Impact of sleep on respiratory muscle function

Sleep has well recognised effects on respiratory muscle function, most of which are detrimental. Upper airway dilator muscle function is compromised, which predisposes to obstruction, particularly during rapid-eye-movement sleep (REM). The diaphragm and accessory muscles of respiration are differently affected by sleep. Diaphragmatic function is largely preserved, which is essential for the maintenance of adequate ventilation during sleep. However, accessory muscle function is reduced, particularly during REM sleep, which may have adverse effects on lung mechanics. These changes contribute to hypoventilation and worsening ventilation-perfusion mismatching, particularly in patients with chronic lung disease such as COPD, with resulting oxygen desaturation.

[Myotonic dystrophy and bundle-branch re-entrant tachycardia]

We report the case of a 37-year-old man diagnosed with myotonic dystrophy who presented atrial fibrillation with high ventricular rate. While being treated with amiodarone, he suffered cardiac arrest. The electrophysiological study disclosed bundle-branch reentrant ventricular tachycardia and ventricular fibrillation. Catheter ablation of the right bundle branch was performed and a bicameral defibrillator was implanted. The mechanisms and treatment of arrhythmias in these patients are discussed.

Congenital muscular dystrophy with adducted thumbs, ptosis, external ophthalmoplegia, mental retardation and cerebellar hypoplasia: a novel form of CMD

At least six different forms of congenital muscular dystrophy are associated with structural changes of the central nervous system, and three of these have been mapped: merosin-deficient congenital muscular dystrophy on chromosome 6q2, Fukuyama congenital muscular dystrophy on chromosome 9q31, and muscle eye brain disease on chromosome 1p32. Walker-Warburg syndrome, congenital muscular dystrophy with calf hypertrophy, pontocerebellar hypoplasia, and normal eyes, and congenital muscular dystrophy with severe mental retardation and cerebellar cysts are nosologically distinct and have been excluded from the known congenital muscular dystrophy loci with structural changes of the central nervous system. Here, we describe a novel congenital muscular dystrophy syndrome which is phenotypically distinct from the recognized forms of congenital muscular dystrophy with brain involvement. Two siblings, a boy and a girl, were born to consanguineous parents from Sicily. Both children were born with adducted thumbs and toe contractures. They were floppy from birth, walked late, showed profound generalized muscle weakness including facial muscles, elevated creatine kinase levels of 200-700U/l, and histological changes compatible with muscular dystrophy. In addition, both showed ptosis, external ophthalmoplegia, mild mental retardation, and mild cerebellar hypoplasia on MRI. Immunocytochemistry showed normal expression of muscle membrane proteins including laminin alpha 2, laminin beta 2, and alpha-dystroglycan. Linkage analysis excluded the candidate loci on chromosomes 6q2, 9q31, and 1q32. The gene locus for congenital muscular dystrophy 1B, MDC 1B, on chromosome 1q42 was also excluded. Adducted thumbs are a distinct clinical sign that has not been reported in congenital muscular dystrophy before and should facilitate recognition of further patients with this disorder.

Rigid spine syndrome with chronic respiratory failure

Rigid spine syndrome (RSS) is a rare myopathic ailment characterized by mild axial and proximal muscle weakness. Muscle contraction in these patients causes limitation of neck and trunk flexion, scoliosis, and mild joint deformity. We report the case of a 30-year-old man with RSS who presented with severe restrictive ventilatory defect (forced vital capacity, 1.53 L, 39% of predicted), mild scoliosis (Cobb's angle 12), proximal muscle weakness and stiff back. Creatine phosphokinase was 986 IU/L. Muscle biopsy of the right vastus lateralis revealed increased variation in muscle fiber diameter, proliferation of endomysium, and type I fiber atrophy. Round and whorled fibers indicating myopathic change were found on sections stained with nicotinamide adenine dinucleotide dehydrogenase and succinate dehydrogenase. RSS was diagnosed based on myopathic findings and clinical presentation. Nocturnal chronic respiratory failure and fragmented sleep developed. He was treated with continuous positive airway pressure and had recovered his normal daily activity by 1-year follow-up. We suggest that patients with RSS should be assessed for possible ventilatory failure; treatment with nasal continuous positive airway pressure or bilevel continuous positive airway pressure therapy should be considered.

Lamin A/C mutations with lipodystrophy, cardiac abnormalities, and muscular dystrophy

Mutations in the lamin A/C gene are found in Emery-Dreifuss muscular dystrophy, limb girdle muscular dystrophy with cardiac conduction disturbances, dilated cardiomyopathy with conduction system disease, and familial partial lipodystrophy. Cases with lamin A/C mutations presenting with lipodystrophy in combination with cardiac and/or skeletal muscle abnormalities are described.

Cardiomyopathy is independent of skeletal muscle disease in muscular dystrophy

Dystrophin and its associated proteins, the sarcoglycans, are normally expressed in heart and skeletal muscle. Mutations that alter the expression of these membrane-associated proteins lead to muscular dystrophy (MD) and cardiomyopathy in humans. Because of the timing and nature of the accompanying cardiomyopathy, it has been suggested that cardiomyopathy develops as a secondary consequence of skeletal muscle dysfunction in the muscular dystrophies. To determine whether skeletal muscle dystrophy contributes to the development of sarcoglycan-mediated cardiomyopathy, we used mice lacking gamma-sarcoglycan and inserted a transgene that "rescued" gamma-sarcoglycan expression only in skeletal muscle. Gamma-sarcoglycan was expressed in skeletal muscle under the control of the skeletal muscle-specific myosin light chain 1/3 promoter. Gamma-sarcoglycan-null mice expressing this transgene fully restore gamma-sarcoglycan expression. Furthermore, the transgene-rescued mice lack the focal necrosis and membrane permeability defects that are a hallmark of MD. Despite correction of the skeletal muscle disease, focal degeneration and membrane permeability abnormalities persisted in cardiac muscle, and notably persisted in the right ventricle. Therefore, heart and skeletal muscle defects are independent processes in sarcoglycan-mediated muscular dystrophies and, as such, therapy should target both skeletal and cardiac muscle correction to prevent sudden death due to cardiomyopathy in the muscular dystrophies.

Recurrent pneumothoraces associated with nocturnal noninvasive ventilation in a patient with muscular dystrophy

Although a common complication of mechanical ventilation in acute respiratory failure, spontaneous pneumothorax has been rarely reported among patients on chronic, intermittent, noninvasive positive pressure support. We report the first case of recurrent pneumothoraces associated with nocturnal bilevel positive airway pressure ventilation via a nasal mask.A 26-year old man with chronic respiratory failure secondary to an unclassified neuromuscular condition suffered four separate episodes of spontaneous pneumothorax over a 12-month period. Two episodes occurred while he was asleep on bilevel positive airway pressure support. He was found to have numerous subpleural blebs, and we propose a mechanism for their development. Following open pleurodesis and blebectomy, the patient has not had another pneumothorax. Given the increasing utilization of chronic nocturnal bilevel positive airway pressure ventilation, we suggest that healthcare providers and patients be made aware of this potentially life-threatening complication.

Neuromuscular scoliosis: causes of deformity and principles for evaluation and management

Scoliosis is commonly associated with a variety of neuromuscular disorders including conditions affecting upper and lower motor neurons as well as myopathies. Contained herein is a discussion of the spectrum of neuromuscular disorders that have been associated with scoliosis and related spinal deformities. Management, including surgical treatment in such patients, is summarized including indications, expectations, and impact on trunk balance, pulmonary function, and appearance.

Severe progressive form of congenital muscular dystrophy with calf pseudohypertrophy, macroglossia and respiratory insufficiency

A novel form of congenital muscular dystrophy in four unrelated patients is proposed. Congenital hypotonia, markedly increased CK, calf pseudohypertrophy and proximal weakness were common early findings. Two cases were severely affected since infancy and never walked. The phenotypical homogeneity was not very evident until advanced stages of the disease. All the patients showed catastrophic progression of the weakness, severe restrictive respiratory insufficiency, macroglossia, peculiar extreme amyotrophy of hands and feet, and a round and 'puffy' face. All patients became tetraplegic and required mechanical ventilation. Two cases had signs of mild cardiac involvement. The only non-tracheotomised patient died of respiratory complications. No mental retardation or specific brain abnormalities were observed. All patients showed secondary deficit of laminin 2 and up-regulation of laminin 5 in muscle. Expression of -dystroglycan was severely reduced in two available muscle samples. The known loci for congenital muscular dystrophies were excluded in the only consanguineous case by linkage analysis. Clinical, immunohistochemical and genetic findings strongly suggest a distinct entity.

Collagen VI involvement in Ullrich syndrome: a clinical, genetic, and immunohistochemical study

BACKGROUND

Ullrich congenital muscular dystrophy (UCMD) is a form of merosin-positive congenital muscular dystrophy characterized by proximal contractures, distal laxity, rigidity of the spine, and respiratory complications. Recently, a deficiency of collagen VI on muscle and skin biopsy together with recessive mutations in the collagen 6A2 gene were reported in three families with UCMD. However, the clinical spectrum, frequency, and level of heterogeneity of this disorder are not known.

SUBJECTS AND METHODS

The authors studied 15 patients (aged 3 to 23.6 years) with a clinical diagnosis of UCMD. Linkage analysis to the three collagen VI genes was performed in all informative families (n = 7), whereas immunohistochemical analysis of collagen VI expression in muscle was performed in the remaining cases.

RESULTS

An immunocytochemical reduction of collagen VI was observed in six patients. Three of the six patients belonged to informative families, and haplotype analysis clearly suggested linkage to the COL6A1/2 locus in two cases and to the COL6A3 loci in the third case. In the remaining nine patients, primary collagen VI involvement was excluded based on either the linkage analysis (four families) or considered unlikely based on normal immunolabeling of collagen VI. Age and presentation at onset, the distribution and severity of weakness and contractures, and the frequency of nonambulant patients were similar in the patients with and without collagen VI involvement. Distal laxity, rigidity of the spine, scoliosis, failure to thrive, and early and severe respiratory impairment were found in all patients by the end of the first decade of life, irrespective of their maximum motor functional ability or their collagen status.

CONCLUSIONS

These results suggest that collagen VI involvement is relatively common in UCMD (40%); however, the role of this molecule was excluded in a number of cases, suggesting genetic heterogeneity of this condition.

Management of myogenic ptosis

OBJECTIVE

To review the genetics, clinical features, and management of patients affected by myogenic ptosis.

DESIGN

Retrospective, noncomparative interventional case series.

PARTICIPANTS

Twenty-eight patients with myogenic ptosis.

METHODS

A review of all patients with myogenic ptosis between 1992 and 2000 was made in a tertiary oculoplastics practice.

MAIN OUTCOME MEASURES

Ocular and systemic findings associated with myogenic ptosis were examined. Patients were diagnosed clinically, and ancillary tests (including genetic tests and muscle biopsy histologic findings) were reviewed. Surgical management principles and complications are discussed.

RESULTS

Most of our ptosis patients had chronic progressive external ophthalmoplegia (43%), oculopharyngeal muscular dystrophy (OPMD; 18%), and myotonic dystrophy (18%). Fifty percent of myogenic ptosis patients in our series underwent frontalis suspensions. Twenty-one percent of patients who initially had operations at our institution had minor complications, most related to corneal exposure. The most common ocular finding other than ptosis and ophthalmoplegia was pigmentary retinopathy (25%). The most common systemic finding in our patients was dysphagia (43%). Genetic testing for OPMD was highly sensitive. Muscle biopsy results for mitochondrial myopathies were less accurate as adjunctive diagnostic tests.

CONCLUSIONS

Myogenic ptosis should be considered in the differential diagnosis of any atypical ptosis presentation. To avoid complications, surgery should be performed only when the visual axis is obscured. We recommend the use of silicone slings in any patient with severe ptosis and less than 8 mm of levator function. Genetic testing of patients with myogenic ptosis is important to allow accurate diagnosis and to permit appropriate counseling on potentially life-threatening health issues.

Alpha-sarcoglycan deficiency featuring exercise intolerance and myoglobinuria

An 8-year-old boy was referred for recent onset of easy fatigue. He showed hyperCKemia and mild scapular winging. Muscle biopsy on the quadriceps muscle demonstrated slight fibre size variability. Dystrophin was normally distributed, carnitine palmitoyl transferase and glycolytic enzymes had normal activities. In the following years the patient developed exercise intolerance and myoglobinuria. Immunohistochemistry showed marked reduction of alpha-sarcoglycan, confirmed by Western blotting. Molecular analysis revealed compound heterozygosity with Arg284Cys and Glu137Lys substitutions, corresponding to nucleotide changes C850 T and G409 A in the gene. At present the patient, 20 years old, shows mild proximal weakness with prominent involvement of the paraspinal muscles, dorsal kyphosis and lumbar hyperlordosis. Exercise intolerance and myoglobinuria, already described in Becker muscular dystrophy, should be also considered among the possible presentations of sarcoglycan deficiencies.

Pseudohypertrophic muscular dystrophy with pulmonary valve stenosis: an unusual association

A patient with pulmonary valve stenosis associated with pseudohypertrophic muscular dystrophy is reported. The anomalies were detected by two-dimensional echocardiography and elevated serum enzymes, conformed by right ventriculography and muscles biopsy. The association between these two pathologies is unknown.

Hyperzincemia with systemic inflammation: a heritable disorder of calprotectin metabolism with rheumatic manifestations?

A boy had infantile-onset systemic inflammation, growth failure, hepatosplenomegaly, anemia, leukocytopenia, progressive muscular dystrophy, and hypercalprotectinemia, resulting in marked hyperzincemia. His mother had a history of chronic arthritis since childhood and also showed hypercalprotectinemia/hyperzincemia. We postulate an inherent defect in calprotectin metabolism.

Nonmuscular involvement in merosin-negative congenital muscular dystrophy

The spectrum of nonmuscular involvement in six children with merosin-negative congenital muscular dystrophy is described. In all children, biochemical, neuroradiologic, cardiac, and neurophysiologic studies were performed. Cerebral structures that were myelinated at gestation, including internal capsule, corpus callosum, brainstem, and cerebellar white matter, demonstrated no abnormalities, whereas the periventricular and subcortical white matter, which were myelinated in the first postnatal year, demonstrated signs of leukoencephalopathy. Cerebrospinal fluid analysis revealed an elevated albumin cerebrospinal fluid to serum ratio in the younger children. Electroencephalogram results were abnormal in the two elder children. One child suffered from congestive cardiomyopathy. The increase in nerve conduction velocity in these children over the years lagged behind those of healthy patients, pointing to a demyelinating neuropathy. We conclude that in merosin-negative congenital muscular dystrophy patients, nonmuscular involvement includes the central and peripheral nervous system and the heart. The pattern of myelination of the brain and nerve conduction slowing suggests a myelination arrest. Merosin deficiency can give rise to a congestive cardiomyopathy, which is of no clinical relevance in the majority of children.

[Neurogenic spinal deformities. I. Conservative and surgical treatment of spinal deformities]

Neurogenic spinal deformities develop primarily due to insufficient dynamic stabilization against gravity. Unilateral muscle overactivity is another but rare cause. The aim of treatment is to provide stability as well as to prevent deformity. In mild cases, the treatment of choice is a spinal brace because stabilization can be combined with residual mobility and adequate correction of shape. Seating shells are more readily accepted but less appropriate for this purpose. In severe cases, surgery is a good option despite the considerable effort involved and high rate of complications.

Impact of pregnancy on respiratory capacity in women with muscular dystrophy and kyphoscoliosis. A case report

BACKGROUND

Restriction of the chest wall in pregnancy prevents adaptive physiologic hyperventilation. This in turn might gradually promote respiratory insufficiency.

CASE

Two consecutive pregnancies occurred in a woman with severe kyphoscoliosis due to juvenile muscular dystrophy. The patient died postpartum.

CONCLUSION

Pregnancies with restrictive lung diseases, including severe scoliosis and kyphoscoliosis, should be considered high risk and thus should be monitored and managed carefully.

Oculopharyngeal muscular dystrophy complicating airway management

Oculopharyngeal muscular dystrophy (OPMD) is an uncommon autosomal dominant disorder characterized by late onset and slow progression. Complications of OPMD include ptosis and progressive dysphagia leading to eventual malnutrition and aspiration. We report a rare case of OPMD complicating mechanical ventilator management following emergent surgery. OPMD and the resulting dysphagia contributed to multiple intubations, tracheostomy, aspiration pneumonia, and a prolonged hospital course. Awareness of the possibility of OPMD in intubated patients with a history of dysphagia is crucial for avoidance of complications.

Sleep disorders in children with neurologic diseases

Pediatric neurologic diseases are often associated with different kinds of sleep disruption (mainly insomnia, less frequently hypersomnia or parasomnias). Due to the key-role of sleep for development, the effort to ameliorate sleep patterns in these children could have important prognostic benefits. Study of sleep architecture and organization in neurologic disorders could lead to a better comprehension of the pathogenesis and a better treatment of the disorders. This article focuses on the following specific neurologic diseases: nocturnal frontal lobe epilepsy and abnormal motor behaviors of epileptic origin, evaluating differential diagnosis with parasomnias; achondroplasia, confirming the crucial role of craniofacial deformity in determining sleep-disordered breathing; neuromuscular diseases, mainly Duchenne's muscular dystrophy and myotonic dystrophy; cerebral palsy, evaluating either the features of sleep architecture and the importance of the respiratory problems associated; headaches, confirming the strict relationships with sleep in terms of neurochemical and neurobehavioral substrates; and finally a review on the effectiveness of melatonin for sleep problems in children with neurologic syndromes and mental retardation, blindness, and epilepsy.

[Assessment of quality of life in patients with chronic obstructive bronchitis]

The investigation performed in 117 patients with chronic obstructive bronchitis (COB) revealed a significant decline in quality of life (QL) with progressive disease. Decrement of QL level in patients with stage I and II COB has been found to be primarily associated with activation of the sympathetic nervous system and progressing of metabolic myocardial dystrophy. With stage III COB decline in QL is also caused by reduction of volume of the functional pulmonary parenchyma.

[The circulatory system in children suffering from progressive muscular dystrophy]

The aim of the study was to present the state of circulatory system in course of progressive muscular dystrophy. The results of clinical examination, as well as electrocardiography, echocardiography, cardiac catheterization, chest x-ray and histopathology of the tissues of the chest and vessels were described.

Distinguishing cardiac features of a novel form of congenital muscular dystrophy (Salih cmd)

The cardiac features of a novel form of congenital muscular dystrophy (Salih CMD) are described in two adolescent siblings. The patients presented with severe hypotonia at birth, associated with delayed development. They could walk independently and managed to maintain walking after 13 years of age. Their muscle immunohistochemistry differed from that seen in Duchenne and Becher muscular dystrophy (DMD and BMD), severe childhood autosomal recessive muscular dystrophy (SCARMD) due to sarcoglycan deficiency (sarcoglycanopathies), and lamininalpha2 (merosin)-deficient CMD. However, both patients had associated cardiomyopathy. Electrocardiography (ECG) in Salih CMD was characterized by delayed atrioventricular (AV) conduction, left anterior fascicular block (left axis deviation), and left atrial enlargement without evidence of atrial dysarrhythmia. Echocardiography showed features of severe left ventricular dysfunction with estimated left ventricle ejection fraction (LVEF) of 25% at 16 years-of-age in the older patient. A year later, multigated aquisition MUGA scan showed LVEF of 21% and dilatation of the right ventricle. Echocardiography and MUGA scan were normal in the younger patient at 15 years-of-age. ECG, echocardiography, and MUGA scan are effective techniques for diagnosing and monitoring the cardiomyopathy in Salih CMD. They can also distinguish it from features seen in the other common forms of MD, including DMD, BMD, and sarcoglycanopathies.

Swallowing in myotonic muscular dystrophy: a videofluoroscopic study

OBJECTIVES

(1) To determine how swallow function in patients with myotonic muscular dystrophy (MD) differs from that of healthy controls, (2) to identify the contributors to and predictors of improvement, and (3) to evaluate strategies that facilitate swallowing.

DESIGN

Observational.

SETTING

University medical center.

PARTICIPANTS

Eighteen adults with myotonic MD (age range, 24-58 yr) and 60 healthy adult control subjects (age range, 18-73 yr).

INTERVENTIONS

Swallow facilitation strategies.

MAIN OUTCOME MEASURES

Between-group comparisons of mean bolus transit times, onsets of swallow gestures, and displacement measures obtained by dynamic lateral view videofluoroscopy.

RESULTS

The MD patients' bolus transit times were significantly longer, and onsets of some swallow gestures were significantly delayed. Upper esophageal sphincter opening was prolonged (myotonic MD,.61 +/-.13s; control,.5 +/-.11s). Hyoid displacement was significantly less in men with myotonic MD (1.9 +/-.05 cm) than in male controls (2.4 +/-.68 cm); this difference was not observed between control and myotonic women. Of particular importance was the markedly reduced pharyngeal constriction found in the MD group.

CONCLUSIONS

Weakness associated with the disease, as opposed to myotonia, was the most significant contributor to impairment. Persons at risk for aspiration may be identified by a measure of pharyngeal area. Selected strategies to facilitate pharyngeal clearing are worthwhile.

[Echocardiography in storage and neuromuscular disorders]

Storage disorders and neuromuscular disorders may lead to cardiac involvement which can be visualized by echocardiography. In storage disorders like hypothyroidism, haemochromatosis, amyloidosis, mucopolysaccharidosis and Fabry's disease, myocardial thickening and systolic dysfunction can be found. In amyloidosis, atrial enlargement and abnormal texture of the myocardium are additional findings. In advanced haemochromatosis all cardiac chambers may be dilated. In hypothyroidism and amyloidosis, a pericardial effusion can be present. In haemochromatosis and amyloidosis, a restrictive filling pattern may be detected using Doppler-sonography. Mucopolysaccharidosis and Gaucher's disease may lead to aortic and mitral stenosis. In neuromuscular disorders like glycogenosis, mitochondriopathy and myotonic dystrophy, myocardial thickening and systolic dysfunction are found, in spinal muscular atrophy myocardial thickening and in muscular dystrophy Becker/Duchenne systolic dysfunction. An abnormal myocardial texture may be present in glycogenosis, isolated left ventricular abnormal trabeculation (ILVAT) in mitochondriopathy, myotonic dystrophy and muscular dystrophy Becker/Duchenne. Using Doppler-sonography an impaired relaxation of the left ventricle may be detected in mitochondriopathy, myotonic dystrophy and spinal muscular atrophy. Most of these echocardiographic findings are unspecific and may be overlooked, especially if the storage or neuromuscular disorder is yet unknown. Establishing a correct diagnosis is important, since healing or functional improvement is possible in many of these disorders.

Limb girdle muscular dystrophy type 2A presenting with cardiac arrest

The occurence of respiratory failure in progressive neuromuscular disorders is well recognized. This failure is observed most commonly in Duchenne dystrophy but sometimes occurs in Becker's, limb-girdle, and facioscapulohumeral dystrophies. Patients usually present acutely or subacutely with cyanosis and cor pulmonale, with severe decompensation often being precipitated by an acute intercurrent infection. However, cardiopulmonary arrest is an uncommon presentation. A male diagnosed with limb-girdle muscular dystrophy type 2A who presented with cardiopulmonary arrest that was precipitated by an upper respiratory tract infection is presented. The nocturnal application of noninvasive intermittent positive pressure ventilation with a bilevel positive airway pressure (Bi-PAP) device improved his symptoms and quality of life without resorting to more-invasive and more-restrictive forms of support. This report demonstrates an unusual presentation of limb-girdle muscular dystrophy and documents that nocturnal nasal administration of continuous airway pressure using the Bi-PAP device may be sufficient to maintain adequate ventilation in such patients.

[Surgery for blepharoptosis in muscular dystrophy]

In some muscular dystrophies there is ocular involvement characterized by blepharoptosis and ophthalmoplegia. These conditions occur in chronic progressive external ophthalmoplegia, oculopharyngeal muscular dystrophy, mitochondrial myopathy, myotonic dystrophy, and ocular myasthenia, among others. Although they differ in their systemic clinical manifestations and in genetic inheritance, ocular involvement is common to all of them. Manifestations include bilateral progressive blepharoptosis with or without extraocular muscle malfunction. During surgical repair of the ptotic eyelid, consideration must be given to eyeball movements, in addition to maximal eyelid elevation, and to avoiding overcorrection and consequent corneal overexposure, leading to dryness and visual impairment. With these muscular dystrophic disorders, resection of the levator muscle or blepharoplasty alone does not suffice. Follow-up shows that most patients need a secondary repair after a short while. Operative correction uses a frontalis sling for eyelid elevation and support. A series of 8 patients with these diseases, operated on by various surgical techniques during the past 7 years, is presented.

Evaluation of heart involvement in gamma-sarcoglycanopathy (LGMD2C). A study of ten patients

Thorough non-invasive cardiovascular studies were conducted in a series of ten gamma-sarcoglycanopathy Gypsy patients with the founder C283Y mutation in 13q12. Results were compared with those obtained in an age-matched group of normal boys and girls. The studies included electrocardiographic and echocardiographic evaluations using pulsed wave Doppler tissue imaging to assess regional diastolic function and myocardial velocities at various levels. This study confirms the significant electrocardiographic abnormalities described in previous studies. Furthermore, measurement of myocardial velocity at different levels demonstrated an abnormal relaxation pattern in the tricuspid annulus in four of the oldest patients, which strongly suggests intrinsic myocardial involvement of the right ventricle. To our knowledge, these specific studies have not been previously performed in a clinically and genetically homogeneous group of gamma-sarcoglycanopathy patients and suggest primary myocardial involvement probably due to gamma-sarcoglycan deficiency in cardiac muscle fibres. Our results could be of interest in the follow-up of these patients and the prevention and treatment of late cardiological complications.

Merosin-deficient congenital muscular dystrophy with mental retardation and cerebellar cysts unlinked to the LAMA2, FCMD and MEB loci

We report a case of congenital muscular dystrophy with secondary merosin deficiency, structural involvement of the central nervous system and mental retardation in an 8-year-old girl from a consanguineous family. She had early-onset hypotonia, generalized muscle wasting, with weakness especially of the neck muscles, joint contractures, mental retardation and high creatine kinase. Muscle biopsy showed dystrophic changes with partial deficiency of the laminin alpha(2) chain. Cranial magnetic resonance imaging revealed multiple small cysts in the cerebellum, without cerebral cortical dysplasia or white matter changes. The laminin alpha(2) chain (6q2), Fukuyama type congenital muscular dystrophy (9q31-q33) and muscle-eye-brain disease (1p32-p34) loci were all excluded by linkage analysis. We suggest that this case represents a new entity in the nosology of congenital muscular dystrophy.

Evaluation of dysrhythmia in children with muscular dystrophy

Myocardial involvement and dysrhythmia are common findings with muscular dystrophy and are among the leading causes of death. The authors evaluated rhythm and conduction abnormalities in children with muscular dystrophy by electrocardiography, signal-averaged electrocardiography, and Holter monitoring. Twenty-nine patients (mean age, 8 years) and 29 healthy control subjects were included in the study. Sixty-two percent of patients had electrocardiographic abnormalities defined as deep Q waves in V6, tall R waves in V1, and QRS axis deviation. The cardiomyopathy index was significantly greater in the patient group whereas QT and QTc dispersion values showed no significant difference. Holter monitoring revealed premature atrial and ventricular contractions more frequently than normal. However all were classified as Lown I and II. Mean heart rate was significantly higher in the patient group. The electrocardiograms of 41% of the patients showed late potentials. No relationship with these changes and cardiac function was observed. During the study, one patient died whose cardiomyopathy index was longer and had late potentials detected with signal-averaged electrocardiography. In conclusion, standard electrocardiography, cardiomyopathy index, signal-averaged electrocardiography, and Holter monitoring are valuable and reliable monitoring methods in children with muscular dystrophy.

Changing ventilator: An option to take into account in the treatment of persistent vomiting during nasal ventilation

Problems related with nasal intermittent positive pressure ventilation (NIPPV) are nasal and mouth dryness, soreness on the bridge of the nose, eye irritation and epistaxis. Gastrointestinal distention due to air swallowing has been reported in half of the patients. Acceleration of digestive function with drugs or reduction of the volume delivered to alleviate gastric distension are considered as the conventional treatment. It is also possible that the problem disappears spontaneously after a few weeks of NIPPV. We present a patient in whom conventional treatment was unsuccessful. When we changed to a different ventilator, symptoms disappeared, and the new one was very well tolerated. In our experience, changing ventilators should be included in the management of gastrointestinal distension due to NIPPV, especially if conventional procedures, such as drugs or gas flow modifications, fail.

[A pilot study to establish a support system using SpO2 monitoring system and videoconference system for patients under home mechanical ventilation]

Development of portable ventilators has enabled patients suffering from respiratory failure to live outside hospitals. The number of patients with neuromuscular disorders receiving home mechanical ventilation (HMV) has been increasing year by year. However, Japanese social support services are not sufficient for these patients. Thus, we tried to establish a system to support patients under HMV using SpO2 monitoring system and videoconference system. Pulse oximeter was connected to a portable personal computer, which stores real-time data and send daily data to hospital. The computer in our hospital receives patient's data and prints out it as a trend-graph, which enables medical staffs to know patient's condition. When SpO2 deteriorates significantly, alarm system works automatically to warn patient's family. In case SpO2 worsens more severely, alarm also warns medical staffs in our hospital to call the patient to confirm patient's condition and to give advices. Videoconference system was also introduced to communicate quickly and correctly. Thirty-four patients with progressive muscular dystrophy attended this study after informed consents. They used these systems in the period between discharge and first visit to hospital. Videoconference system was utilized in only two patients, because it required a digital line. These systems were effective in decreasing anxieties of patients and their families about HMV. According to daily check, 16 of 34 patients showed temporary deterioration of respiratory condition, although all patients had been in good condition in hospital. Loosening of the belt of nasal mask, air leak from opened mouth were frequent causes for the deteriorations. These problems could be corrected smoothly after discussion and advices. Thus this system was very useful to establish good respiratory management in a short period. Monitoring system also detected troubles of ventilators. Two patients showed progressive worsening of SpO2 day by day, however we could not find any problems in their respiratory managements. When we checked the ventilator, there were lumps of dust at the upper-pressure limit valves, which caused air leak. It was revealed that 3 of 27 ventilators had the same troubles, which caused leaks more than 10% of the flow volume. This fact proved that this system was also effective to prevent severe troubles from unexpected problems about HMV. Videoconference system enabled us to communicate quickly and correctly. It was also convenient to give advices. It is quite difficult for ordinary people to explain and understand physical condition and methods to handle respirator with only oral communication. Visual communication solved these troubles almost completely. Although there are some problems about this system including high cost and quality of picture, it is undoubtedly powerful tool. It is natural for patients with respiratory failure to wish to stay their home, when they possessed portable respirators. So it is important to decrease the risk related to HMV. We verified that the combination of monitoring system and multimedia can produce effective support system. It is important to improve these systems and cut down the cost for popularization.