Sleep/Wake Modulation of Polysomnographic Patterns has Prognostic Value in Pediatric Unresponsive Wakefulness Syndrome

Scoping Review on the Diagnosis, Prognosis, and Treatment of Pediatric Disorders of Consciousness

BACKGROUND AND OBJECTIVES

Comprehensive guidelines for the diagnosis, prognosis, and treatment of disorders of consciousness (DoC) in pediatric patients have not yet been released. We aimed to summarize available evidence for DoC with >14 days duration to support the future development of guidelines for children, adolescents and young adults aged 6 months-18 years.

METHODS

This scoping review was reported based on Preferred Reporting Items for Systematic reviews and Meta-Analyses-extension for Scoping Reviews guidelines. A systematic search identified records from 4 databases: PubMed, Embase, Cochrane Library, and Web of Science. Abstracts received 3 blind reviews. Corresponding full-text articles rated as "in-scope" and reporting data not published in any other retained article (i.e., no double reporting) were identified and assigned to 5 thematic evaluating teams. Full-text articles were reviewed using a double-blind standardized form. Level of evidence was graded, and summative statements were generated.

RESULTS

On November 9, 2022, 2,167 documents had been identified; 132 articles were retained, of which 33 (25%) were published over the past 5 years. Overall, 2,161 individuals met the inclusion criteria; female patients were 527 of 1,554 (33.9%) cases included, whose sex was identifiable. Of 132 articles, 57 (43.2%) were single case reports and only 5 (3.8%) clinical trials; the level of evidence was prevalently low (80/132; 60.6%). Most studies included neurobehavioral measures (84/127; 66.1%) and neuroimaging (81/127; 63.8%); 59 (46.5%) were mainly related to diagnosis, 56 (44.1%) to prognosis, and 44 (34.6%) to treatment. Most frequently used neurobehavioral tools included the Coma Recovery Scale-Revised, Coma/Near-Coma Scale, Level of Cognitive Functioning Assessment Scale, and Post-Acute Level of Consciousness scale. EEG, event-related potentials, structural CT, and MRI were the most frequently used instrumental techniques. In 29/53 (54.7%) cases, DoC improvement was observed, which was associated with treatment with amantadine.

DISCUSSION

The literature on pediatric DoCs is mainly observational, and clinical details are either inconsistently presented or absent. Conclusions drawn from many studies convey insubstantial evidence and have limited validity and low potential for translation in clinical practice. Despite these limitations, our work summarizes the extant literature and constitutes a base for future guidelines related to the diagnosis, prognosis, and treatment of pediatric DoC.

Neuroimaging and neurophysiological diagnosis and prognosis in paediatric disorders of consciousness

The diagnosis and prognosis of disorders of consciousness (DOC) such as coma, unresponsive wakefulness syndrome, or minimally conscious state are especially challenging in children. In some paediatric patients with severe acquired brain injury, medical comorbidities or developmental factors may obscure the detection of signs of consciousness via clinical assessments, thus leading to misdiagnosis. To circumvent these biases, patients benefit from multimodal assessments that combine behavioural, neuroimaging, and neurophysiological measures. In this review, we provide original data for such diagnostic procedures in children. Neuroimaging is largely underdocumented in children and most neurophysiological research consists of a cohort study design aimed at providing prognostic markers for clinical outcomes. The scarcity of available data on complementary diagnostic approaches in children makes it difficult to establish clear paediatric guidelines. Although there is preliminary evidence for the applicability of paradigms involving event-related potentials as support for diagnosis in children, more well-designed studies need to be conducted to promote evidence-based practices in paediatric DOC.

Novel qEEG Biomarker to Distinguish Anti-NMDAR Encephalitis From Other Types of Autoimmune Encephalitis

Objective

To establish the diagnostic biomarker of electroencephalogram (EEG) to distinguish between anti-N-methyl-d-aspartate receptor encephalitis (NMDARE) and other types of autoimmune encephalitis (other AEs).

Methods

We reviewed the clinical records of 90 patients with acute encephalitis who were treated in our institution between January 2014 and October 2020. We enrolled the patients who fulfilled the diagnostic criteria for possible AE (pAE) defined by Graus et al. (pAE criteria) and then classified into definite NMDARE and other AEs. We investigated the main syndrome and analyzed all admission EEGs using EEG power value (PV). Statistical significance was tested using the Mann–Whitney U test or Fisher’s exact test.

Results

Twenty-five patients fulfilled the pAE criteria and were classified into 9 with definite NMDARE (median age: 21 years; 8 women) and 12 with other AEs (median age: 37.5 years; 6 women). Four were eventually excluded. Speech dysfunction (9/9 vs. 4/12, p = 0.005) and movement disorders (6/9 vs. 1/12, p = 0.016) were more frequent in NMDARE than in other AEs. The PV analyses revealed the novel quantitative EEG (qEEG) index, namely, fast slow ratio (FSR) (PV of total beta/PV of total theta + delta). The median FSR (0.139 vs. 0.029, p = 0.004) was higher for NMDARE than other AEs, and the receiver operating characteristic curve area of FSR was 0.86 (95% CI 0.70–1.00). A cutoff value of 0.047 yielded a specificity of 0.75 and a sensitivity of 1.00. Focusing on patients who did not meet the “probable NMDARE criteria” in Graus 2016 (proNMDARE criteria) (n = 10), the pretest probability of NMDAR antibody test was 0.30 (3/10), which increased in patients with an FSR greater than the cutoff (n = 5) to 0.60 (3/5).

Conclusions

The NMDARE group highlighted speech dysfunction and movement disorders, and a novel qEEG index FSR accurately distinguished the NMDARE patients from other AEs. The FSR is a promising diagnostic marker for NMDARE that indicates the positive results of NMDAR antibodies in patients with AE when combined with the proNMDARE criteria.

Brain Data in Pediatric Disorders of Consciousness: Special Considerations

SUMMARY

The diagnosis and management of disorders of consciousness in children continue to present a clinical, research, and ethical challenge. Though the practice guidelines for diagnosis and management of disorders of consciousness in adults are supported by decades of empirical and pragmatic evidence, similar guidelines for infants and children are lacking. The maturing conscious experience and the limited behavioral repertoire to report consciousness in this age group restrict extrapolation from the adult literature. Equally challenging is the process of heightened structural and functional neuroplasticity in the developing brain, which adds a layer of complexity to the investigation of the neural correlates of consciousness in infants and children. This review discusses the clinical assessment of pediatric disorders of consciousness and delineates the diagnostic and prognostic utility of neurophysiological and neuroimaging correlates of consciousness. The potential relevance of these correlates for the developing brain based on existing theoretical models of consciousness in adults is outlined.

EEG Assessment in Patients With Disorders of Consciousness: Aims, Advantages, Limits, and Pitfalls

This study presents a brief review of literature exploring simple EEG-polygraphic examinations and procedures that can be carried out at a patient's bedside. These include EEG with a common electrode array and sleep evaluation. The review briefly discusses more complex analytical techniques, such as the application of advanced EEG signal processing methods developed by our research group, to define what type of consistent markers are suitable for clinical use or to better understand complex patient conditions. These advanced analytical techniques aim to detect relevant EEG-based markers that could be useful in evaluating patients and predicting outcomes. These data could contribute to future developments in research.

Parametric Description of EEG Profiles for Assessment of Sleep Architecture in Disorders of Consciousness

We propose a fully parametric approach to the assessment of sleep architecture, based upon the classical electroencephalographic criteria, applicable also to the recordings of patients with disorders of consciousness (DOC). Sleep spindles and slow waves are automatically detected from the matching pursuit decomposition of overnight EEG recordings. Their evolution can be presented in the form of EEG profiles, yielding a continuous description of sleep architecture, compatible with the classical criteria used in sleep staging. We propose assessment of these EEG profiles by five parameters, which can be combined by a linear classifier, assessing the quality of sleep architecture. Proposed methodology is evaluated on 59 overnight EEG recordings from 19 patients from a hospital for children with severe brain damage, in relation to their behavioral diagnosis according to the Coma Recovery Scale-Revised. Presented results indicate robustness of the proposed approach, which may serve as a valuable aid in diagnosis of DOC patients. Complete software environment for computing and presentation of EEG profiles is freely available from http://svarog.pl .

International survey on diagnostic and prognostic procedures in pediatric disorders of consciousness

AIMS

1. to investigate diagnostic and prognostic procedures routinely used by international professionals to assess children with disorders of consciousness (DoC); 2. to explore use and availability of internal and national guidelines for pediatric DoC; 3. to identify international differences in diagnostic/prognostic protocols.

METHODS

The International Brain Injury Association DoC Special Interest Group emailed a survey link to 43,469 professionals. The survey included questions on diagnostic/prognostic procedures and guidelines for children with DoC.

RESULTS

Data on 82 respondents [(50% physicians) primarily from Europe (43.9%)and North America (37.8%)] were analyzed. Common diagnostic tools included the Glasgow Coma Scale for clinical assessment (94%), the Coma Recovery Scale-Revised for outcome measurement (57%), and cerebral MRI (94%). Clinical features used most frequently to inform prognosis varied with patient age. Few respondents used national (28%) admission protocols for children with DoC, and most were unaware of published national guidelines for diagnostic (72%) and prognostic (85%) procedures. Compared to North American respondents, more European respondents were physicians and used neurophysiological data for prognosis.

CONCLUSIONS

This international survey provides useful information about diagnostic and prognostic procedures currently used for children with DoC and highlights the need for guidelines to promote best practices for diagnosis/prognosis in pediatric DoC.

Disordered Consciousness or Disordered Wakefulness? The Importance of Prolonged Polysomnography for the Diagnosis, Drug Therapy, and Rehabilitation of an Unresponsive Patient With Brain Injury

ABSTRACT

Disorders of consciousness may follow brain injury, due to impairments of wakefulness and/or awareness. Polysomnography can identify elements that may be ascribed to impairments of specific neuroanatomical areas. Recognizing which impairments affect each patient is crucial for diagnosis, prognosis, and to select an appropriate therapy. We present a pediatric case of insufficient wakefulness in a patient with severe disability following a pilocytic astrocytoma. Polysomnography was crucial for diagnosis, as it detected a well-structured pattern with daytime sleep initiations in the REM sleep phase. Treatment with modafinil was successful, as confirmed by polysomnography, leading to partial recovery of the patient's consciousness and communication ability. We suggest that polysomnography is a useful diagnostic tool to direct the pharmacotherapy and rehabilitation of states of reduced consciousness.