Introduction: In amyotrophic lateral sclerosis (ALS), respiratory muscle involvement is highly predictive of survival and quality of life (QOL). There is compelling evidence that non invasive ventilation (NIV) prolongs survival by several months and improves QOL more than any other currently available treatment. Frequent testing of pulmonary function and regular evaluations are recommended since 1999 by the American Academy of Neurology in order to take appropriate treatment decisions.
State of art: There are numerous tests available to evaluate respiratory status in ALS and it is important to know their sensitivity and specificity to recognize clinical risk situations. Some recent data suggest that sniff nasal pressure and maximal inspiratory pressure (MIP) can be performed reliably by most ALS patients and are more sensitive to decrements in inspiratory muscle strength than spirometry or arterial blood gasometry.
Perspectives: Airway obstruction caused by ineffective coughing is the principal cause of intolerance to NIV. Several factors other than respiratory muscle strength may affect pulmonary function: postural changes, nutritional status, infectious disease, drugs.
Conclusion: The neurologist has to coordinate multidisciplinary care, with attention to individual patient preferences, and with a frank and compassionate discussion between the patient, the family, the physicians and the caregivers.