Paradoxical vocal cord motion: A review focused on multiple system atrophy

Upper airway manifestations of anti-IgLON5 disease: Otorhinolaryngological point of view

INTRODUCTION

Anti-IgLON5 disease is a recently described neurological disorder with multisystemic features. The disease is characterized by the presence of IgLON5 antibodies in serum and cerebrospinal fluid. Our objective is to describe in detail the otorhinolaryngological manifestations of this disease, which are frequent and may include dysphagia, dysarthria, vocal cord paralysis and laryngospasm.

METHODS

In this study, we present a series of 9 patients with anti-IgLON5 disease and otolaryngological manifestations. Patients were evaluated between July 2012 and March 2022 by video-polysomnography, fiber-optic laryngoscopy, and functional endoscopic evaluation of swallowing.

RESULTS

The median age was 71 years, and 5 (56%) were female. Video-polysomnography showed a NREM/REM parasomnia in 6 patients (67%), obstructive sleep apnea in 8 (88%), stridor during sleep in 7 (78%) and central apneas in 1 (11%). Six out of the 9 patients (67%) presented episodes of acute respiratory failure that required mechanical ventilation, 6 had vocal fold palsy with 4 of them requiring tracheostomy (3 had to be performed on an emergency basis). Dysphagia occurred in 8 patients (89%). Prominent upper airway secretion and sialorrhea was also present in 3 cases.

CONCLUSION

The anti-IgLON5 disease exhibits extensive otolaryngological symptoms, mainly affecting the upper airway. These symptoms affect the quality of life and can be life-threatening. Prompt acute management is essential for stridor, dyspnea, and dysphagia. Given the potential severity of the symptoms and rarity of the disease, it is important for otolaryngologists to be familiar with anti-IgLON5 disease.

LEVEL OF EVIDENCE

Level 4.

Vocal Fold Motion Impairment in Neurodegenerative Diseases

Vocal fold motion impairment (VFMI) is the inappropriate movement of the vocal folds during respiration, leading to vocal fold adduction and/or abduction problems and causing respiratory and vocal impairments. Neurodegenerative diseases (NDDs) are a wide range of disorders characterized by progressive loss of neurons and deposition of altered proteins in the brain and peripheral organs. VFMI may be unrecognized in patients with NDDs. VFMI in NDDs is caused by the following: laryngeal muscle weakness due to muscular atrophy, caused by brainstem and motor neuron degeneration in amyotrophic lateral sclerosis; hyperactivity of laryngeal adductors in Parkinson's disease; and varying degrees of laryngeal adductor hypertonia and abductor paralysis in multiple system atrophy. Management of VFMI depends on whether there is a presence of glottic insufficiency or insufficient glottic opening with/without severe dysphagia. VFMI treatment options for glottic insufficiency range from surgical interventions, including injection laryngoplasty and medialization thyroplasty, to behavioral therapies; for insufficient glottic opening, various options are available based on the severity and underlying cause of the condition, including continuous positive airway pressure therapy, botulinum toxin injection, tracheostomy, vocal fold surgery, or a combination of interventions. In this review, we outline the mechanisms, clinical features, and management of VFMI in NDDs and provide a guide for physicians who may encounter these clinical features in their patients. NDDs are always progressive; hence, timely evaluation, proper diagnosis, and appropriate management of the patient will greatly affect their vocal, respiratory, and swallowing functions as well as their quality of life.

“Peculiar” Snoring in a 40-Year-Old Patient: A Case Report and Review of Literature

This is a case description of a patient with previously diagnosed rapid eye movement sleep behavior disorder (RBD) and nocturnal enuresis, who complained about a “peculiar sound” while sleeping and, occasionally, while awake during intensive exercise, for the last three months. A home audio recording, which his wife obtained while he was sleeping, showed a high-pitched sound identified as stridor. Full video polysomnography revealed no apneas or hypopneas. The flow-volume loop yielded an inspiratory plateau, indicating variable extrathoracic obstruction. The upper and lower respiratory system computed tomography did not show any anomalies or mechanical lesions (e.g., masses and scars). Fiberoptic laryngoscopy revealed an abnormal activity of the vocal cord abductor during quiet breathing and inspiration in a supine position, leading to partial obstruction. A positive dopamine transporter scan and the coexistence of stridor, RBD, and nocturnal enuresis were diagnostic for multiple system atrophy. The patient was treated with continuous positive airway pressure as a symptomatic therapy for stridor and levodopa.

Hypothalamic-Bulbar MRI Hyperintensity in Anti-IgLON5 Disease with Serum-Restricted Antibodies: A Case Report and Systematic Review of Literature

BACKGROUND

Anti-IgLON5 disease is a rare neurodegenerative tauopathy that displays heterogeneity in clinical spectrum, disease course, cerebrospinal fluid (CSF) findings, and variable response to immunotherapy. Sleep disorders, bulbar dysfunction, and gait abnormalities are common presenting symptoms, and conventional brain MRI scanning is often unrevealing.

OBJECTIVE

To provide a comprehensive overview of the literature and to assess the frequency of symptoms, MRI findings, and treatment response in patients with IgLON5 autoimmunity in the serum and CSF or restricted to serum.

METHODS

We examined a 65-year-old woman with bulbar-onset IgLON5 disease with serum-restricted antibodies, and we also performed a systematic review of all confirmed cases reported in the English literature.

RESULTS

We identified 93 patients, included our case. Clinical data were obtained in 58 subjects, in whom the most frequent symptoms were sleep-disordered breathing, dysphagia, parasomnias, dysarthria, limb or gait ataxia, stridor or vocal cord paresis, movement disorders, and postural instability. Distinct MRI alterations were identified in 12.5% of cases, as opposed to unspecific or unremarkable changes in the remaining patients. T2-hyperintense non-enhancing signal alterations involving the hypothalamus and the brainstem tegmentum were observed only in the present case. Inflammatory CSF was found in half of the cases and serum-restricted antibodies in 4 patients. Treatment with immunosuppressant or immunomodulatory drugs led to sustained clinical response in 19/52 patients.

CONCLUSION

Anti-IgLON5 autoimmunity should be considered in patients with sleep disorders, bulbar syndrome, autonomic involvement, and movement disorders, and high-field brain MRI can be of diagnostic help.

Nocturnal stridor in multiple system atrophy: Video-polysomnography and clinical features

INTRODUCTION

Nocturnal stridor, a life-threatening condition linked to respiratory failure and sudden death during sleep, is a serious issue in patients with multiple system atrophy (MSA). However, little is known about polysomnographic findings and clinical features of MSA patients with nocturnal stridor. Hence, we investigated video-polysomnography (VPSG) findings and clinical features associated with nocturnal stridor in patients with MSA.

METHODS

We retrospectively analyzed the clinical data of patients with MSA (n = 49) who underwent overnight VPSG for the evaluation of sleep-disordered breathing. The presence of nocturnal stridor was confirmed based on overnight VPSG findings. Clinical data, including VPSG findings and clinical features, were compared between MSA patients with and without nocturnal stridor.

RESULTS

Nocturnal stridor was present in 31 (63.3%) patients with MSA. Patients with stridor showed significantly higher apnea-hypopnea, respiratory disturbance, and oxygen desaturation indices than those without stridor (P = 0.024, P = 0.049, and P = 0.006, respectively). Patients with stridor had more severe axial motor features, more impaired activities of daily living, and longer disease duration than those without stridor (P = 0.012, P = 0.036, and P = 0.003, respectively). However, there were no significant between-group differences in sex, age at disease onset, MSA subtype, parkinsonian features, cerebellar ataxia, residual urine volume, or systolic and diastolic blood pressure change.

CONCLUSIONS

MSA with nocturnal stridor is related to higher apnea indices in conjunction with higher O₂ desaturation index, more severe axial motor features, more impaired activities of daily living, and longer disease duration.

Laryngeal Movement Disorders in Multiple System Atrophy: A Diagnostic Biomarker?

Background

Multiple system atrophy (MSA) is a rare neurodegenerative disorder, and its parkinsonian variant can be difficult to delineate from Parkinson's disease (PD). Despite laryngeal dysfunction being associated with decreased life expectancy and quality of life, systematic assessments of laryngeal dysfunction in large cohorts are missing.

Objectives

The objective of this study was to systematically assess laryngeal dysfunction in MSA and PD and identify laryngeal symptoms that allow for differentiating MSA from PD.

Methods

Patients with probable or possible MSA underwent flexible endoscopic evaluation of swallowing performing a systematic task protocol. Findings were compared with an age‐matched PD cohort.

Results

A total of 57 patients with MSA (64 [59–71] years; 35 women) were included, and task assessments during endoscopic examination compared with 57 patients with PD (67 [60–73]; 28 women). Patients with MSA had a shorter disease duration (4 [3–5] years vs 7 [5–10]; P < 0.0001) and higher disease severity (Hoehn & Yahr stage 4 [3–4] vs 3 [2–4]; P < 0.0001). Of the patients with MSA, 43.9% showed clinically overt laryngeal dysfunction with inspiratory stridor. During endoscopic task assessment, however, 93% of patients with MSA demonstrated laryngeal dysfunction in contrast with only 1.8% of patients with PD (P < 0.0001). Irregular arytenoid cartilages movements were present in 91.2% of patients with MSA, but in no patients with PD (P < 0.0001). Further findings included vocal fold motion impairment (75.4%), paradoxical vocal fold motion (33.3%), and vocal fold fixation (19.3%). One patient with PD showed vocal fold motion impairment.

Conclusion

Laryngeal movement disorders are highly prevalent in patients with MSA when assessed by a specific task protocol despite the lack of overt clinical symptoms. Our data suggest that irregular arytenoid cartilage movements could be used as a clinical marker to delineate MSA from PD with a specificity of 1.0 and sensitivity 0.9. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Isolated stridor without any other sleeping breathing disorder diagnosed using drug-induced sleep endoscopy in a patient with multiple system atrophy: A case report

RATIONALE

Multiple system atrophy (MSA) is a rare neurodegenerative disease characterized by Parkinsonism and autonomic dysfunction or cerebellar ataxia. MSA can be accompanied by stridor caused by laryngeal stenosis secondary to vocal cord dysfunction.

PATIENT CONCERN

A 60-year-old woman with MSA, complaining of difficulty in breathing during sleep. Her bed partner reported witnessing grunting-like sounds during sleep.

DIAGNOSIS

Isolated stridor without any other sleeping breathing disorder diagnosed using drug-induced sleep endoscopy (DISE) in a patient with MSA.

INTERVENTIONS

On polysomnography, there was no obstructive sleep apnea. Using DISE, abnormally adducted vocal cords during inspiratory respiration were identified, leading to a diagnosis of stridor. We prescribed positive airway pressure to resolve the stridor.

OUTCOME

Our patient was also prescribed continuous positive airway pressure for the treatment of nocturnal stridor, and it is improved.

LESSONS

In summary, when MSA patients present with nocturnal stridor, it is important to evaluate the exact diagnosis and cause of stridor in patients by confirming the movement of vocal cords using DISE, as well as polysomnography.

Vocal Fold "Paralysis": An Early Sign in Multiple System Atrophy

Multiple system atrophy (MSA) is a neurodegenerative disease characterized by a cerebellar syndrome, autonomic dysfunction, and extrapyramidal signs. Extrapyramidal signs may manifest as parkinsonism as well as dystonia, which is the involuntary contraction of a muscle(s) resulting in an abnormal posture. MSA belongs to a family of diseases known as α-synucleinopathies which are associated with dream enactment reflecting REM sleep behavior disorder (RBD). In patients with MSA, dystonia or paresis may involve the laryngeal muscles resulting in vocal fold hypomobility. We identified four individuals presenting with vocal complaints and subsequently diagnosed with vocal fold "paralysis." Within one year, each patient developed neurologic symptoms and upon evaluation by a movement disorders specialist was diagnosed with probable MSA. Our findings highlight the importance of screening by otolaryngologists when patients are diagnosed with vocal fold hypomobility. Specifically, patients should be assessed for RBD by questioning others if he/she acts out their dreams. The presence of RBD raises clinical suspicion for a synucleinopathy such as MSA. Untreated patients with MSA experiencing nocturnal stridor and breathing disorders have an increased risk for sudden death. Therefore, early evaluation by a movement disorders specialist to promptly diagnose MSA may have a substantial effect on morbidity and mortality in this high-risk patient population.

The Shaking Palsy of the Larynx-Potential Biomarker for Multiple System Atrophy: A Pilot Study and Literature Review

In its early stages multiple system atrophy (MSA), a neurodegenerative movement disorder, can be difficult to differentiate from idiopathic Parkinson's disease (PD), and emphasis has been put on identifying premotor symptoms to allow for its early identification. The occurrence of vegetative symptoms in addition to motor impairment, such as orthostatic hypotension and neurogenic bladder dysfunction, enable the clinical diagnosis in the advanced stages of the disease. Usually with further disease progression, laryngeal abnormalities become clinically evident and can manifest in laryngeal stridor due to impaired vocal fold motion, such as vocal fold abduction restriction, mostly referred to as vocal fold paresis, or paradoxical vocal fold adduction during inspiration. While the pathogenesis of laryngeal stridor is discussed controversially, its occurrence is clearly associated with reduced life expectancy. Before the clinical manifestation of laryngeal dysfunction however, abnormal vocal fold motion can already be seen in patients that might not yet fulfill the diagnostic criteria of MSA. In this article we summarize the current literature on pharyngolaryngeal findings in MSA and report preliminary findings from a pilot study investigating eight consecutive MSA patients. Patients showed varying speech abnormalities. Only 2/8 patients exhibited laryngeal stridor. However, during FEES, all patients presented with irregular arytenoid cartilages movements and vocal fold abduction restriction. 3/8 showed vocal fold fixation and 1/8 paradoxical vocal fold motion. All patients presented with oropharyngeal dysphagia, 5/8 with penetration or aspiration events. We suggest that specific abnormal vocal fold motion can help identifying MSA patients and may allow for delimiting this disorder from idiopathic PD. These findings therefore may serve as a novel clinical biomarker for MSA. Based on the available data and our preliminary clinical experience we developed a standardized easy-to-implement task-protocol to be performed during flexible endoscopic evaluation of swallowing (FEES) for detection of MSA-related pharyngolaryngeal movement disorders. Furthermore, we initiated a prospective study to evaluate the diagnostic utility of this protocol.

Acoustic Characteristics of Stridor in Multiple System Atrophy

Nocturnal stridor is a breathing disorder prevalent in patients with multiple system atrophy (MSA). An improved understanding of this breathing disorder is essential since nocturnal stridor carries a poor prognosis (an increased risk of sudden death). In this study, we aimed to classify types of stridor by sound analysis and to reveal their clinical significance. Patients who met the criteria for probable MSA and had undergone polysomnography (PSG) were recruited. Patients were then assessed clinically with sleep questionnaires, including the Pittsburgh Sleep Quality Index, and the Hoehn and Yahr scale. Nocturnal stridor and snoring were analyzed with the Multi-Dimensional Voice Program. Nocturnal stridor was recorded in 22 patients and snoring in 18 patients using the PSG. Waveforms of stridors were classified into rhythmic or semirhythmic after analysis of the oscillogram. Formants and harmonics were observed in both types of stridor, but not in snoring. Of the 22 patients diagnosed with stridor during the present study, fifteen have subsequently died, with the time to death after the PSG study being 1.9 ± 1.4 years (range 0.8 to 5.0 years). The rhythmic waveform group presented higher scores on the Hoehn and Yahr scale and the survival outcome of this group was lower compared to the semirhythmic waveform group (p = 0.030, p = 0.014). In the Kaplan Meier's survival curve, the outcome of patients with rhythmic waveform was significantly less favorable than the outcome of patients with semirhythmic waveform (log-rank test, p < 0.001). Stridor in MSA can be classified into rhythmic and semirhythmic types and the rhythmic component signifies a poorer outcome.

[Pursed Lips Inspiration for Vocal Cord Dysfunction]

Paradoxical vocal cord motion (PVCM) during vocal cord dysfunction (VCD) generally occurs spasmodically and transiently. After we had experienced 36 cases of VCD and successfully treated with conservative treatment including "pursed lips inspiration" method, we experienced a boy who had persistent PVCM. It was observed his PVCM vanished when he breathed in through pursed lips, while it appeared again when he stopped pursed lips inspiration. An airway reflex has been reported where the negative pressure in the subglottic space resulting from the inspiratory effort against a narrowed glottis activates the vocal cord adductor. VCD is considered to have both acceleration of laryngeal closure reflex against airway stimuli and active adductive movement of vocal cords against negative pressure in the subglottic space as underlying factors. The pursed lips inspiration method enables VCD patients not only to accomplish slow and light breathing but also to decrease the difference in the pressure between the supra--and subglottic space by occluding the nasal cavity and voluntary puckering up of the mouth which generate negative pressure in the supraglottic space. This is the first report of the pursed lips inspiration method as a treatment for VCD. Pursed lips inspiration is a simple method which is easy to perform anytime, anywhere without any special equipment, and is considered to be worth trying for VCD.

Parabrachial nucleus involvement in multiple system atrophy

Multiple system atrophy (MSA) is associated with respiratory dysfunction, including sleep apnea, respiratory dysrhythmia, and laryngeal stridor. Neurons of the parabrachial nucleus (PBN) control respiratory rhythmogenesis and airway resistance.

OBJECTIVES

The objective of this study is to determine whether there was involvement of putative respiratory regions of the PBN in MSA.

METHODS

We examined the pons at autopsy in 10 cases with neuropathologically confirmed MSA and 8 age-matched controls. Sections obtained throughout the pons were processed for calcitonin-gene related peptide (CGRP) and Nissl staining to identify the lateral crescent of the lateral PBN (LPB) and the Kölliker-Fuse nucleus (K-F), which are involved in respiratory control. Cell counts were performed using stereology.

RESULTS

There was loss of CGRP neurons in the PBN in MSA (total estimated cell counts for the external LPB cluster was 12,584 ± 1146 in controls and 5917 ± 389 in MSA, p<0.0001); for the external medial PBN (MPB) cluster it was 15,081 ± 1758 in controls and 7842 ± 466 in MSA, p<0.001. There was also neuronal loss in putative respiratory regions of the PBN, including the lateral crescent of the LPB (13,039 ± 1326 in controls and 4164 ± 872 in MSA, p<0.0001); and K-F (5120 ± 495 in controls and 999 ± 308 in MSA, p<0.0001).

CONCLUSIONS

There is involvement of both CGRP and putative respiratory cell groups in the PBN in MSA. Whereas the clinical implications of CGRP cell loss are still undetermined, involvement of the LPB and K-F may contribute to respiratory dysfunction in this disorder.

Exercise-induced laryngeal obstruction: natural history and effect of surgical treatment

The current follow-up study concerning the supraglottic type of exercise-induced laryngeal obstruction (EILO) was performed to reveal the natural history of supraglottic EILO and compare the symptoms, as well as the laryngeal function in conservatively versus surgically treated patients. A questionnaire-based survey was conducted 2-5 years after EILO was diagnosed by a continuous laryngoscopy exercise (CLE) test in 94 patients with a predominantly supraglottic obstruction. Seventy-one patients had been treated conservatively and 23 with laser supraglottoplasty. The questionnaire response rate was 70 and 100% in conservatively treated (CT) and surgically treated (ST) patients, respectively. A second CLE test was performed in 14 CT and 19 ST patients. A visual analogue scale on symptom severity indicated improvements in both the groups, i.e. mean values (± standard deviations) declined from 73 (20) to 53 (26) (P < 0.001) in the CT group and from 87 (26) to 25 (27) (P < 0.001) in the ST group. At follow-up, ST patients reported lower scores regarding current level of complaints, and higher ability to perform exercise, as well as to push themselves physically, all compared to CT patients (P < 0.001). CLE scores were normalized in 3 of 14 (21%) CT and 16 of 19 (84%) ST patients (Z = -3.6; P < 0.001). In conclusion, symptoms of EILO diagnosed in adolescents generally decreased during 2-5 years follow-up period but even more after the surgical treatment. Patients with supraglottic EILO may benefit from supraglottoplasty both as to laryngeal function and symptom relief.

An autopsy report on multiple system atrophy diagnosed immunohistochemically despite severe ischaemic damage: a new approach for investigation of medical practice associated deaths in Japan

A 60-year old man with a 10-year history of multiple system atrophy (MSA) was found in respiratory arrest. After 4 months of respiratory support with two episodes of septic shock, he died. Autopsy disclosed severe atrophy of the mesencephalon, brainstem, medulla oblongata and cerebellum. Gallyas–Braak, α-synuclein and ubiquitin-positive inclusions in the cytoplasm of glial cells were evident, despite the severe ischaemic damage due to respiratory arrest and subsequent respiratory support for 4 months. The cause of respiratory arrest was not identified, but could be explained by the natural history of MSA. The bereaved family, who had suspected malpractice, was satisfied with the explanation based on the investigation performed by eight expert doctors, one expert nurse, two coordinator nurses and two lawyers in the model project promoted by the Japanese government.

[Experimental vocal cord abduction impairment with an artificial vocal cord]

Non-invasive positive pressure ventilation (NPPV) has recently been applied to the patients with multiple system atrophy (MSA) with various respiratory complications including vocal cord abduction impairment and respiratory disturbance by the central origin. Any consensus guidelines on setting up the inspiratory positive airway pressure (IPAP) and expiratory one (EPAP), however, have not been raised yet. To investigate this problem, we made the upper airway tract model with moderately and severely narrow glottis using a training/test lung and the artificial vocal cord which was developed for a humanoid talking robot in Waseda University. The artificial vocal cord was molded out of a high performance thermoplastic rubber in imitation of the human larynx. Previous studies using with a high-speed camera and a sound analyzer showed that the artificial vocal cord resembled human larynx closely both morphologically and functionally. The opening and closing movements of the artificial vocal cord were observed fiberscopically under various conditions of IPAP (4-20 cmH2O) and EPAP (4-10 cmH2O). The maximal glottic width during inspiration and expiration were measured by a pair of calipers on the video-monitored display. Both of the moderately and the severely narrow artificial vocal cords without non-paralytic factors showed typical paradoxical movement showing adduction in inspiration and abduction in expiration, which is characteristic to vocal cord abductor impairment seen in MSA. In the model with moderately severe narrow glottis, this paradoxical movement was released under any positive pressures of continuous (CPAP) and bilevel (Bilevel PAP) modes. In the model with severely narrow glottis, however, there existed a threshold in setting up the optimal EPAP to release the paradoxical movement. In conclusion, EPAP-leading procedure seems to be preferable to IPAP-leading procedure to dilate the narrow glottis as a pneumatic splint in the managements of the patients with MSA presenting with a paralytic type of vocal cord abductor impairment.