We present a case of OPCA with severe respiratory failure due to vocal cord dyskinesia. This vocal cord dyskinesia was found by fiberoptic bronchoscopy and confirmed by laryngeal electromyogram. Tracheal fenestration and drug therapy of halloperidol were successful for clinical improvement. To our knowledge, this is the first report of vocal cord dyskinesia in OPCA. We emphasized that OPCA could complicate vocal cord dyskinesia, causing severe respiratory failure.
Olivo-ponto-cerebellar atrophy is a disorder of multiple system atrophies including SND and SDS. We have found no report of the vocal cord dysfunction leading to acute respiratory failure in OPCA, although SDS complicated with vocal cord paralysis occasionally has led to acute respiratory failure.[1-3] This report describes a patient with severe respiratory failure due to vocal cord dyskinesia in OPCA.
CASE REPORT
A 54-year-old housewife was admitted to Saga Medical School in July 1985 when she had cerebellar ataxia. Her head CT scan showed atrophies of cerebellar, pons and midbrain and then the diagnosis of OPCA was made by these findings. She had been well, except for cerebellar ataxia, until July 1987 when exertional dyspnea developed first. Then she was admitted to our hospital on July 7, 1987. The patient was in mild respiratory distress, afebrile with pulse rate of 124 beats per minute and respiratory rate of 28 breaths per minute. Inspiratory stridor was audible and breath sounds were diminished at both lung fields. She was alert and the neurological examination revealed dysarthria, disphonia and disturbance of saccadic eye movement. Moreover, she had an upper limb tremor, an incoordination of extremities and a wide-based gate. Laboratory tests were normal except for the erythrocyte sedimentation rate of 64 mm/h. There was no elevation of antibody titers against virus. Electrocardiogram and chest roentgenogram did not show any abnormal findings. Arterial blood gas levels on room air were pH, 7.37; [PO.sub.2], 51.8 mm Hg; and [PCO.sub.2], 52.6 mm Hg. Pulmonary function studies showed that the total vital capacity was 1,440 ml (56 percent of predicted) and the forced expiratory volume in 1 was 980 ml (68 percent of predicted). The peak expiratory flow rate was 1.8 L/s and V50 and V25 were 0.69 and 0.49 L/s, respectively. The flow volume curve showed a pattern consistent with upper airway obstruction. Fiberoptic bronchoscopy demonstrated bilateral abduction weakness and involuntary movements of vocal cords (Fig 1) and their findings were confirmed by video. The electromyogram of the intrinsic laryngeal muscles is shown in Figure 2. In normal subjects, the characteristic phasic changes in activity are present in respiration and phonation. The CT and PCA muscles are active during inspiration, and the activity of the PCA is especially obvious. The TA is active during expiration. Phonation induces the activity of the CT and TA, but the activity of the PCA varies according to the pitch of the voice.[4] In this patient, single-action potentials were observed during inspiration in the CT. The PCA and TA were active during neither inspiration nor expiration (Fig 2, left). Her phonation induced the marked activity of the CT, but the TA showed a little activity of less than 100 [mu]V during respiration and phonation (Fig 2, right). These findings did not show the paralysis of the internal laryngeal muscles, but the disturbance of their coordination. The dyspnea became progressively more frequent and severe. Four days after admission she underwent the tracheostomy due to severe respiratory failure and ten days later the tracheal fenestration, and her dyspnea disappeared. After halloperidol was administered, the disturbance of coordination improved gradually.
DISCUSSION
Olivo-ponto-cerebellar atrophy is included in MSA which was described by Graham and Oppenheimer[5] and Bannister and Oppenheimer[6] on the basis of neuropathologic studies. The MSA shows degeneration of the cerebellar, extrapyramidal and autonomic systems. The OPCA starts with cerebellar ataxia and extrapyramidal signs, but fewer autonomic signs. Her head CT findings show atrophies of the pontine base and cerebellar cortex with dilatation of the fourth ventricle. In this patient, the diagnosis of OPCA was made on the basis of the cerebellar ataxia and of the atrophies of cerebellar, pons and midbrain on the head CT. When her oral cavity was stimulated, dyspnea and postural tremors were worsened and then inspiratory stridor was audible. We bronchoscopically observed the disturbance of bilateral vocal cord abduction and the involuntary movements of vocal cords. The findings of the electromyogram demonstrated this to be not the paralysis, but the dyskinesia of the internal laryngeal muscles. These results suggest that dyskinesia of the vocal cords is complicated in OPCA. We found no report of vocal cord dyskinesia complication in OPCA, but several reports have found vocal cord paralysis in SDS. In 1979, Williams et al[1] described that eight out of 12 patients with SDS were found to have severe bilateral paralysis of vocal cord abduction. Bannister et al[2] reported, in 1981, that three cases of SDS with laryngeal stridor severe enough to require tracheostomy and the histologic studies showed marked atrophy of the posterior cricoarytenoid muscle, so the patients' stridor was caused by the selective paralysis of these muscles. The present case emphasizes the fact that vocal cord dysfunction can occur in OPCA. Respiratory failure due to such vocal cord dysfunction can lead to sudden death. It is very important to be aware of this complication in OPCA in order to avoid sudden death.
REFERENCES
[1] Williams A, Hanson D, Calne DB. Vocal cord paralysis in Shy-Drager syndrome. J Neurol Neurosurg Psychiatr 1979; 42:151-53
[2] Bannister R, Gibson W, Michaels L, Oppenheimer DR. Laryngeal abductor paralysis in multiple system atrophy: a report on three necropsied cases, with observation on the laryngeal muscles and the nuclei ambigui. Brain 1981; 104:351-68
[3] Morikawa I, Maeyama T, Shin T, Watanabe H, Matsuda T, Kuroda Y. A case of Shy-Drager syndrome with bilateral vocal cord dysfunction. Pract Otol 1987; 80:1087-92
[4] Guindi GM, Bannister R, Gibson WPR, Payne JK. Laryngeal electromyography in multiple system atrophy with autonomic failure. J Neurol Neurosurg Psychiatr 1981; 44:49-53
[5] Graham JG, Oppenheimer DR. Orthostatic hypotension and nicotine sensitivity in a case of multiple system atrophy. J Neurol Neurosurg Psychiatr 1969; 32:28-34
[6] Bannister R, Oppenheimer DR. Degenerative diseases of the nervous system associated with autonomic failure. Brain 1972; 95:457-74
COPYRIGHT 1989 American College of Chest Physicians
COPYRIGHT 2004 Gale Group
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