging from 13.9% to 39.3%. Two studies reported PDU in which tranquillizers (59%) were the most prevalent psychotropic drugs followed by anticonvulsants (35%) and antidepressants (26-34%).

CONCLUSIONS

Patients with ABI experience lifelong consequences, regardless the cause of ABI, that have a high impact on them and their surroundings. More insight into the magnitude of NPS and PDU, through prevalence studies, is necessary to achieve suitable provision of care for these patients.

Estimated Prevalence of the Target Population for Brain-Computer Interface Neurotechnology in the Netherlands

BACKGROUND

People who suffer from paralysis have difficulties participating in society. Particularly burdensome is the locked-in syndrome (LIS). LIS patients are not able to move and speak but are cognitively healthy. They rely on assistive technology to interact with the world and may benefit from neurotechnological advances. Optimal research and design of such aids requires a well-defined target population. However, the LIS population is poorly characterized and the number of patients in this condition is unknown.

OBJECTIVE

Here we estimated and described the LIS patient population in the Netherlands to define the target population for assistive (neuro)technology.

METHODS

We asked physicians in the Netherlands if they had patients suffering from severe paralysis and communication problems in their files. Physicians responding affirmatively were asked to fill out a questionnaire on the patients' status.

RESULTS

We sent out 9570 letters to general practitioners (GPs), who reported 83 patients. After first screening, the GPs of 46 patients received the questionnaire. Based on the responses, 26 patients were classified as having LIS. Extrapolation of these numbers resulted in a prevalence of 0.73 patients per 100 000 inhabitants. Notable results from the questionnaire were the percentage of patients with neuromuscular disease (>50%) and living at home (>70%).

CONCLUSIONS

We revealed an etiologically diverse group of LIS patients. The functioning and needs of these patients were, however, similar and many relied on assistive technology. By characterizing the LIS population, our study may contribute to optimal development of assistive (neuro)technology.

The vegetative state/unresponsive wakefulness syndrome: a systematic review of prevalence studies

One of the worst outcomes of acquired brain injury is the vegetative state, recently renamed 'unresponsive wakefulness syndrome' (VS/UWS). A patient in VS/UWS shows reflexive behaviour such as spontaneous eye opening and breathing, but no signs of awareness of the self or the environment. We performed a systematic review of VS/UWS prevalence studies and assessed their reliability. Medline, Embase, the Cochrane Library, CINAHL and PsycINFO were searched in April 2013 for cross-sectional point or period prevalence studies explicitly stating the prevalence of VS/UWS due to acute causes within the general population. We additionally checked bibliographies and consulted experts in the field to obtain 'grey data' like government reports. Relevant publications underwent quality assessment and data-extraction. We retrieved 1032 papers out of which 14 met the inclusion criteria. Prevalence figures varied from 0.2 to 6.1 VS/UWS patients per 100 000 members of the population. However, the publications' methodological quality differed substantially, in particular with regards to inclusion criteria and diagnosis verification. The reliability of VS/UWS prevalence figures is poor. Methodological flaws in available prevalence studies, the fact that 5/14 of the studies predate the identification of the minimally conscious state (MCS) as a distinct entity in 2002, and insufficient verification of included cases may lead to both overestimation and underestimation of the actual number of patients in VS/UWS.

A rare sequela of acute disseminated encephalomyelitis

Acute disseminated encephalomyelitis is a demyelinating disease, typically occurring in children following a febrile infection or a vaccination. Primary and secondary immune responses contribute to inflammation and subsequent demyelination, but the exact pathogenesis is still unknown. Diagnosis of acute disseminated encephalomyelitis is strongly suggested by temporal relationship between an infection or an immunization and the onset of neurological symptoms. Biopsy is definitive. In general, the disease is self-limiting and the prognostic outcome is favorable with anti-inflammatory and immunosuppressive agents. Locked-in syndrome describes patients who are awake and conscious but have no means of producing limb, speech, or facial movements. Locked-in syndrome is a rare complication of acute disseminated encephalomyelitis. We present a case of incomplete locked-in syndrome occurring in a 34-year-old male secondary to acute disseminated encephalomyelitis. Our case is unique, as acute disseminated encephalomyelitis occurred in a 34-year-old which was poorly responsive to immunosuppression resulting in severe disability.