Consensus-Based Care Recommendations for Pulmonologists Treating Adults with Myotonic Dystrophy Type 1.

PURPOSE OF REVIEW: Myotonic dystrophy type 1 (DM1) is a severe, progressive genetic disease that affects approximately 1 in 2,500 individuals globally [Ashizawa et al.: Neurol Clin Pract 2018;8(6):507-20]. In patients with DM1, respiratory muscle weakness frequently evolves, leading to respiratory failure as the main cause of death in this patient population, followed by cardiac complications [de Die-Smulders et al.: Brain 1998;121(Pt 8):1557-63], [Mathieu et al.: Neurology 1999;52(8):1658-62], [Groh et al.: Muscle Nerve 2011;43(5):648-51]. This paper provides a more detailed outline on the diagnostic and management protocols, which can guide pulmonologists who may not have experience with DM1 or who are not part of a neuromuscular multidisciplinary clinic. A group of neuromuscular experts in DM1 including pulmonologists, respiratory physiotherapists and sleep specialists discussed respiratory testing and management at baseline and during follow-up visits, based on their clinical experience with patients with DM1. The details are presented in this report. RECENT FINDINGS: Myotonic recruited 66 international clinicians experienced in the treatment of people living with DM1 to develop and publish consensus-based care recommendations targeting all body systems affected by this disease [Ashizawa et al.: Neurol Clin Pract. 2018;8(6):507-20]. Myotonic then worked with 12 international respiratory therapists, pulmonologists and neurologists with long-standing experience in DM respiratory care to develop consensus-based care recommendations for pulmonologists using a methodology called the Single Text Procedure. This process generated a 7-page document that provides detailed respiratory care recommendations for the management of patients living with DM1. This consensus is completely based on expert opinion and not backed up by empirical evidence due to limited clinical care data available for respiratory care management in DM patients. Nevertheless, we believe it is of relevance for professionals treating adults with myotonic dystrophy because it addresses practical issues related to respiratory management and care, which have been adapted to meet the specific issues in patients with DM1. SUMMARY: The resulting recommendations are intended to improve respiratory care for the most vulnerable of DM1 patients and lower the risk of untoward respiratory complications and mortality by providing pulmonologist who are less experienced with DM1 with practical indications on which tests and when to perform them, adapting the general respiratory knowledge to specific issues related to this multiorgan disease.

Screening for early symptoms of respiratory involvement in myotonic dystrophy type 1 using the Respicheck questionnaire.

Symptoms of respiratory involvement are frequently present but overlooked by patients with Myotonic Dystrophy type 1 (DM1). A respiratory symptom checklist was designed to test whether a DM-specifically designed checklist to detect symptoms of respiratory involvement (The Respicheck Questionnaire) could help patients be more aware of their respiratory problems, if any, and help clinicians in identifying potential candidates for intervention. The Respicheck questionnaire was administered to 58 consecutive adult-onset patients with genetically determined DM1 who did not complain of respiratory involvement per history at enrollment. Based on respiratory function test results patients were divided into 3 groups: A, (n = 17) having no signs of respiratory involvement; B (n = 13), patients having borderline results on respiratory assessments and having no need for respiratory intervention; C, (n = 28) patients having respiratory impairment requiring intervention. Respiratory test results and Respicheck scores were analyzed. Respicheck total score and subscales correlated positively with global respiratory impairment. Respicheck appears to be able to discriminate between patients having a higher level of respiratory dysfunction from those having a lower risk of respiratory involvement. This might allow to better target efforts and resources in respiratory management in DM1.

The prognostic value of spirometric tests in Amyotrophic Lateral Sclerosis patients.

OBJECTIVE: Amyotrophic lateral sclerosis (ALS) patients tend to develop progressive respiratory muscle weakness, leading to ventilatory failure and ineffective cough, principal causes of morbidity and mortality. Since patients are usually unaware of these symptoms, these are generally not noticed until the advanced stages and are associated with poor prognosis. The monitoring of respiratory function on a regular basis is therefore of great importance. Despite the availability of several pulmonary function tests, none of them was found to be the best indicator of the disease progression throughout the course of this condition. The main aim of our work was to evaluate the prognostic value of these respiratory measures evaluated in a brief period of observation and their correlation with motor functional impairments in an ALS cohort. PATIENTS AND METHODS: Patients with ALS who had respiratory assessments performed and functional motor scales administered at baseline and six months later were included. All patients were assessed with forced vital capacity, both in seated and supine position (FVC; sFVC), peak expiratory flow (PEF), peak expiratory cough flow (PCEF), the revised ALS functional rating scale (ALSFRS-R), at baseline and after six months, and their disease progression rate (ΔFS) was obtained. RESULTS: We included 73 patients with probable or definite ALS according to El-Escorial revised Criteria. At baseline, PCEF and PEF significantly correlated with ALSFRS-R total, bulbar and spinal subscores and ΔFS, while FVC% significantly correlated with ΔFS. After 6 months all the respiratory parameters significantly correlated with ALSFRS-R and all its subscores. Longitudinally, FVC%, sFVC% and PCEF significantly correlated with ΔFS and some of ALSFRS-R subscores. As concerns the survival analysis, monthly declines of FVC% and sFVC%, significantly correlated with the survival. The worse prognosis in terms of survival was finally found in those whose FVC% and sFVC% dropped below their respective cut-offs. CONCLUSION: Throughout the course of ALS disease, the monitoring of several respiratory markers, namely FVC, sFVC, PEF and PCEF, plays a critical role in predicting the prognosis of these subjects, both in terms of survival and functional ability. The implementation of monthly cut-offs in the evaluation of FVC and sFVC may allow a faster recognition of those patients with worse prognosis and therefore an optimized tailored clinical care, as well as a better stratification in clinical trials.