Early diagnosis and stage classification of vocal cord abductor paralysis in patients with multiple system atrophy.

OBJECTIVES: Vocal cord abductor paralysis (VCAP) is a life threatening complication which may cause nocturnal sudden death in patients with multiple system atrophy. However, the early diagnosis of VCAP is often difficult to make on routine laryngoscopy performed during wakefulness, as stridor, which is the sole symptom of VCAP in the early stage, develops only during sleep. The aim was to investigate laryngeal dysfunction in patients with multiple system atrophy while awake and asleep. METHODS: Seven patients with multiple system atrophy with nocturnal stridor and five control patients were studied. Vocal cord movement was analysed by laryngoscopy while the patients were awake and also during sleep induced by intravenous diazepam. RESULTS: When awake, for the seven patients with multiple system atrophy normal movement of the vocal cords occurred in three, mild abduction restriction in three, and paradoxical movement in one. When asleep, however, all showed obvious paradoxical movement with high pitched inspiratory stridor. In controls, there were no differences in the vocal cord movement between wakefulness and sleep. From these findings, VCAP could be divided into four stages: stage 0 (normal) with normal vocal cord movement during both wakefulness and sleep, stage 1 (mild VCAP) with normal movement during wakefulness and paradoxical movement during sleep, stage 2 (moderately severe VCAP) with abduction restriction during wakefulness and paradoxical movement during sleep, and stage 3 (severe VCAP) with an almost midline position for the vocal cords during both wakefulness and sleep. CONCLUSIONS: Laryngoscopy during sleep can disclose subclinical VCAP, making an early diagnosis of VCAP in patients with multiple system atrophy. Stage 2 of VCAP seems to be a suitable stage for tracheostomy in patients with multiple system atrophy.     

A case of juvenile Parkinson disease with vocal cord abductor paralysis in the course of malignant syndrome]

We report a 60-year-old woman with juvenile Parkinson disease (PD) with vocal cord abductor paralysis (VCAP). She had suffered from juvenile PD for 30 years. She was admitted in February 1998 to our clinical unit, because of malignant syndrome induced by dehydration. Neurological examination revealed disturbance of consciousness, hand tremor, dyskinesia of the trunk and all extremities, and rigidity. Laboratory examinations disclosed leukocytosis, renal dysfunction, hypermyoglobinemia, and elevation of the serum creatine kinase. Six days after admission, dyspnea and inspiratory stridor were noted, and the respiratory distress worsened. Endoscopy of the upper airways revealed that the vocal cord was in the midline or paramedian position. There are some cases of PD with VCAP, but such a case is very rare in Japan. We discussed the pathogenic mechanisms of these conditions, and speculated that VCAP was associated with malignant syndrome in our case.     

Vocal cord abductor paralysis (VCAP) in Parkinson''s disease: difference from VCAP in multiple system atrophy

Vocal cord abductor paralysis (VCAP) is rare in Parkinson's disease (PD), while it is frequent in multiple system atrophy (MSA). Although VCAP is a life-threatening complication it has not yet been clarified whether there is any difference in the mechanism of VCAP between PD and MSA. Examining 3 autopsy-proven PD patients who developed severe VCAP requiring tracheostomy, we found the following differences in the mechanism of VCAP between MSA and PD: (1) clinical and laryngofiberscopic examination showed that VCAP in PD was not exacerbated during sleep, unlike in MSA; (2) On histological examination of the intrinsic laryngeal muscles, the posterior cricoarytenoid muscle demonstrated no abnormalities in PD, while the muscle showed characteristic neurogenic atrophy in MSA. There seemed to be two types of VCAP, namely the nonparalytic type observed in PD, and the paralytic type observed in MSA. Severe dysphagia requiring tube-feeding was common among PD patients who presented with VCAP. Although the relationship between VCAP and dysphagia is unknown, one should be aware of the possibility of fatal VCAP in PD patients with severe dysphagia.     

Morphometric study of nucleus ambiguus in multiple system atrophy presenting with vocal cord abductor paralysis

AIM: To identify lesions responsible for vocal cord abductor paralysis (VCAP) in multiple system atrophy (MSA), we performed a morphometric study of the nucleus ambiguus which innervates the intrinsic laryngeal muscles. METHODS: Two autopsied cases of MSA presenting with VCAP and one control were examined. Both cases of MSA showed selective neurogenic atrophy of the posterior cricoarytenoid muscles among the intrinsic laryngeal muscles, while no abnormalities were seen in the control. From a block of the medulla oblongata, sections 10 microm thickness were cut serially without spacing and stained with cresyl violet. The ambiguus neurons were counted in all the sections to make a histogram. RESULTS: In the control case, ambiguus neurons showed densely populated areas and sparsely populated areas alternately with significant difference in the mean neuronal density between two areas. In MSA, ambiguus neurons were significantly decreased in number at all levels. It indicates that the neurogenic atrophy of the posterior cricoarytenoid muscle is derived from the neuronal loss of the nucleus ambiguus. CONCLUSION: Though it has still been controversial whether or not the ambiguus neurons are decreased in number in MSA with VCAP, we speculated possible reasons for the disagreement on the involvement of the nucleus ambiguus as follows: different mechanism of VCAP are playing role, and histometric data have been disturbed by factors such as split-cell counting error and marked variation in the distribution of the ambiguus neurons.     

Homozygous Machado–Joseph disease presenting as REM sleep behaviour disorder and prominent psychiatric symptoms

A male patient carrying the homozygous gene for Machado-Joseph disease (MJD) presented at age 43 with sleep disturbances and psychiatric symptoms followed by ataxic speech and gait. A polysomnogram (PSG) showed decreased rates of sleep time and stage rapid eye movement (REM) and an increased rate of 'stage 1-REM with tonic EMG' (Tachibana et al., 1975); all compatible with REM sleep behaviour disorder (RBD). Molecular gene analysis at age 59 showed that the CAG repeat units in the MJD gene were 60 and 60, smaller than the reported lengths for homozygous MJD patients (63-70 and 66-72). In addition to sleep disturbances, in particular RBD, psychiatric symptoms may be important clinical features in both heterozygous and homozygous MJD.     

Sleep disorders in Machado–Joseph disease: A dopamine transporter imaging study

ObjectivesSleep disorders, especially restless legs syndrome (RLS) and rapid eye movement sleep behavior disorder (RBD), are common in spinocerebellar ataxia type 3 or Machado–Joseph disease (MJD), and a possible underlying dopaminergic dysfunction is implicated. This study assessed the relationship between sleep disorders in MJD and dopamine transporter (DAT) densities.Patients and methodsTwenty-two patients with MJD and twenty healthy subjects were enrolled in this study. MJD patients underwent clinical sleep evaluation and polysomnography. SPECT with [^99mTc]-TRODAT-1, was performed in all subjects.ResultsDAT densities were significantly reduced in MJD group when compared to controls. No significant correlation was found between DAT densities and RLS or RBD in MJD.ConclusionOur study failed to demonstrate a clear correlation between sleep disorders and DAT densities in MJD patients, hence suggesting that extrastriatal and non-presynaptic dopamine pathways could be implicated in MJD-related sleep disorders.     

The close relationship between life-threatening breathing disorders and urine storage dysfunction in multiple system atrophy

Survival of multiple system atrophy (MSA) depends on whether a variety of sleep-related breathing problems as well as autonomic failure (AF) occur. Since the brainstem lesions that cause respiratory and autonomic dysfunction overlap with each other, these critical manifestations might get worse in parallel. If so, the detection of AF, which is comparatively easy, might be predictive of a latent life-threatening breathing disorder. In 15 patients with MSA, we performed autonomic function tests composed of postural challenges and administered a questionnaire on bladder condition, as well as polysomnography and laryngoscopy during wakefulness and under anesthesia. Polysomnographic variables such as the apnea-hypopnea index (AHI) and oxygen saturation (SpO₂) and the findings of laryngoscopy were compared with the degree of cardiac and urinary autonomic dysfunction. AHI, mean SpO₂ and the lowest SpO₂ showed significant correlations with urine storage dysfunction. In addition, patients with vocal cord abductor paralysis (VCAP) or central sleep apnea (CSA) contributing to nocturnal sudden death had more severe storage disorders than those without. On the other hand, no significant relationship between polysomnographic variables and orthostatic hypotension was observed except in the case of mean SpO₂. These results indicate that life-threatening breathing disorders have a close relationship with AF, and especially urine storage dysfunction. Therefore, longitudinal assessment of deterioration of the storage function might be useful for predicting the latent progress of VCAP and CSA.     

HTLV-I associated myelopathy with bilateral abductor vocal cord paralysis--case report]

We have reported a 50-year-old woman with HTLV-I associated myelopathy (HAM) who had bilateral abductor vocal cord paralysis. The symptoms and signs were slowly progressive spastic paraplegia, dysuria, inspiratory stridor, and snoring during sleep. She had no hoarseness. Titers of anti-HTLV-I antibody were elevated in both the serum and cerebrospinal fluid. FEV1.0% on the spirogram was reduced to 66%. The fiberscopic examination demonstrated the abductor limitation of the vocal cords during the inspiratory phase. During induced sleep after the intravenous administration of thiopental sodium, this abductor paralysis was worsened, producing a high pitched inspiratory stridor. The adduction was not disturbed at all. Needle electromyogram of the posterior crico-arytenoid muscle which is a sole abductor muscle revealed the high amplitude up to approximately 1.0 mV (normal less than 0.8 mV) with poor interference pattern, indicating neurogenic changes. After 2 months course of prednisolone (60 mg/alternative day), FEV1.0% was recovered to be 92% with the improvement of the gait disturbance, which suggests the abductor vocal cord paralysis is related to HAM. The abductor vocal cord paralysis in HAM would require a careful follow-up observation to protect the respiratory failure in the advanced stage.     

Sleep Disorders in Machado�CJoseph Disease: Frequency, Discriminative Thresholds, Predictive Values, and Correlation with Ataxia-Related Motor and Non-Motor Features

Sleep disorders are common complaints in patients with neurodegenerative diseases such as spinocerebellar ataxia type 3 (SCA3) or Machado–Joseph disease (MJD)—SCA3/MJD. We evaluated the frequency of sleep disorders in SCA3/MJD patients against controls matched by age and gender, and correlated data with demographic and clinical variables. The main sleep disorders evaluated were rapid eye movement (REM) sleep behavior disorder (RBD), restless leg syndrome (RLS), and excessive daytime sleepiness (EDS). We recruited 40 patients with clinical and molecular-proven SCA3/MJD and 38 controls. We used the following clinical scales to evaluate our primary outcome measures: RBD Screening Questionnaire, International RLS Rating Scale, and Epworth Sleepiness Scale. To evaluate ataxia-related motor and non-motor features, we applied the International Cooperative Ataxia Rating Scale, the Scale for the Assessment and Rating of Ataxia, and the Unified Parkinson’s Disease Rating Scale part III. Psychiatric manifestations were tested with the Hamilton Anxiety Scale, and Beck Depression Inventory. The frequency of RBD and RLS were significantly higher in the SCA3/MJD group than in the control group (p < 0.001). There was no difference between both groups with regard to EDS. The accuracy of RDBSQ to discriminate between cases and controls was considered the best area under the ROC curve (0.86). Within-SCA3/MJD group analysis showed that anxiety and depression were significantly correlated with RDB, but not with RLS. Additionally, depression was considered the best predictive clinical feature for RDB and EDS.     

Excessive fragmentary myoclonus in Machado–Joseph disease

ObjectiveMachado–Joseph disease (MJD) is a neurodegenerative disease which usually presents several clinical findings including cerebellar ataxia and other extracerebellar features, such as Parkinsonism, dystonia, peripheral neuropathy, and lower motor neuron disease. Some data have demonstrated a high frequency of sleep disorders in these patients, including excessive daytime sleepiness (EDS), insomnia, obstructive sleep apnea (OSA), rapid eye movement (REM) sleep behavior disorder (RBD), and restless legs syndrome (RLS). Herein, we aimed to describe the high frequency of excessive fragmentary myoclonus (EFM) in MJD.Materials and methodsWe recruited 44 patients with MJD and 44 healthy controls. All participants underwent an all-night polysomnography (PSG). EFM was evaluated and defined in accordance to the criteria of the American Academy of Sleep Medicine.ResultsHalf of the MJD patients (n = 22) had EFM diagnosed through PSG, though no healthy control participant presented this finding (P < .0001). In the MJD group, older participants and men had a higher frequency of EFM. There was no correlation between EFM and the following data: body mass index (BMI), apnea–hypopnea index (AHI), EDS, loss of atonia during REM sleep, periodic limb movements during sleep (PLMS), RLS, RBD, ataxia severity, the number of cytosine–adenine–guanine trinucleotide (CAG) repeats, disease duration, sleep efficiency, sleep fragmentation, and sleep stage percentages between patients with or without EFM.ConclusionEFM is highly prevalent in patients with MJD. Our study demonstrates that EFM must be included in the clinical spectrum of sleep disorders in MJD patients.     

Bilateral abductor vocal cord paralysis (Gerhardt syndrome) in the Shy-Drager syndrome

Ten consecutive patients with a progressive pan-autonomic failure of the Shy-Drager syndrome were investigated. Movement disorders of the vocal cords were examined with a fiber-optic laryngoscope as well as a video-recorder. Moderate to severe vocal cord paralysis was present in five of ten patients. The vocal cords were almost immobile during inspiration, while there was no limitation of the adduction during phonation. In two cases, grade of vocal cord paralysis was asymmetric. One patient developed peculiar twisting-like dystonic movements of the vocal cord. Polygraphic studies revealed that SaO2 was lowered in spite of tachypnea during sleep. In two cases, the expiratory flow volume curve in effort-dependent portion near TLC showed a plateau and the inspiratory part of the curve also showed a plateau indicating constant flow. These functional disorders suggest an upper airway obstruction probably due to the vocal cord dysfunction. There was no vocal cord paralysis in two patients who had neither snore nor stridor. Development of a severe vocal cord dysfunction usually manifested itself clinically as stridor, snore or respiratory failure requiring tracheostomy. There was little information on the pathology of the vagal nerves and nuclei supplying motor control to the laryngeal muscles. The mechanism of the selective involvement of abductor muscle (posterior muscle) of the vocal cord (Gerhardt syndrome) remains unsolved. Vocal cord paralysis should be looked for since it can result in respiratory failure leading to death.     

Daytime hypoxemia, sleep-disordered breathing, and laryngopharyngeal findings in multiple system atrophy

BACKGROUND: The mechanism underlying nocturnal sudden death in patients with MSA remains unclear. It may be explained by upper airway obstruction, such as vocal cord abductor paralysis; an impairment of the respiratory center, such as Cheyne-Stokes respiration; or an impaired hypoxemic ventilatory response. OBJECTIVE: To investigate the mechanism of sleep-disordered breathing in multiple system atrophy (MSA). DESIGN: We recruited 21 patients with probable MSA who were admitted sequentially to our hospital, and performed daytime blood gas analysis, pulmonary function tests, polysomnography, and fiberoptic laryngoscopy during wakefulness and with the patient under anesthesia. RESULTS: A decrease in arterial oxygen pressure and an increase in alveolar-arterial oxygen gradient significantly correlated with disease duration (P = .045 and .046, respectively). Polysomnography demonstrated Cheyne-Stokes respiration in 3 (15%) of 20 patients. Fiberoptic laryngoscopy during wakefulness showed that 3 (14%) of the 21 patients exhibited vocal cord abductor paralysis, and laryngoscopy under anesthesia showed that 9 (45%) of 20 patients exhibited vocal cord abductor paralysis. Laryngoscopy under anesthesia also revealed that 11 (55%) of 20 patients showed upper airway obstruction in places other than the vocal cords, including obstruction at the base of the tongue or soft palate. In addition, it demonstrated novel laryngopharyngeal findings, such as floppy epiglottis and airway obstruction at the arytenoid. CONCLUSIONS: We observed daytime hypoxemia with an increased alveolar-arterial oxygen gradient, Cheyne-Stokes respiration, and novel abnormal laryngopharyngeal movements in patients with MSA. We also found that laryngoscopy under anesthesia might be useful for evaluating upper airway obstruction. The significance of these findings to the mechanism of sudden death in those with MSA needs to be examined.     

Not paralysis, but dystonia causes stridor in multiple system atrophy

Electromyography (EMG) was performed in 10 patients with multiple system atrophy, laryngeal or pharyngeal symptoms, or both. In patients with stridor, EMG during quiet breathing revealed persistent tonic activity in both abductor and adductor vocal cord muscles. In patients with dysphagia, the cricopharyngeal muscle showed persistent EMG activity throughout all phases of swallowing. Botulinum toxin injection into the adductor muscle determined subjective improvement and reduced tonic EMG activity. Therefore, the cause of stridor in multiple system atrophy is dystonia of the vocal cords.     

Laryngeal electromyography with separated surface electrodes in patients with multiple system atrophy presenting with vocal cord paralysis

When recording the activity of the posterior cricoarytenoid muscle (PCA) with surface electrodes, there is contamination from the surrounding muscles such as the cricopharyngeal muscle. We therefore devised a new oesophageal catheter electrode of the separate type, having three individual surface electrodes for the PCA, cricopharyngeal muscle and diaphragm. The records obtained with this catheter demonstrated satisfactory separation between PCA and cricopharyngeal muscle activities. We used this catheter in patients with multiple system atrophy presenting with vocal cord paralysis, who were awake or asleep. There were two interesting electromyographical findings, which were inspiratory activity of the adductor muscle (the thyroarytenoid muscle) and fade-out of the abductor muscle, that is, PCA activity during sleep. Although vocal cord paralysis is one of the most serious life-threatening complications, the precise mechanism has not been clarified. We believe that our catheter may be useful in investigating the mechanism of vocal cord paralysis which could cause sudden death in neurodegenerative disorders, including multiple system atrophy.     

Laryngeal dystonia in a case of severe motor and intellectual disabilities due to Japanese encephalitis sequelae

Laryngeal dystonia is characterized by stridor due to vocal cord dystonia and is observed in extrapyramidal disorders. Recently, botulinum toxin injection has been used as a primary therapy. Generally, severe motor and intellectual disabilities (SMID) are frequently complicated by various types of respiratory disorders. We report a SMID case with Japanese encephalitis sequelae showing repeated vocal cord abductor disturbance due to laryngeal dystonia, in addition to generalized dystonia, in whom MRI revealed basal ganglia lesions. Tracheostomy was effective for the case, and we believe that botulinum toxin injection may be inappropriate in SMID, both ethically and technically. Also, laryngeal dystonia should be considered as a cause of respiratory disorders in SMID.     

Mechanisms to control degradation of polyglutamine-containing protein]

Machado-Joseph disease (MJD)/Spinocerebellar ataxia type 3 (SCA3) is neurodegenerative disease which is caused by polyglutamine expansion in a responsible gene product, MJD1/Ataxin3. MJD1 has now been shown to undergo ubiquitylation and degradation by proteasome-dependent pathway. MJD1 with expanded polyglutamine tract was more resistant to degradation than normal MJD1. We established an in vitro system of ubiquitylation of MJD1, thereby biochemically purified activity to mediate polyubiquitylation of MJD1 from rabbit reticulocyte lysate. An AAA-family ATPase VCP was isolated from the active fraction, and found to binds to MJD1. Furthermore, UFD2a, a mammalian ubiquitin-chain assembly factor (E4), associated with VCP and induced polyubiquitylation of MJD1. UFD2a markedly promoted ubiquitylation and degradation of MJD1 with expanded polyglutamine tract, resulting in the clearance of MJD1 protein. In contrast, dominant-negative mutant UFD2a reduced the degradation rate of MJD1, leading to the formation of intracellular aggregation. In Drosophila model, overexpression of UFD2a significantly suppressed the neurodegeneration induced by expression of MJD1 with expanded polyglutamine tract. These findings suggest that E4 is a rate-limiting factor of degradation of pathologic polyglutamine-containing proteins, and may give a potential tool for gene therapy to control the clinical conditions of MJD.     

Slowly progressive motor neuron disease associated with paralysis of the abductor muscles of the vocal cords

Some cases of slowly progressive motor neuron disease with bilateral paralysis of the vocal cord abductor muscles have recently been published. We report a case with a more than forty year's course occurring in a family in which one brother and probably 2 cousins died of motor neuron disease.     

Synapses in the hereditary ataxias.

The goal of this investigation was the systematic assessment of synapses in the hereditary ataxias by the immunocytochemical and immunofluorescent visualization of SNAP-25, a protein of the presynaptic membrane. Sections were prepared from the cerebellar cortex, dentate nucleus, basis pontis, inferior olivary nuclei, and the spinal cord in 57 cases of autosomal dominant and recessive ataxia. The neuropathological phenotype included 18 cases of olivopontocerebellar atrophy (OPCA), 14 cases of familial cortical cerebellar atrophy (FCCA), 4 cases of Machado-Joseph disease (MJD), and 21 cases of Friedreich's ataxia (FA). Among the autosomal dominant ataxias, spinocerebellar ataxia type 1 (SCA-1), SCA-2, MJD/SCA-3, and SCA-6 were represented. Expanded guanine-adenine-adenine trinucleotide repeats were confirmed in 7 patients with FA. The abundance of SNAP-25 was estimated by comparing the fluorescence of the regions of interest to that of the frontal cortex, which was considered unaffected by the disease process. Despite severe Purkinje cell loss, abundant SNAP-25 reaction product remained in the molecular layer of FCCA and OPCA. Among the cases of OPCA, those identified as SCA-2 showed the most severe overall synaptic destruction in cerebellum and brain stem. In SCA-1, which caused either OPCA or FCCA, significant synaptic loss was restricted to the inferior olivary nuclei. Sparing of cerebellar cortex and inferior olivary nuclei was the rule for MJD/SCA-3 and FA, though the dentate nucleus showed reduced SNAP-25 immunoreactivity in both ataxias. In FA, preservation of SNAP-25 in the dentate nucleus was characteristic of long survival. Severe cases with short survival revealed synaptic depletion of the dentate nucleus. At the level of the spinal cord, synaptic loss in the dorsal nuclei of Clarke characterized FA and MJD/SCA-3. The inexorable clinical progression of the hereditary ataxias could not be attributed to synaptic loss in a single anatomic structure of cerebellum, brain stem, or spinal cord. Nevertheless, synaptic loss in dentate and inferior olivary nuclei correlated more precisely with the severity of the ataxia than the changes in the cerebellar cortex.     

Electrophysiological features of central motor conduction in spinocerebellar atrophy type 1, type 2, and Machado-Joseph disease

OBJECTIVES—To characterise electrophysiologicallythe central motor conduction of spinocerebellar atrophy type 1 (SCA1),type 2 (SCA2), and Machado-Joseph disease (MJD).
METHODS—Motor evoked potentials (MEPs) triggeredby transcranial magnetic stimulation (TMS) was used to investigate thefunctions of corticospinal tracts of 10 patients with SCA1, 10 withMJD, and eight with SCA2 in addition to pathological study of thespinal cord in a patient with SCA1.
RESULTS—Central motor conduction time (CMCT) wasextremely prolonged and the MEP threshold increased in all patientswith SCA1, whereas both were normal in patients with SCA2 or MJD. TheMEP size in MJD was larger than normal, but was normal in SCA1 andSCA2. A pathological investigation of the corticospinal tract of thespinal cord of a patient with SCA1 showed selective loss of largediameter fibres.
CONCLUSIONS—SCA1, SCA2, and MJD differ in theirpathophysiological features of the central motor tract and can bedifferentiated from each other by MEP values for the lower limbmuscles, even though their neurological symptoms are sometimes similar.