Evidence for Beneficial Effect of Daily Use of Mechanical Insufflation-Exsufflation in Patients With Neuromuscular Diseases.

BACKGROUND: Daily application of mechanical insufflation-exsufflation (MI-E) is used increasingly in patients with neuromuscular diseases (NMDs) to prevent pulmonary congestion and thereby respiratory tract infections, although its beneficial effect remains uncertain. We, therefore, conducted a systematic review, registered in PROSPERO (CRD42020158278), to compile available evidence for daily MI-E use in subjects with NMDs and stable respiratory condition. METHODS: We performed a systematic comprehensive search of MEDLINE, Embase, CINAHL, and Web of Science up to December 23, 2021. We excluded articles studying the effect of MI-E in case of acute respiratory failure or infections and studies comparing different MI-E devices and settings. Studied outcomes were prevalence and severity of respiratory infections, lung function, respiratory characteristics, and patient satisfaction. We performed a meta-analysis using DerSimonian-Laird random effects model and assessed methodological quality by using the Alberta Heritage Foundation for Medical Research tool. RESULTS: A total of 3,374 records were screened, of which 25 were included, studying 608 subjects. One randomized controlled trial (RCT) found a trend toward reduced duration of respiratory infections compared to air stacking (AS) that was not statistically significant. Long-term effects on pulmonary function tests (PFT) results were reported in one RCT and one retrospective study, with mixed results regarding vital capacity. Most studies compared PFT results before and immediately after MI-E use. Meta-analysis showed an overall beneficial effect of MI-E on cough peak flow (CPF) compared to unassisted CPF (mean difference 91.6 L/min [95% CI 28.3-155.0], P < .001). Subject satisfaction was high, though possibly influenced by major bias. CONCLUSIONS: There is limited evidence available to support beneficial effects of daily use of MI-E in clinically stable subjects with NMDs, with the possible exception of increased CPF immediately after MI-E application. Lack of longitudinal studies preclude conclusions regarding long-term effects. The very limited data comparing MI-E to AS preclude comparisons.

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.

Respiratory muscle function in patients with nemaline myopathy.

In this cross-sectional study, we comprehensively assessed respiratory muscle function in various clinical forms of nemaline myopathy (NM) including non-volitional tests for diaphragm function. Forty-two patients with NM were included (10 males (25-74 y/o); 32 females (11-76 y/o)). The NM forms were typical (n=11), mild (n=7), or childhood-onset with slowness of movements (n=24). Forced vital capacity (FVC) and maximal inspiratory pressure were decreased in typical NM in comparison with childhood-onset NM with slowness (32.0 [29.0-58.5] vs 81.0 [75.0-87.0]%, p<0.01, and 35.0 [24.0-55.0] vs 81.0 [65.0-102.5] cmH2O, p<0.01). Eight patients with childhood-onset NM with slowness had respiratory muscle weakness. There was a low correlation between FVC and Motor Function Measure scores (r=0.48, p<0.01). End-inspiratory diaphragm thickness and twitch mouth pressure were decreased in patients requiring home mechanical ventilation compared to non-ventilated patients with normal lung function (1.8 [1.5-2.4] vs 3.1 [2.0-4.6] mm, p=0.049, and -7.9 [-10.9- -4.0] vs -14.9 [-17.3- -12.6], p=0.04). Our results show that respiratory muscle weakness is present in all NM forms, including childhood-onset NM with slowness, and may be present irrespective of the degree of general motor function impairment. These findings highlight the importance for screening of respiratory function in patients with NM to guide respiratory management.

Short-term effect of air stacking and mechanical insufflation-exsufflation on lung function in patients with neuromuscular diseases.

Air stacking (AS) and mechanical insufflation-exsufflation (MI-E) aim to increase cough efficacy by augmenting inspiratory lung volumes in patients with neuromuscular diseases (NMDs). We studied the short-term effect of AS and MI-E on lung function. We prospectively included NMD patients familiar with daily AS or MI-E use. Studied outcomes were forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and peak expiratory flow (PEF) prior to, immediately after, and up to 2 h after treatment. Paired sample T-test and Wilcoxon signed-rank test was used. Sixty-seven patients participated. We observed increased FVC and FEV1 immediately after AS with a mean difference of respectively 0.090 L (95% CI 0.045; 0.135, p < .001) and 0.073 L (95% CI 0.017; 0.128, p = .012). Increased FVC immediately after MI-E (mean difference 0.059 L (95% CI 0.010; 0.109, p = .021) persisted 1 hour (mean difference 0.079 L (95% CI 0.034; 0.125, p = .003). The effect of treatment was more pronounced in patients diagnosed with Spinal Muscular Atrophy, compared to patients with Duchenne muscular dystrophy. AS and MI-E improved FVC immediately after treatment, which persisted 1 h after MI-E. There is insufficient evidence that short-lasting increases in FVC would explain the possible beneficial effect of AS and MI-E.

Natural history of respiratory muscle strength in spinal muscular atrophy: a prospective national cohort study.

BACKGROUND: Respiratory complications are the most important cause of morbidity and mortality in spinal muscular atrophy (SMA). Respiratory muscle weakness results in impaired cough, recurrent respiratory tract infections and eventually can cause respiratory failure. We assessed longitudinal patterns of respiratory muscle strength in a national cohort of treatment-naïve children and adults with SMA, hypothesizing a continued decline throughout life. METHODS: We measured maximal expiratory and inspiratory pressure (PEmax and PImax), Sniff Nasal inspiratory pressure (SNIP), peak expiratory flow (PEF), and peak cough flow (PCF) in treatment-naïve patients with SMA. We used mixed-models to analyze natural history patterns. RESULTS: We included 2172 measurements of respiratory muscle function from 80 treatment-naïve patients with SMA types 1c-3b. All outcomes were lower in the more severe phenotypes. Significant differences in PEF were present between SMA types from early ages onwards. PEF decline was linear (1-2%/year). PEF reached values below 80% during early childhood in types 1c-2, and during adolescence in type 3a. PEmax and PImax were severely lowered in most patients throughout life, with PEmax values abnormally low (i.e. < 80 cmH2O) in virtually all patients. The PEmax/PImax ratio was < 1 throughout life in all SMA types, indicating that expiratory muscles were most affected. All but SMA type 3b patients had a lowered PCF. Patients with types 2b and 3a had PCF levels between 160 and 270 L/min, those with type 2a around 160 L/min and patients with type 1c well below 160 L/min. Finally, SNIP was low in nearly all patients, most pronounced in more severely affected patients. CONCLUSIONS: There are clear differences in respiratory muscle strength and its progressive decline between SMA types. We observed lower outcomes in more severe SMA types. Particularly PEF may be a suitable outcome measure for the follow-up of respiratory strength in patients with SMA. PEF declines in a rather linear pattern in all SMA types, with clear differences at baseline. These natural history data may serve as a reference for longer-term treatment efficacy assessments.

A Randomized Trial of Initiation of Chronic Noninvasive Mechanical Ventilation at Home vs In-Hospital in Patients With Neuromuscular Disease and Thoracic Cage Disorder: The Dutch Homerun Trial.

BACKGROUND: There is an increasing demand for home mechanical ventilation (HMV) in patients with chronic respiratory insufficiency. At present, noninvasive ventilation is exclusively initiated in a clinical setting at all four centers for HMV in the Netherlands. In addition to its high societal costs and patient discomfort, commencing HMV is often delayed because of a lack of hospital bed capacity. RESEARCH QUESTION: Is HMV initiation at home, using a telemonitoring approach, noninferior to in-hospital initiation in a nationwide study? STUDY DESIGN AND METHODS: We conducted a nationwide, randomized controlled noninferiority trial, in which every HMV center recruited 24 patients (home [n = 12] vs hospital [n = 12]) with a neuromuscular disease or thoracic cage disorder, all with an indication to start HMV. Change in arterial CO2 (Paco2) over a 6-month period was considered the primary outcome, and quality of life and costs were assessed as secondary outcomes. RESULTS: A total of 96 patients were randomized, most of them diagnosed with neuromuscular disease. We found a significant improvement in Paco2 within both groups (home: from 6.1 to 5.6 kPa [P < .01]; hospital: from 6.3 to 5.6 kPa [P < .01]), with no significant differences between groups. Health-related quality of life showed significant improvement on various subscales; however, no significant differences were observed between the home and hospital groups. From a societal perspective, a cost reduction of more than €3,200 ($3,793) per patient was evident in the home group. INTERPRETATION: This nationwide, multicenter study shows that HMV initiation at home is noninferior to hospital initiation, as it shows the same improvement in gas exchange and health-related quality of life. In fact, from a patient's perspective, it might even be a more attractive approach. In addition, starting at home saves over €3,200 ($3,793) per patient over a 6-month period. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT03203577; URL: www.clinicaltrials.gov.

Phrenic neuropathy and diaphragm dysfunction in neuralgic amyotrophy.

OBJECTIVE: To describe the clinical phenotype and recovery of diaphragm dysfunction caused by neuralgic amyotrophy in a large cohort of patients, to improve accurate awareness of this entity, and to encourage adoption of a standardized approach for diagnosis and treatment. METHODS: This observational cohort study recruited adult patients with neuralgic amyotrophy and symptoms of idiopathic phrenic neuropathy from the database of the Dutch expert center for neuralgic amyotrophy and the Dutch centers for home mechanical ventilation. Demographic and clinical information on diagnosis, symptoms, and recovery was obtained from chart review. We attempted to contact all patients for a follow-up interview. RESULTS: Phrenic neuropathy occurs in 7.6% of patients with neuralgic amyotrophy. Unilateral diaphragmatic dysfunction and bilateral diaphragmatic dysfunction are frequently symptomatic, causing exertional dyspnea, orthopnea, disturbed sleep, and excessive fatigue. Diagnostic practices varied widely and were often not optimally targeted. The majority of patients experienced at least moderate recovery within 2 years. CONCLUSION: We recommend screening every patient with neuralgic amyotrophy for diaphragm dysfunction by asking about orthopnea and by performing upright and supine vital capacity screening and diaphragm ultrasound in cases of suspected phrenic neuropathy to optimize diagnosis and care.

Pneumothorax as a complication of lung volume recruitment.

Lung volume recruitment involves deep inflation techniques to achieve maximum insufflation capacity in patients with respiratory muscle weakness, in order to increase peak cough flow, thus helping to maintain airway patency and improve ventilation. One of these techniques is air stacking, in which a manual resuscitator is used in order to inflate the lungs. Although intrathoracic pressures can rise considerably, there have been no reports of respiratory complications due to air stacking. However, reaching maximum insufflation capacity is not recommended in patients with known structural abnormalities of the lungs or chronic obstructive airway disease. We report the case of a 72-year-old woman who had poliomyelitis as a child, developed torsion scoliosis and post-polio syndrome, and had periodic but infrequent asthma attacks. After performing air stacking for 3 years, the patient suddenly developed a pneumothorax, indicating that this technique should be used with caution or not at all in patients with a known pulmonary pathology.

Pneumothorax as a complication of lung volume recruitment / Pneumotórax como complicação associada ao recrutamento do volume pulmonar

Lung volume recruitment involves deep inflation techniques to achieve maximum insufflation capacity in patients with respiratory muscle weakness, in order to increase peak cough flow, thus helping to maintain airway patency and improve ventilation. One of these techniques is air stacking, in which a manual resuscitator is used in order to inflate the lungs. Although intrathoracic pressures can rise considerably, there have been no reports of respiratory complications due to air stacking. However, reaching maximum insufflation capacity is not recommended in patients with known structural abnormalities of the lungs or chronic obstructive airway disease. We report the case of a 72-year-old woman who had poliomyelitis as a child, developed torsion scoliosis and post-polio syndrome, and had periodic but infrequent asthma attacks. After performing air stacking for 3 years, the patient suddenly developed a pneumothorax, indicating that this technique should be used with caution or not at all in patients with a known pulmonary pathology.

O recrutamento do volume pulmonar envolve técnicas de insuflações pulmonares profundas para se atingir a capacidade de insuflação máxima em pacientes com fraqueza da musculatura respiratória, a fim de aumentar o pico de fluxo da tosse e assim auxiliar a manutenção da patência de vias aéreas e melhorar a ventilação. Uma dessas técnicas é o empilhamento de ar, na qual se utiliza um ressuscitador manual para insuflar os pulmões. Embora as pressões intratorácicas possam aumentar consideravelmente, não há relatos de complicações por empilhamento de ar. Entretanto, atingir a capacidade de insuflação máxima não é recomendado em pacientes com anormalidades na estrutura pulmonar ou doença obstrutiva crônica das vias aéreas. Relatamos o caso de uma paciente de 72 anos que teve poliomielite quando criança, desenvolveu escoliose de torção e síndrome pós-pólio e tinha exacerbações de asma periódicas, mas infrequentes. Após realizar empilhamento de ar por 3 anos, a paciente subitamente desenvolveu pneumotórax, mostrando que essa técnica deve ser utilizada com cuidado ou não ser utilizada por pacientes com patologia pulmonar conhecida.

[Lung volume recruitment in impending respiratory failure]. / Longvolumerekrutering bij dreigend respiratoir falen.

Lung volume recruitment can improve peak cough flows and respiratory compliance in patients who either do or do not require mechanical ventilation. There are several lung volume recruitment techniques: air stacking, glossopharyngeal breathing and mechanical insufflation-exsufflation with cough assist devices. The principle of lung volume recruitment is based on the insufflation of air in the lungs after maximal inspiration. In air stacking, a manual resuscitation bag is used for insufflation. Glossopharyngeal breathing requires the use of oropharyngeal and laryngeal muscles by the patient. The mechanical cough assist device exsufflates the air after insufflation. These techniques may prevent pulmonary complications, hospital admission and tracheotomy in patients with a reduced ability to cough, a proclivity towards atelectasis and recurrent airway infections. The combination of long-term mechanical ventilation with lung volume recruitment has led to further improvement in the prognosis of chronic respiratory failure. More patients may potentially benefit from lung volume recruitment than only those being converted from short-term to long-term mechanical ventilation.

[Obesity hypoventilation syndrome--serious but reversible providing weight is lost]. / Obesitas-hypoventilatiesyndroom: ernstig, maar reversibel bij gewichtsreductie.

Obesity hypoventilation syndrome (OHS) is a condition in which obesity and chronic hypoventilation during waking hours are combined. Patients with OHS are more likely to be hospitalized and to require intensive-care monitoring compared with patients with similar degrees of obesity without hypoventilation. Treatment with chronic non-invasive positive pressure ventilation (NPPV) is associated with a lower morbidity and mortality. We present 2 cases of OHS; in the first case, a 56-year-old woman, we show that it is very important to diagnose and treat OHS at an early stage in order to avoid severe morbidity. In the second case, a 31-year-old man, we show that if a patient with OHS and chronic NPPV looses a significant amount of weight NPPV can be discontinued. Patients with OHS should be treated in a multidisciplinary team in order to achieve significant weight loss, so NPPV could be a temporary treatment or even be avoided.

Incidence of parvovirus B19 infection among an unselected population of pregnant women in the Netherlands: A prospective study.

OBJECTIVE: To evaluate seroprevalence of anti-parvovirus B19 IgG immunoglobulins and the rate of seroconversion in seronegative pregnant women. DESIGN: Prospective assessment of anti-parvovirus B19 IgG immunoglobulins in an unselected population of pregnant women booked for antenatal care from 1998 to 2000. SETTING: Maternity departments of an academic hospital and four affiliated teaching hospitals in the Netherlands. SUBJECTS: Two thousand five hundred and sixty seven pregnant women. MAIN OUTCOME MEASURES: Seroprevalence of anti-parvovirus B19 IgG immunoglobulin in the first trimester of pregnancy and subsequent seroconversion in those women who were tested negative for parvovirus B19 antibodies in the first trimester of pregnancy. RESULTS: The estimated seroprevalence of anti-parvovirus B19 IgG immunoglobulins among the study population is 70% (95% CI: 68-71) in the first trimester of pregnancy. Seven hundred and seventy nine women tested negative for parvovirus B19 antibodies in the first trimester of pregnancy. Paired testing in these women confirmed 18 seroconversions. Based on these findings the estimated incidence of maternal parvovirus B19 infection in this population among seronegative Dutch women is 2.4% (95% CI: 1.4-3.7). CONCLUSION: Maternal infection with parvovirus B19 is relatively common. However, it is argued that in the Netherlands routine assessment of parvovirus antibodies in pregnant women is not warranted as there is a low risk of adverse fetal outcome and measures to prevent the parvovirus B19 infection and its consequences are very limited.

The incidence of congenital cytomegalovirus infections in The Netherlands.

Cytomegalovirus (CMV) is one of the most common causes of congenital infection without an effective treatment or an effective vaccine available to date. The emphasis has to be on preventive strategies, which rely on the epidemiological situation. The incidence of congenital CMV infections, however, is not known for The Netherlands. Therefore, a prospective virological study was carried out in a population of 7,524 pregnant women and 7,793 newborns. CMV-specific IgG antibodies were determined in cord blood by ELISA. When CMV antibodies were present, a CMV specific PCR was performed on the throat swab. A positive PCR was confirmed by urine culture. In addition, the seroepidemiology for CMV was investigated in the metropolitan region (Amsterdam and Rotterdam) which has a different ethnic composition. Congenital CMV infection was found in 7 infants (0.9 per 1,000). None had symptoms at birth or during 24 month follow-up. Carriage or CMV was 41%, with a variation between 35% and 100% depending on ethnicity. The ethnic composition in the south-eastern region was different from that in large cities, but similar to that in the rest of the country. The incidence of congenital CMV infections in The Netherlands is the lowest described to date, which does not justify special preventive policies.

Congenital cytomegalovirus infection after recurrent infection: case reports and review of the literature.

Cytomegalovirus (CMV) is one of the most common causes of congenital infections in developed countries with reported incidences varying between 0.15% and 2.0%. The effects of congenital CMV infection may vary from a congenital syndrome to an asymptomatic course. Infants that are asymptomatic at birth may still present handicaps at a later age. It is generally accepted that symptoms of congenitally infected children are more severe after primary infection than after recurrent infection. In this article, we present two case reports which demonstrate that the outcome of recurrent maternal CMV infection may be severe. In the first case, early pregnancy serology showed positive IgG and IgM, but negative IgA, whereas at the time of diagnosed fetal death, 5 weeks later, there was only positive IgG. The second case showed positive IgG and negative IgM and IgA both in early pregnancy and after delivery. Since in both cases CMV was isolated from several organs, these findings are compatible with recurrent rather than primary CMV infection. In the reported patients, fetal death and necrotising enterocolitis occurred after a congenital CMV infection, with mothers having pre-existing immunity to CMV. In conclusion, these case reports and review of the literature emphasise that the outcome of recurrent maternal CMV infection may be severe and that congenital CMV infection should be considered in cases of pregnancy loss and necrotising enterocolitis with recurrent maternal CMV infection.

Seroprevalences of herpes simplex virus type 1 and type 2 among pregnant women in the Netherlands.

BACKGROUND: In the Netherlands 73% of cases of neonatal herpes are caused by herpes simplex virus type 1 (HSV-1), whereas in the United States a majority are caused by HSV type 2 (HSV-2). GOAL To understand this difference we undertook a seroepidemiological study on the prevalence of HSV-1 and HSV-2 among pregnant women. STUDY DESIGN: Type-specific antibodies to HSV-1 and HSV-2 were detected by enzyme-linked immunosorbent assay (ELISA) in serum samples from 1,507 pregnant women in Amsterdam, Rotterdam, and Nijmegen. RESULTS: The prevalence of HSV-1 was 61% in Nijmegen, 73% in Amsterdam, and 75% in Rotterdam. The prevalence of HSV-2 was 11% in Nijmegen, 35% in Amsterdam, and 27% in Rotterdam. CONCLUSION: The seroprevalence of HSV-1 and HSV-2 antibodies among pregnant women in the Netherlands shows significant geographical differences, which were attributed to ethnical variation. However, the epidemiologic differences did not correlate with the incidence of neonatal herpes in the Netherlands.

Congenital cytomegalovirus infection: review of the epidemiology and outcome.

UNLABELLED: Cytomegalovirus (CMV) is one of the most common viral causes of congenital infection. A future decision to lower its incidence by vaccination will depend on epidemiological conditions within a country and on the safety of the vaccine to be used, because a life vaccine may cause latency and subsequent reactivation that still may harm the fetus. The aim was to review the epidemiological studies published so far, with respect to factors that affect the incidence of congenital CMV infection, and factors that may influence its outcome, such as preexisting maternal immunity. The study included the data of 19 studies that were retrieved from a MEDLINE search during the period 1977 to 1997. The incidence of congenital CMV infection varied between 0.15% and 2.0% and seemed to correlate with the level of preexisting immunity in the population. Although preexisting maternal immunity was reported to strongly reduce transmission, the severity of congenital CMV infection (symptoms at birth and or sequelae later in life) was not significantly greater after virus transmission due to a primary infection of the mother as compared with recurrence or reinfection. The data indicate that preexisting immunity of the mother does not significantly mitigate the outcome of congenital infection. Moreover, life vaccines may bear a serious risk when transmittable to the fetus. TARGET AUDIENCE: Obstetricians and Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader will be able to describe the natural course of a CMV infection, to list the potential sequelae of a congenital CMV infection, to outline potential strategies to prevent transmission of CMV, and to summarize the diagnostic work up of a patient with a potential CMV infection.