Aquiles J. Roncoroni

Recurrence of thymic hyperplasia after thymectomy in myasthenia gravis: Its importance as a cause of failure of surgical treatment

Persistence of symptoms in patients with myasthenia gravis who have undergone previous thymectomy has been attributed to thymus remnants. Patients with partial or no recovery were studied 40 +/- 31 months (mean +/- SD) after surgery, which had been carried out by the transcervical approach in 20 and trans-sternal approach in four. Lateral x-ray tomography of the mediastinum after injection of air showed images compatible with residual thymus gland in 18 patients (75 percent). Thirteen of these underwent reoperation by the trans-sternal approach, and thymic tissue was found in 11 (85 percent). After repeated thymectomy, 67 percent of the patients improved clinically. Therefore, it is quite reasonable to infer that incomplete removal of the thymus was responsible, at least partly, for failure of the first procedure.

Breathing control in neurological diseases

Abstract. Control of ventilation depends on a brainstem neuronal network that controls activity of the motor neurons innervating the respiratory muscles. This network includes the pontine respiratory group and the dorsal and ventral respiratory groups in the medulla, which contain neurons that fire primarily during inspiration, post-inspiration, or expiration. The ventral respiratory group includes the pre-Bötzinger complex, which contains neurokinin-1 receptor immunoreactive neurons critical for respiratory rhythmogenesis. Structural and degenerative disorders affecting this network produce abnormalities of respiration, including sleep apnea and various patterns of dysrhythmic breathing, not infrequently associated with disturbances of cardiovagal and sympathetic vasomotor control. This emphasizes the important interactions between the respiratory and cardiovascular control networks in the medulla. Common disorders associated with impaired cardiorespiratory control include brainstem stroke or compression, syringobulbia, Chiari malformation, high cervical spinal cord injuries, and multiple system atrophy. This review focuses on the functional organization of the respiratory control network and common causes of impaired control of respiration.

Is asthma in the elderly really different

To examine the nature of asthma in the elderly, we compared older (group 1: 65 years or older, n = 50) with younger patients (group 2: <40 years, n = 99) and to determine the influence of long-standing disease, elderly asthmatics with early onset (group A: onset before 40, n = 22) were compared with patients developing symptoms later in their lives (group B: onset after 40, n = 22). Blood eosinophilia and IgE value ≥100 IU/l were more frequent in younger patients. Short symptom-free periods were more frequent among older asthmatics (78.5 vs. 45.4%, p < 0.001). Only 31.2% of older patients had only mild symptoms. Requirement of systemic steroids was higher in the elderly population. The worst FEV1 was lower in older patients (54.4 ± 17.3 vs. 71.8 ± 18.5%, p {FC96}& 0.001). Patients with early-onset asthma showed more frequently shorter symptom-free periods (93.3 vs. 53.3%, p <0.05), higher emergency admissions/year, and hospitalizations/year. Best FEV1 (group 1: 66.7 ± 13.7% vs. group 2: 90.3 ± 15.1%, p < 0.005) and worst FEV1 (46.2 ± 13.1 vs. 61.0 ± 13.2%, p < 0.01) were lower in early-onset patients. A higher systemic steroid requirement, a lower best and worst FEV1, shorter symptom-free periods and a lesser proportion of patients with only mild symptoms were observed in patients older than 65 with early-onset asthma compared with those younger than 40 years. Elderly patients with a shorter duration of asthma were not different from young patients. Our study strongly suggests that severity of asthma and development of irreversible airflow obstruction depend on the duration of disease.

Nutritional Assessment of Patients with Neuromuscular Diseases

Pessolano FA, Súarez AA, Monteiro SG, Mesa L, Dubrovsky A, Roncoroni AJ, De Vito EL: Nutritional assessment of patients with neuromuscular diseases. Am J Phys Med Rehabil 2003;82:182–185. Objective To study the nutritional status of patients with Duchenne muscular dystrophy and amyotrophic lateral sclerosis. Design A total of 34 Duchenne muscular dystrophy and seven amyotrophic lateral sclerosis patients were studied. Body mass index, patient’s body weight for zero muscle mass as a percentage of the theoretical weight for zero muscle mass, and creatinine-height index were calculated. Results Substantial differences were found between body mass index and percentage of expected weight for zero muscle mass. No amyotrophic lateral sclerosis patients were classified as overweight by body mass index, whereas five were overweight by the percentage of expected weight for zero muscle mass method. Five Duchenne muscular dystrophy patients were classified as overweight by body mass index, and 30 were overweight by the percentage of expected weight for zero muscle mass. According to the creatinine-height index, no patient with amyotrophic lateral sclerosis or Duchenne muscular dystrophy showed normal body muscle mass. No correlation was found between creatinine-height index, percentage of expected weight for zero muscle mass, and body mass index. Conclusions The body mass index should be used with caution for the evaluation of the nutritional status of patients with amyotrophic lateral sclerosis and Duchenne muscular dystrophy. Indices that incorporate the assessment of the compartmental distribution of muscle and fat are more sensitive.

Features of Asthma in the Elderly

Asthma has been considered a rare disease in the elderly, but recent studies have shown that it is as common in the elderly as in the middle-aged population. Diagnosis of asthma is often overlooked in older patients, leading to undertreatment. Spirometry, determination of expiratory flow lability, and histamine challenge tests are tools that are as useful for the evaluation of elderly asthmatics as they are for younger patients. Asthma is more severe in the elderly, especially in long-standing asthmatics. Treatment of asthma in the elderly should follow the same stepwise guidelines that are recommended for all age groups, though it will require more intense monitoring. An aggressive treatment approach to mild and moderate asthma in young people is the best hope of changing the future trends of asthma in the elderly.

Evaluation of bronchodilator response in patients with airway obstruction

The aim of this study was to define the most useful index of expressing bronchodilator response and to distinguish between asthma and COPD. A prospective study was carried out of bronchodilator response in 142 asthmatics and 58 COPD patients in a university hospital. Reversibility was expressed as: 1. absolute change (delta abs); 2. % of initial (delta %init); 3. % of predicted (delta %pred) and 4. % of maximum possible response (delta %max). Dependence on forced expirations volume in 1 sec (FEV1) as % of predicted and sensitivity and specificity for diagnosis of asthma were established. A relationship between delta abs and initial FEV1 was not found in asthma (delta abs vs. % initial FEV1. r = 0.07) or COPD (r = 0.02). delta %pred did not show a correlation in asthma (r = 0.10) or COPD (r = 0.06). delta %init was dependent on the baseline value in asthma (r = 0.38, P < or = 0.001) but not in COPD (r = 0.18, P = n.s.). delta max was dependent in both. The combination of best sensitivity and specificity to separate asthma and COPD was obtained with delta abs (70.4 or 70.6%). The worst specificity for asthma diagnosis was obtained with delta %init (50%). The best likelihood ratios were obtained with delta abs and delta %pred and the worst likelihood ratio with delta %init. delta %init is not recommended as an index for differential diagnosis between asthma and COPD; 2) delta %init overscores bronchodilator response in patients with low FEV1. The independence of each bronchodilator response index should be verified in clinical trials for each selected sample.

Plexogenic Arteriopathy Associated with Pulmonary Vasculitis in Systemic Lupus Erythematosus

Pulmonary arterial hypertension and compulmonale were found in a woman with inactive systemic lupus erythematosus (SLE). The patient died of right heart failure 5 years later. Postmortem study showed SLE reparative lesions, plexogenic arteriopathy and vasculitis in the lung vessels. Since no active SLE was found, the pulmonary vasculitis was attributed to plexogenic arteriopathy.

Reactive Hemophagocytic Syndrome Associated With Disseminated Strongyloidiasis

ABSTRACT: The reactive hemophagocytic syndrome is a condition characterized by systemic proliferation of benign hemophagocytic histiocytes, fever, cytopenia, abnormal liver function, and frequently coagulopathy and hepatospleno- megaly. Its occurrence has been documented in association with viral, bacterial, fungal, and parasitic infections; a wide spectrum of malignant neoplasms; some miscellaneous disorders; and Phenytoin. Disseminated strongyloidiasis is reported in a patient with systemic lupus erythematosus treated with corticosteroids in whom a reactive hemophagocytic syndrome developed and who finally died. This reactive hemophagocytic syndrome is reported for the first time in strongyloidiasis and may not have been recognized in former reports.

Fat embolism of the lungs

Abstract A case of accidental oil pulmonary embolism producing shock and pulmonary edema is presented. Cardiorespiratory function studies showed hyperventilation, anoxemia, and pulmonary arterial hypertension with increased blood flow. Supportive treatment with noradrenaline, oxygen, and adrenocorticotrophin resulted in complete recovery.

Bilateral Carotid Body Paraganglioma and Central Alveolar Hypoventilation

A 62-year-old woman with a bilateral carotid body paraganglioma presented, 2 years after the removal of the right one, with signs of right-heart failure. Hypoxemia, hypercapnia, polycythemia and pulmonary hypertension with normal ventilatory capacity were found. Central alveolar hypoventilation was diagnosed on the basis of absence of ventilatory response and sensation to provoked hypercapnia, prolonged breath-holding time and correction of hypercapnia by voluntary hyperventilation.