| The authors report the case of a 16-month-old male with suspected leigh disease, which was diagnosed on the basis of the clinical manifestations, abnormal lactate stimulation test, proton magnetic resonance spectroscopy, and neuroradiologic findings. Progressive stridor resulting from bilateral vocal cord paralysis and hypoventilation was evident. The authors suggest that for infants or children who exhibit vocal cord paralysis, mitochondrial disorders, such as leigh disease, should be considered. ( info) |
2/104. Infantile lipid storage myopathy with nocturnal hypoventilation shows abnormal low-affinity muscle carnitine uptake in vitro. An infant with respiratory insufficiency, cardiomyopathy, lipid storage myopathy and low muscle carnitine was diagnosed as having 'Ondine's curse' because of recurrent nocturnal hypoventilation. carnitine uptake was studied in 20-day-old cultured muscle, where two distinct saturable transport components are recognized: the high- and low-affinity-uptake. Experimental evidence suggests that low-affinity-uptake is muscle-specific, operating at physiological carnitine concentration. In the patient's cultured myotubes, the low-affinity-uptake K(m) was 260% of controls (P < 0.01), whereas kinetic parameters of high-affinity uptake were normal. The high K(m) indicates an immature or altered carnitine muscle carrier, which may decrease the physiologic carnitine uptake. ( info) |
3/104. Late-onset central hypoventilation with hypothalamic dysfunction: a distinct clinical syndrome. Idiopathic central hypoventilation has occasionally been reported in previously well children after infancy. The relationship between this late-onset central hypoventilation syndrome (LO-CHS) and congenital central hypoventilation syndrome (CCHS) has not been established. Both CCHS and LO-CHS have been associated with neural crest tumors, such as ganglioneuroblastoma and ganglioneuroma, and they generally occur in the presence of a histologically normal central nervous system. At least 10 case reports of idiopathic LO-CHS featured evidence of hypothalamic dysfunction (HD), including hyperphagia, hypersomnolence, thermal dysregulation, emotional lability, and endocrinopathies. We report on a case of LO-CHS/HD successfully treated by nasal intermittent positive pressure ventilation (NIPPV). Despite the commonalties with CCHS, we propose that LO-CHS/HD is a distinct clinical syndrome. In addition to the markedly different age at presentation, features of hypothalamic dysfunction are not seen in CCHS. review of the literature was undertaken to further clarify the full spectrum of the disease. ( info) |
4/104. hypoventilation after high unilateral cervical chordotomy in a patient with preexisting injury of the phrenic nerve. Unilateral cervical chordotomy for the relief of intractable pain is a well accepted procedure but is not without hazard. Postoperative respiratory failure is not an uncommon occurrence, but the likelihood increases with a number of factors, particularly preexisting pulmonary abnormalities or previous contralateral cervical chordotomy. Preoperative assessment of the pulmonary function of patients who are about to have cervical chordotomy is emphasized to predict and anticipate potential postoperative respiratory failure. ( info) |
| We report the case of a 13-year-old boy with acetylcholinesterase deficiency, a congenital myasthenic syndrome, who developed sleep hypoventilation syndrome during a period of rapid growth. His symptoms were insidious and life-threatening despite changes in strength or lung volume measurements that were not marked. He responded well to noninvasive nocturnal ventilation, with reversal of symptoms and normalization of blood gases. His lung volumes, but not motor function, improved after treatment. ( info) |
6/104. Unexpectedly severe sleep and respiratory pathology in patients with amyotrophic lateral sclerosis. Daytime fatigue and sleep disturbance are frequent complaints in patients with amyotrophic lateral sclerosis (ALS). However, polysomnographic data are sparse. Nocturnal respiratory insufficiency may occur despite nearly normal daytime pulmonary function. We describe the clinical presentation and polysomnographic findings in two patients with clinically and electrophysiologically confirmed ALS with minimal weakness but excessive daytime sleepiness. polysomnography in the first patient showed a respiratory disturbance index of 43.5, and profound oxygen desaturations to 62%. The second patient had prolonged periods of hypoventilation, with oxygen saturations oscillating between 86 and 83%. Both patients showed severe sleep maintenance insomnia with a sleep efficiency < 40% and frequent arousals while asleep. Application of continuous positive airway pressure (CPAP) restored normal nocturnal ventilation, blood oxygenation and sleep parameters in the first patient; compliance, however, was poor. The second patient was unable to tolerate CPAP. We conclude that ALS patients with excessive daytime sleepiness or insomnia should undergo polysomnography to adequately diagnose nocturnal respiratory insufficiency and sleep disturbance. compliance with treatment, however, may be poor. ( info) |
7/104. Dysfunction of phrenic pacemakers induced by metallic rescue blankets. Phrenic pacing can restore diaphragmatic contractions in patients with central respiratory paralysis. It relies on radiofrequency transmission of energy from an external unit to implanted receivers through circular coil antennas. The case of a patient is reported in whom severe hypoventilation occurred following the use of a metallic rescue blanket. The phenomenon was confirmed in two subsequent patients and during benchmark tests. Possible mechanisms include reflection and diffusion of high frequency waves by a Faraday-like effect. patients with implanted devices relying on telemetric control or powering, and their care givers, should be warned against the use of metallic rescue sheets. ( info) |
8/104. Hypoxic ventilatory depression in a patient with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes. We describe a case of a 21-year-old man with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) who presented with hypoxic ventilatory depression. He had chronic hypoventilation, which was not explained by weakness of respiratory muscles. His hypercapnic ventilatory response was not impaired. In contrast, hypoxic ventilatory depression was observed in the isocapnic progressive hypoxic response test. After exposure to hypoxic conditions, his respiratory frequency decreased and tidal volume was unchanged. The hypoxic ventilatory depression was partially blocked by pretreatment with aminophylline. In conclusion, we need to be careful with patients with MELAS who are hypoxaemic because a vicious circle of hypoxia and hypoventilation can occur. ( info) |
| A case of neonatal myotonic dystrophy (MD) is presented. A 35 week old 3570 g baby was born to a mother affected by MD and pregnancy-induced unstable diabetes. Soon after birth, he developed apnea, severe hypoglycemia, hypocalcemia, hypotonia and mild respiratory distress. His clinical course improved during the following days, but persistent episodes of desaturation and/or cyanosis did not subside; hypotonia was mild. A polysomnographic recording showed mixed central and obstructive apnea. dna testing showed trinucleotide repeat expansion mutations diagnostic of MD. The baby was discharged with home-sleep monitoring and breast-feeding. Recurrent apnea/bradycardia was the main clinical feature in this case of congenital MD, with increased risk of an acute life-threatening event. ( info) |
10/104. Malignant hyperinflation of the nondependent lung during chest surgery. Unilateral malignant hyperinflation of the lungs during positive pressure mechanical ventilation was described during aggressive respiratory therapy of unilateral lung disease or in situations of significant difference in compliance between the two lungs. We report a case of malignant hyperinflation of the nondependent lung during chest surgery. The differential diagnosis and treatment with differential lung ventilation are described. ( info) |