Posterior fossa tumors and their impact on sleep and ventilatory control: A clinical perspective

The integrated brain network that controls respiration

Respiration is a brain function on which our lives essentially depend. Control of respiration ensures that the frequency and depth of breathing adapt continuously to metabolic needs. In addition, the respiratory control network of the brain has to organize muscular synergies that integrate ventilation with posture and body movement. Finally, respiration is coupled to cardiovascular function and emotion. Here, we argue that the brain can handle this all by integrating a brainstem central pattern generator circuit in a larger network that also comprises the cerebellum. Although currently not generally recognized as a respiratory control center, the cerebellum is well known for its coordinating and modulating role in motor behavior, as well as for its role in the autonomic nervous system. In this review, we discuss the role of brain regions involved in the control of respiration, and their anatomical and functional interactions. We discuss how sensory feedback can result in adaptation of respiration, and how these mechanisms can be compromised by various neurological and psychological disorders. Finally, we demonstrate how the respiratory pattern generators are part of a larger and integrated network of respiratory brain regions.

Lesions causing central sleep apnea localize to one common brain network

Objectives

To characterize the specific brain regions for central sleep apnea (CSA) and identify its functional connectivity network.

Methods

We performed a literature search and identified 27 brain injuries causing CSA. We used a recently validated methodology termed “lesion network mapping” to identify the functional brain network subtending the pathophysiology of CSA. Two separate statistical approaches, the two-sample t-test and the Liebermeister test, were used to evaluate the specificity of this network for CSA through a comparison of our results with those of two other neurological syndromes. An additional independent cohort of six CSA cases was used to assess reproducibility.

Results

Our results showed that, despite lesions causing CSA being heterogeneous for brain localization, they share a common brain network defined by connectivity to the middle cingulate gyrus and bilateral cerebellar posterior lobes. This CSA-associated connectivity pattern was unique when compared with lesions causing the other two neurological syndromes. The CAS-specific regions were replicated by the additional independent cohort of six CSA cases. Finally, we found that all lesions causing CSA aligned well with the network defined by connectivity to the cingulate gyrus and bilateral cerebellar posterior lobes.

Conclusion

Our results suggest that brain injuries responsible for CSA are part of a common brain network defined by connectivity to the middle cingulate gyrus and bilateral cerebellar posterior lobes, lending insight into the neuroanatomical substrate of CSA.

Prevalence of Sleep Disturbances in Pediatric Cancer Patients and Their Diagnosis and Management

Sleep disturbances represent an understudied yet common source of distress among pediatric cancer patients and survivors, with deleterious effects on quality of life. Sleep issues stem from multiple risk factors, yet individual contributors are difficult to isolate, consequently impeding the identification of targets for intervention. In many pediatric cancer patients, disrupted sleep and its negative impact on quality of life continue into adulthood and may affect various functional domains. This literature review highlights the types and prevalence of sleep disturbances in pediatric cancer patients during active treatment and through survivorship. Potential etiological and risk factors for disturbed sleep are summarized, including the effects of cancer and its treatment, psychosocial and family factors, as well as individual-patient aspects, such as genetics, mood and coping skills. While existing assessment and management strategies are reviewed, the literature is incomplete, and significant gaps emerge in our understanding of sleep disturbances in pediatric cancer patients and survivors. The review concludes with recommendations of areas where further research is needed. The aims of this review include increasing clinicians' awareness of sleep disturbances as a significant source of poor quality of life in pediatric cancer patients and survivors and directing researchers to gaps in our understanding of sleep disturbances in pediatric cancer patients and survivors.

Brain tumours result in sleep disorders in children and adolescents

BACKGROUND AND OBJECTIVES

Sleep disturbances are frequently reported in children with brain tumours. The objective of our cross-sectional study was to systematically examine sleep in these children. We hypothesised that children with tumours involving the sleep-wake-regulatory areas have an altered sleep-wake-regulation.

METHODS

Sixty-one patients aged 0-18 years and with a diagnosis of a primary brain or cervical medullary tumour were included. They were categorised based upon tumour location into two groups - those affecting the sleep-wake regulatory regions, i.e. brain stem, basal forebrain, hypothalamus, thalamus, and posterior fossa compressing the brain stem and those that did not. Sleep history, questionnaire surveys, polysomnography, and multiple sleep latency test were used, as indicated clinically. Surveys included Pediatric Daytime Sleepiness Scale, Children's Sleep Habits Questionnaire, Strengths and Difficulties Questionnaire, and Pediatric Quality of Life Inventory, Multidimensional Fatigue Scale and Generic Core Scale.

RESULTS

Patients with tumours involving the sleep-wake regulatory areas were sleepier/more fatigued (p = 0.03). Sleep apnoea was observed in 86% of all the patients and comorbid narcolepsy in 8%, without group differences (p ≥ 0.12). Patients with tumours involving the sleep-wake-regulatory areas had more emotional problems (p = 0.04), were more affected by mental health problems (p < 0.001), and had poorer quality of life (p ≤ 0.03).

CONCLUSIONS

Many children with brain tumours suffer from disturbed sleep, poor mental health, and low quality of life. We recommend that systematic sleep evaluation is included in their routine care along with psychological and social support.

Functional Convergence of Autonomic and Sensorimotor Processing in the Lateral Cerebellum

The cerebellum is involved in the control of voluntary and autonomic rhythmic behaviors, yet it is unclear to what extent it coordinates these in concert. We studied Purkinje cell activity during unperturbed and perturbed respiration in lobules simplex, crus 1, and crus 2. During unperturbed (eupneic) respiration, complex spike and simple spike activity encode the phase of ongoing sensorimotor processing. In contrast, when the respiratory cycle is perturbed by whisker stimulation, mice concomitantly protract their whiskers and advance their inspiration in a phase-dependent manner, preceded by increased simple spike activity. This phase advancement of respiration in response to whisker stimulation can be mimicked by optogenetic stimulation of Purkinje cells and prevented by cell-specific genetic modification of their AMPA receptors, hampering increased simple spike firing. Thus, the impact of Purkinje cell activity on respiratory control is context and phase dependent, highlighting a coordinating role for the cerebellar hemispheres in aligning autonomic and sensorimotor behaviors.

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During unperturbed respiration, Purkinje cells signal ongoing sensorimotor processing

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After perturbation, mice advance their simple spike activity, whisking, and inspiration

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Altering simple spike activity affects the impact of whisker stimulation on respiration

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Cerebellar coordination of autonomic and sensorimotor behaviors is context dependent

Anesthetic Management of Patients Undergoing Open Suboccipital Surgery

The posterior cranial fossa with its complex anatomy houses key pathways regulating consciousness, autonomic functions, motor and sensory pathways, and cerebellar centers regulating balance and gait. The most common posterior fossa pathologies for which neurosurgical intervention may be necessary include cerebellopontine angle tumors, aneurysms, and metastatic lesions. The posterior cranial fossa can be accessed from variations of the supine, lateral, park-bench, prone, and sitting positions. Notable complications from positioning include venous air embolism, paradoxic air embolism, tension pneumocephalus, nerve injuries, quadriplegia, and macroglossia. An interdisciplinary approach with careful planning, discussion, and clinical management contributes to improved outcomes and reduced complications.

Predicting postoperative tracheostomy requirement in children undergoing surgery for posterior fossa tumors

PURPOSE

Posterior fossa tumor (PFT) resection can be associated with postoperative respiratory failure. We aimed to identify risk factors predicting tracheostomy dependence in children after PFT resection.

METHODS

Retrospective chart review of all children undergoing PFT resection from April 2007 to May 2017 at our institution was performed.

RESULTS

A total of 197 patients were included; 12 (6.1%) required tracheostomy placement at a mean 69.1 days postoperatively (SD 112.7, range 7-388). Patients requiring tracheostomy were younger (3.4 vs. 6.8 years, p < 0.01), more likely to have postoperative dysphagia (91.7% vs. 17.3%, p < 0.01), and more likely to have an ependymoma (41.7% vs. 15.1%, p < 0.01) or astrocytoma (25.0% vs. 8.1%, p < 0.01). Patients with eventual tracheostomy were less likely extubated immediately postoperatively (45.5% vs. 79.6%, p < 0.01), had longer intubation duration postoperatively (5.7 vs. 0.5 days, p < 0.01), and had higher rates of reintubation within 48 h (63.6% vs. 1.3%, p < 0.01). Patients requiring tracheostomy had longer hospital length of stay (45.8 vs. 15.3 days, p < 0.01) and ICU stay postoperatively (13.5 vs. 2.1 days, p < 0.01). Of those requiring tracheostomy, three (25.0%) were decannulated by 1 year postoperatively. Decannulation rates did not vary by age (p < 0.47), extubation failure (p < 0.24), duration of intubation (p < 0.10), tumor histology (p < 0.23), or tumor grade (p < 0.13).

CONCLUSION

Lower cranial neuropathy following PFT resection is common. Identifying risk factors correlated with need for tracheostomy can help identify patients who may benefit from early tracheostomy, reducing prolonged intubation trauma, time on mechanical ventilation, and length of stay.

Effects of ipratropium bromide on the occurrence of postoperative respiratory complications in craniectomy patients with COPD: A nationwide multicenter retrospective study

INTRODUCTION

Postoperative pulmonary complications (PPCs) are common and associated with increased morbidity, mortality, and medical cost. They are gaining increasing concerns among patients receiving neurological surgery. Chronic obstructive pulmonary disease (COPD) affect a large section of whole population and is also one of the risk factors of PPCs in the perioperative setting. Ipratropium bromide is the inhalation solution for the treatment of COPD. Studies showed the perioperative nebulization of ipratropium bromide could increase the lung function and decrease the incidence of postoperative pneumonia in COPD patients underwent thoracic surgery. The purpose of this study is to investigate the effect of perioperative nebulization of ipratropium bromide on PPCs in COPD patients underwent neurosurgical surgery.

METHODS AND ANALYSIS

This study is a multicenter retrospective study in China. Patients who meet the inclusion/exclusion criteria are selected from 7 neurosurgical centers in China. According to whether ipratropium bromide is used in perioperative period, the patients are divided into exposure group and control group. The primary outcome is the incidence of postoperative pneumonia. Secondary outcomes are unplanned intubation, postoperative mechanical ventilation ≥ 48 hours, respiratory failure, atelectasis, death, and length of stay.

ETHICS AND DISSEMINATION

This study was approved by the ethics committee (EC) of the School of Public Health, Fudan University, Shanghai, China. Waived by the ethics committee, no written consent form was obtained since we used the registry data. The study results will be communicated via publication.

TRIAL REGISTRATION NUMBER

ChiCTR1900022552.

Brief report: Metabolic acidosis in newborn infants following maternal use of acetazolamide during pregnancy

 The information regarding fetal effects of acetazolamide use during pregnancy and lactation is sparse. We report the clinical and pharmacodynamic characteristics of maternal acetazolamide use and the timing of its effects on acid-base balance in three cases who presented with metabolic acidosis in the newborn period. We found that the infants' clinical status soon after birth was inconsistently correlated with maternal drug dose and concentrations of medication in maternal serum. However, there was low transfer of the drug in breast milk and its use did not affect clinical symptomatology. We also present a review of literature on this subject to help consolidate our current knowledge on this topic.

ECG derived Cheyne-Stokes respiration and periodic breathing are associated with cardiorespiratory arrest in intensive care unit patients

BACKGROUND

Cheyne-Stokes respiration and periodic breathing (CSRPB) have not been studied sufficiently in the intensive care unit setting (ICU).

OBJECTIVES

To determine whether CSRPB is associated with adverse outcomes in ICU patients.

METHODS

The ICU group was divided into quartiles by CSRPB (86 patients in quartile 1 had the least CSRPB and 85 patients in quartile 4 had the most CSRPB). Adverse outcomes (emergent intubation, cardiorespiratory arrest, inpatient mortality and the composite of all) were compared between patients with most CSRPB (quartile 4) and those with least CSRPB (quartile 1).

RESULTS

ICU patients in quartile 4 had a higher proportion of cardiorespiratory arrests (5% versus 0%, (p=.042), and more adverse events over all (19% versus 8%, p=.041) as compared to patients in quartile 1.

CONCLUSIONS

CSRPB can be measured in the ICU and it's severity is associated with adverse outcomes in critically ill patients.

Epidemiology and short-term surgical outcomes of children presenting with cerebellar tumors

OBJECTIVE

Posterior fossa tumor surgery in children poses a significant morbidity and mortality. Large multi-institutional datasets characterizing the epidemiology and morbidity of children undergoing posterior fossa tumor surgery are lacking. The objective of this study is to describe the epidemiology and short term surgical outcomes of children presenting with cerebellar tumors.

PATIENTS AND METHODS

A retrospective review of the Kids Inpatient Database (KID) for all hospital discharges in 2012 with a diagnosis of cerebellar tumor (ICD-9 diagnosis code 191.6) was performed and filtered with the ICD-9 procedure code 01.59 (other excision or destruction of lesion or tissue of brain). All children in this cohort were compared with all other children discharged without cerebellar tumors recorded in the database.

RESULTS

A total of 461 (1.7/10,000 discharges) children with a diagnosis of cerebellar tumor who had surgical resection of their tumor were discharged during 2012. Compared with the control group, children undergoing cerebellar tumor excision had an increased length of hospital stay (8 vs. 2 days, p < 0.001), discharge to skilled nursing home facilities/home health care (12% vs. 4.6%, p < 0.001), increased hospital charges ($125,747 vs. $14,018, p < 0.001), and mortality (0.87% vs. 0.3%, p = 0.028). Hydrocephalus was treated via external ventriculostomy (EVD) (31%, n = 143) and/or shunt (17%, n = 78), and patients who required an EVD were more likely to receive a shunt (56% vs. 26%, p < 0.001). Mechanical ventilation (7.8%) and ultimately tracheostomy (1.5%) was necessary in few children following cerebellar tumor excision.

CONCLUSIONS

As expected, surgical treatment of cerebellar tumors in children may pose significant morbidity. Our exploratory study identifies these patients as a potential high-risk cohort in the United States that may require intensive airway management, treatment of hydrocephalus and long-term nursing support.

Spectrum of sleep disorders in a patient with spinocerebellar ataxia 13

We report the case of a 52-year-old female with spinocerebellar ataxia (SCA) 13. She presented with complaints of insomnia and had a history of restless legs syndrome. Her polysomnogram revealed that she had a significantly elevated periodic limb movement index, mild obstructive sleep apnea, and the absence of REM sleep. Sleep disorders have previously been described in patients with SCA 1, SCA 2, SCA 3, and SCA 6. To our knowledge, this is the first description of sleep disorders in a patient with SCA 13.