The Dilemma of Hydrocephalus in Prolonged Disorders of Consciousness

Classifying disorders of consciousness using a novel dual-level and dual-modal graph learning model

BACKGROUND

Disorders of consciousness (DoC) are a group of conditions that affect the level of awareness and communication in patients. While neuroimaging techniques can provide useful information about the brain structure and function in these patients, most existing methods rely on a single modality for analysis and rarely account for brain injury. To address these limitations, we propose a novel method that integrates two neuroimaging modalities, functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI), to enhance the classification of subjects into different states of consciousness.

METHOD AND RESULTS

The main contributions of our work are threefold: first, after constructing a dual-model individual graph using functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI), we introduce a brain injury mask mechanism that consolidates damaged brain regions into a single graph node, enhancing the modeling of brain injuries and reducing deformation effects. Second, to address over-smoothing, we construct a dual-level graph that dynamically construct a population-level graph with node features from individual graphs, to promote the clustering of similar subjects while distinguishing dissimilar ones. Finally, we employ a subgraph exploration model with task-fMRI data to validate the interpretability of our model, confirming that the selected brain regions are task-relevant in cognition. Our experimental results on data from 89 healthy participants and 204 patients with DoC from Huashan Hospital, Fudan University, demonstrate that our method achieves high accuracy in classifying patients into unresponsive wakefulness syndrome (UWS), minimally conscious state (MCS), or normal conscious state, outperforming current state-of-the-art methods. The explainability results of our method identified a subset of brain regions that are important for consciousness, such as the default mode network, the salience network, the dorsal attention network, and the visual network. Our method also revealed the relationship between brain networks and language processing in consciousness, and showed that language-related subgraphs can distinguish MCS from UWS patients.

CONCLUSION

We proposed a novel graph learning method for classifying DoC based on fMRI and DTI data, introducing a brain injury mask mechanism to effectively handle damaged brains. The classification results demonstrate the effectiveness of our method in distinguishing subjects across different states of consciousness, while the explainability results identify key brain regions relevant to this classification. Our study provides new evidence for the role of brain networks and language processing in consciousness, with potential implications for improving the diagnosis and prognosis of patients with DoC.

Analysis of Factors Related to the Efficacy of Consciousness-Regaining Therapy for Prolonged Disorder of Consciousness: A Retrospective Cohort Study

OBJECTIVE

To analyze the factors related to the efficacy of consciousness-regaining therapy (CRT) for prolonged disorder of consciousness.

METHODS

A retrospective analysis was conducted on the case data of 114 patients with prolonged disorder of consciousness (pDOC) admitted to the Department of Functional Neurosurgery of Tianjin Huanhu Hospital from January 2019 to January 2022 to explore the relevant factors that affect the efficacy of CRT for pDOC. Next, basic information on the cases, data on pDOC disease assessment, CRT methods, and efficacy evaluation were collected.

RESULTS

These 114 patients were grouped, and a comparative analysis was done based on the efficacy at the end of treatment. Of these, 61 cases were allotted to the ineffective group and 53 cases to the effective group. There was a lack of statistical difference (P > 0.05) between the 2 groups based on gender, age, etiology, acute cerebral herniation, emergency craniotomy surgery, emergency decompressive craniectomy, time from onset to start of CRT, and CRT duration (P > 0.05). However, secondary hydrocephalus, CRT methods, JFK Coma Recovery Scale-Revised grading before treatment, and extended Glasgow Outcome Scale score at six months after treatment were found to be statistically different. The results of binary logistic regression analysis showed that the type of therapy (OR = 0.169, 95% CI: 0.057-0.508) affected the efficacy of CRT (P < 0.05).

CONCLUSIONS

Personalized awakening therapy using various invasive CRT methods could improve the efficacy of therapy for pDOC compared with noninvasive therapy.

Medical, Neurologic, and Neuromusculoskeletal Complications

For patients with disorders of consciousness (DoC), treating the medical, neurologic, and neuromuscular complications not only stabilizes their medical disturbances, but minimizes confounding factors that may obscure the ability to accurately identify the level of consciousness and increase the chance of patients' neurologic and functional recovery. Lack of reliable communication and low-level function of patients with DoC make it challenging to diagnose some of the complications. Skilled clinical observation will be imperative to appropriately care for the patients.

Prognosis and enhancement of recovery in disorders of consciousness

Disorders of consciousness after severe brain injury encompass conditions of coma, vegetative state/unresponsive wakefulness syndrome, and minimally conscious state. DoC clinical presentation pose perplexing challenges to medical professionals, researchers, and families alike. The outcome is uncertain in the first weeks to months after a brain injury, with families and medical providers often making important decisions that require certainty. Prognostication for individuals with these conditions has been the subject of intense scientific investigation that continues to strive for valid prognostic indicators and algorithms for predicting recovery of consciousness. This manuscript aims to provide an overview of the current clinical landscape surrounding prognosis and optimizing recovery in DoC and the current and future research that could improve prognostic accuracy after severe brain injury. Improved understanding of these factors will aid healthcare professionals in providing optimal care, fostering hope, and advocating for ethical practices in the management of individuals with DoC.

Common Data Elements for Disorders of Consciousness: Recommendations from the Working Group on Neuroimaging

BACKGROUND

Over the past 5 decades, advances in neuroimaging have yielded insights into the pathophysiologic mechanisms that cause disorders of consciousness (DoC) in patients with severe brain injuries. Structural, functional, metabolic, and perfusion imaging studies have revealed specific neuroanatomic regions, such as the brainstem tegmentum, thalamus, posterior cingulate cortex, medial prefrontal cortex, and occipital cortex, where lesions correlate with the current or future state of consciousness. Advanced imaging modalities, such as diffusion tensor imaging, resting-state functional magnetic resonance imaging (fMRI), and task-based fMRI, have been used to improve the accuracy of diagnosis and long-term prognosis, culminating in the endorsement of fMRI for the clinical evaluation of patients with DoC in the 2018 US (task-based fMRI) and 2020 European (task-based and resting-state fMRI) guidelines. As diverse neuroimaging techniques are increasingly used for patients with DoC in research and clinical settings, the need for a standardized approach to reporting results is clear. The success of future multicenter collaborations and international trials fundamentally depends on the implementation of a shared nomenclature and infrastructure.

METHODS

To address this need, the Neurocritical Care Society's Curing Coma Campaign convened an international panel of DoC neuroimaging experts to propose common data elements (CDEs) for data collection and reporting in this field.

RESULTS

We report the recommendations of this CDE development panel and disseminate CDEs to be used in neuroimaging studies of patients with DoC.

CONCLUSIONS

These CDEs will support progress in the field of DoC neuroimaging and facilitate international collaboration.

A New Clinical Protocol for a Timely Diagnosis and Treatment of Hydrocephalus in Patients with Severe Acquired Brain Injury

BACKGROUND

Secondary hydrocephalus is a well-known complication of severe acquired brain injuries (sABIs) often diagnosed during inpatient rehabilitation. Currently, there is no gold standard for its detection. Therefore, we designed a novel clinical diagnostic protocol that integrates clinical, functional, biochemical and neuroradiological assessments to improve the accuracy of its diagnosis in patients with sABIs.

METHODS

This prospective cohort study will be conducted in a tertiary referral rehabilitation center in Italy. A historical cohort of patients will be compared with a prospective cohort undergoing the new clinical diagnostic protocol.

EXPECTED RESULTS

The expected results include an increase in the proportion of diagnosed cases, a reduced incidence of clinical complications, an increase in the rehabilitative outcomes at discharge, a significant reduction in the length of hospital stay, and useful information about the diagnostic and prognostic value of the neuroradiological characteristics.

CONCLUSION

We expect that this clinical diagnostic protocol will result in a more appropriate assessment and timely treatment of secondary hydrocephalus in patients with sABIs, with the ultimate goal of improving their prognosis. In addition, it could be adopted by other rehabilitation centers to improve hydrocephalus diagnosis and treatment, thereby reducing the length of hospital stay and accelerating recovery with benefits for both patients and hospitals.

Towards modern post-coma care based on neuroscientific evidence

Background

Understanding the mechanisms underlying human consciousness is pivotal to improve the prognostication and treatment of severely brain-injured patients. Consciousness remains an elusive concept and the identification of its neural correlates is an active subject of research, however recent neuroscientific advances have allowed scientists to better characterize disorders of consciousness. These breakthroughs question the historical nomenclature and our current management of post-comatose patients.

Method

This review examines the contribution of consciousness neurosciences to the current clinical management of severe brain injury. It investigates the major impact of consciousness disorders on healthcare systems, the scientific frameworks employed to identify their neural correlates and how evidence-based data from neuroimaging research have reshaped the landscape of post-coma care in recent years.

Results

Our increased ability to detect behavioral and neurophysiological signatures of consciousness has led to significant changes in taxonomy and clinical practice. We advocate for a multimodal framework for the management of severely brain-injured patients based on precision medicine and evidence-based decisions, integrating epidemiology, health economics and neuroethics.

Conclusions

Major progress in brain imaging and clinical assessment have opened the door to a new era of post-coma care based on standardized neuroscientific evidence. We highlight its implications in clinical applications and call for improved collaborations between researchers and clinicians to better translate findings to the bedside.

Experiences of family caregivers of patients with post-traumatic hydrocephalus from hospital to home: a qualitative study

Background

Post-traumatic hydrocephalus (PTH) is a complication of traumatic brain injury (TBI) that requires treatment and postoperative care. The shunt is one of the main treatments for PTH, which presents with dysfunction and infection. Considering brain injury, hydrocephalus shunt malfunction, and infection, family caregivers need to be responsible for caring for PTH patients, recognizing shunt malfunction and infection, and managing those patients accordingly from hospital to home. Understanding the experiences and needs of caregivers is beneficial for knowing their competency and quality of health care, ameliorating and ensuring future transition care. The study aimed to explore the feelings, experiences, and needs of family caregivers when caring for patients with TBI, PTH and shunts.

Methods

This was exploratory research of a purposive sample of 12 family caregivers of adult patients with TBI, PTH and shunts in five neurosurgery departments at a general hospital in Zhengzhou, Henan Province, China, using a semi-structured interview method. Data were collected from October 2021 to March 2022 before being analyzed by content analysis methods.

Results

Caregivers required professional and social knowledge and support in the areas of TBI, PTH and shunts, caregiving interventions, psychological care needs, and health insurance, just as caregivers do, but unlike other general caregivers, care for patients with TBI, PTH, and shunt is fraught with uncertainty and the need to manage shunt setting, and caregivers often experience 'complex emotional reaction' during the transitional period, where care needs and complex emotions may lead to a lack of caregiver confidence, which in turn may affect caregiving behaviors, and experiences that affect care may be mediated through caregiving confidence. The perceived availability of resources, particularly those that are still available to them when they return home, has a significant impact on participants' emotional response and sense of confidence.

Conclusions

The emotional response and the impact of stressor caregivers after TBI, PTH, and shunt was important, and sometimes confidence in care appeared to be an intermediate and useful factor that needed to be considered as health professionals prepared to develop care resources on how to manage and empower patients with TBI, PTH, and shunt. Meanwhile, there may be gaps and inequities in supportive care for patients diagnosed with TBI, PTH, and shunt in China.

Therapies to Restore Consciousness in Patients with Severe Brain Injuries: A Gap Analysis and Future Directions

Background/Objective

For patients with disorders of consciousness (DoC) and their families, the search for new therapies has been a source of hope and frustration. Almost all clinical trials in patients with DoC have been limited by small sample sizes, lack of placebo groups, and use of heterogeneous outcome measures. As a result, few therapies have strong evidence to support their use; amantadine is the only therapy recommended by current clinical guidelines, specifically for patients with DoC caused by severe traumatic brain injury. To foster and advance development of consciousness-promoting therapies for patients with DoC, the Curing Coma Campaign convened a Coma Science Work Group to perform a gap analysis.

Methods

We consider five classes of therapies: (1) pharmacologic; (2) electromagnetic; (3) mechanical; (4) sensory; and (5) regenerative. For each class of therapy, we summarize the state of the science, identify gaps in knowledge, and suggest future directions for therapy development.

Results

Knowledge gaps in all five therapeutic classes can be attributed to the lack of: (1) a unifying conceptual framework for evaluating therapeutic mechanisms of action; (2) large-scale randomized controlled trials; and (3) pharmacodynamic biomarkers that measure subclinical therapeutic effects in early-phase trials. To address these gaps, we propose a precision medicine approach in which clinical trials selectively enroll patients based upon their physiological receptivity to targeted therapies, and therapeutic effects are measured by complementary behavioral, neuroimaging, and electrophysiologic endpoints.

Conclusions

This personalized approach can be realized through rigorous clinical trial design and international collaboration, both of which will be essential for advancing the development of new therapies and ultimately improving the lives of patients with DoC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-021-01227-y.

A Precision Medicine Framework for Classifying Patients with Disorders of Consciousness: Advanced Classification of Consciousness Endotypes (ACCESS)

BACKGROUND

Consciousness in patients with brain injury is traditionally assessed based on semiological evaluation at the bedside. This classification is limited because of low granularity, ill-defined and rigid nomenclatures incompatible with the highly fluctuating nature of consciousness, failure to identify specific brain states like cognitive motor dissociation, and neglect for underlying biological mechanisms. Here, the authors present a pragmatic framework based on consciousness endotypes that combines clinical phenomenology with all essential physiological and biological data, emphasizing recovery trajectories, therapeutic potentials and clinical feasibility.

METHODS

The Neurocritical Care Society's Curing Coma Campaign identified an international group of experts who convened in a series of online meetings between May and November 2020 to discuss and propose a novel framework for classifying consciousness.

RESULTS

The expert group proposes Advanced Classification of Consciousness Endotypes (ACCESS), a tiered multidimensional framework reflecting increasing complexity and an aspiration to consider emerging and future approaches. Tier 1 is based on clinical phenotypes and structural imaging. Tier 2 adds functional measures including EEG, PET and functional MRI, that can be summarized using the Arousal, Volition, Cognition and Mechanisms (AVCM) score (where "Volition" signifies volitional motor responses). Finally, Tier 3 reflects dynamic changes over time with a (theoretically infinite) number of physiologically distinct states to outline consciousness recovery and identify opportunities for therapeutic interventions.

CONCLUSIONS

Whereas Tiers 1 and 2 propose an approach for low-resource settings and state-of-the-art expertise at leading academic centers, respectively, Tier 3 is a visionary multidimensional consciousness paradigm driven by continuous incorporation of new knowledge while addressing the Curing Coma Campaign's aspirational goals.