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 sleepdisordered 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%)

Sudden death has been reported in patients with multiple system atrophy (MSA), although the frequency of this event has not been well delineated. We investigated the frequency and potential causes of sudden death in patients with MSA. During the 5-year observation period, 10 of 45 patients with probable MSA died. The causes of death included sudden death of unknown etiology (seven patients), aspiration pneumonia (one patient), asphyxia after vomiting (one patient), and lung cancer (one patient). The mean survival time of patients with sudden death was 63.0 +/- 24.7 months (range, 39-116 months). Among seven patients who experienced sudden death, six were found to have died during sleep. Among these patients, two had been treated with tracheostomy and three with continuous positive airway pressure (CPAP) or noninvasive positive pressure ventilation (NPPV) during sleep, suggesting that these treatments do not always prevent sudden death in patients with MSA. Nocturnal sudden death should be recognized as the most common mechanism of death in patients with MSA.

The c-jun protein functions as a transcription factor for many genes, and the p53 protein functions as a negative regulator of cellular proliferation, which is related to the apoptosis pathway that induces DNA damage. It has recently been shown that c-jun promotes keratinocyte proliferation and p53 induces apoptosis of various cells. In this study, the presence of c-jun and p53 in cholesteatoma was demonstrated by immunoblotting assays using polyclonal rabbit anti-c-jun antibody and monoclonal anti-p53 protein antibody, respectively. The cholesteatoma tissue incubated with anti-c-jun antibody showed the staining of keratinocytes on the basal and spinous layers of epithelium. The c-jun protein was localized in the basal layer of normal skin, and the p53 protein was present in the nucleus of keratinocytes in the granular layer of cholesteatoma epithelium. The keratinocytes of normal external ear canal skins and normal human skins were slightly stained in the granular layer of the epidermis. The present findings suggest that c-jun and p53 proteins have a role in keratinocyte differentiation, proliferation, and apoptosis in the cholesteatoma.

To determine whether tremulous arytenoid movements predict the severity of glottic stenosis in patients with multiple system atrophy (MSA), 28 MSA patients and 14 age-matched controls underwent fiberoptic laryngoscopy with video monitoring during wakefulness and under anesthesia induced by intravenous injection of propofol. Presence or absence of tremulous arytenoid movements was recorded during wakefulness. The ratio of glottic stenosis (%), which represents the extent of airway narrowing under anesthesia, was obtained by measuring the inspiratory glottic angle during wakefulness and under anesthesia. The median ratio of glottic stenosis was significantly higher in patients with MSA (57.5%) than in control subjects (0.5%). Tremulous arytenoid movements were characterized by shaking movements of the arytenoid region including the vocal folds, which are most apparent in the arytenoid cartilage. In this study, tremulous arytenoid movements were observed in 18 (64.2%) of 28 patients with MSA, who displayed a significantly higher median ratio of glottic stenosis (71.2%) than other patients (34.9%). None of the control subjects exhibited tremulous arytenoid movements. A clear correlation existed between the ratio of glottic stenosis and disease duration. Our observations indicate that tremulous arytenoid movements are a marker of the severity of glottic stenosis, which confers an increased risk of upper airway obstruction in patients with MSA.

These findings suggest that caspase-3 and caspase-8 play important roles in programmed cell death, which results in the accumulation of keratin debris during the growth of cholesteatoma. Nuclear factor-kappaB was found in cholesteatoma epithelium, but the transcription factor appeared to be inactivated.