 Traditional tests of pulmonary function allow assess whether the person has any commitment in the respiratory system, whether obstructive, restrictive or mixed. To run these tests it is necessary that the patient understands and performs a forced expiratory maneuver to obtain reliable results. In the particular case of SCA, performing these tests it is very difficult due to the presence of cognitive impairment of varying degrees. This results in underdiagnosis of early changes in the lung parenchyma during the therapeutic window, committing the proper monitoring and treatment offered to these patients. 